oleds, oxide tfts, and display week preview...

OLEDs, OXIDE TFTs, AND DISPLAY WEEK PREVIEW ISSUE

Official Monthly Publication of the Society for Information Display • www.informationdisplay.orgMar./Apr. 2013Vol. 29, No. 2

Mar-Apr Cover_SID Cover 3/22/2013 4:11 PM

http://www.informationdisplay.org

See Us at Display Week 2013, Booth #727

Thin Films pC2_Layout 1 3/22/2013 2:40 PM Page C2

http://www.tfdinc.com

mailto:[email protected]

2 Editorial: The Future Awaits and SID Can Be Your Guide!n By Stephen P. Atwood

3 Industry News: Panasonic Closes Plasma-TV Assembly Plant in Shanghain By Jenny Donelan

4 Guest Editorial: The Challenges and Opportunities of Large OLED TVsn By Ho-Kyoon Chung

6 2013 SID Honors and Awards This year’s winners of the Society for Information Display’s Honors and Awards include the Karl FerdinandBraun Prize, the Jan Rajchman Prize, the Slottow–Owaki Prize, and the Lewis & Beatrice Winner Award.n By Jenny Donelan

12 Frontline Technology: RGB Color Patterning for AMOLED TVsRGB color patterning is one of the key technologies for manufacturing large-sized AMOLED TVs. Twocompeting approaches are currently being used to realize RGB subpixels. One requires a more difficult man-ufacturing process but has better color purity; the other is easier to manufacture but requires optimization inalgorithms to overcome some weaknesses. n By Jang Hyuk Kwon

16 Frontline Technology: Oxide TFTs for AMOLED TVsAMOLED TVs using promising oxide semiconductors and thin-film transistors (TFTs) have been unveiled.This article will present the issues, challenges, and concerns of oxide TFTs for AMOLED TVs.n By Jin-Seong Park

20 Frontline Technology: Zinc-Oxynitride TFTs: Toward a New High-Mobility Low-CostThin-Film SemiconductorDemands for high-performance, low-cost, and low-energy-consumption displays continue to drive the devel-opment of new semiconductor materials. The success of the metal-oxide-semiconductor IGZO for displaybackplanes has triggered even more activity, and zinc oxynitride is proposed as a possible solution.n By Yan Ye

26 Display Marketplace: AMOLED Production: Entering a New Era?Active-matrix organic light-emitting-diode (AMOLED) displays have many attractive features that have ledcompanies to attempt to manufacture them, but one country – Korea – currently accounts for the vastmajority of AMOLED-display manufacturing capacity. Ambitious investment plans in China, Japan, andTaiwan could change this balance over the next several years.n By Paul Semenza

30 Enabling Technology: Flexing and Stretching So you work in displays? You may soon be working in flexible electronics too. Author Jason Heikenfeld,associate professor with the School of Electronic and Computing Systems at the University of Cincinnati,looks at several of the most interesting developments in flexible electronics.n By Jason C. Heikenfeld

36 Show Review: Alpha and Omega: Most Exciting Display Technologies at CESGiant TVs, ultra-high definition, IGZO, and more were among the display showstoppers at this year’s Consumer Electronics Show in Las Vegas. n By Steve Sechrist

41 First Look: A Preview of the Events Scheduled for Display Week 2013

46 Symposium Preview: Plan Ahead for the 2013 SymposiumMake the most of Display Week 2013 with this advance look at this year’s technology sessions.n By Jenny Donelan

51 SID News: SID Bay Area Chapter Hosts a Glimpse into the Future of Displaysn By Stephen Atwood

56 Sustaining Members

56 Index to Advertisers

Information Display 2/13 1

MARCH/APRIL 2013VOL. 29, NO. 2

InformationDISPLAYcontents

For Industry News, New Products, Current and Forthcoming Articles, see www.informationdisplay.org

INFORMATION DISPLAY (ISSN 0362-0972) is published 6 times ayear for the Society for Information Display by Palisades ConventionManagement, 411 Lafayette Street, 2nd Floor, New York, NY 10003;William Klein, President and CEO. EDITORIAL AND BUSINESSOFFICES: Jay Morreale, Editor-in-Chief, Palisades ConventionManagement, 411 Lafayette Street, 2nd Floor, New York, NY 10003;telephone 212/460-9700. Send manuscripts to the attention of theEditor, ID. SID HEADQUARTERS, for correspondence on sub-scriptions and membership: Society for Information Display, 1475 S. Bascom Ave., Ste. 114, Campbell, CA 95008; telephone 408/879-3901, fax -3833. SUB SCRIP TIONS: Information Display is distributedwithout charge to those qualified and to SID members as a benefit ofmembership (annual dues $100.00). Subscriptions to others: U.S. &Canada: $75.00 one year, $7.50 single copy; elsewhere: $100.00 oneyear, $7.50 single copy. PRINTED by Wiley & Sons. PERMISSIONS:Abstracting is permitted with credit to the source. Libraries are per-mitted to photocopy beyond the limits of the U.S. copyright law forprivate use of patrons, providing a fee of $2.00 per article is paid to theCopyright Clearance Center, 21 Congress Street, Salem, MA 01970(reference serial code 0362-0972/13/$1.00 + $0.00). Instruc tors arepermitted to photocopy isolated articles for noncommercial classroomuse without fee. This permission does not apply to any special reportsor lists published in this magazine. For other copying, reprint orrepublication permission, write to Society for Information Display, 1475S. Bascom Ave., Ste. 114, Campbell, CA 95008. Copy right © 2013Society for Information Display. All rights reserved.

In the Next Issue ofInformation Display

3-D Trends and Display WeekShow Review• Display Industry Awards• Products on Display• Evaluating Color Gamut• High-Frame-Rate Dual-Projector 3-D Debuts with The Hobbit

• Creating 3-D Imagery with a Binocular Fusion Camera

• New Frontiers in 3-D Displays• Optical Dry Bonding• AMOLED-Panel Market

SIDSOCIETY FOR INFORMATION DISPLAY

OLEDs, OXIDE TFTs, AND DISPLAY WEEK PREVIEW ISSUE

Official Monthly Publication of the Society for Information Display • www.informationdisplay.orgMar./Apr. 2013Vol. 29, No. 2

Mar-Apr Cover_SID Cover 3/22/2013 4:11 PM Page 1

Cover Design: Acapella Studios, Inc.

ON THE COVER: This year’s winners ofthe Society for Information Display’s Honorsand Awards include Dr. Isamu Akasaki,who will receive the Karl Ferdinand BraunPrize; Mr. Marc Baldo, who will beawarded the Jan Rajchman Prize; Dr. Hoi-Sing Kwok, who will be awardedthe Slottow–Owaki Prize; and Dr. ShigeoMikoshiba, who will receive the Lewis &Beatrice Winner Award.

ID TOC p1 pgs_Layout 1 3/23/2013 9:41 PM Page 1



The Future Awaits and SID Can Be YourGuide

by Stephen Atwood

Welcome to the March/April 2013 issue of Information Display magazine. Last-minute preparations are well under way for the 50th annual SID Display Week event in Vancouver. With all the excitement around OLED technol-ogy, we could not have predicted a better convergence oftopics for this issue: OLED and Oxide-TFT technology, the

SID Symposium preview, and our cover story on the SID Honors & Awards recipientsfor 2013. It’s one of the biggest issues we have ever produced and with our new bi-monthly schedule we wanted to make sure you had plenty to read between now andDisplay Week.As I worked on this issue and also attended some recent SID activities, it occurred

to me that this may be the best time ever to be an SID member. Not only is there anamazing array of new technology innovations going on in our industry, but the oppor-tunities to learn about those innovations through the resources available to membershave never been better. For example, the SID on-line webinar program is now gainingtraction with almost a dozen recent additions covering topics such as 3-D stereoscopicdisplays, oxide TFTs, user interfaces (UIs), and the latest advances in LCD technology.These presentations come from some of the most widely respected experts in the fieldand are available online only to SID members. Also in this issue you can read about the recent San Francisco Bay Area chapter

conference on display technologies for the future. These types of local programs areloaded with presentations by the highest caliber of technology experts and are avail-able to all SID members. They provide invaluable opportunities to make new contactsand leverage the knowledge base of the industry for your own company’s benefit. You can also read about the upcoming papers being presented at the SID Symposium

as part of Display Week 2013. If you are not sure about becoming a member, plan oncoming to Vancouver and taking in the papers and exhibitions. Spend the next yearexploring what your new membership can do for you and I’m certain you will becomea believer like me.Our cover story this month is about the SID 2013 Honors and Awards, recognizing

the many achievements of those who have invested so much of their careers to further-ing the field of displays. As I have written previously, while the honors are beingbestowed on them, the real honor is to those of us who have the privilege of knowingthem, working with them, learning from them, and using their innovations to build better products that enrich people’s lives. Each year we do our best to capture theirachievements in the biographies and citations thoughtfully compiled by our own JennyDonelan. But nothing we write can come close to documenting a lifetime’s worth ofideas, challenges, setbacks, inspirations, and successes that these individuals havegiven to our industry. All I can say is that in those moments when you look at a greatnew product or technology, take a moment to reflect on all the human effort that hasprobably gone into making the “overnight success” happen. Great innovation neverreally happens overnight and so much of the technology that we take for granted todaywas built layer upon layer, almost like a brick wall, with each new advancement lever-aging the achievements of the previous level for its support. I’m sure you, as you readthis story, will come away with something from the award recipients’ lives and work you can relate to. Take the time to reach out to them and say “Congratulations and

2 Information Display 2/13

Executive Editor: Stephen P. Atwood617/306-9729, [email protected]

Editor-in-Chief: Jay Morreale212/46 0-9700, [email protected]

Managing Editor: Jenny Donelan603/924-9628, [email protected]

Advertising Sales Manager: Joseph Tomaszewski201-748-8895, [email protected]

Advertising Sales Representative: Roland Espinosa201-748-6819, [email protected]

Editorial Advisory BoardStephen P. Atwood, Chair

Azonix Corp., U.S.A.Helge Seetzen

TandemLaunch Technologies, Westmont, Quebec,Canada

Allan KmetzConsultant, U.S.A.

Larry WeberConsultant, U.S.A.

Guest EditorsMaterials

Ion Bita, Qualcomm MEMS TechnologiesOLEDs

Ho-Kyoon Chung, Sungkyunkwan UniversityOxide TFTs

Arokia Nathan, University of Cambridge3D Trends

Nikhil Balram, Ricoh InnovationsTouch and Interactivity

Geoff Walker, Intel Corp. e-Paper and Tablets

Russel Martin, Qualcomm MEMS Technologies Lighting

Sven Murano, Novaled AG Novel Displays

Brian Schowengerdt, University of Washington Very-High-Resolution Displays

David Trczinski, Avid Digital Signage

Terry Schmidt, Christie Digital SystemsAlan Koebel, Christie Digital Systems

Contributing EditorsAlfred Poor, ConsultantSteve Sechrist, ConsultantPaul Semenza, NPD DisplaySearchJason Heikenfeld, University of Cincinnati

InformationDISPLAY

The opinions expressed in editorials, columns, and feature articles do not necessarily reflect the opinions ofthe Executive Editor or Publisher of Information DisplayMagazine, nor do they necessarily reflect the position ofthe Society for Information Display.

editorial

(continued on page 55)

ID Editorial Issue2 p2,55_Layout 1 3/28/2013 11:03 AM Page 2






Panasonic Closes Plasma-TVAssembly Plant in Shanghai

Earlier this year, news-media outlets includingThe Wall Street Journal and The Japan Timesreported that Panasonic Corporation was closing its plasma-TV assembly plant inShanghai, China. Panasonic media represen-tative Jim Reilly later confirmed this newswith Information Display. The Shanghaioperations have been relocated to PanasonicAVC Networks Shandong Company, Ltd., anexisting LCD monitor-making facility inShandong, China. “The plasma and LCDoperations will both be consolidated at thatlocation,” said Reilly.Panasonic’s move to streamline operations

is not surprising in the face of steadily declin-ing plasma-TV sales worldwide. “In the great scheme of things, it’s not that big of an impact,” says Paul Gagnon, Director of Global TVResearch for NPD DisplaySearch. Gagnonbelieves the closure is more a reflection ofmarket conditions than a game changer forplasma. However, as has been the case for years,

reports of plasma’s demise are premature.Panasonic showed 16 new plasma TVs at CES 2013. The Shanghai plant that closedwas assembling TVs rather than making thepanels, says Gagnon, noting that Panasoniccontinues to manufacture PDPs in Japan.Panasonic is not actually the biggest producerof plasma TVs; that honor goes to Samsung,according to Gagnon. These two companies,plus LG, are the last manufacturers of plasmaTVs in the world.

– Jenny Donelan

industry news Architects of World ClassDisplay EnhancementsEuropTec USA is a specialist in glass processing and fabrication for the display industry. As an expert in various �nishing and processing technologies, we design and manufacture products for display applications.

PRODUCT & CAPABILITIES:® ™

APPLICATIONS:

EuropTec Ad 2013.indd 1 1/9/13 2:53 PM

See Us at Display Week 2013, Booth 715

VISITINFORMATION

DISPLAY ON-LINEFor daily displayindustry news

www.informationdisplay.org

Industry News Issue2 p3_Layout 1 3/22/2013 3:11 PM Page 3


http://www.europtecusa.com


The Challenges and Opportunities of LargeOLED TVs

by Ho-Kyoon Chung

OLED TVs were the talk of the Consumer ElectronicsShow in 2012, and this year’s CES featured attention-getting OLED televisions as well: 55-in. curved OLED TVsfrom Samsung Display and LG Display and a 56-in. 4KOLED TV from Sony and Panasonic. These were impres-

sive demonstrations, and it was encouraging to see more players, such as Sony andPanasonic, coming into the game. However, there are customers anxiously waiting tobuy these TVs at affordable prices. And what happened to earlier promises that largeOLED TVs would be in production by the second half of 2012?

It is difficult to tell exactly what’s happening at each company and what its futurefuture plans are in terms of investment and production volume. Obviously, manufac-turing challenges remain, especially for high yields. Another challenge is how, from amarketing perspective, to differentiate OLED TV from the LED-backlit LCD TV,which has excellent picture quality and is becoming ever thinner.

Challenges of Manufacturing OLED TVsIt is interesting to note that the two leading OLED-TV companies, Samsung Displayand LG Display, have taken different approaches to TFT backplanes as well as toOLED RGB color patterning. The details of the technology are described in the articles, “Oxide TFTs for AMOLED TVs” by Jin-Seong Park and “RGB Color Pattering in AMOLED TVs” by Jang Hyuk Kwon in this issue of Information Display.

You may ask why each company chose their different path and which one will bethe winner. In my opinion, one company has chosen an approach that is an extensionof a well-established process for small-OLED mobile displays, and the other has chosen a cost-effective and relatively easy approach to manufacturing large OLEDTVs – even though it has not been fully proven for mass production. It is probably tooearly to tell which one will be the eventual winner.

However, considering the recent success of LED-backlit LCD TVs, the manufactur-ing process for OLED TVs must meet the following requirements in order to competewith these incumbents. First, the cost of manufacturing must be lower than (or at leastequivalent to) the cost of LCD TVs because most consumers will not pay a high premium just for the sake of owning an OLED TV. In order to reduce the cost, thefirst priority of OLED R&D should be the development of processes and equipmentthat use the entire motherglass without cutting, from TFT to OLED fabrication. Second, the manufacturing process should be readily extendable to ultra-high-resolution TVs. This requirement necessitates careful consideration when choosingthe TFT-array technology and OLED color-patterning method. In order to drive asmany as 24 million subpixels for 4K TV; for example, not only the TFT but the metal-lization process must be developed to meet the requirements. Also, the color pattern-ing must have the scalability to handle the subpixel resolution down to ~100 µm inlarge substrates, and the top emission structure needs to be developed for large OLEDpanels.

Future Outlook of OLED TV There is good news regarding OLED TV in that people now see the potential of largeOLED TV as the ultimate television — something they want to have in their livingroom. As far as a consumer transition from LED-backlit LCDs to OLED TVs is concerned, there are two schools of thought; it will be abrupt or gradual. Those who


guest editorial

(continued on page 55)

SID EXECUTIVE COMMITTEEPresident: B. BerkeleyPresident-Elect: A. GhoshRegional VP, Americas: D. EcclesRegional VP, Asia: B. WangRegional VP, Europe: J. RaspTreasurer: Y. S. KimSecretary: H. SeetzenPast President: M. Anandan

DIRECTORSBangalore: T. RuckmongathenBay Area: J. PollackBeijing: X. YanBelarus: V. A. VyssotskiCanada: T. C. SchmidtDayton: D. G. HopperDelaware Valley: J. W. Parker IIIDetroit: J. KanickiFrance: J-P. ParneixHong Kong: H. LeungIndia: G. RajeswaranIsrael: G. GolanJapan: K. KondohKorea: K.-W. WhangLatin America: A. MammanaLos Angeles: L. TannasMid-Atlantic: J. KymissisMid-Europe: H. De SmetNew England: S. AtwoodPacific Northwest: A. AbileahRussia: I. N. KompanetsSingapore: X. W. SunSouthwest: S. O’RourkeTaipei: J. ChenTexas: Z. YanivU.K. & Ireland: S. DayUkraine: V. SerganUpper Mid-West: B. Bahadur

COMMITTEE CHAIRS50th Anniversary: L. TannasAcademic: P. BosArchives: R. DonofrioAudit: S. O’RourkeBylaws: T. LoweChapter Formation – Europe: H. De SmetConventions: P. DrzaicConventions – Europe: I. SageDefinitions & Standards: T. FiskeDisplay Industry Awards: R. MelcherHonors & Awards: F. LuoI-Zone: J. KanickiInvestment: Y. S. KimLong-Range Planning: A. GhoshMembership: H.-S. KwokNominating: A. AnandanPublications: H. SeetzenSenior Member Grade: A. GhoshWeb Site: H. SeetzenWeb Activities: L. Palmateer

CHAPTER CHAIRSBangalore: S. SambadamBay Area: G. WalkerBeijing: N. XuBelarus: A. SmirnovCanada: A. KitaiDayton: J. C. ByrdDelaware Valley: J. BlakeDetroit: S. PalvaFrance: J. P. ParneixHong Kong: M. WongIndia: S. KauraIsrael: I. Ben DavidJapan: K. KondoKorea: Y. S. KimLatin America: V. MammanaLos Angeles: P. Joujon-RocheMid-Atlantic: G. MelnikMid-Europe: H. J. LempNew England: J. GandhiPacific Northwest: K. YugawaRussia: V. BelyaevSingapore/Malaysia: C. C. ChaoSouthwest: M. StrnadTaipei: C. C. WuTexas: R. FinkU.K. & Ireland: M. JonesUkraine: V. SorokinUpper Mid-West: P. Downen

SOCIETY FOR INFORMATION DISPLAY1475 S. Bascom Ave., Ste. 114, Campbell, CA 95008408/879-3901, fax -3833 e-mail: [email protected]://www.sid.org

ID Guest Editorial Issue2 p4_Layout 1 3/22/2013 3:16 PM Page 4


http://www.sid.org

Turn up the energy. Turn down the heat.SINTERING?

XENON Corporation37 Upton DriveWilmington, MA 01887 U.S.A.www.xenoncorp.com1-800-936-6695

Only pulsed light provides the high peak-power

pulses necessary to sinter conductive inks while keeping

temperatures cool enough to avoid damage to heat-sensitive

substrates — the key challenge when printing on paper and

plastic. When you need to turn up the energy and turn down

the heat, turn to the leaders in pulsed light.

Leaders in pulsed light

Let’s find a solution to your sintering challenges.

Go to www.xenoncorp.com/sinter1 to learn more about Xenon’s sintering solutions.


Untitled-1 1 3/22/2013 3:57:05 PM

http://www.xenoncorp.com/sinter1

http://www.xenoncorp.com

http://www.radiantzemax.com/Change

THE RECIPIENTS of the Society forInformation Display’s 2013 Honors andAwards may be diverse in terms of the displaytechnologies they pursue – GaN-based semi-conductors, phosphorescent OLEDs, LCDs,PDPs – and in geographical location – Japan,Massachusetts, Hong Kong – but they have atleast two things in common: vision and a clearsense of purpose. As a young researcher inTokyo, Isamu Akasaki became intrigued bygallium nitride’s potential for blue-light emit-ters, despite the fact that the technology wasconsidered yesterday’s news by many scien-tists — another promising piece of researchthat had not worked out. Akasaki saw some-thing more in the material – specifically, hesaw tiny, well-formed crystallites – but he also saw that it might someday contribute todisplay systems in a major way. After yearsof hard work, he, and the rest of the world,discovered he was right.

Another young researcher, Marc Baldo,then a graduate student at Princeton, fell under

a spell after he built his first OLED in the lab.The deep red color of the OLED he made bothsurprised and entranced him. He continued tofocus on OLEDs and went on to contribute tothe development of the first phosphorescentOLEDs.

Slottow –Owaki Prize recipient Hoi-SingKwok and Lewis & Beatrice Winner Awardrecipient Shigeo Mikoshiba are both highlyrespected scientists, but their awards fromSID this year reflect their vision for educationand community-based efforts. Kwok saw theneed for a display-based research center inHong Kong and went on to create it, whichincluded raising the all-important funds.Mikoshiba, a busy educator and researcher,recognized the importance of volunteering histime to the display industry, and devoted many efforts to the furthering of SID. His vision and continued sense of purpose – he has volun-teered continuously for more than 30 years —raised up not only SID, but the industry as a whole. Besides, as he told Information Display, such efforts are ultimately as enrich-ing to the volunteer as to those he helps.

The SID Board of Directors, based on recommendations made by the Honors &

Awards Committee, grants these annualawards based upon outstanding achievementsand significant contributions to the displayindustry. This year’s winners should takepride in this acknowledgment of their tremendous accomplishments.

2013 SID Honors and Awards This year’s winners of the Society for Information Display’s Honors and Awards include Dr. Isamu Akasaki, who will receive the Karl Ferdinand Braun Prize for his seminal contributions to the development of high-quality single-crystal GaN-based semiconductorsand their PN-junction blue LEDs and lasers; Dr. Marc Baldo, who will receive the JanRajchman Prize for his outstanding contributions to the discovery of phosphorescent-OLEDdevices; Dr. Hoi-Sing Kwok, who will be awarded the Slottow-Owaki Prize for providingeducation and training in display technology to many students and professionals in the Asiaregion through the creation of a display research center; and Dr. Shigeo Mikoshiba, who will receive the Lewis & Beatrice Winner Award for his sustained exceptional contributions to SID for over 30 years.

by Jenny Donelan

Jenny Donelan is the Managing Editor ofInformation Display Magazine. She can bereached at [email protected].

6 Information Display 2/130362-0972/2/2013-006$1.00 + .00 © SID 2013

SID’s best and brightest

The 2013 award winners will be honored at the SID

Honors & Awards Banquet, which will take place Mondayevening, May 20, 2013, during

Display Week at the VancouverConvention Centre.

Tickets cost $75 and must be purchased in advance – tickets will not be available on-site.

Visit www.displayweek.orgfor more information.

ID Donelan p6-10_Layout 1 3/22/2013 4:41 PM Page 6


http://www.displayweek.org

Karl Ferdinand Braun PrizeThis award is presented for an outstandingtechnical achievement in, or contribution to,display technology.

Dr. Isamu Akasaki, Professor at MeijoUniversity, will receive the Karl FerdinandBraun Prize “for his seminal contributions tothe development of high-quality single-crystalGaN-based semiconductors and their PN-junction blue LEDs and lasers.”

In 1969, researchers succeeded in growingsingle-crystal gallium nitride on a sapphiresubstrate. Two years later, the first blue LEDwith an MIS structure was created. Theseadvances prompted excitement about thedevelopment of GaN-based blue-light emit-ters, but just several years later, most gallium-nitride researchers had withdrawn from thefield. They could neither grow electronic-grade high-quality GaN single crystals norcontrol their electrical conductivity. Both features were key to the development of high-performance blue-light emitters and high-power high-speed transistors.

About that time, an engineer named IsamuAkasaki, then working at Matsushita ResearchInstitute Tokyo (MRIT), became intrigued byGaN’s potential for use in blue-light emitters.With the idea in mind that electronic devicesand the materials used to make them must be robust, he thought GaN could be the bestcandidate since it is very stable physically and chemically, even though it was difficult to form high-quality crystals with it.

Said Akasaki, “I realized the great potentialof GaN as a blue luminescent material when Ifound tiny yet high-quality crystallites embed-ded in HVPE-grown crystals containing manycracks and pits. I was intuitively convincedthat conductivity control could be achieved ifthis kind of quality could be made over anentire wafer.”

His eventual success with GaN-based semi-conductors ultimately contributed to displaysystems ranging from traffic lights to cellphones, to high-resolution TVs, digital signage, and more. “Akasaki transferred thesebasic technologies to industry and made fun-damental contributions to information-displaytechnology,” says Yasushi Nanishi, a Professorat Seoul National University.

It is one thing to pursue a brilliant idea, butit is another to pursue it and eventually suc-ceed after others have dismissed it. “That asingle scientist’s determination and dedicationovercame a barrier that researchers throughoutthe world had become resigned to, and theimpact of the multiple applications derivedfrom this achievement, make this a truly greatinvention,” says colleague Maseo Ikeda.

Akasaki received his undergraduate degreefrom Kyoto University and doctoral degreefrom Nagoya University. In 1952, he joinedKobe Kogyo Corp. (now, Fujitsu, Ltd.). In1959, he moved to Nagoya University, wherehe worked as a research associate and an associate professor. In 1964, he became Headof the Basic Research Laboratory IV and General Manager of the SemiconductorDepartment, both at MRIT. He returned toNagoya University in 1981. Akasaki hasauthored and/or co-authored more than 700international journal/conference papers and 30 book chapters and has been awarded 123Japanese patents (including 110 patentsrelated to group III nitrides) and 90 foreignpatents related to nitrides.

Jan Rajchman PrizeThis award is presented for an outstandingscientific or technical achievement in, or con-tribution to, research on flat-panel displays.

Marc Baldo, SID member and Professor atthe Massachusetts Institute of Technology,will receive the Jan Rajchman Prize “for hisoutstanding contributions to the discovery ofphosphorescent-OLED devices.”

While a graduate student at Princeton, Marc Baldo helped develop phosphorescentOLEDs. Prior to this development, all

OLEDs were fluorescent, but fluorescenceharnesses only spin 0, or singlet, excitons.Since singlets represent only 25% of the totalnumber of excitons generated by electricalexcitation, successful exploitation of theremaining 75% promised to increase OLEDefficiencies by a factor of 4.

According to Russell Holmes, AssociateProfessor with the Department of ChemicalEngineering and Materials Science at the University of Minnesota, “This work by Marc(and co-workers in the groups of ProfessorsStephen Forrest and Mark Thompson) permit-ted an immediate quadrupling in the effi-ciency of these devices by harvesting typicallydark triplet exciton states. This work, pub-lished in Nature in 1998, represented a keyenabling step for the development of anOLED-display industry and sparked an explosion of research into highly efficientphosphorescent emitters.”

The materials and structures Baldo workedon were later commercialized by UniversalDisplay Corp. Phosphorescent materials arenow found in many commercial products,especially cell-phone displays.

Baldo received his bachelor of engineeringdegree from the University of Sydney and hisPh.D. from Princeton University. When askedwhat led him to his chosen field, he says, “Iwas very interested in the novelty of buildingdevices based on molecules. I liked the ideaof designing materials and devices atom byatom. I found that it was possible to make adevice in an afternoon. It was an exciting


Dr. Isamu AkasakiMarc Baldo


time. When I built my first OLED, I remem-ber the shock of the beautiful deep red color.I was hooked.”

OLEDs have been the “next big thing” for along time, and while each year brings progressin terms of commercial devices, that progresshas been slower than initially surmised bymany enthusiasts. Baldo says, “The challengefor OLEDs has been that they are an entirelynew technology, unlike any previous semicon-ductor device or display technology. Conse-quently, the industry has not been able to drawon many existing technologies. From thedevices themselves, to the packaging, to themanufacturing process, to the backplanes thatdrive the displays, everything has had to bedeveloped specifically for OLEDs. Eventoday, with devices that are stable and effi-cient, we are still working on the manufactur-ing process. I think the advantages of OLEDswill make it all worthwhile, but it has been alot of work. We still do not know all that ispossible with OLEDs.”

Slottow–Owaki PrizeThe Slottow–Owaki Prize is awarded for out-standing contributions to the education andtraining of students and professionals in thefield of information displays.

Dr. Hoi-Sing Kwok, SID fellow and Professor at Hong Kong University of Scienceand Technology, will be awarded the Slottow–Owaki Prize, “for providing education andtraining in display technology to many studentsand professionals in the Asia region throughthe creation of a display research center.”

Dr. Hoi-Sing Kwok established the Centerfor Display Research (CDR) at the HongKong University of Science and Technologyin 1995. Many scientific institutions have aspecific program of research in semiconduc-tors, he explains, but not many have programsfor displays. “Yet, displays are a large marketthat is one-third to one-half that of semicon-ductors,” he says. “There are a lot of opportu-nities in display research.” Initially, Kwokwas able to convince the government to provide about US$2 million to start CDR.

CDR has since evolved to become a centerof excellence in display research, generating

many noteworthy research results and trainingnumerous doctoral and postdoctoral studentsfor work in the display industry. Kwok andhis students have also produced significantintellectual properties in these research fields,obtaining 65 U.S. and Chinese patents thusfar.

“Professor Kwok is an anchor of the dis-play community in the Hong Kong, Taiwan,and China regions,” says Ching Tang, DorisJohns Cherry Professor of Chemical Engi-neering at the University of Rochester. “Hehas contributed to a wide range of displaytechnologies, from LCOS to OLED, and from



Dr. Hoi-Sing Kwok

Hiroyuki Mori, “For hissignificant contributionsto the development ofoptical films for liquid-crystal displays includingTN and OCB modes.”Dr. Mori received his B.S.

and M.S. degrees in applied physics fromthe University of Tokyo and his Ph.D. fromthe Liquid Crystal Institute at Kent StateUniversity.

Kälil Käläntär, “For hismany contributions to thescience and technology ofliquid-crystal-displaybacklights, including lightguides, optical micro-reflectors, and light-shap-

ing devices. Dr. Käläntär is a senior scientistat Global Optical Solutions. He has Ph.Dsin Optics from Toyohashi University ofTechnology and Tohoku University.

Takatoshi Tsujimura,“For his contributions tothe development ofAMOLED displays andand OLED lighting.” Mr. Tsujimura is GeneralManager and OLED

Division Head for Konica Minolta, Inc. He has a degree from Tokyo University.

Baoping Wang, “For hismany contributions to thedevelopment of field-emission displays and the shadow-mask plasmadisplay panel.” Dr. Wang is a Professor of

Electronics at Southeast University. Hereceived his Ph.D. in electronic engineeringfrom Southeast University.

2013 SID Fellow AwardsThe grade of fellow is conferred annually upon SID members of outstanding

qualifications and experience as scientists or engineers whose significant contributions to the field of information display have been widely recognized.

Gopalan (Raj)Rajeswaran, “For his pioneering contributionsto the development, manu-facture, and commercial-ization of AMOLEDdisplays. Dr. Rajeswaran

is Chief Executive Officer with Moser BaerTechnologies. He earned his Ph.D. in elec-trical engineering from SUNY Buffalo.


creating new device architectures to advancing display-manufacturing processes. The directimpact is that a large group of professionals ofdiverse skills from his research group are nowmaking their own contributions in both academics and the display industries.”

Former student Dr. Haiying Chen of APTElectronics writes, “Fourteen years ago, Ijoined Prof. Kwok’s group as a Ph.D candi-date. That was a big challenge for me, a grad-uate with materials science and engineeringbackground only. Prof. Kwok was very niceand patient. He gave me enough space andfreedom to learn, to think, to plan, and to try.I benefited quite a lot during the four-year

study and research under Prof. Kwok, espe-cially in learning how to think and to workindependently.”

Throughout his professional career, Kwokhas supervised 42 Ph.D. dissertations, 20 master’s theses, and 80 B.S. senior projects.He has co-authored one book, “Photoalign-ment of Liquid Crystalline Materials: Physicsand Applications (Wiley/SID series),” andover 380 journal papers

His greatest satisfaction as a teacher? “Tosee the students grow and contribute to theindustry. And sometimes to see them becom-ing more knowledgeable than I and teachingme back.”

Lewis & Beatrice Winner AwardThe Lewis & Beatrice Winner Award for Distinguished Service is awarded to a Societymember for exceptional and sustained serviceto SID.

Dr. Shigeo Mikoshiba, SID Life Fellow,Jan Rajchman Prize winner, and ProfessorEmeritus at The University of Electro-Com-munications in Tokyo, Japan, will receive theLewis & Beatrice Winner Award “for his sustained exceptional contributions to SID for over 30 years.”

Dr. Shigeo Mikoshiba is a life-longresearcher, educator, and gifted scientist whoreceived SID’s Jan Rajchman Prize in 2007


Keiji Ishii, “For outstanding contributions to thedevelopment of the 145-in.-diagonal super-high-vision (8K x 4K) plasma display panel.” Mr. Ishiiis a Senior Research Engineer with the Display &Functional Devices Research Division, Science &Technology Research Laboratories, at JapanBroadcasting Corporation (NHK). He received

his B. E. and M. E. degrees in electrical engineering from Saga University.

Ryuichi Murai, “For outstanding contributions tothe development of the 145-in.-diagonal super-high-vision (8K x 4K) plasma display panel.” Mr. Muraiis a researcher at Panasonic Corp. He received hisB.E. and M.E. degrees in electronic engineeringfrom Osaka University.

In-Byeong Kang, “For his leading contribu-tions to the development of manufacturable film-patterned-retarder 3D displays and in-plane-switching-based liquid-crystal panels.” Dr. Kangis Senior Vice President and Head of the LG Display Laboratory at LG Display Co. He earnedhis Ph.D. in electronic engineering from the

University of South Australia.

Isao Kawahara, “For his contributions to theresearch and development of the moving-picture-resolution metric for display panels.” Mr. Kawahara has retired as a senior manager forimage quality at Panasonic Corp. He received hisM.E. degree in electric engineering from Kyoto University.

Qun (Frank) Yan, “For the development of thecalcium-magnesium-oxide protective layer forhigh-luminous-efficacy plasma display panels.”Dr. Yan is Chief Scientist of the plasma displaypanel (PDP) business unit within Changhong Electronics Group. He holds a Ph.D. in physicsfrom Vanderbilt University.

Takehiro Zukawa, “For the development of thecalcium-magnesium-oxide protective layer forhigh-luminous-efficacy plasma display panels.”Mr. Zukawa is a Staff Engineer with PanasonicPlasma Display Corp., Ltd. He received his M.S.degree in engineering from Toyama University.

Hidefumi Yoshida, “For his significant contribu-tions to the science and technology of liquid-crystal displays, including the multi-domain vertical-alignment mode.” Dr. Yoshida is a ChiefTechnical Research Fellow with Sharp Corp. He has a Ph.D. in engineering from Tokyo Instituteof Technology.

2013 SID Special Recognition Awards Presented to members of the technical, scientific, and business community (not necessarily SID members)

for distinguished and valued contributions to the information-display field.


for contributions to PDP and LCD backlight-ing technology. Yet he has also through theyears found time to serve and promote theSociety for Information Display. He joinedSID in 1975, and since 1981 has continuouslyserved SID, its Japan Chapter, Japan Display,and IDW. He has been President and Secre-tary of SID, as well as chair and member ofcountless committees. He has also served asan associate editor for both the Journal of theSID and Information Display.

“I have known and worked with Prof.Mikoshiba for a great many years,” says SIDmember Alan Sobel. “He has worked tire-lessly and indefatigably for SID in a numberof capacities.”

Mikoshiba says it has not always been easyto find the time to volunteer, especially whilebalancing university research, education, andadministrative duties (not to mention family

obligations). “Nevertheless, I enjoyed myvolunteer activities very much,” he says.Through these volunteer activities, Mikoshibasays he got to know many people who werehelpful not only in terms of those activitiesbut for his research work. Last but not least,volunteer work enriches one’s personality,says Mikoshiba.

Mikoshiba earned his bachelor’s and mas-ter’s degrees in plasma physics at the TokyoInstitute of Technology. His doctoral degree,also in plasma physics, is from the Universityof Alberta. Mikoshiba says he became inter-ested in display technology while working forHitachi starting in 1973, at about the time thatPDPs, LCDs, and FEDs were all emerging. n



Dr. Shigeo Mikoshiba

The Society for Information Display is indebted to the followingcompanies, who each donated $2000

to sponsor a prize:

Braun Prize AU Optronics Corp.

Rajchman Prize Sharp Corp.

Slottow-Owaki Prize Fujitsu, Ltd., and Dr. Tsutae Shinoda

daw

ar.c

om

1 0 1 6 N O R T H L I N C O L N A V E P I T T S B U R G H , P A 1 5 2 3 3 P H : 1 . 8 0 0 . 3 6 6 . 1 9 0 4 / 4 1 2 . 3 2 2 . 9 9 0 0 E : S A L E S @ D A W A R . C O M

A M E R I C A N M A D E

Sensor manufacturing in the USA at Dawar’s Pittsburgh facility

Full U.S. based engineering support

Rugged Design - All glass construction that provides ≥ 9H pencil hardness and superior optics

Enhanced Sensitivity - Light touch for effortless input with finger, glove or conductive stylus

Gesture Capability - pinch, flick, tap, click and rotate

Standard Product - Controller Board solutions from 4.3"W - 24"W - Chip on Flex solutions from 4.3"W - 17"

Customization - Decorative front lens available for tablet PC look

System tuning at Dawar's Pittsburgh facility

Multi-Touch Projected Capacitive Touch Screens

Come visit us at Display Week 2013, BOOTH 309

ojectouch PrTMulti-

ouch Scre Ted Capacitivoject

eensouch Scr

o.c

wa

.S. based engineering supportFull U

acturing in the USSensor manuf

.S. based engineering support

s Pittsbur’arwt DaA aacturing in the US

aw

d

acilitygh fs Pittsbur

ar's Pittsburwt Daem tuning atsyS

aortion - DecomizatCus

- Chip on Fleontroduct - Cd PrtandarS

e Capability - pinch, flick, tapturGes

tyluse sonductive or cvgloed Sensitivity - Light tEnhanc

s and superior opticsdnesharRugged Design - All glas

acilitygh far's Pittsbur

or tablet PC lookailable fvont lens ae frtiva

om 4.3"W - 17"x solutions fr- Chip on Fleom 4.3"W - 2d solutions froller Boarontr

etota, click and re Capability - pinch, flick, tap

tyluss input with fingerortlesor effouch fed Sensitivity - Light t

s and superior opticsvides ot prtruction thaonss cRugged Design - All glas

or tablet PC look

om 4.3"W - 17"4"W om 4.3"W - 2

e

, s input with finger

9H pencil ≥vides

1 9 0 4 / 4. 3 6 6 .P H : 1 . 8 0 0T H L I N C1 6 N O R1 0

A L E S @ D1 2 . 3 2 2 . 9 9 0 0 E : S1 9 0 4 / 4S B U R G H , PV E P I T TO L N AT H L I N C

O MCA R .WAA L E S @ D2 3 3 A 1 5



See PixClear™

Introducing PixClear™, zirconia nanocrystals for electronics and semiconductor applications. One of the highest-index nano-materials available, delivering perfectly clear dispersions in solvents, monomers and polymers for seamless integration into your products.

• High Refractive Index, >1.85• Highly Transparent at the Visible

Wavelengths• Low Haze Coatings Even at High

Nanocrystal Loading, >80 wt%• Improved Scratch Resistance and

Hardness• For Use in Touch Screens, CMOS Image

Sensors, LEDs and OLEDs

order online at:w w w . p i x e l l i g e n t . c o m / i d a p r i l

O r c a l l 8 7 7 - 3 3 3 - 9 2 4 5 e x t . 3 2


We bring quality to light.

www.instrumentsystems.com

light measurement

Proven instruments for fast and accurate testing of

luminance chromaticity contrast ratio viewing angle dependent properties homogeneity

DTS 140 spectroradiometer LumiCam 1300 imaging photometer and colorimeter DTS 500 positioner

Display Test & Measurement

NEW: DMS and ConoScope product line from Autronic-Melchers

1-2 Ad Display 85,725x254_311012.indd 2 31.10.12 10:57


Ad template for INDD.indt 1 3/22/2013 5:13:17 PM

http://www.pixelligent.com/idapril

http://www.instrumentsystems.com

ALL COLOR TVs sold today realizecolor images through combinations of pixelsthat, in turn, consist of RGB subpixels. Liquid-crystal-display (LCD) TV uses back-lighting as the light source and color filters forthe RGB subpixels, which are patterned byphotolithography or ink-jet printing. Sinceorganic light-emitting diodes (OLEDs) areself-emissive, we can realize RGB subpixelsby direct deposition of RGB emission materialsfor each subpixel (RGB side-by-side) or byfiltering white-OLED light through RGBcolor filters (WOLED + CF). Currently, thereis much debate with regard to which approach will be the winner in the large-sized OLED-TV market. This article describes the pros and cons of each technology and presents an outlookfor future OLED technology development.

RGB Side-by-Side Patterning byShadow MaskCurrently, the active-matrix organic light-emitting-diode (AMOLED) pixels for mobileapplications are manufactured by evaporationof small-molecule light-emitting materialsthrough metal shadow masks. When one-color material is being deposited, the othercolor areas are blocked by this mask. Figure 1schematically shows the shadow-mask technology for red, green, and blue pixel patterning of AMOLEDs.

RGB Color Patterning for AMOLED TVsRGB color patterning is one of the key technologies for manufacturing large-sized AMOLEDTVs. Two competing approaches are currently being used to realize RGB subpixels. Onerequires a more difficult manufacturing process but has better color purity; the other is easierto manufacture but requires optimization in algorithms to overcome some weaknesses.

by Jang Hyuk Kwon

Jang Hyuk Kwon is with the Department ofInformation Display, Kyung Hee University,Seoul, Korea. He can be reached at [email protected].


frontline technology

Substrate

Source

ItemsCurrent Status

(generation 3.5 evaporator)

Pixel-Pixel Align< 5µm± ~10µm

± ~5µmMargin: ± 15µm

< ±5µm

Shadow Effect

Pixel Pitch Variation

Total Pitch Variation

Alignment Accuracy

MetalShadowMask

Fig. 1: A typical shadow-mask technology for pixel patterning shows green and blue pixelsbeing blocked. The table at bottom shows the dimensional capability of the shadow-mask process to date.

Kwon p12-15_Layout 1 3/22/2013 5:32 PM Page 12


Current shadow-mask technology is alreadymature and does not present any serious diffi-culties when used on substrates up to 750 mm× 650 mm (which represents ¼ of a Gen 5.5substrate of 1500 mm × 1300 mm). However,this technology cannot be used for Gen 8 sub-strates for AMOLED-TV production because glass and mask sagging become critical issues. A new process technology called Small

Mask Scanning (SMS) has been developed bySamsung for large-area TV manufacturing. Inorder to circumvent the sagging problem ofthe substrate and the mask, the glass substrateis moved during pixel deposition while boththe small-area shadow masks and the linearevaporation sources are kept stationary (seeFig. 2). The merits of the SMS process are (1) practically, the same small-molecule materials used for mobile application can beused for TVs, and therefore good synergyexists between the two applications, and (2)the benefits of low power and long lifetimeand the color purity of the RGB side-by-sidepixel configuration are maintained. One major drawback is that achieving

pattern accuracy becomes more difficult for

larger substrates (such as Gen 8 and above)and higher resolution [ultra-definition (UD)and above], which are both necessary fornext-generation TVs. To be more specific,any misalignment will result in color mixingand non-uniformity of the subpixels. Maskwindow variation with multiple patterningprocesses can also be a serious problem forreal mass production. Further technologydevelopment is needed in order to increasemanufacturing yield as well as to improvescalability in substrate size and high resolution.

White OLEDs with Color Filters The approach of white OLEDs with color filters (WOLED + CF) has received a greatdeal of attention because of its simpler processand attendant benefit of using the existingcolor-filter infrastructure.1 This method caneasily overcome the inherent complexity ofRGB side-by-side patterning with the shadowmasks. White emission can be achieved bymixing three primary colors (red, green, andblue) or two complementary colors (yellowand blue) in the emissive layers. Generally,WOLEDs consisting of small organic mole-

cules have a multilayer structure with two ormore emitting layers in a simple stack or tandem OLED structure. Figure 3 shows several structures devel-

oped to realize white-OLED devices. Amongthese, the tandem OLED structure has meritsin terms of longer lifetime and higher effi-ciency; however, the manufacturing process isa bit more complicated. The tandem devicewith two emissive layers as shown in Fig. 3can greatly reduce current level to achieve therequired brightness value of each pixel andmore than doubling lifetime. The tandemdevice can also easily achieve very high effi-ciency because both efficiency values of eachsingle cell are combined.1 In the beginning of2013, LG Electronics announced commercialproduction of 55-in. AMOLED displays thatuse the tandem WOLED + CF approach. (In the CES Review in this issue of ID, authorSteve Sechrist notes that LG planned to beginshipping these units in Korea in February of2013.)One problem with the WOLED + CF

approach is that light-output efficiency isreduced to 30% of the efficiency of RGB side-


Fig. 2: The OLED RGB process using SMS (left) is compared with the WOLED + CF process (right) in terms of pixel structure, methodology,and pros and cons.

RGB (SMS): Samsung Display WOLED: LG Display

EmittingColorFilter

RGB

PixelStructure

Process

Merits

Demerits

Low Power & Long LifetimeRelatively Good Viewing Angle

Relatively Difficult ProcessColor Mixing IssueThickness Uniformity

Easy Process with > Gen. 8 GlassHigh Resolution

High Power ConsumptionViewing Angle IssueShort Lifetime

Method

W-RGBW

Chuck

Glass

Open MaskSource

Glass

MaskLinear Source

GlassScanning

Layer


by-side because of the light absorption induced by the color-filter pigments. This problem can be minimized if the RGBW four-pixel colorsystem is employed. Theoretically, the RGBWsystem can have about ~50% light output dueto the mixing of white colors for bright images and thereby compensate this for the light loss.2However, there is a trade-off between the reduc-tion of power consumption and the degradationof color purity. More circuitry to drive thewhite pixel is needed and light output effi-ciency to each RGB subpixel depends on thewhite spectrum of WOLEDs. Therefore, thelight output efficiency of actual displays maynot reach this ~50% theoretical level. Anotherissue lies in the color variation on viewingangle because thick organic layers in the tan-dem structure result in several possible opticalpaths, which can distort color. Overall, amore than two-times-higher power consump-tion and a much shorter lifetime can be a realconcern in AMOLED TVs using the WOLED+ CF system. However, a combination ofnew OLED materials and optimum color-ren-dering algorithms may be able to solve thelifetime, power consumption, and color char-acteristics issues, as discussed in Ref. 2.

Future Prospects in Color PatterningSeveral companies are trying to develop alter-native technologies to replace the currentshadow-mask process used for large-area TVapplications. Solution-process printing tech-nologies such as ink-jet printing3 and nozzleprinting4,5 have been proposed as pixel-patterning methods. These processes will be the ultimate objective for pixel-patterningmethods for AMOLED displays since usingthem is fairly simple and does not require anyvacuum equipment. Several material companies are developing

soluble materials for these solution processes.However, it is not an easy task to developgood soluble materials because OLED life-time is very sensitive to impurities, film quality,and environmental conditions. (One suchpossible solution is discussed in the IndustryNews story, “Merck to Use Epson Ink Tech-nology for Large OLED Displays,” in the January/February issue.) Among the RGBmaterials, blue has the shortest relative life-time. Device lifetimes of red and green OLED devices with solution printing processes are sufficiently extended to be of practical use.Consequently, a process involving blue

thermal deposition of the entire active areawith an open mask after the solution printingof red and green subpixels is being developedto overcome these lifetime issues. Recently,significant progress has been made in thedevelopment of soluble materials and theprocess for AMOLED fabrication. Hence, itis expected that solution printing processeswill be available in the near future. Laser-printing technologies have also been

proposed as pixel-patterning methods, suitable for large-area displays. Laser-induced thermal-imaging (LITI) technology6 was firstreported by Samsung. This technology usesdonor films with a laser-light-absorbing layerand a transfer organic layer. Laser light isconverted into thermal energy as it shines on the light-absorbing layer. Subsequently,the transfer layer melts and transfers to thesubstrate. The company is focusing on thismethod only for small-sized high-resolutiondisplay applications. This process is very sensitive to particles because any contami-nated particles can fix onto the substrate during the transfer process. Small-sizedapplications are better with regard to minimiz-ing yield loss.



Fig. 3: Above are shown the merits and demerits of various WOLED structures (EML = emissive layer).

StructureItems

Efficiency

Lifetime

Process

<Single EML>

CathodeETL

Single EML

HTLHIL HIL

Anode Anode

AnodeHIL

Glass Glass

Glass

Yellow Phosphor

HTL

HTLYellow EML

Blue EML Blue EMLBlue EML

HTLHIL

ETLR + G EML

HTLHIL

AnodeGlass

BlueEmissive

Emissive

Unit

Unit

Yellow

Charge Generation Layer

ETL ETL ETLCathode Cathode Cathode

<Multiple EML> <Color conversion> <Tandem>

Single EML Multiple EML Colorconversion Tandem

: Best, : Good, : Normal, : Bad


http://informationdisplay.org/IDArchive/2013/JanuaryFebruary/IndustryNews.aspx

Laser-induced pattern-wise sublimation(LIPS) technology7 has also been reported asan alternative to LITI technology. Both tech-nologies are fundamentally very different. InLIPS technology, emissive organic layers onthe light-absorbing metal layer are depositedon glass and then attached to two substrates,one organic deposited substrate and oneactive-matrix backplane under vacuum.Finally, a laser scans the organic layer to forma pattern through sublimation transfer fromthe organic layer to the active-matrix back-plane. Sony reported this process and demon-strated a 25-in. AMOLED panel at DisplayWeek 2007. In this process, similar thermalevaporation temperatures for host and dopantmolecules are required. Patterning of phos-phorescent materials using this methodologyis difficult because phosphorescent materialshave much higher evaporation temperaturesoriginated by high molecular weights. Todate, no additional progress has been shownwith this process.

Refinements Needed for Progress inBoth ProcessesCurrently, the two main patterning processes,SMS and WOLED + CF, are being intensivelydeveloped for commercialization. Gen 8 linesfor both technologies have been alreadyinvested in for the production evaluation of55-in. AMOLED-TV applications. Both tech-nologies are rapidly improving. Additionalpossible processes such as solution printingand LIPS are also being investigated. In thenear future, significant progress in solutionprinting processes in particular is expected.

References1C.-W. Han, K.-M. Kim, S.-J. Bae, H.-S.Choi, J.-M. Lee, T.-S. Kim, Y.- H. Tak, S.-Y. Cha, and B.-C. Ahn, SID SymposiumDigest of Technical Papers 43, 279 (2012).2J. P. Spindler, T. K. Hatwar, M. E. Miller, A. D. Arnold, M. J. Murdoch, P. J. Kane, J. E. Ludwicki, and S. A. Van Slyke, SID Symposium Digest of Technical Papers 36, 36 (2005).3D. Lee, J. Chung, J. Rhee, J. Wang, S. Hong,B. Choi, S. Cha, N. Kim, K. Chung, H. Gregory, P. Lyon, C. Creighton, J. Carter,M. Hatcher, O. Bassett, M. Richardson, and P. Jerram, SID Symposium Digest of TechnicalPapers 36, 527 (2005).4W. F. Feehery, SID Symposium Digest ofTechnical Papers 38, 1834 (2007).

5M. O’Regan, IMID/IDMC/ASIA Display ’08Digest, 27 (2008). 6S. T. Lee, J. Y. Lee, M. H. Kim, M. C. Suh,T. M. Kang, Y. J. Choi, J. Y. Park, J. H. Kwon, H. K. Chung, J. Baetzold, E. Bellmann, V. Savvateev, M. Wolk, and S. Webster, SID Symposium Digest of

Technical Papers 35, 1008 (2004).7T. Hirano, K. Matsuo, K. Kohinata, K. Hanawa, T. Matsumi, E. Matsuda, R. Matsuura, T. Ishibashi, A. Yoshida, and T. Sasaoka, SID Symposium Digest of Technical Papers 38, 1592 (2007). n


Embedded Computer Systems

Touch Screen Solutions Optical Enhancements

Custom Enclosures LED Backlight / Driver Design

877.FPD.JACO / 877.373.5226 e-mail: [email protected]

NEED HELP WITH YOUR DISPLAY SOLUTION?

www.jacodisplays.com

AS-9100 Registered ISO-9001 Registered

EXPERIENCE MATTERS! PROVIDING DISPLAY SOLUTIONS FOR OVER FIFTEEN YEARS



http://www.jacodisplays.com

SINCE flexible and transparent amorphousIn-Ga-ZnO (indium gallium zinc oxide orIGZO) thin-film transistors (TFTs) werereported in 20041, tremendous progress hastaken place with regard to amorphous-oxidesemiconductor devices as TFT backplanes.These devices enable high-performance flat-panel displays (FPDs), including active-matrix organic light-emitting-diode displays(AMOLEDs).2 Many FPD manufacturerssuch as Samsung, LG, Sharp, and AUO havealready announced significant investment inlarge-sized AMOLED panel production basedon oxide-semiconductor devices in 2012.Although small-sized AMOLEDs for cellphones using low-temperature polysilicon(LTPS) TFTs are already in large-scale pro-duction at Samsung, it is quite significant tohear announcements about adopting oxide-semiconductor devices as backplanes forlarger-sized AMOLEDs. According to recentpress reports, LG Electronics will sell 55-in.AMOLED TVs to consumers in the first quarterof 2013 (see the CES review in this issue).

For several decades, wide-bandgap oxidematerials, including ZnO, Al-doped ZnO, Ga-doped ZnO, SnO2, In2O3, InZnO, and InSnO,have been intensively investigated for sensor,optoelectronics, photovoltaic, and transparent-electrode applications due to their high trans-

parency: > 80% at visible range and carrierconcentrations of 1018/cm3. Interestingly,those materials have been reported to havegood semiconducting behavior under a rangeof deposition parameters, doping elements,and post-annealing processes. The amorphousstructure in the oxide semiconductor is alsoimportant in avoiding the problems of carriertrapping and low mobility caused by a poly-crystalline structure. The key property thatenables the formation of an amorphous struc-ture is “crystal frustration” – i.e., the threematerials (In, Sn, and Zn) all tend to form different crystal structures on their own, sotogether will not permit the formation of poly-crystalline structures. Thus, based on a number of papers and reports,2–4 amorphous-oxide-semiconductor TFTs combining In, Sn,and/or Zn elements have generally exhibitedreasonable field-effect mobility (µfe, greaterthan 10 cm2/V-sec), a high on/off ratio for thedrain current, and very low leakage current(less than 10 fA). Accordingly, amorphous-oxide semiconductors may be considered theultimate solution for producing large AMOLEDTV panels at low cost.

Many researchers and engineers still haveconcerns regarding certain critical deviceissues of oxide-semiconductor devices. Theseare required further improvements in mobility,stability, pixel design, and electrodes.

The Need for High Mobility High mobility, greater than 100 cm2/V-sec inLTPS TFTs, is very important for small-sizedAMOLED panels because the pixel-drivingTFT and the embedded circuits need to oper-

ate at relatively high speed and high currentwithin small pixel dimensions.

For large-sized AMOLED TVs, the mobilityrequirement is generally predicted to be over30 cm2/V-sec, depending on display resolutionand pixel-circuit designs, because OLED pixels need high current in order to emit lightthrough electrical current injection. Manyresearchers have reported various oxide-semiconductor materials and structures thatcan achieve high-mobility TFTs. Interestinglyenough, as we learn about the electronicnature of oxide semiconductors, we find the mobility may be controllable in the 1–30 cm2/V-sec range, as long as the deviceinstability is not a concern. Also, a few resultshave been demonstrated with a mobility ofalmost 100 cm2/V-sec with a TFT as a unitcell, showing an indium tin oxide (ITO)/IGZOor indium zinc oxide (IZO)/IGZO tandemactive structure.5

Robust Oxide TFTsInstability is perhaps the most important issuethat may block the practical application ofoxide TFTs to AMOLED displays. Recentefforts have been focused on understandingdevice instability and improving long-termstability. To investigate the stability of oxideTFTs, many researchers have considered fourpractical stress conditions: negative/positivebias, temperature, illumination, and environ-ment (humidity).6,7 Upon application of thefour stresses, the oxide TFT generally onlyexhibits a Vth shift without a change in mobility,as shown in Fig. 1(a). This may occur byeither charge trapping at the channel/gate-

Oxide TFTs for AMOLED TVsAMOLED TVs using promising oxide semiconductor and thin-film transistors (TFTs) havebeen unveiled. This article will present the issues, challenges, and concerns of oxide TFTs for AMOLED TVs.

by Jin-Seong Park

Jin-Seong Park is a professor at HanyangUniversity. His research focuses on oxide-semiconductor materials and devices, flexibleAMOLEDs, and thin-film encapsulations. He can be reached at [email protected].



ID Park p16-19_Layout 1 3/22/2013 5:48 PM Page 16


insulator interface or charge injection into thegate-dielectric bulk. Occasionally, it has beenobserved that the devices spontaneouslyrecover their initial state after a relaxationperiod without any thermal annealing.

It is also critical to accelerate the Vth shift by applying two stress conditions simultaneously.8Although several groups have reported possi-bilities such as oxygen vacancy, hole trapping,and electron injection, the origin of the degra-dation mechanism is still under investigation.

In order to improve the stability of oxideTFTs, researchers have taken steps includingoptimized structure,9 suitable gate-insulatormaterials,10 impermeable passivation layers,11

robust semiconductors,12 and post-annealingtreatments.13 By comparing bottom-gateTFTs with a back-channel-etch (BCE) or anetch-stopper (ES) structure [Fig. 1 (b)],researchers showed that the stability of an ES-type device was superior to that of a BCE-type device, which may be attributable to theformation of defective interfacial layers. Forgate insulators, the superior stability of theSiOx or AlOx gated devices can be attributedto the suppression of hole injection or trap-ping in the gate dielectric, owing to relativelylarge valence-band offset and less hydrogencontent. In addition, low-permeable passiva-tions such as AlOx and SiONx exhibited betterstability in devices under stress conditions.

In oxide semiconductors, robust oxide TFTshave a higher oxygen content in the activelayers during the deposition process and post-treatment. In general, in terms of materialsand structures, robust oxide TFTs had lesshydrogen and higher oxygen compositions tosuppress a Vth shift under four practical stressconditions.

It is very difficult to design oxide-TFTstructures with a selection of proper materialsbased on large-sized mass-production equip-ment. Therefore, it may be impossible to fabricate perfect and stable oxide TFTs byusing conventional processes, structures, andequipment because the electronic conductionmechanism in oxide semiconductors dependson controlling defect systems such as oxygenvacancy and hydrogen incorporation, as wellas cation composition. TFT structures arevery well suited to existing a-Si TFT produc-tion lines, but various process factors stillneed to be closely considered. Making stableoxide TFTs that perform well in the finalapplication requires very tight control of theprocesses, materials, and equipment.

A Pixel-Circuit Design for Oxide TFTsBesides the mobility and stability issues, thereis another problem to solve in order to realizelarge-sized AMOLED panels: the pixel-circuitdesign. It is well known that the use of oxideTFTs can result in an AMOLED panel withthe simplest pixel circuit, as shown in Fig. 1(c),because of the amorphous nature of the mate-rials and the resulting highly uniform electri-cal properties. If the TFTs are uniform (longrange and short range) and stable (bias stress),a simple circuit structure is the only thing thatis needed. If the TFTs are non-uniform andunstable, non-uniform OLED luminance mayoccur due to the different parameters of theswitching TFT on each pixel. These problemscan be fixed by using circuit-design technolo-gies such as a compensated circuit (5T+2C,etc.) . Grain boundaries and device instabilityare important factors to consider in regard tonon-uniformity. When AMOLEDs based onoxide TFTs are demonstrated, the oxide TFTsshould exhibit no significant variation in Vthand µfe during prolonged operation.

Unfortunately, as mentioned above, thedegradation of oxide TFTs is unavoidableunder stress conditions. While the variationof µfe and Vth is less important in an AMOLED

switching transistor, the current-inducedthreshold-voltage shift should be seriouslyconsidered for AMOLED driving transistors.It has been reported that a Vth shift of the driv-ing transistor by 0.1 V induces variations inthe resulting luminance of the OLED pixelsby approximately 20%, which reflects the factthat the brightness of each pixel stronglydepends on the drain current.14 Therefore,OLED displays should employ complex compensation circuits that have four or moreTFTs, such as 4T2C, 5T2C, and 6T2C circuits,with 4T2C meaning that the circuit involvesfour transistors and two capacitors.3 In addi-tion, an oxide semiconductor exhibits n-type-like properties, indicating that the major carrier in a channel is an electron. In an aver-age OLED pixel circuit, a compensation circuit such as that shown in Fig. 2 should beemployed in order to utilize n-type oxideTFTs, unlike the case for p-type LTPS TFTs,where this is not required.

Low-Resistivity ElectrodesRegarding large-sized AMOLED panels, theproper material for gate, source, and drainelectrodes must be chosen. Large, high-resolution, and fast-frame-rate panels require


Fig. 1: (a) Gate-voltage vs. drain-current chart represents the evolution of a transfer curve as afunction of bias-temperature-illumination stress. (b) The schematics of etch-stopper (ES) andback-channel-etch (BCE) structures are illustrated. (c) This conventional pixel design for anAMOLED panel uses two transistors and one capacitor.


electrodes with low resistivity, such as Al andCu. However, Al has poor adhesion and easily oxidizes during the AMOLED processes.The Cu element easily diffuses and incorpo-rates into the oxide semiconductor and gateinsulator through thermal annealing and electro-migration, as is well-known, while showingthe degradation of electrical properties such asmobility and stability. Recently, AUO appliedTi/Al/Ti electrodes to 37-in. AMLCDs, andSamsung Electronics applied Cu-based buslines to a 15-in. AMLCD.17,18 Also, LG Display has adopted Cu-based electrodes in its55-in. AMOLED-TV product.

Oxide-TFT Prospects for AMOLED TVsFrom a market perspective, some observers inthe display industry have deep concerns aboutthe competitiveness of AMOLED TV basedon oxide TFTs. As shown in Table 1, oxidesemiconductors have promising possibilities;these initially led to a great deal of attention.Phrases such as “low-cost-based AMOLEDbackplane technology” or “like amorphous-silicon (a-Si:H) TFT technology forAMOLEDs” were used to describe progresstoward the commercialization of AMOLEDTV panels. Today, many companies havestruggled to reduce fabrication costs in orderto compete not only with AMOLED TV panels based on LTPS TFTs, but also withhigh-quality active-matrix liquid-crystal-

display (AMLCD) TV panels based on a-Si:HTFTs.

To minimize the fabrication cost of anactive-matrix backplane, it is important toreduce the number of photolithography masks.Current a-Si:H LCDs employ 4–5 masks,using a gray mask (also called a halftonemask) to pattern the source/drain electrodesand the channel in a single mask step. Samsung Display recently demonstratedAMOLED displays based on oxide TFTs,employing seven masks with an ES structure.19

As mentioned above, the ES-type devicenot only has superior stability, but also hasexcellent uniformity in the electrical proper-

ties because the ES layer can prevent thedegradation of active layers during the follow-ing dry- or wet-etch process. The ES processin oxide TFTs is the contradictory factor withregard to fabrication cost and productionyield. Thus, Sharp and LG Display havedemonstrated mass-produced AMLCD andAMOLED backplanes with ES-type structuresto guarantee the quality of the panels with uniform device performance. However, thesecompanies have intensively developed a process with fewer mask steps (e.g., a BCE-type structure), resulting in a high-selectivewet-etchant and self-passivation layer. To balance fabrication cost and yield in large-sized AMOLED displays, a BCE-type devicemay be an inevitable selection. While thehigh-quality gate-insulator process may dete-riorate the uniformity and performance ofdevices by damaging the active layer, a top-gate device configuration can be a possiblesolution in reducing the number of masks and parasitic capacitance for large-sizedAMOLEDs.

Oxide TFT: A Solution AwaitingSolutionsSince small-sized AMOLED displays havebeen successful in the display marketplace,there is no doubt that AMOLED displays havethe potential to become a superior displaytechnology for TV. However, as far as thebackplane technology is concerned, it is notyet clear which technology is suitable forlarge-sized AMOLEDs. Since 55-in. AMOLEDTV panels were first demonstrated in 2012,many manufacturers and researchers havestruggled to realize solutions to the followingproblems: mobility, stability, and yield.



Table 1: Shown is a comparison of AMOLED panel designs based on polysilicon,amorphous silicon, and oxide TFTs.

AMOLED Panel Poly-Si TFT a-Si:H TFT Oxide TFT

Semiconductor Poly-crystalline Si Amorphous Si Amorphous IGZO

TFT uniformity Poor Good Good

Pixel circuit Complex Complex Simple/Complex

(5T + 2C etc.) (4T + 2C, 5T + 2C) (2T + 1C/6T + 2C)

Channel mobility ~100 cm2/V-sec 1 cm2/V-sec >10 cm2/V-sec

TFT type PMOS (CMOS) NMOS NMOS

TFT mask steps 5 ~ 11 4 ~ 5 5 ~7

Cost/Yield High/Medium Low/No data Low/Medium

Fig. 2: This circuit diagram of a pixel (AMOLED panel based on a-IGZO TFTs) shows exam-ples from (a) Samsung Display and (b) Sharp and Semiconductor Energy Laboratory (SEL).

DATA[m] ELVDD DATA ANODE

OLED

CATHODE

G1G2G3

C

DrTr

V0

ELVSS

(a) 5 Transistors + 2 Capacitors (b) 5 Transistors + 1 CapacitorBy Sharp and SEL[16]By Samsung Display[15]

VINIT

VREF

T1

T2

C1

C2

T3

T5

T4

SCAN[n]

SCAN[n+3]

EMB[n]]


Recently, some research groups havereported a c-axis-aligned IGZO layer as arobust active layer, a large-sized (over Gen 8)sputtered target, and a high-mobility oxidematerial such as InZnSnO. Although devicedegradation and electronic-conduction mecha-nisms have been investigated in oxide TFTs,interdisciplinary researches from theoreticalcalculation to device engineering haveincreased drastically in recent times. As wegain deeper understanding into oxide semi-conductors and processes, they will no doubtbecome the solution to realizing large-sizedAMOLED TVs in the marketplace.

References1K. Nomura, H. Ohta, A. Takagi, T. Kamiya,M. Hirano and H. Hosono, Nature 432, 488(2004).2J. S. Park, W. J. Maeng, H. S. Kim and J. S.Park, Thin Solid Films 520, 1679 (2012).3T. Kamiya, K. Nomura, and H. Hosono, Sci. Technol. Adv. Mater. 11, 044305 (2010).4J. K. Jeong, Semicond. Sci. Technol. 26,034008 (2011).5S. I. Kim, C. J. Kim, J. C. Park, I. Song, S. W. Kim, H. Yin, E. Lee, J. C. Lee, and Y. Park, IEEE Electron Device Meeting(IEDM 2008), 1 (2008).6J. K. Jeong, H. W. Yang, J. H. Jeong, Y. G.Mo, and H. D. Kim, Appl. Phys. Lett. 93,123508 (2008).7J. H. Shin, J. S. Lee, C. S. Hwang, S. H. K.Park, W. S. Cheong, C. W. Byun, J. I. Lee,and H. Y. Chu, J. ETRI 31, 62 (2009).8K. H. Lee, J. S. Jung, K. S. Son, J. S. Park, T. S. Kim, R. Choi, J. K. Jeong, J. Y. Kwon,B. Koo, and S. Lee, Appl. Phys. Lett. 95,232106 (2009).9J. Y. Kwon, K. S. Son, J. S. Jung, K. H. Lee,J. S. Park, T. S. Kim, K. H. Ji, R. Choi, J. L, Jeong, B. Koo, and S. Lee, Electrochem.Solid-State Lett. 13/6, H213 (2010).10J. S. Jung, K. S. Son, K. H. Lee, J. S. Park,T. S. Kim, J. Y. Kown, K. B. Chung, J. S.Park, B. Koo, and S. Lee, Appl. Phys. Lett. 96,193506 (2010).11S. I. Kim, S. W. Kim, C. J. Kim, and J. S.Park, J. Electrochem. Soc. 158 (2), H115(2011).12H. S. Kim, et al., Appl. Phys. Lett. 97,102103 (2010).13K. H. Ji, et al., Appl. Phys. Lett. 98, 103509(2011).14H. J. In and O. K. Kwon, IEEE ElectronDevice Lett. 30, 377 (2009).

15Y. G. Mo, M, Kim, C. K. Kang, J. H. Jeong,Y. S. Park, C. G. Choi, H. D. Kim, and S. S.Kim, SID Symposium Digest Tech Papers 40,37 (2010).16T. Tanabe, S. Amano, H. Miyake, A. Suzuki, R. Komatsu, J. Koyama, S. Yamazaki, K. Okazaki, M. Katayama, H. Matsukizono, Y. Kanzaki, and T. Matsuo,SID Symposium Digest Tech. Papers 42, 88(2012).17M. C. Hung, et al., 2010 Intl. Workshop onTAOS, Tokyo, Japan.18J. H. Lee, et al., SID Symposium DigestTech. Papers 40, 625 (2010).19H. D. Kim, J. S. Park, Y. G. Mo, and S. S. Kim, 9th Intl. Meeting on InformationDisplays, 3-1 (2009). n

J O I N S I DWe invite you to join SID to participate in shaping the futuredevelopment of:• Display technologies and display-related products

• Materials and components for displays and display applications

• Manufacturing processes and equipment

• New markets and applicationsIn every specialty you will find SIDmembers as leading contributors totheir profession.

http://www.sid.org/Membership.aspx

Display Week 2013SID International Symposium,

Seminar & ExhibitionMay 19–24, 2013

Vancouver Convention CenterVancouver, British Columbia, Canada

www.displayweek.org

Submit Your News ReleasesPlease send all press releases and new productannouncements to:

Jenny DonelanInformation Display Magazine411 Lafayette Street, Suite 201

New York, NY 10003Fax: 212.460.5460

e-mail: [email protected]


http://www.sid.org/membership.aspx



THE CARRIER MOBILITY of a semi-conductor material, which is a measure ofhow fast mobile electrons or holes can movein the material under an applied electric field,is a key parameter for determining the per-formance of an electronic device. For active-matrix thin-film-transistor (TFT) displays,high mobility is related to high resolution,high refresh rate, low energy consumption,and high manufacturing yield.This article will look at the achievable

performance of indium-gallium-zinc-oxide(IGZO) as well as that of other metal-oxidesemiconductor materials for TFT applications.Efforts to make IGZO TFTs prevalent in display manufacturing are still ongoing as are searches for even better semiconductormaterials that will match the high perform-ance of low-temperature polysilicon (LTPS)TFTs and the low cost of amorphous-silicon(a-Si) TFTs. Zinc oxynitride (ZnON) isdescribed here as one possible path to realiz-ing these performance and cost goals.

a-Si and LTPSa-Si is widely used as a TFT channel material.Although the field-effect mobility of an a-Si

TFT is below 1 cm /V-sec, the low cost of thematerial and its TFT fabrication set a bench-mark for cost-effective production. LTPS typ-ically has a mobility of 50–150 cm2/V-sec.

However, because the cost to fabricate LTPSTFTs is much higher than that for a-Si TFTs,LTPS is used today mostly for high-end small-area display products. Recently, amorphous

Zinc-Oxynitride TFTs: Toward a New High-Mobility Low-Cost Thin-Film SemiconductorDemands for high-performance, low-cost, and low-energy-consumption displays continue to drive the development of new semiconductor materials. The success of the metal-oxide semiconductor IGZO for display backplanes has triggered even more activity, and zinc oxynitride is proposed as a possible solution.

by Yan Ye

Yan Ye has been working on the developmentof new technology at Applied Materials formore than 20 years. He can be reached at [email protected].



2

30

20

Noannealing

350C 450C 550C 650C

IGZO: dep using Ar only

IGZO: dep using Ar and 2% O2

Ref: Ye and Hussain, AKT internal, 2011

Annealing Condition

Hall mobility, cm

2V-1s-1

10

0

Fig. 1: The Hall mobility of a-IGZO films is shown before and after annealing at different temperatures.

ID Ye p20-24_Layout 1 3/22/2013 5:52 PM Page 20


indium-gallium-zinc-oxide (a-IGZO), one ofthe metal-oxide semiconductors developed inthe last decade, has been used to successfullymake display backplanes with a mobilityhigher than that of a-Si TFTs at a cost lowerthan that of LTPS TFTs. It is of interest to know whether the mobility

of an IGZO TFT can reach a level similar to that of an LTPS TFT through process optimiza-tion. A wide range of measurements of thefield-effect mobility of IGZO TFTs, which areextracted from I–V measurements, have beenreported in the literature. Although TFT field-effect mobility is a key parameter for validat-ing channel-layer performance, its intrinsiclimit is difficult to establish based on existentdata. In fact, accurate field-effect-mobilityassessment relies on precise measurements of the I–V transfer curve, channel width and length, capacitance, etc. It is sensitive to TFT fabrica-tion, measurement, calculation, and human error.Hall mobility, the carrier mobility attained

from Hall-effect measurement, is a moredirect measurement of the material itself.Therefore, Hall mobility is more suitable forcomparing different materials, although certain limitations or errors can also exist.Figure 1 plots the Hall mobility of amorphous-IGZO of a composition of about 1:1:1:4attained in a test. These data suggest thatmobility achieved by a-IGZO should behigher than that of a-Si, but not LTPS.

Single-Metal OxidesSeveral mechanisms limit electron or holetransport inside n- or p-type semiconductors.Single-metal oxides, such as ZnO, In2O3, andSnO2, have been studied intensively as trans-parent conductive oxides (TCOs) for decadesand as semiconductors for TFTs in the lastdecade. Figure 2 shows the Hall mobility atdifferent carrier concentrations for doped andundoped ZnO films. It is clear that two mech-anisms limit carrier transport in the material:grain-boundary-limited transport and ionizedimpurity scattering. ZnO is normally poly-crystalline. The boundaries between the crystalline grains can trap charges, deplete the carriers around them, and interrupt theelectron transport across them, presentingpotential barriers with respect to the conduc-tion-band minimum [Fig. 3(a)]. The barrierheight decreases with increasing carrier con-centration until Coulombic ionized impurityscattering dominates as the mechanism-limiting electron-carrier transport.

As shown in Fig. 2, the transition point atwhich the ionized impurity scattering mecha-nism becomes dominant is at a carrier concen-tration of ~1020 cm-3 in ZnO. It is worth noting that in single-crystal Si, the transitionpoint at which ionized impurity scatteringbecomes dominant compared to phonon scattering is at a carrier concentration of ~1017 cm-3. For other single-metal oxides, it is observed

that high mobility can be achieved at high carrier concentration where the material ismore like a conductor than a semiconductor.For example, In2O3:H films attain a mobilityabove 100 cm2/V-sec at a carrier concentra-tion over ~1020 cm-3, characterizing as con-ductors. In fact, it is difficult to make a single-metal oxide film with a high mobilityand a low carrier concentration as desired forTFTs. Therefore, it is necessary to search forother options.

Multi-Metal Oxides The grain-boundary-limited transport problemencountered in single-metal oxides can beaddressed effectively by forming multi-metaloxides, as shown in Fig. 3(b). Since multiplemetals are involved in forming the crystallinestructure of the film during deposition, undera balanced ratio, preferential growth of a crystalline structure from any metal used canbe interrupted by the presence of other metals.a-IGZO, with a composition of about 1:1:1:4,is a good example in this category. However, it is observed that even though

there is no clear grain boundary in a-IGZO,electron transport is still limited by a potentialbarrier just as it results from grain-boundary-limited transport, showing an increase inmobility with an increase in carrier concentra-tion [Fig. 3(d)]. The barrier remains the dom-inant mechanism limiting the mobility at carrier concentrations up to ~1020 cm-3 with


Fig. 2: Mechanisms limiting Hall mobility are shown based on the Hall-mobility measurementof various doped or undoped ZnO films at different carrier concentrations.

Carrier concentration, cm-3

Ref.: Minami, MRS Bulletin/August 2000

Ionized impurity scattering m1

Grain-boundary scattering mG

(m1-1+mG-1)-1

Hall mobility, cm

2V-

1s-1

103

102

101

1001019 1020 1021 1022


no signs of Coulomb scattering or defectreduction taking over. Therefore, the mecha-nism resulting in this barrier is strong.Notably, the mobility-carrier concentrationrelationship remains the same even for single-crystalline IGZO as shown in Fig. 3. A percolation conduction model has been usedto explain the barrier. Conceptually, the potential barrier in IGZO

may also be explained based on the model ofs-orbital wave-function overlap. In an idealcase for a multi-metal oxide, as illustrated forIGZO in Fig. 3(b), the distance of the interac-tion between s-orbitals of neighboring metal

cations should be larger than that of cationsites. However, it may not occur everywherein reality. Even by excluding the complexityof randomness in an amorphous phase, it maynot be thermodynamically favorable to packcations of different metals at an equal dis-tance, as described in the ideal case. In addi-tion, different metals may interact with othersdifferently, making the interaction distancebetween cations from different metals morecomplicated. Therefore, it is very likely thatthere will be some locations where the sitedistance is larger than the interaction distancebetween cations, causing interruptions on the

conduction-band minimum that will give riseto potential barriers. This model may alsoexplain why mobility is reduced in a highlydoped single-metal oxide, even though no significant grain-boundary-limited transport ispresent, and why a ternary compound such asIGO or IZO may result in a higher mobility asreported due to less complexity than otherquaternary compounds.It is possible to achieve a higher mobility

by changing the composition of a multi-metaloxide, i.e., making an IGZO with a differentratio. When making a film with an unbal-anced ratio, crystalline structures grow rela-



Fig. 3: The barrier resulting from grain boundary commonly encountered in a single-metal oxide (a) can be suppressed by forming either amulti-metal oxide (b) or a single-metal oxynitride (c). Data plotted in (d) show that the mobility of a-IGZO or c-IGZO increases as carrier con-centration increases, indicating that a potential barrier, similar to that due to grain-boundary-limited transport, exists. Data plotted in (e) showthat several as-deposited ZnON films attained from a 50°C process follow a different trend compared with IGZO.

(3a)

(3c)Carrier concentration, cm-3

Carrier concentration, cm-3

100

10

1016 1018 1019 1020 1021

1016

Single-crystalline

AmorphousIGZO films

ZaON-1ZaON-2ZaON-3

Ref.: Ye, et al, J. Appl.

Ref.: Kamiya, et al, Sci. TechAdv. Mater. 11 (2010)

Phys. 106, (2009)

HQ a-IGZO

c-IGZO1 LQ a-IGZOc-IGZO5

IGZO films

1017

1017 1018 1019 10201

10

Hall mobility, cm2V-1s-1

Hall mobility, cm2V-1s-1

Path 1

Path 2

Single-metal oxide:

Multi-metal oxide:

ZnON, ZnON:Al, ZnON:Sn, InON,.

ZnO, SnO2, In2O3, Ga2O3Grain boundary

Ideal model for Possible model for

Ref.: Nomura, et al, Nature, 432, (2004).

a-IGZO a-IGZO

BarrierEc

EvEf

InGaZnO, InSnZnO ... (Quaternary)ZnSnO, InZnO, InWO, ... (Ternary)

Single-metal oxynitride:

(3e)

(3b)

(3d)

The binary compound is more likelyin polycrystalline phase. In a filmwith a low carrier concentrationdesired for TFT, a barrier resultingfrom grain boundary scatteringlimits electron mobility.

By utilizing O and N as anions, crystallinegrowth even with single-metal cations can besuppressed. Therefore, the barriers due toboth grain boundary and multi-metal cationsmay be minimized, and high mobility can beattained.

The film can be made as amorphous andtherefore the barrier from grain boundary canbe eliminated.However, a barrier due to multi-metal cationsmay exist to impede electron transport,resulting in a low mobility that is not expected.


tively easily if the defect level is kept low, andthus barriers associated with grain-boundary-limited transport return. Besides, barriersassociated with multi-metal cations still exist, just as in a ternary compound or a highly doped binary compound. Therefore, the improvement in mobility thus far with a carrier concentra-tion suitable for TFTs is limited.

Zinc OxynitridesThe barriers resulting from both grain bound-ary and multi-metal cations can be suppressedby forming a single-metal cation (Zn) andmulti-anion (O and N) metal oxynitride suchas zinc oxynitride (ZnON), as shown in

Fig. 3. Since both oxygen and nitrogen areused as anions, which require different crystalline structures in the compound, thearrangement of zinc cations in the film is disordered. The film can be depositedthrough a reactive sputtering process using ametallic zinc target and reactant gases such asoxygen and nitrogen. Composition and crystalline structure of the film can be variedby controlling the competition of reactionsbetween zinc and nitrogen and between zincand oxygen, which can be achieved by adjust-ing the flow rate ratio of oxygen and nitrogenalong with the associated pressure, tempera-ture, and power used in the process.

Figure 4 shows films deposited at differentoxygen flow rates under a high nitrogen flowrate of 500 or 300 sccm in a reactive sputter-ing process. When no oxygen gas is intro-duced and oxygen unintentionally remainingor is carried into the chamber is minimized, aZn3N2 film is produced. Zn3N2 film is poly-crystalline as observed by X-ray diffraction(XRD) and grazing-angle XRD (GXRD).When a small amount of oxygen gas is intro-duced, the growth of the Zn3N2 crystallinestructure is interrupted because the reactionbetween zinc and oxygen starts to competewith the reaction between zinc and nitrogen.For a flow rate of oxygen between 5 and 40


Fig. 4: Shown is the change in Hall mobility and crystalline structure in the films deposited at different oxygen flow rates in a reactive sputteringprocess using a Zn- or Al-doped Zn target. In the sputtering process, the flow of nitrogen gas remains high. By adjusting a dominant reactionfrom between Zn and N to between Zn and O, zinc nitride (Zn3N2), zinc oxynitride (ZnON), nitrogen-doped zinc oxide (ZnO:N), and zinc oxide(ZnO) films can be produced. High mobility is attained in the films in which crystalline structures of Zn3N2 and ZnO are suppressed.

As-deposited film from a 50C process

Hall Mobility, cm2V-1s-1

500 sccm N2, Zn300 sccm N2, Zn500 sccm N2, Zn:Al300 sccm N2, Zn:Al

n-type semiconductor50

40

30

20

10

0

0

Zn3N2 ZnON ZnO:NXRD XRDXRDXRD

4000 800

30 40 50 60 70

600

400

200

0

4000

3000

2000

1000

0

030 40 50 60 70 70 80

0

16000

12000

8000

4000

8000

6000

4000

2000

06020 30 40 50

8000

6000

4000

2000

800

600

400

200

0

3000

2000

1000

0

030 40 50 60 70

222

32400

332 440

444

721

611

631

521

8000

6000

4000

2000

... . Zn3N2 (cubic)

100

101

002

102 103

112110

100

100

101

101

002

002

102

102

103

103

112

112

110

110

100

101

002

102 103

112110

.. .... ZnO (hex)

.... ZnO (hex) .... . ZnO (hex)

.... ZnO (hex)

222

32400

332

440

444

721

611

631

521

.. .... Zn3N2 (cubic)

0 sccm O2, 500 sccm N2 20 sccm O2, 500 sccm N2 50 sccm O2, 500 sccm N2 180C, 50 sccm O2, 100 sccm N2

GXRD GXRD

Diffraction angle 2qDiffraction angle 2qDiffraction angle 2q

Intensity

Intensity

Diffraction angle 2q

Ref.: Ye, et al 2010 Fall, MRS

GXRD

10 20 5030 40

O2 flow rate, sccm

ZnO


sccm in the test (Fig. 4), crystalline structuresfor both Zn3N2 and ZnO crystalline structureshave been significantly suppressed and filmsdeposited are either amorphous or highly disordered nanocrystalline ZnON films. Theamorphous fraction and composition of ZnONfilms vary depending on reactions involved inthe film-deposition process. As the oxygen flow rate is increased to

about 50 sccm, the reaction rate of zinc withoxygen becomes higher than that of zinc withnitrogen, and ZnO crystalline structuresemerge. However, nitrogen is still embeddedin the film, as indicated by the shift of ZnO-crystalline peaks in XRD and GXRD measure-ment. Since the film has a clear zinc-oxidecrystal-line structure, it is often called nitro-gen-doped zinc oxide (ZnO:N). The reactionbetween zinc and oxygen becomes dominantas oxygen flow further increases or nitrogengas decreases, and the film becomes a ZnOfilm even though a lot of nitrogen is still pres-ent in the process. It is evident that the reac-tion rate between zinc and oxygen is muchhigher than the reaction rate between zinc andnitrogen in the reactive sputtering process.This also explains why an abnormally highratio of nitrogen over oxygen is often neededto produce a ZnON film, why the transitionregime from Zn3N2 to ZnON is very small,and why a Zn3N2 crystalline structure can besuppressed even by a small amount of residualoxygen.Although the films made from the process

can be Zn3N2, ZnON, ZnO:N, or ZnO, Hall-effect measurements show all of the films produced are n-type semiconductors. There-fore, the mobility of the films should rely onthe conduction band of the materials. Theresult in Fig. 4 shows a clear trend that thehigher mobility is achieved in the films inwhich the Zn3N2 and ZnO crystalline structureis suppressed. The variation of mobility in aZnON film depends on its composition, amor-phous fraction, and possible defects in thefilm. Table 1 shows the mobility of a ZnON

film before and after annealing. It is clear thatmobility increases significantly from 38 to135 cm2/V-sec, while the carrier concentrationis reduced, most likely due to defect reductionin the film through annealing.Another interesting difference between

IGZO and ZnON is illustrated in Fig. 3(e).Several ZnON films tested have shown anincrease in Hall mobility as carrier concentra-tion decreases in the region to below 1020 cm-3,which is different than the trend reported forIGZO. This indicates that in the ZnON films,ionized impurity scattering remains dominanteven in a region where it is relatively weak,which, in turn, indicates that the potential barrier on the conduction-band minimum inthe ZnON films is relatively low. Actually, ZnON should be closer to the

ideal model shown in Fig. 3(b) if the disorder-ing from the multi-anions is not too severe.Since only Zn serves as the cation in theZnON films, the interactions between neigh-boring cations are more uniform, and the distribution of metal cations is less complex,despite their amorphous arrangement. Thisincreases the probability of maintaining aninteraction distance larger than the distancebetween the cation sites. Therefore, thedegree of interruptions on the conduction-band minimum, or potential barriers, in thesingle-metal oxynitride should be reducedcompared to that of IGZO film. As a result, ahigher mobility than IGZO can be achieved.ZnON has some unique characteristics

compared to other metal oxides. For example,the wet-etch rate of ZnON is at least 10 timesfaster than that of IGZO. However, ZnON ismore resistant to dry plasma. Under typicalplasma dielectric etching or metal-etch process conditions, the etch rate of ZnON isabout 10 times slower than that of IGZO. It is also observed that the surface of ZnON

is more hydrophilic than other oxides. It canabsorb moisture and pollutants in the air andform weak acids or bases that accelerate oxidation of the film from the top surface

down in a catastrophic way. Typically, theshelf life of ZnON is about several weeks if itis exposed to air without any passivation orprotection. Annealing, however, can signifi-cantly extend the shelf life of ZnON film fromseveral weeks to several years. ZnON TFTsare often less sensitive to ambient conditionstested against other TFTs of the same struc-ture. However, the threshold voltage, Vth, ofZnON TFTs is often more negative comparedto other metal-oxide TFTs. As experiencedwith any other new semiconductor, the inte-grated process to fabricate ZnON TFTs will bedifferent from that for IGZO, and somechanges will have to be implemented. Someof these features are challenges that need to beaddressed, but some of the unique film prop-erties can be utilized to improve the TFT stability and reduce the costs for manufactur-ing TFT backplanes. So far, ZnON active-matrix TFT backplanes for a 3.8-in. QVGAdisplay have been tested with yields close to100%. A field-effect mobility of about 100 cm2/V-sec has also been achieved bygroups with ZnON TFTs.In summary, IGZO TFTs have successfully

demonstrated higher mobility than a-Si TFTsand lower cost than LTPS TFTs. Even thoughefforts to fully implement IGZO TFTs in dis-play manufacturing are still ongoing, searchesfor even better semiconductor materials haveclearly already started. In order to make TFTswith a performance as high as that for LTPSTFTs and as low cost as that for a-Si TFTs,breakthroughs are needed. ZnON TFTs havebeen demonstrated here as one candidate toachieve this goal, but more progress is expectedin the future. n



Table 1: Hall mobility and carrier concentration of a ZnON film are shown beforeand after annealing.

Resistivity Hall Mobility CarrierFilm Ohm-cm cm2 V-1 S-1 Concentration cm-3

ZnON as deposited (50°C process) 2.7E-02 38.5 -9.06E+18

After anneal at 400°C for 1 hour 1.6E-02 135 -2.82E+18

Submit Your News ReleasesPlease send all press releases and newproduct announcements to:

Jenny DonelanInformation Display Magazine411 Lafayette Street, Suite 201

New York, NY 10003Fax: 212.460.5460

e-mail: [email protected]



DELO.us · Tel 978.254.5275

COME SEE US AT SID 2013Vancouver / CanadaMay 21 – 23 · Booth # 539

For Display and Touch Panel Bonding

High transmission / no yellowing

Excellent humidity resistance

Optional 2nd curing mechanism for shadow curing

Optically Clear Adhesives

Visit our websitewww.DELO.de/en/display-bonding


Ads p25.indd 1 3/22/2013 8:27:15 PM

http://www.DELO.de/en/display-bonding

http://www.koe-americas.com

AMONG the many compelling featuresof active-matrix organic lighting-emitting-diode (AMOLED) displays are image quality(wide color gamut, viewing angle, and highcontrast), thinness, and weight (no backlightand the potential to be made on a single sub-strate, which could be plastic or metal), andmanufacturing process (simple stack, smallamounts of materials, and few optical films).During the decade since the first AMOLEDdisplays were produced, dozens of companieshave made at least some efforts toward massproduction. Despite the promise of the technol-ogy, the reality has been that developing theequipment, materials, and manufacturingprocesses to make OLED displays at highyield rates has been very difficult. Even thedominant firms, Samsung Display and LGDisplay, have struggled to scale the technol-ogy to make TV panels. At the same time,TFT-LCD technology has continued to improve,most recently in the form of 4K × 2K panels.Through 2012, the vast majority of AMOLED-

display manufacturing capacity has been inKorea, primarily with Samsung Display butincreasingly with LG Display as well throughinvestments in Gen 8 fabs for TV panels (Fig. 1). There is a great deal of uncertaintywith regard to future production plans, but itis likely that there will be several new fabs in

China, as well as a resurgence from companies such as Japan Display, Inc. (JDI), Panasonic,AU Optronics Corp. (AUO), and Innolux, allof which have implemented restructuring andconsolidation of existing AMOLED-displayfabs. The key to building out new capacitywill be to master manufacturing technologiesthat enable scaling to large substrate sizes.

Korea: Samsung Display and LG DisplaySamsung Display, the result of the merger ofSamsung Mobile Display and Samsung Electronics’s LCD business, is the dominantproducer of AMOLED displays, starting massproduction in 2007 and accounting for morethan 95% of shipments in 2012. The com-pany’s capacity thus far has been built around

AMOLED Production: Entering a New Era?Active-matrix organic light-emitting-diode (AMOLED) displays have many attractive featuresthat have led companies to attempt to manufacture them, but one country – Korea – currentlyaccounts for the vast majority of AMOLED-display manufacturing capacity. Ambitiousinvestment plans in China, Japan, and Taiwan could change this balance over the next several years.

by Paul Semenza

Paul Semenza is Senior Vice President withNPD DisplaySearch. He can be reached at [email protected].


display marketplace

Fig. 1: AMOLED-display manufacturing capacity has been centered in Korea, but new orexpanded production is expected in other countries over the next few years. Note: Taiwancapacity includes AUO’s Singapore fab. Source: DisplaySearch Quarterly FPD Supply/Demand& Capital Spending Report.

ID Semenza p26-29_Layout 1 3/22/2013 8:38 PM Page 26


Gen 4 and, starting in 2011, Gen 5.5 lines,which focus on displays for smartphones andother mobile devices. These lines use the low-temperature poly-

silicon (LTPS) approach for the fabrication ofthe active-matrix backplanes, which are thencut in half (for the Gen 4) or quarters (for the Gen 5.5) for organic-material deposition. Vapor deposition of RGB subpixels is achieved primarily via fine-metal-mask patterning. Samsung has been using its Gen 5.5 A2 line,which consists of five phases, to experimentwith new manufacturing technologies, includ-ing laser-induced thermal imaging (LITI) formaterials deposition, flexible substrates, andthin-film encapsulation. (For more about current large-area OLED-display manufactur-ing processes, see the article “RGB Color Patterning for AMOLED TVs” in this issue.)LG Display did not start mass production of

AMOLED displays for mobile devices until2011, as it focused on high-resolution andwide-viewing-angle LCDs for mobile devices.The company also started out with Gen 4 production, but within one year, pilot Gen 8production began, focusing on AMOLED-TVpanels. The company began shipping 55-in. TV panels at the end of 2012, but is not expected to manufacture in large volumes until 2014,when it starts deposition on full Gen 8 sub-strates (it is currently using half Gen 8 sheetsfor organic-material deposition) in its M2 fab.LG Display has adopted two new approaches

in its Gen 8 fab – oxide-TFT backplanes andwhite OLEDs with a color filter. Both ofthese approaches are believed to enable scal-ing to larger substrate sizes – the oxide-TFTapproach because it can use modified a-SiTFT processes and the white-OLED approachbecause it does not require the deposition ofindividual red, green, and blue organic emit-ters on the subpixels. In order to fabricateRGB subpixels, color-filter material is thenpatterned on top of the white-OLED emittingarea. The process to add color filters is mucheasier than the process to deposit RGBorganic materials.Samsung Display has also announced that it

will begin Gen 8 production, although theexact timing is not clear. This new fab willcut the LTPS backplane into six sheets fororganic-material deposition. Samsung hasbeen developing a proprietary evaporationtechnique called small-mask scanning, inwhich a linear vapor-deposition source isscanned along the mask, which is believed to

allow for scaling to larger substrate sizes thanis the case when using a fine metal mask witha point source. Samsung is also believed to bedeveloping oxide-TFT backplanes and white-OLED deposition for future Gen 8 production,as it may be easier to scale than LTPS backplanes.While Samsung will have the largest

AMOLED-display manufacturing capacitythrough 2014, it is possible that LG Displaycould catch up in 2015 if it continues on itscurrent Gen 8 investment path. Samsungwould likely maintain its market share forsome time, however, as it continues toincrease smartphone-display production and ismoving toward the production of panels fortablet PCs and other larger-screen sizes. Theoutcome may depend on whether Samsungpursues OLED TV as rapidly as LG Displayor focuses instead on smaller, mobile displays.

Japan: Fewer, Larger PlayersJapan Display, Inc., (JDI) was formed via themerger of the mobile-display businesses ofHitachi, Toshiba, and Sony, and producesAMOLED displays using Gen 2 (formerlyHitachi) and Gen 4 (formerly Toshiba) fabs;Sony did not transfer its AMOLED-displayassets to the new company. JDI is planning toadd new capacity to the Gen 4 line (organicdeposition on half-substrates), with the capa-bility to process WOLED or RGB. JDI hasalso acquired Panasonic’s Gen 6 a-Si LCDline and will install equipment to convert thefab to LTPS production in 2013, with organic-material deposition on the substrate cut intosixths.Sony, historically a leader in AMOLED-

display production, previously producedAMOLED displays for its Clie PDAs, as wellas the first AMOLED TVs. Sony has main-tained its facilities and integrated into SonySemiconductor and is currently producingvery-high-end AMOLED monitors for mastervideo and medical applications.Panasonic has been developing AMOLED-

display production for years at its R&D center.In 2012, it installed ink-jet tools at a line inHimeji for AMOLED-TV pilot production.The company has been pursuing AMOLED-display production with oxide backplanes,ink-jet printing, and Sumitomo Chemical’s(much of the original patent portfolio wasacquired from Cambridge Display) solublepolymer AMOLED materials (as opposed tomore common small-molecule materials that

are vapor deposited through a fine metalmask). In July 2012, Panasonic announced ajoint development program with Sony basedon printing technologies. Other companies in Japan with ongoing

AMOLED-display efforts include Epson, Ortus, and Sharp; however, none are anticipated tobegin mass production in the near future.

Taiwan: Consolidation, LimitedProductionAUO has two OLED lines for the productionof small-to-medium OLED products, based on LTPS backplane and evaporation color patterning, a Gen 3.5 line, and a half Gen 4line (AFPD in Singapore). In 2012, the com-pany started a Gen 6 line using oxide-TFTbackplanes and the full deposition of whiteOLEDs; it is believed that Sony’s 56-in. RGB4K × 2K AMOLED TV was produced byAUO. Innolux owns a former TPO Gen 3.5fab that uses LTPS backplanes with whiteOLEDs and a Chimei EL Gen 3.5 fab that previously produced bottom-emissionAMOLEDs. Wintek has also been developingAMOLED-display production.

China: Many Announcements, LittleCapacity Thus FarThere are many panel makers in China thathave built R&D lines for AMOLED produc-tion, including BOE, CCO, Shenzhen ChinaStar Optoelctronics, IRICO, Tianma, UDT,and Visionox. Most of these fabs are Gen 2,with the exception of Shenzhen China StarOptoelectronic Technology’s (half Gen 4) fab,and all use LTPS backplanes and RGB pat-terning. BOE, China Star, Hehui Opto,IRICO, Lai Bao, and Truly have announcedtheir intention to go into production with Gen4 fabs over the next few years; BOE, ChinaStar, Tianma, and Visionox are planning Gen5.5 fabs, and Foxconn has announced itsintention to build a Gen 6 line. Finally, BOEis planning a Gen 8 AMOLED-display fab for making TV panels in Beijing, using oxideTFTs and white OLEDs.For a number of these companies, the

schedule and probability of success are uncer-tain. Many are driven by provincial initiativesto develop high-technology manufacturing,but the supply chain and human-resource poolare limited in some cases. However, a steady stream of new ventures is targeting AMOLED-display production. Among the newest players are IMEC, which announced that it intends to



build a Gen 3.5 AMOLED fab in Nanjing,with help from JGroup. Blue Excited Tech-nology (BEX) plans to produce small AMOLED displays based on blue-coating technologydeveloped at Xinyang Normal University; the company plans to build a Gen 4 fab usingoxide-TFT blue OLED material and colorconversion for color patterning.

Scaling Up to Larger Substrate SizesMost existing AMOLED-display fabs are Gen 4 or smaller. This is due to limitations in scaling both the TFT backplane array andorganic materials deposition to larger sub-strate sizes. As with TFT-LCDs, there is animperative in the AMOLED-display industryto move to larger fab sizes in order to increaserevenues and reap economies of scale; somuch of the industry focus is in these twoareas of manufacturing technology.In the past, AMOLED backplanes have

been limited to Gen 4 substrates. This wasbecause LTPS was the only TFT technology

that was able to drive the OLED devices,which are diodes, with sufficient levels of current density. LTPS fabs were limited toGen 4 because of the need for an annealingstep that typically uses excimer lasers. Due tolimitations in laser power, the Gen 4 substratewas the largest area that could be annealed bythe laser in a reasonable amount of processingtime. However, developments over the pastrecent years have reduced some of these barriers. First, more powerful excimer lasers,as well as multiple scanning, have enabledGen 6 and potentially larger LTPS backplanes.Second, oxide-TFT technology, which is simi-lar to standard a-Si TFTs but provides higherlevels of current density, has been broughtinto mass manufacturing, enabling Gen 8AMOLED backplanes to be produced.It is common in AMOLED-display manu-

facturing to cut the TFT-array substrate downto a smaller size for the back-end process oforganic-material deposition. This is due tolimitations in the standard process for evapo-

rating organic material from a point sourcethrough a fine metal mask to define the sub-pixels. The use of this technique at Gen 4 andlarger sizes has been difficult, due to issuessuch as sagging of the mask, shadowing andangular-distortion induced by the large angles,and the necessity of cleaning the masks. Samsung has recently been working on scan-ning a linear source across a mask, whichcould address some of these challenges;another approach is vertical scanning, inwhich both the mask and substrate are oriented vertically.To scale up to very large substrate sizes,

however, it is likely that new approaches areneeded (Fig. 2). Two that have been in devel-opment for some time are LITI and ink-jetprinting. In LITI, the organic material isembedded in a sacrificial film that is put ontop of the substrate and then exposed to alaser, which causes a transfer of the organicmaterials to the substrate. In ink-jet printing,the organic materials are suspended in solu-

display marketplace


Fig. 2: While the use of a fine metal mask is the most prevalent method for deposition of the organic material layers in AMOLED displays, newerlarger fabs are pursuing other approaches that might be more easily scaled to large sizes. Source: DisplaySearch.


tion, which is then forced through ink-jet printheads onto the substrate. While these tech-niques show great promise, neither has beenput into mass production. (The January/Feb-ruary Industry News section of ID magazinediscusses new ink technology developed byMerck and Epson for the manufacture of largeOLED displays.)

The newest approach to be tried is thewhite-OLED approach combined with the useof color filters, which LG Display is using (asdescribed earlier); in this approach, a singlelayer of white-emitting material is depositedon the substrate and a color-filter layer is usedto define the RGB (sometimes RGBW) sub-pixels. This approach eliminates the need forseparate deposition steps for each of the primary colors, a source of many of the challenges with fine-metal-mask deposition.A downside is the added complexity of acolor-filter layer and the potential for lowerefficiency due to absorption losses.

Next Steps Several upcoming fabs are planning to adoptboth oxide-TFT backplanes and whiteOLEDs, as these technologies appear to bemost easily scaled to larger substrate sizes. Itshould be noted that both of these techniquesare new to mass production, and it is likelythat there are unforeseen barriers to mass production that could impact schedules andoutput. Finally, it cannot be forgotten thatAMOLED displays currently face competitionfrom TFT-LCDs in virtually every screen sizeand application. Thus, it is imperative thatAMOLED-display manufacturing costs, currently a multiple of equivalent LCDs inlarge sizes, come down dramatically. In somecases, notably in China, AMOLED displaysare viewed as an entry into the FPD industrythat has greater potential than LCD manufac-turing, which has become mature andextremely competitive.

A different approach to the production ofAMOLED displays could be in flexible displays. It is extremely difficult for LCDs tobe made in fully flexible, or even curved, formats, due to challenges with cell-gap maintenance and backlighting optics. Tech-nologies such as electrophoretic technologyare very amenable to flexible formats, but donot have the visual performance required forvideo and other key applications. AMOLED-display technology is one of the few displaytechnologies that has demonstrated the ability

to be made in thin, flexible formats with littlediminution of display performance.

Both Samsung Display and LG Display areworking on the production of AMOLED displays on flexible substrates and face a different set of manufacturing challenges;notably, manufacturing yield and performanceof the TFT backplane on flexible substrates

and the requirement for some sort of thin-filmencapsulation to protect the organic materials.Neither of these challenges has been sur-mounted in mass production, and it is likelythat we will see a series of steps, first usingflexible substrates to make fixed, possiblycurved, displays, and then moving to full flexibility in future product generations. n



http://www.dontech.com

http://informationdisplay.org/IDArchive/2013/JanuaryFebruary/IndustryNews.aspx

WHEN I began my academic career in 2005, I thought my display days were over. The dominance of LCDs was clear; what researchwas there left to do? Was I ever wrong, asdisplays have remained a rich area of work forme and countless other people, and there con-tinues to be numerous needs for novel display technologies. Since I became involved with displays more than a decade ago, I have worked with and published on just about every display type: plasma/liquid/solid, emissive/transmissive/reflective/transparent, flexible/rollable, 3-D, etc.

More and more, I find myself working inflexible electronics too, and the segue intoflex has been quite natural. Why? Well, likemany of us “display folk,” I have always beenintimately familiar with low-cost and large-area microfabrication, hybrid integration oforganic and inorganic materials, low-tempera-ture processing, and print-based patterning.Furthermore, to make something rollable, theforemost enabler is often to make the entiredevice as thin as possible, typically <100 µmthick. Display engineers are constantly look-ing for ways to thin down the materials in adisplay to bring about better aesthetic appeal, impact resistance, and the thinness and lightness required for devices such as smartphones. The point is that if you work in displays, you are

often highly qualified to work in flexible/rollable electronics as well.

In this article, I hope to show that others inthe display community a few things they mayhave not seen before by touching on some ofthe interesting things happening in flexible/stretchable electronics. This is not a compre-hensive review by any stretch (or flex); rather,I hope to convince readers that flex is a grow-ing and exciting area with applications thatmight complement more traditional work indisplays by citing some examples of this workbeing done in the industry.

PARC: A logical place to begin this samplingis the Palo Alto Research Center (PARC), aprime source of display and print experts flex-ing their muscles (or devices) in the flexible-electronics area. PARC was an early pioneerin the late 1990s in flexible-display technol-ogy, due, in part, due to efforts in Gyricon’sbichromal ball technology for electronic paper(a rotating charged ball with black on one sideand white on the other), and also, in part, to itsdeep expertise in print-based patterning. Ifyou look at PARC’s activities today (Fig. 1),you will see a broad spectrum of flexibleelectronic technologies ranging from flexiblebatteries with a bend radius of <3 mm and acapacity >5 mA-hr/cm2, jet-patterned active-matrix backplanes (680-µm pixels), and aflexible 75-dpi PIN image sensor array, just toname a few. PARC develops these technolo-gies through a variety of projects rangingfrom basic materials science all the way to fullsystems prototyping/demonstration. Accord-

ing to Janos Veres, Program Manager forPrinted Electronics at PARC, “Flexible andprinted electronics is a field rich in opportuni-ties for PARC to deliver high-value innova-tion by combining its expertise in material science, device and circuit design, processtechnology, and prototyping. Our clientsrange from chemical companies to makers ofconsumer products.” A great deal of PARC’spioneering work in printed displays is nowbeing deployed in exploring the limits ofprinted circuits and their use, for example, insmart sensor systems. PARC has recentlydemonstrated printed, disposable, blastdosimeters that monitor traumatic brain injuryin soldiers on the battlefield. The tape-likeblast dosimeter records the severity and thenumber of blast events during 1 week in orderto enable early administration of medical care.The fully functional sensors are fabricated bymethods such as lamination, die cutting, solu-tion processing, and printing – all compatiblewith inexpensive roll-to-roll processing.

American Semiconductor and MC10:Let’s say that you are a display integrated circuit or row/column driver expert, and youare excited about chip-on-glass, but think thatflex has nothing to do with you or with a traditional CMOS foundry. Think again!Today, the very high temperatures and ultra-high-resolution capabilities found in Sifoundries can be realized in rollable form.Compared to conventional flexible thin-film-transistors (TFTs), you can obtain a few 100×improvements: an increase in the best mobili-

Flexing and Stretching So you work in displays? You may soon be working in flexible electronics too. Author JasonHeikenfeld, associate professor with the School of Electronic and Computing Systems at theUniversity of Cincinnati, looks at several of the most interesting developments in flexible electronics.

by Jason C. Heikenfeld

Jason C. Heikenfeld is an Associate Professorin the School of Electronic and ComputingSystems of the University of Cincinnati; telephone 513/556-4763, e-mail: heikenjc@ ucmail.uc.edu.


enabling technology

ID Heikenfeld p30-34_Layout 1 3/22/2013 8:49 PM Page 30


ties for amorphous transistors on plastic from~1 cm2/V-sec to ~100s of cm2/V-sec for crystalline Si and a reduction in the featuresizes from approximately 5 to15 µm for display lithography down to approximately50–150 nm. The key enabler for flexing is thesame: make the CMOS film as thin as possible.

As shown in Fig. 2, American Semiconductoruses a wafer-thinning process on silicon-on-insulator (SOI) substrates to make flexible ICswith from 10 to 10,000s of chips per wafer.However, to reduce fragility, the companyapplies a polyimide film before the thinningprocess is performed to remove the thick Sisupport wafer. CMOS wafers thinned to <20 µm have been demonstrated to achieve a bend radius of 5 mm with no change in the electrical characteristics after flexing.American Semiconductor is a flexible elec-tronics and services provider that performs

flexible hybrid systems development as wellas design engineering, including design, veri-fication, layout, and testing. It now also pro-vides FleX Silicon-on-Polymer technology forflexible CMOS. Initial production runs of itsFleX technology have begun, and regardingfuture volume product, Richard Chaney, General Manager at American Semiconductor,notes, “FleX is a repeatable, manufacturableprocess demonstrated in prototype volumesand is currently supported using a Jazz Semiconductor CMOS foundry silicon. Weconvert advanced ICs from commercialfoundries into flexible chips by using our proprietary low-cost FleX process and inte-grating them with printed electronics to formflexible hybrid systems. This new technologyis ultra-thin, rugged, bendable, and low cost.Our FleX technology provides logic, memory,and wireless capability that is orders of

magnitude faster and smaller than printedTFTs for features that have always beenrequired but never before available in flexibleelectronics.” So, as a side note, if you want torealize a completely rollable display with norigid parts, you now have every componentavailable to you in order to make this a reality.

Now, can you take flexible Si electronicsone step further, making them conformal,stretchable, and biocompatible? The Universityof Illinois and startup MC10 have answeredthat affirmatively, demonstrating severalexciting new conformal electronics in recentyears (Fig. 3). They have shown sophisticated“epidermal electronics” that is applied to theskin in a manner similar to that of a temporarytattoo or expandable electronics on a ballooncatheter for sensing or for localized deliveryof therapy. The key to moving beyond flex tostretch/conformal is the ribbon-like sections


Fig. 1: PARC’s wide spectrum of foundational flexible electronic components and systems include a growing library of additively printed devicesand circuits, novel approaches for compliant packaging of components, and flexible sensor arrays. Source: PARC.

Flex Electronic Building Blocks at PARC

Amplifier

Temperature sensor

Ring oscillator

Decoder Complementary logicRF Inductor Coils Flexible Image Sensor

Compliant High-Density InterconnectFlexible Memory

Active matrix TFT

Flex battery

Shift register

Example Flexible Systems/Components at PARC


between functional “islands” of Si. Theseinterconnecting ribbons have a concertina-likegeometry and can be stretched by more than 50%, which is also just about how much human skin can stretch. One of MC10’s mottos hasbeen “electronics anywhere,” and, morerecently, the company has been focusing onreshaping electronics to conform to the humanbody for digital health applications. Accord-ing to Amar Kendale, MC10’s VP of Strategy& Market Development, “Epidermal electron-ics enable constant medical monitoring every-where. MC10’s ultra-thin skin-mounted sensors can manage conditions continuously so thatthey do not worsen or reach a crisis.” Thisconstant monitoring is made possible by usingdevices that are so thin that activities such asfootball, firefighting, or sleeping can be per-formed without any interference from thedevice, with medical data provided wirelesslyvia Bluetooth or other communication means.

Corning: Glass substrates are a familiararea to most of us in the display industry.Corning, Asahi, and several others have now

released super-thin glass that challenges thenotion that flex means low-temperature processing and the need for sophisticatedmoisture/gas barrier layers. Flex electronicsthat require dimensional and thermal stability,hermeticity, transparency, and a high surfacequality on which to build may work betterwith flexible glass than with plastic substrates.Even polyimide substrates are not compatiblewith conventional poly-Si temperatures, andstainless steel has its own host of issues (suchas the need for planarization). Glass, on theother hand, can be made with the fusion draw process invented at Corning, such that the outer glass surface is never touched during forming,providing a pristine surface. Dr. Sean Garnerof Corning notes that “Corning Willow Glassis an enabling component for both display and non-display applications that allows for thinner, lighter weight, or conformal device designs.”

Willow Glass allows processing up to500°C and is available in samples down to athickness of 100 µm. This certainly satisfiesflexibility and bending down to several centi-

meters in radius and allows roll-to-roll processing (see examples performed by ITRIin Fig. 4). However, at the present time, it isnot yet thin enough for personal foldable orrollable applications, a capability that currently only plastic substrates can provide.When it comes to substrates for flexible appli-cations, your options are as follows: you cannow process on conventional transparentPEN/PET flex substrates at <150°C, you canuse yellow-colored polyimide which allows abit higher temperature processing up to~350°C and is the workhorse of all flexibleelectronic interconnects in the electronicsindustry, and now you have access to transpar-ent glass that allows all the processing tem-peratures and materials that can be found in aconventional modern LCD manufacturingfacility. Furthermore, as mentioned previ-ously, the world of crystalline Si is now flexible, so there are many options.

Flex Tech: In flexible electronics, there isroom for everyone (Fig. 5). Organizationssuch as the FlexTech Alliance (formerly the

enabling technology


Fig. 2: Above (left) are examples of flexible ICs based on American Semiconductor’s Flexible Si CMOS (FleX) technology. At upper right areflexible, transparent CMOS foils; at lower right, the company’s roadmap for developing and delivering the technology. Source: American Semiconductor.

Flex ICs Tested, Concave and Convex Flexible & Semi-transparent CMOS Foils

FleX Silicon-on-Polymer Roadmap

TRL4

TRL6

Today

TRL7


U.S. Display Consortium) and the market research firm IDTechEx in Europe broadly cover flexible electronics, and, not surprisingly, many of their reports include developments in dis-plays. FlexTech’s view of major flexible-electronics opportunities is two-fold: (1) flexible and printed electronics enable human-scaleproducts – conformable, portable, or wearable– for healthcare, energy, and displays/e-booksand (2) new, distributed manufacturing withprinted electronics is possible for customized,diversified products. These will be manufac-tured closer to the end user and will be acces-

sible to both large and small manufacturers. There is no doubt in the market either. Consider these highly compelling market forecasts byIDTechEx: “The market for printed and thin-film electronics will be $9.46 billion in 2012;42.5% of that will be predominately organic electronics such as OLED display modules. Of the total market in 2012, 30% will be printed.Initially, photovoltaics, OLED displays, and e-paper displays grew rapidly, followed by TFT circuits, sensors, and batteries. By 2022, themarket will be worth $63.28 billion, with 45%printed and 33% of that on flexible substrates.”1

So How Close Are We? Compelling, exciting, and transformative areall good descriptors of some the technologydemonstrations now being seen in flexible electronics. So what is holding us back? Well, as we know for applications such as displays,in some cases it is a technological hurdle (stable TFTs and no moisture penetration forflexible OLEDs) and sometimes it is marketpull. (Polymer Vision’s beautiful rollable dis-plays relied on E Ink’s monochrome reflectivetechnology, which in those days lacked theresponse time suitable for video rates. This


Fig. 3: State-of-the-art medical applications for flex Si incorporate specially designed “ribbons” in between functional Si “islands” to allowfully conformal, even stretchable, electronics.

Fig. 4: Above are examples of roll-to-roll processes implemented by ITRI (Taiwan) on Corning’s flexible Willow Glass, and, at right, a plot ofbend stress vs. bend radius.

“Epidermal” Electronics

Willow Glass with Edge Tab Roll to Roll Ag Ink Printing

Roll to Roll Polymer Film Roll to Roll Laser ITO

Bend Radius (cm)

0.1 mm thickness0.2 mm thickness

200

400

300

100

00 5 10 15 20 25 30

500

Bend Stre

ss (M

Pa)

PatterningLamination

antenna

in the bottle outside the bottle

LED

wirelesspower coil

strainsensortemperature

gaugeECG/EMGsensor

Stretchable Electronics


shortcoming may have allowed touch-screensmartphones and tablets with full-color LCDsto absorb consumer demand for the potentialrollable product.) Since the polarizers usedfor LCDs cause the panels to be too thick foruse in a rollable display. The future may belimited to rollable OLED displays or e-Paper;however, smartphones do not need to wait forrollable displays to switch over to simple flexfor thinness and impact resistance.Other technologies such as flexible elec-

tronics for medical applications have greatmomentum toward commercialization, butgaining acceptance and approval in medical devices involves a long pathway with numerous regulatory and other hurdles that must be cleared. Roll-to-roll manufacturing has been fully proven as well, including ITRI’s demonstration several years ago of all the electronics needed to enable a smart-card device. The fundamentals andinfrastructure for flexible electronics are quite sound, and continued work is needed in finding the right applications. You often have to pro-vide something highly desirable to consumers

that they will pay extra for, since at the time of market entry, the competition is rigid electron-ics, which have beaten the difference betweenmanufacturing cost and price down to a razor-thin margin. Only in the longer term will low-cost arguments such as roll-to-roll manu-facturing potentially allow for more flex products to win market share based on costalone.So, again, do you work in displays? How

long will it be before you work in flexibleelectronics too? It may be sooner than you realize. It is quite clear that whether yourinterest is in displays or in other areas of flexible electronics, exciting enabling tech-nologies are now available, and flexible elec-tronics and displays will become ever morepervasive in our work and daily lives.

Reference1http://www.idtechex.com/research/reports/printed-organic-and-flexible-electronics-fore-casts-players-and-opportunities-2012-2022-000301.asp n

enabling technology

Fig. 5: A view of flexible/printed electronics materials, products, and markets as shown by theFlexTech Alliance.

MATERIALS

Non-Crystaline MaterialsNanomaterialsFlexible substrates

R2R ManufacturingPrinting and PatterningPolymer/Organic Synthesis

MembranesSensors/DetectorsThin-film transistors

Smart Bandages & ClothingNeuro Prosthetic DevicesSensor NetworksSolar Cells

Military/First RespondersMedicalAgriculture/Civil InfrastructureEnergy

PROCESSES

DEVICES/INTEGRATION

PRODUCTS

MARKETS


http://www.idtechex.com/research/reports/printed-organic-and-flexible-electronics-forecasts-players-and-opportunities-2012-2022000301.asp


http://www.glthome.com

http://www.glthome.com/3-2_LCDbacklight.html

http://www.glthome.com/

Join Today SUSTAINING MEMBERSHIPS

Sustaining or corporate members of SID are companies and universities who are deeply involved in the display industry, typically providing papers for the Digest or JSID and speakers for events, as well as providing minor financial support to SID. In return they receive discounts, free memberships, and valuable marketing benefits that enhance their brand and business opportunities.

GOLD SUSTAINING MEMBER-$7,500 annual membership fee

10% discount on 5 ~10’ x 10’ exhibit booths at SID’s Display Week Symposium & Exhibition

10 free individual memberships with benefits as noted on the right Company name in event bulletins and in each issue of Information

Display magazine Company logo on sid.org for brand support & search engine

optimization (SEO) Company video, whether company intro or product specific,

embedded on sid.org’s corporate membership page Four half-page ads in Information Display magazine during the

membership period 14 points toward ranking in the next year’s booth selection

SILVER SUSTAINING MEMBER-$3,000 annual membership fee

10% discount on up to 3 ~10’ x 10’ exhibit booths at SID’s Display Week Symposium & Exhibition


Display magazine Company logo & link on sid.org for brand support & search engine

optimization (SEO) One half-page ad in Information Display magazine during the

membership period 7 points toward ranking in the next year’s booth selection

SUSTAINING MEMBER-$1,000 annual membership fee

10% discount on one ~10’ x 10’ exhibit booth at SID’s Display Week Symposium & Exhibition


Display magazine Company name & link on sid.org for brand support & search

engine optimization (SEO) 1 point toward ranking in the next year’s booth selection

INDIVIDUAL MEMBERSHIP - $100 annual membership fee

Online access to the Digest of Technical Papers, Journal of SID, Information Display Magazine, and proceedings of many affiliated conferences and their archives

Hard copy mailing of Information Display Magazine Optional hard copy mailing of Journal of SID, add $50/year Optional multiple year discount: $190 for two year membership

(5% discount) or $270 for three year membership (10% discount) Discounts on SID-Wiley book series on display technology Discounts on SID-affiliated conferences such as Asia Display,

International Display Workshops, the International Display Research Conference, and other information display meetings

Networking infrastructure including chapter technical meetings, access to SID’s online job mart, online member search, and more!

Name Sustaining Basic $1000 Silver $3000 Gold $7500

Individual One Year $100 Two Years $190 Three Years $270

Student One Year $5 (Full time student ID required)

JSID by Mail? Add $50 per year for JSID by mail (no multi-year discounts available)

Amount Signature

Card Type Visa MasterCard Am Ex (UnionPay with any of these logos is OK)

Card Number Expiration Date Name on Card Phone

Mailing Address

Email

Email opt-out Click to opt out of event & ID Mag notifications, etc.

Please fill in the details above and fax form to +1 (408) 879-3833 or email it to [email protected]. Please use the space below to list your card billing address if it differs from the mailing address, as well as

the names & emails of any members as part of a Sustaining membership. Add a second sheet of paper if necessary.

Untitled-1 1 3/22/2013 11:27:13 PM


ONE of the best things about being partof SID is the opportunity to see the “alpha andomega” of the display industry. This includesproducts or technologies that start in the lab or are just the germ of an idea to product concepts and then to shipping displays. Pixel-dense UHD TVs, anti-reflective materials, andalmost any display technology that is breakingnews today was first dreamed of, then dis-cussed, then prodded and poked at during SID’s Display Week; sometimes years before making it to the CES show floor in January. Let’s take a look at the “omega” side of displays andsome key trends uncovered at this year’s CES.

UHD Thunder: China Struts Its StuffThe unmistakable display technology of noteat CES was ultra-high definition (UHD). Justas 3-D was all the rage 2 years ago, most vendors this year had UHD offerings, includ-ing all tier-one companies, the Taiwanese LCD makers, and almost every Chinese mainlandbrand. Remarkably, it was the 84-in. UHDTV that seemed to be near-mandatory in LasVegas, with almost every brand showing mul-tiple TVs boasting a large-screen 4K x 2K set.

Among the China-based notables showing 84-in. UHD sets were TCL (also with a 110-in. model) Skyworth (see Fig. 1), Westinghouse,Haier, and Hisense with five models, making

that China-based company the one with themost 4K sets. The Hisense units ranged from50 in. to an eye-popping 110 in. on the diago-nal with a pixel resolution of 3840 × 2160(see below). The products looked very closeto commercial status – they were not just prototypes. To get a look at the competition

tier-one brands are facing from Chinese com-panies, see the specifications for Hisense’sflagship XT900 4K models, which it calls U-LED TVs.Hisense XT900 U-LED 4K TV Specifications• UHD (3840 × 2160) native resolution,

120 Hz

Alpha and Omega: Most Exciting DisplayTechnologies at CESGiant TVs, ultra-high definition, IGZO, and more were among the display showstoppers atthis year’s Consumer Electronics Show in Las Vegas.

by Steve Sechrist

Steve Sechrist is a display-industry analystand contributing editor to Information Display magazine. He can be reached [email protected] or by cell at 503/704-2578.


show review

Fig. 1: This 4K China Skyworth UHD TV is sourced from CMI Display Taiwan. Photo courtesy Steve Sechrist.

ID Sechrist p36-40_Layout 1 3/22/2013 9:07 PM Page 36


• WiFi enabled• Smart TV with Google TV• 65-, 84-, and 110-in. screen sizes• 3-D• Smart-TV functionality• Precise local dimming• “Mega” dynamic contrast ratio (the back-

light can be completely turned off in local regions to greatly extend thedynamic range)

• Multi-screen play• Detachable camera (Skype calling,

gesture, and facial recognition)• Voice-control remote that allows voice

activation for on-off and channel changing.As far as LCD fab sources for the giant

110-in.-diagonal panels is concerned, I wastold in the TCL booth by product managerJain Peng “Konan” Jiao that the fab used byTCL was a result of its Joint Venture Gen 8.5with Samsung, called China Star Optoelec-tronics Tech (CSOT). Other panel makerswith a 4K offering at CES included Sharp(using its IGZO technology), Samsung, LG,Sony, Panasonic, and Toshiba.

4K Monitors at CES will ProbablyShip FirstIt’s interesting to note that the PanasonicUHD-class 20-in. hybrid tablet/display with a15:9 aspect ratio could be used as a tablet ordesktop monitor. The device includes an IPS4K × 2K panel and was shown at CES running Windows 8 with an Intel i5 Core (1.8 GHz) and up to 16 GB of memory.

With this technology, Panasonic seems tobe looking to extend desktop monitors into anew class of device that can also serve doubleduty as a tablet (albeit in this case, a mightybig one.) The company said it is targetingprofessionals who need very high resolution(photographers, engineers, and architects.)Perhaps another way to look at the product isas a portable “all-in-one” desktop PC with theadvantage that it can be taken into the field.

LG, Sharp, and ViewSonic all showedexamples of smaller 4K displays with 30-in.panels, and while the LG 30-in. unit was aprototype (found nested in a window wall inthe booth), specs include 153 ppi, 500 nits,and 99% of the RGB color gamut. This panelis probably aimed at OEM customers.

Meanwhile, Sharp claimed the “world’sthinnest” 4K monitor with its 32-in. diagonalmodel, which is less than 1.5 in. thick and isbased on its new zinc-oxide-TFT technology.

This panel also sports a 10-point discretetouch screen, as IGZO allows for more discrete sensors. According to Sharp, IGZOcan cycle the power-down state of the panel at a very high rate, enabling a far “quieter” electromagnetic environment. This allows the use of much higher sensitivity devices thatcannot work with conventional AMLCD panels (see the IGZO write-up below.)

This Sharp monitor was announced inNovember 2012 prior to CES. It has a pixeldensity of 137 ppi and will retail at around$5000. ViewSonic showed its 32-in. 4K monitor at CES and said the product willlaunch “sometime in 2013” with pricing to be announced.

4K Empowers 3-DIn the booth of Hisense, based in Qingdao,China, the company was using a 60-in. UHDto show off its autostereoscopic 3-D technol-ogy. Hisense went so far as to give the prod-uct a model number (GF60XT980), while atthe same time calling it a “proof-of-conceptmodel,” with no price or ship date. “By usinga Hisense ultra-high-definition 2160p panel,even at half the normal screen resolution,viewers can still enjoy a truly high-definition

picture,” according to Peter Erdman, HisenseGroup VP.

In terms of the images used at the show, thecompany did a very good job of simulatingdepth with its autostereoscopic prototype. It’simportant to note it was not displaying com-mercial 3-D film content, but rather multi 3-Dlayering content that demonstrated the tech-nology in a subtler way. On-axis viewing was discernably better than viewing from the sides. Hisense did say it was using a face-trackingtechnology to adjust the 3-D sweet spot, andthis may have been “overloaded” with thelarge crowds viewing the screen at the show.

Hisense also showed a transparent 3-D display for digital-signage applications (Fig. 2). The company used an LCD front-plane with passive 3-D capabilities and amounted backlight with a 1-m (or so) gap inbetween where merchandise can be placed.The objective was to demonstrate how to usethe LCD with current 3-D virtual content overany real merchandise in the background. In a storefront configuration, a window withmerchandise behind it can be displayed.Hisense sees applications in real-estate demos, window advertisements, showcases,and around the home.


Fig. 2: Hisense showed transparent 3-D technology for digital-signage applications at CES.Photo courtesy Steve Sechrist.


Most UHD TVs shown at CES were 3-Dcapable. Some of the vendors were usingUHD to create an autostereo TV image.These included Dimenco, showing an 11.6-in.switchable prototype using the company’s“Nabla” lenticular lens and new liquid-crystalcell design with low-voltage switching.Dimension Technologies, Inc. (DTI) also hadan autostereoscopic technology on hand, withan 8-view, glasses-free display using a uniquetime-multiplex backlight system. Dolbyshowed a new autostereo panel they devel-

oped with Taiwan-based CMI by using aPhilips lenticular lens along with stereo imageprocessing by Dolby, converted to multi-viewand streamed over a Vudu encoding format.Stream TV showed a set (UHD 60 in. at2160p) with a non-lenticular 3-D stack com-bining diffractive and refractive optics toguide light in the right direction within anestablished viewing distance.

On the standard (glasses-based) 3-D side,most major players (Sony, LG, Samsung, etc.)continued to show their active and passive

3-D technology, including Vizio, whichdemonstrated passive technology in two sets:65- and 70-in. models in its XVT (UHD TV)Smart-TV series.

Content is Still King, But Where Is It?What was interesting at CES was that 4Kglass (UHD TVs) seemed more prevalent thanthe content needed for viewers to take advan-tage of the high-pixel-density displays. It isthe familiar Catch-22 cycle: there is no con-tent, so no one buys the displays, so no onemakes the content since no one is waiting toview it.

One way HDTV overcame this content hurdle was through the DTV transition andthrough over-the-air broadcasts of HD con-tent. In that vein, LG did show a 2012 jointpilot venture with KBS (Korean BroadcastingSystem) that used 4K over the air. Theantenna technology used for this venture was on display in LG’s booth.

This, along with full-HD up-scaling and ofcourse producing (or re-mastering) originalfilm content to air on giant, high-pixel-densityscreens will eventually fill the 4K contentpipe and help drive demand as we move fromfull-HD into new UHD-display frontiers. It’shard to imagine the 500 lines of last century’sSDTV lasting for more than 50 years in lightof the DTV transition, full-HD broadcasts,and even the (albeit limited) 3-D sports andevent broadcasts of today. (For more aboutthe timeline for UHD broadcasts, see NHK’sarticle, “Super Hi-Vision as Next-GenerationTelevision and Its Video Parameters” in theNovember/December 2012 issue of ID.)

Biomimicry: Sharp’s Moth-EyeTechnologyAn example of the aforementioned alpha–omega technology progression from SID toCES is the Moth-Eye nanotechnologydescribed at SID 2011 in a presentation show-ing how it enabled a dramatic reduction inglare. At this year’s CES, prominent in theSharp booth was none other than a Moth-Eyedemonstration of how this “biomimicry” anti-glare technology will be used by Sharp toremove glare from indoor screens, with anaim toward tuning it for outdoor purposes inthe long term (Fig. 3).

Moth Eye creates nanohexagonal patternsof bumps on a film surface (spaced 300 nmapart) that are smaller (200 nm) than thewavelength of visible light, creating a contin-

show review


Fig. 3: Sharp Moth-Eye display shows technology introduced at SID in 2011. Photo courtesySteve Sechrist.


http://informationdisplay.org/IDArchive/2012/NovemberDecember/FrontlineTechnologySuperHiVisionasNextGen.aspx

uous refractive-index gradient (removing theair–lens interface.) Moth Eye gets its namefrom nature, which uses this strategy in com-mon night-flying moths to prevent lightreflection and thus help the moths concealthemselves from predators. Early reports ofthe technology go back as far as 2003, withdevelopment credited to MacDermid Autotype(Autoflex film) and Fraunhofer Institute forSolar Energy in Germany.

Truth be told, commercial Moth Eye wasfirst revealed by Sharp at CEATEC in Japanlast October, when the company announced itsAquos Quattron (3D XL vintage) with sizesranging from 46 to 80 in., all due to featurethe new technology in 2013 product roll-outs.

The Move to Giant TVsAt the pre-show press conference, Sharp (andothers) indicated the company will continueits large-and-larger display strategy, selling displays that top out at 90-in. on the diagonal. At the press conference, Sharp said it willmigrate to the 90-in. sets from the current 80-in. ones based, in part, on U.S. consumernumbers that show the plus 60-in. category isthe fastest growing size in the TV space. In2011, 60-in. sets were just 4% of the LCD-TVmarket in terms of revenue, according toSharp. That number has grown to 20% ofLCD-TV revenue. The company plans tooffer 21 models that are 60 in. and up, atprices as high as $10,000. Look for more bigsets from all major LCD players as they tran-sition to UHD sets in the middle of this year.

China’s Full-HD Mobile DisplaysEven with the Mobile World Congress eventtaking place just weeks after CES, the Chinasmartphone brands all used CES to launchfull-HD handheld displays that are sure todominate the wireless smartphone and tabletspace in 2013. Tier-one brands such as Samsung and LG only hinted at these newhigher-pixel-density models. Case in pointwas Huawei, which announced a 5-in. 1080pdisplay with an impressive 443-ppi pixel density in its new flagship Ascend D2 DreamPhone. The Grand S (flagship model) fromZTE is a 440-ppi 5-in. 1080p display. OtherChina-based brands to offer a full-HD hand-held included the Vizio Via (5-in. full-HDscreen), the Alcatel Scribe X (with a 1080p 5-in. display), and the Lenovo K900 with a5.5-in. 1080p IPS display that uses an LGAMLCD panel.

Sony’s new flagship Xperia Z smartphone(Fig. 4) attracted lots of attention on press dayat CES. The phone features a 5-in. 1080p display and a remarkable water-resistant design. Meanwhile, Sharp announced its continuous-grain-silicon (CGS) 5.1-in. smartphone forthe Japanese wireless market that boasts 443ppi. Sharp said its CGS LCD panel is alsoavailable for the OEM market. It first showedthe technology in October at CEATEC, whereits IGZO technology took the Top InnovationAward in electronic components.

The CGS backplane is based on crystallinesilicon, with an electron mobility up to 600times faster than that of ordinary amorphoussilicon and up to 6 times faster than that oflow-temperature polysilicon (LTPS), the current technology in the iPhone retina classiPhone 4, according to Sharp. The panel isbeing made at Sharp’s Mei Plant No. 3, using technology jointly developed along with Semiconductor Energy Labs (SEL) in1998. SEL is the same company that helpedSharp with IGZO. Sharp said its new full-HD


Fig. 4: Sony’s Xperia Z, a water-resistant 5-in. full-HD smartphone, stole the show in themobile space. Photo courtesy Steve Sechrist.


5-in. set also achieves a brightness of 500cm/m2.

OLEDs Almost Eclipsed by UHDSony and Panasonic, along with LG and Samsung, all had an OLED TV story to tell at CES and most (except for LG) were stillsinging the old “sun will come out tomorrow”song with beautiful images and no specificlaunch date. Meanwhile, LG did take theplunge, announcing just prior to CES that ithad begun taking pre-orders for its 55-in.(55EM9700) TV. A February 2013 deliverywas scheduled for the new OLED 55-in. ultra-slim sets in Korea (for about $10,000 a piece).They are due to ship to the U.S. in the March2013 time frame – finally, some progress.LG will be using its white OLED (WOLED)

and color-filter approach to get to market withwhat some call a simpler approach to solvingsome OLED materials lifetime issues. Thisapproach is based on solutions the companydeveloped, in part, by using Kodak patents.

Meanwhile, Samsung is using the tried-and-true RGB color OLED approach that broughtthe company OLED display dominance in thesmall-to-medium display space. To date, no one sells more AMOLED panels than Samsung. (For more about the two differentapproaches, see the article “RGB Color Patterning for AMOLED TVs” in this issue.)Japan-based Sony and Panasonic were both

present at CES with new 56-in. OLED panels,therefore claiming the “world’s largest” titlefrom Korean manufacturers. But at this latestate in the OLED-TV game, one may rightlyask whether without a model number or shipdate, does this have any real meaning?

E Ink Displays at CESE Ink was a Best of CES display winner withan interesting prototype from a Russian-basedcompany, Yota Devices. This was a two-sidedAndroid device, the “Yotaphone,” with a 4.3-in. 720p HD LCD on one side and apower-saving E Ink monochrome display on

the other. This configuration allows thedevice to act as a regular smartphone, but alsoan e-Book reader and platform for applica-tions not requiring the more memory-hungrycolor LCD. The company also had flexibledisplays at an evening post-show event; oneprototype was Central Standard Timing’s“CST-01” bendable watch display that’s wornon the wrist. While multiple E Ink tabletswere present at CES, we were told by MarketingVP Sriram Peruvemba to look for the technol-ogy to begin moving more rapidly in the digital-signage space, as bi-stable, low-power, andultra-thin displays empower a growing classof signage that includes retail shelf labels,hybrid static/dynamic posters, and rugged outdoor displays.

IGZO and New Life for LCDsFinally, this report would not be completewithout mention of the ground-breakingIGZO technology shown at CES by Sharp. In an extended meeting with Sharp engineers,I learned that the technology transforms displays using its indium gallium zinc oxide with “far superior” electron mobility and much smaller thin-film transistors (TFTs) to boostthe pixel aperture ratio (or the amount of lightthat can go through an R, G, or B subpixel).This development is creating a ripple effect

throughout LCD fab design and should enablenot just lower power from fewer backlights,but the ability to modulate the panel power(with cycles down to 1 Hz) depending on content – something Sharp calls “variablerefresh.” This, plus an off-state panel, willcreate a virtually electromagnetic (EM) noise-free sensor environment allowing the panel tointegrate not just discrete multi-touch sensors,but an entire array of new sensor technology(think bio/cellular, as well as UV sensors,atmospheric, olfactory, you name it ...). Inaddition to sensor-integration enablement,IGZO allows for deep pixel integration shownin some Sharp models of up to 1000 pointsper inch. Suffice it to say, the best and brightest were

on display at CES, with China beginning to show major strides not only in keeping pace, but inleading the display industry in key technologyfields. As 2013 dawns, we are beginning tosee the rise of Chinese display technologydominance and perhaps the reassertion of thetried and true LCD (via UHD and IGZO) thatare sure to be major factors in the displayindustry going forward. n

show review



http://www.ocularlcd.com

FIRST LOOK

Visit www.displayweek.org

Society for Information DisplaySID INTERNATIONAL SYMPOSIUM,

SEMINAR, AND EXHIBITION

DISPLAY WEEK 2013May 19–24, 2013

Vancouver Convention Centre, Vancouver, British Columbia, Canada

OLED TV v Oxide TFTs v Touch & Interactivity v 3D v Lighting

Announcing Special Topics of Interest on

SID 2013 First Look Cover p41_Layout 1 3/22/2013 9:14 PM Page 41


42

The Evolution of Displays through InnovationElectronic information displays touch nearly all aspects of modern life.Display Week’s 2013 Keynote addresses will provide a vision of howthe evolution of display technology through innovation will change theshape and look of the displays of the future.

KEYNOTE SPEAKERS

Dr. Kinam Kim, President & CEO, Samsung Display Co.“Displays and Innovation: An Exciting Future”

Our industry is forced to re-invent itself as users are inneed of better and more exciting uses for displays. Theywant rich, dynamic, immersive experiences, which will require innovations in user interface/interaction as well as advancements in panel technologies. Challenges alongthe path to this exciting future will be presented.

Mr. Bill Buxton, Principal Researcher, Microsoft Research, Microsoft Corp.“The Social Life of Devices”

Just as we are learning to manage the complexity imposed upon users by individual devices, the problem is shiftingto that imposed by the ecosystem. Welcome to the shift-ing sands of ubiquitous computing! Managing this complexity is critical to the continued growth of ourindustry. The means of doing so lies in social computing– amongst the society of appliances.

Professor John F. Wager, The Michael and Judith Gaulke EndowedChair Professor of Electrical Engineering, School of EECS, Oregon StateUniversity“Exciting Developments in Oxide-TFT Technology”

Amorphous-oxide semiconductor thin-film transistors(TFTs) are transitioning towards commercialization foractive-matrix liquid-crystal-display (AMLCD) applica-tions. They also appear well-positioned to meet the moredemanding challenges associated with active-matrixorganic light-emitting devices (AMOLEDs). The objec-tive of this talk is to review the origins and current statusof amorphous-oxide-semiconductor (AOS) TFTs fordisplay applications.

2013 SID TECHNICAL PROGRAM TOINCLUDE SPECIAL TECHNOLOGY TRACKS

The Society for Information Display’s annual Symposium at DisplayWeek offers a wide selection of presentations on display technologythat simply cannot be found anywhere else. This year’s technical program consists of 68 technical sessions with over 250 oral presenta-tions and an additional 150 papers to be presented at the Thursdayafternoon Poster Session. Join us in Vancouver (Tuesday, May 21 –Friday, May 24) to hear the latest developments in the display industry.This year’s special areas of focus are OLED TV, Oxide TFTs, Touchand Interactivity, 3D, and Lighting. Here is just a sampling of thosetopics and other innovations you can expect to find at this year’s symposium:

OLED TVThis Special Topic will cover OLEDs specialized for TV applications. Papers onadvanced OLED TV technologies will be included. OLED-based displays haveseveral unique attributes that continue to drive interest for television applications.Also, the explosion in portable video-capable devices such as tablets and smart-phones place high demands for the displays. 3D television application puts ahigher demand on display power, response times, and high dynamic range.

Papers in this session include:v Progress and Commercialization of AMOLED TVv A 55-in. AMOLED TV Using Oxide TFTs and WRGB Designv A 65-in. Amorphous-Oxide-TFT AMOLED TV Using Side-by-Side and

Fine-Metal-Mask Technology

Oxide TFTsOxide-semiconductor technology is emerging as a strong competitor to thin-film silicon technologies for active-matrix backplanes. However, there are several critical issues related to oxide materials and these are associated with theoverall characteristics of mass-produced devices, including stability (over time,temperature, and light), uniformity, mobility, etc. Clearly, to be viable thesedevices need to be made at costs comparable to that of conventional Si-basedTFTs. Sessions related to oxide-based TFTs and displays driven by oxide-based TFTs include:

v Oxide TFTs I & IIv Oxide-TFT Reliabilityv OLED and Oxide-TFT Manufacturingv Oxide-TFT Manufacturing

Touch and InteractivitySince the launch of touch-enabled mobile devices several years ago, touch hasbecome an increasingly crucial component for numerous display products.Touch is in an evolutionary phase now, and this year’s papers reflect the diver-sity of applications, advanced sensors and materials, and touch integration andapplications. The topics to be covered include:

v Touch User Experiencev Touch Integration and Controllersv Touch Applicationsv Touch Sensors, Materials, and Manufacturing

3DPossibly the biggest commercial story in displays in recent years is the arrival of3D-ready TVs. Now that they have arrived, the story is far from over.Researchers continue to pursue the different approaches of active-shutter vs.passive glasses technology, and glasses-free viewing is a major challenge thatmany experts believe must be met in order to make 3D displays truly successful.This year’s presentations also cover topics such as autostereoscopic 3D displays,3D and perception, volumetric and holographic displays, and stereoscopic anddisplay applications. The symposium includes the following sessions:

v Autostereoscopic and Multi-View I & IIv LC Technology for 3D I & IIv Holographic and Volumetric Displaysv Light-Field Displaysv Perception in 3D Displaysv 3D Algorithms and Drivingv 3D Applicationsv 3D Projection Screens

LightingSolid-State lighting has begun to fulfill its promise with regard to saving energyand providing design flexibility. However, LEDs have made more commercialinroads in this area than OLEDs, which are currently available only in high-endarchitectural applications. OLED papers therefore form the bulk of this year’ssolid-state-lighting sessions, as the industry pushes to develop higher-efficiency,higher-performing OLED panels. Other solid-state-lighting papers will focuson trends in LED illumination. The symposium includes the following topics:

v OLED Lighting I & IIv Human Factors on Lightingv Lighting Designs

MARKET FOCUS CONFERENCES

After a very successful debut in 2010, the Market Focus Conferences will onceagain be held in conjunction with Display Week. They will cover the followingtwo topics:

v Touch Gesture Motion (Wednesday, May 22, 2013)v High-Performance Displays (Thursday, May 23, 2013)

Each Market Focus Conference will concentrate on the critical market develop-ment issues facing each of these technologies. Developed in collaboration withIHS, the conference will feature presentations and panel sessions with execu-tives throughout the display supply chain. Conference fees include a continental breakfast, lunch, refreshments, access to the Exhibit Hall and SymposiumKeynote Session on Tuesday morning, and electronic copies of the presentation

First Look Pages p42-43_Layout 1 3/22/2013 9:51 PM Page 42

material. Registration for the Market Focus Conferences does not require acurrent SID membership. Touch Gesture Motion: The 2013 SID Touch Gesture Motion Conference willfocus on next-generation touch, gesture, and motion-based technologies appli-cable to the display industry. The conference will focus on future technologyand interactivity trends – and not so much on what is currently available in themarketplace. Interactive display technologies are one of the most intriguingaspects of the display industry – helping to enable completely new usage modelsin multiple applications. Highlights of the conference will include actualdemonstrations from some of the leading-edge innovators, bringing togethermany of our senses – sight, touch, motion, sound ... .This event builds on the three prior events presented at past Display Week Con-ferences, as well as three separate 2-day TGM conferences. The primary goal isto assure that the events are complementary – with minimal overlap. The objec-tive is to establish a series of non-duplicative events such that delegates can easily justify repeat attendance with the assurance of highly differentiated programs.High-Performance Displays: The 2013 SID High-Performance Displays Conference will highlight next-generation display technologies that offer significant opportunities to enhance the visual experience. The event will focuson performance parameters, more so than the specific display technologies. Thetechnologies necessary to promote improved performance will be highlighted.The event will enable delegates to consider various performance trade-offsrelated to the future of vision-based devices.This event is a new event – but directly focuses on one of the biggest opportuni-ties for both display makers and device manufacturers – to truly differentiatetheir product offerings. The event is expected to garner considerable interestand discussion as various performance parameters are presented and compared. For further updates visit www.imsconferences.com/sidfti/html

SID BUSINESS ENTERPRISE (BUSINESSCONFERENCE AND INVESTORS CONFERENCE)Business Conference: The 2013 SID Business Conference will be held on Monday, May 20, at the Vancouver Convention Centre. It will provide a uniqueforum where attendees will gain insight from leading minds from both WallStreet and the display industry and focus on the theme “Paths to a HealthierDisplay Industry.” Inspirational presentations from industry leaders and IHSanalysts will take an integrated view assessing the current health of the industryand focus on what it would take to improve the health of the industry, identify-ing some specific exciting trends, and its impact on the display supply chain.The Business Conference will feature keynotes and presentations from industryleaders, lively panel sessions, and ample networking opportunities. For further updates visit www.imsconferences.com/sidbc.htmlInvestors Conference: Co-sponsored by Cowen & Co., LLC, a securities and investment banking firm, this Conference, to be held on Tuesday, May 21, willfeature company presentations from leading public and private display compa-nies, intended to appeal primarily to securities analysts, portfolio managers,investors, M&A specialists, and display company executives. For further updates visit www.cowen.com

2013 SID SEMINAR SERIES

Sunday Short CoursesThe Society for Information Display presents four 4-hour short courses on diverse topics related to information display on Sunday, May 19. The tutorials are characterized by technical depth and small class size. The classes will cover the fundamentals of electronic information displays and will be held on the morning and afternoon of the Sunday preceding the Symposium. Full-color tutorial notes will be distributed to all participants and are included in the fee. Ample time will be provided for questions from the audience. The speakers are leaders in theirrespective fields and bring an international perspective to information display.

S-1: Fundamentals of OLED TechnologyS-2: Fundamentals of 3D Computer Vision and Applications to Interactive

Devices S-3: Fundamentals of TFT Backplane Technologies and Progress Made on

Metal-Oxide TFTsS-4: Fundamentals of Touch Technologies

For further details visit www.displayweek.org/Program/SundayShortCourses

Monday Technology / Applications SeminarsThe SID Technology / Applications Seminars to be held on Monday, May 20, present lectures on diverse topics related to electronic information displays. These seminars are tutorial in nature, and an attempt is made to provide information at

three levels. First and foremost, the technical foundations of the topic are treated in detail. Next, recent technical advances are discussed, and, finally, the currentstate of the art and the projection of future trends are analyzed. The Applica-tions Seminars focus on the application and evaluation of information displays. These seminars benefit both newcomers and experienced professionals. Engineersnew to assignments in information display find them especially helpful in gettingup to speed quickly. Experienced professionals attend to keep up with recentdevelopments in fields closely related to their specialties. Managers attending theseminars obtain a broad perspective of the display field and a sense of its recentdynamics. Attendees will receive an excellent set of full-color notes, consisting ofthe instructor’s presentation slides replete with references and illustrations. Ampletime is provided for questions from the audience in each session. The speakers areleaders in their fields who bring an international perspective to information display.Track 1: Display Marketplace

v M-1: The Next Big Thingv M-6: Display Market Trends

Track 2: Mobile Displaysv M-2: Advanced Mobile-Display Technologiesv M-7: Mobile Multimedia Displays

Track 3: Touch and Interactivityv M-3: Status and Future of Touch Technologiesv M-8: Touch-Display Integration

Track 4: Liquid-Crystal Technologyv M-4: Fast-Field-Switching (FFS) Mode and Its Applicationsv M-9: Fast-Switching Technologies for LC Devices toward Low-Power

Display SystemsTrack 5: OLED Displays

v M-5: Challenges of AMOLED TVs and Flexible AMOLED Displaysv M-10: OLED Technology

Track 6: Display Components and Metrologyv M-11: Optical Coatings and Filmsv M-16: Display Measurement Basics and Practical Considerations

Track 7: Lightingv M-12: Backlighting LEDs in General Illumination v M-17: OLED Lighting

Track 8: 3D Technologyv M-13: LC Technology for 3D Applicationsv M-18: Signal Processing for Stereoscopic 3D Displays

Track 9: Oxide TFTsv M-14: Oxide TFTs: Technology Trends in Materials and Processesv M-19: Device Structures and Stability of Oxide TFTs

Track 10: Flexible-Display Technologyv M-15: Flexible OLEDs for Display and Lighting Applicationsv M-20: A Critical and Current Review of the Present and Future Prospects for

e-PaperFor further details visit www.displayweek.org/Program/MondaySeminars

ANNUAL AWARDS LUNCHEON

The annual SID Awards Luncheon will take place at 12:00 Noon on Wednesday, May 22, in Room 301/305 of the Vancouver Convention Centre.

This year’s luncheon speaker will be Prof. Ronald A.Rensink from the Departments of Computer Science andPsychology at the University of British Columbia, Vancouver,Canada. Professor Rensink will discuss “When Vision Science MetInformation Display.”Also, the 2013 Display Industry Awards honoring the bestof the industry in 2012 and the 2013 SID Best-in-Showand I-Zone award winners will be announced. Also, the

SID 2013 honors and award recipients will be acknowledged.

SPECIAL EVENT

The Vancouver Aquarium – Sponsored by Henkel

Come join us on this special event on Wednesdayevening to the Vancouver Aquarium, the largest inCanada and one of the five largest in North America.The Vancouver Aquarium was the first aquarium inthe world to capture and display an orca. For more

details regarding the Vancouver Aquarium, please visit www.vanaqua.org43


http://www.imsconferences.com/sidfti/html

http://www.imsconferences.com/sidbc.html

http://www.cowen.com

http://www.displayweek.org/Program/SundayShortCourses

http://www.displayweek.org/Program/MondaySeminars

http://www.vanaqua.org

Sund

ay, M

ay 1

9Fr

iday

, May

24

Cou

rse

Sem

inar

sBu

s C

onf

Sym

pEx

hibi

ts

Inv.

Con

f.Sy

mp

Exhi

bits

M

FCSy

mp

Exhi

bits

MFC

Sym

p7:

45 A

M-

8:3

0 AM

SID

Bus

Mtg

8:30

AM

- 9

:00

AM9:

00 A

M-

9:3

0 AM

9:30

AM

-10

:00

AM10

:00

AM-

10:3

0 AM

10:3

0 AM

-11

:00

AM11

:00

AM-

11:3

0 AM

11:3

0 AM

-12

:00

PM12

:00

PM-

12:3

0 PM

12:3

0 PM

- 1

:00

PM1:

00 P

M-

1:3

0 PM

1:30

PM

- 2

:00

PM2:

00 P

M-

2:3

0 PM

2:30

PM

- 3

:00

PM3:

00 P

M-

3:3

0 PM

3:30

PM

-4:

00 P

M4:

00 P

M-

4:30

PM

4:30

PM

-5:

00 P

MAu

th. I

nter

.5:

00 P

M-

5:30

PM

5:30

PM

-6:

00 P

M6:

00 P

M-

6:30

PM

6:30

PM

-7:

00 P

M7:

00 P

M-

7:30

PM

7:30

PM

-8:

00 P

M8:

00 P

M-

8:30

PM

8:30

PM

-9:

00 P

M9:

00 P

M-

9:30

PM

9:30

PM

-10

:00

PM

TIM

ETAB

LE

Short CoursesS-3 & S-4

Auth

or In

terv

iew

s

Ora

l Se

ssio

ns9-

14

Wel

com

e &

Keyn

ote

Addr

esse

sBus. Conf. Lunch

Tues

day,

May

21

Mon

day,

May

20

Short CoursesS-1 & S-2

Thur

sday

, May

23

Ora

l Se

ssio

ns

36-4

1

Ora

l Se

ssio

ns20

-25

Exhibits / Exhibitors Forum Sessions /I-Zone

Des

igna

ted

Exhi

bit

Tim

eWed

nesd

ay, M

ay 2

2

Lunc

heon

: D

IA &

Be

st-in

-Sho

w

Awar

ds

Ora

l Ses

sion

s60

-64

Exhibits/Exhibitors Forum Sessions

Ora

l Ses

sion

s65

-69

Auth

or In

terv

iew

s

Market Focus Conference:High-Performance Displays

Ora

l Se

ssio

ns48

-53

Ora

l Se

ssio

ns54

-59

Ora

l Se

ssio

ns32

-35,

70

Auth

or

Inte

rvie

ws

Awar

dsBa

nque

t

Sem

inar

sM

16 -

M20

BusinessConference

Sem

inar

sM

1 - M

5

Sem

inar

sM

11- M

15

Sem

inar

sM

6 - M

10

Investors Conference

Post

er

Sess

ion

Ora

l Se

ssio

ns42

-47

Market Focus Conference:Touch Gesture Motion

Ora

l Se

ssio

ns3-

8

Ora

l Se

ssio

ns26

-31

BusinessConference

Bus. Conf.

Recept.

Ora

l Se

ssio

ns

15-1

9

Exhibits / Exhibitors Forum Sessions /I-Zone

Invest. Conf.

Recept.

Dis

play

Wee

k 2

01

3 O

verv

iew

Vanc

ouve

r Con

vent

ion

Cent

re, V

anco

uver

, Brit

ish

Colu

mbi

a, C

anad

aM

ay 19

–24,

201

3

44


Display Week 2013 Symposium at a Glance

Times Ballroom A Ballroom B Ballroom C Room 118 Room202 Room 205 Times8:00 – 10:20 8:00 – 10:20

10:50 – 12:103

Autostereoscopic and Multi-View I

(Joint with Systems)

4Oxide TFTs I

(Joint with Active Matrix)

5LCD or OLED?

6e-Paper I

7Plasma-Display Devices

8Emerging Displays 10:50 – 12:10

2:00 – 3:209

Autostereoscopic and Multi-View II


10Oxide TFTs II


114K x 2K Displays

12e-Paper II

13Plasma-Display Protective

Layer

14Human Enhancement and

Diagnostics2:00 – 3:20

3:40 – 5:0015

LC Technology for 3D I(Joint with Liquid Crystal)

16Oxide-TFT Reliability


17Blue-Phase LCDs I

18Flexible AMOLEDs

19Phosphors and Quantum-

Dot LEDs3:40 – 5:00

5:00 – 6:00 5:00 – 6:00

9:00 – 10:2020

LC Technology for 3D II(Joint with Liquid Crystal)

21OLED TV

(Joint with OLEDs)

22Blue-Phase LCDs II

23Flexible TFTs

24Novel Measurement Topics

25Advanced LCD Electronics 9:00 – 10:20

10:40 – 12:0026

Holographic and Volumetric Displays


27OLED Displays I

28Advanced Displays

29Flexible Barriers and

Substrates

30Challenges in 3D

Characterization, Motion Blur Analysis, and Monitor

Calibration

31High-Speed Driver

Technologies10:40 – 12:00

2:00 – 3:30 2:00 – 3:30

3:30 – 4:5032

Light-Field Displays(Joint with Systems)

33OLED Displays II

34Fast-Switching LCDs

70Late-News Papers:Flexible OLEDs and Printing Techniques

35OLED Pixel and Driving 3:30 – 4:50

5:00 – 6:00 5:00 – 6:00

9:00 – 10:2036

Perception in 3D Displays(Joint with Applied Vision)

37OLED Materials

38Film and Alignment

39Touch User Experience

40Automotive and Head-Up

Displays (HUD)(Joint with Projection)

41Colors and Image Quality 9:00 – 10:20

10:40 – 12:0042

3D Algorithms and Driving(Joint with Systems)

43OLED Devices I

44Liquid Crystals with Reactive Mesogen

45Touch Integration and

Controllers

46OLED and Oxide-TFT

Manufacturing(Joint with OLED, Active

Matrix, and Manufacturing)

47Human Factors on Lighting(Joint with Applied Vision)

10:40 – 12:00

1:30 – 2:5048

3D Applications(Joint with Applications)

49OLED Devices II

50Low-Power and Sensor-

Integrated Displays

51Touch Applications

52Oxide-TFT Manufacturing(Joint with Active Matrix

and Manufacturing)

53Lighting Designs

(Joint with Applications)1:30 – 2:50

3:10 – 4:3054

Projection Screens(Joint with Projection)

55OLED Manufacturing

56TFT Applications

57Touch Sensors, Materials,

and Manufacturing(Joint with Manufacturing)

58Advanced Substrates and

Manufacturing on Flex(Joint with

e-Paper/Flexible)

59Novel Backlighting

Systems3:10 – 4:30

4:30 – 5:30 4:30 – 5:305:00 – 8:00 5:00 – 8:00

9:00 – 10:20 60Projection Light Sources

61OLED Lighting I

(Joint with OLEDs)

62TFTs for Mobile Display

63Mechanical Reliability Testing for Displays

64Near-to-Eye, Transparent,

and Floating Displays9:00 – 10:20

10:40 – 12:0065

Projection-Display Components

66OLED Lighting II

(Joint with OLEDs)

67TFT Driver Circuits

68Advances in Materials for

Manufacturing

69Energy-Efficient Displays(Joint with Electronics)

10:40 – 12:00

12:00 – 1:00 12:00 – 1:00

Tues

day,

May

21

Author Interviews (Exhibit Hall)

2013 SID Display Week Symposium at a Glance – Vancouver Convention Centre


Wed

nesd

ay, M

ay 2

2Th

ursd

ay, M

ay 2

3Fr

iday

, May

24

Poster Session (Exhibit Hall)

Friday, May 24

SID Business Meeting and Keynote Session (Concourse Hall)

Wednesday, M

ay 22Tuesday, M

ay 21Thursday, M

ay 23



Designated Exhibit Time (Exhibit Hall)

3-D Active-Matrix Devices Applications Applied Vision Electronics Emissive

e-Paper/Flexible Lighting Liquid Crystal Manufacturing Measurement OLEDsOxide TFTs Projection Systems Touch

TECHNOLOGY TRACKS KEY

T

45


THE Society for Information Display’sannual symposium is the foundation of DisplayWeek. Each year, hundreds of papers are pre-sented that convey vital research and develop-ment information, both forward-looking andimmediately practical, in numerous areas ofdisplay technology. The information you willobtain at this year’s Symposium in Vancouver,Canada, is not available at any other venue orfrom any other industry organizations.

As in previous years, sessions are organizedby subcommittees, whose members have chosen the most exciting and informativepapers in their focus areas of display technol-ogy. Those areas include active-matrixdevices, applications, applied vision, displayelectronics, display manufacturing, displaymeasurement, display systems, emissive displays, e-paper and flexible displays, liquid-crystal technology, OLEDs, and projection.

In addition to these regular topics, SID hasdesignated special display topics of interestthat are especially timely and important to ourindustry: OLED TV, oxide TFTs, 3-D, light-ing, and touch and interactivity. Attendees atDisplay Week 2013 have the opportunity togain comprehensive knowledge of each ofthese special topics not only by attending thepresentations during the four-day technicalsymposium, but also through the special Sunday Short Courses and Monday Seminars.SID also offers a display-centric business perspective with the Business and InvestorsConferences and the Market Focus Confer-ences. In addition, be sure to catch this year’s

stellar line-up of keynote speakers (highlighted throughout this article) on Tuesday morningimmediately before the exhibition opens.

The following session highlights are but asmall portion of what awaits attendees at Display Week 2013. Come join us to find outwhat’s happened in our industry over the pastyear – and what’s going to happen in the yearsto come. See you in Vancouver!

Active-Matrix Devices: Oxide TFTStarts to Hit Its StrideLast year’s Active-Matrix Devices (AND)sessions covered topics such as IGZO and 8K × 4K LCDs – providing advance notice oftechnology later shown in products at CES this year. The 2013 AMD papers will continue representing some of the most interesting andimportant news at the Symposium, accordingto subcommittee chair Tohru Nishibe. Amongthe most newsworthy, he says, are two invitedpresentations on oxide semiconductors. Thefirst is “Electronic Structure, Carrier Trans-port, Defects, and Impurities in AmorphousOxide Semiconductors,” by Toshio Kamiya ofthe Tokyo Institute of Technology. “This is agood tutorial and basic analysis that includesnew findings,” says Nishibe. The second is“Development of IGZO-TFT and Creation ofNew Devices Using IGZO-TFTs,” by HajimeImai of Sharp Corp, in collaboration with SEL(Semiconductor Energy Laboratory Co.).“This look at the world’s first IGZO product[shown at CES] will attract a huge audience,”says Nishibe. “Moreover, we’ll have intrigu-ing invited papers from LG Display, SamsungDisplay, and others.”

Other papers of interest are “A 55-in.AMOLED TV Using InGaZnO TFTs Using

WRGB Pixel Design,” by Woo-Jin Nam of LG Display Co. and “Negative-Bias Photodegradation Mechanism in SnO TFTs,”by Masashi Tsubuku of the SemiconductorEnergy Laboratory Co., Ltd. According toNishibe, both these papers will address keyfactors for improving IGZO reliability.

Applications: Expanded Interaction,Emerging DisplaysAs is often the case in the applications sessionsat Display Week, this year’s papers cover anextremely wide range of topics. Of particularnote are two invited papers on “auditory” dis-plays in the session titled Human Enhance-ment and Diagnostics. “Sonification:Multimodal and Auditory Display of Data,”by Bruce Walker of the Georgia Institute ofTechnology, and “Development of Auditoryand Cross-Modal Displays for Assistive Tech-nology,” by Tony Stockman of Queen MaryUniversity of London, describe displays thatboth speak and listen (as well as display visualimagery). They may thus prove useful tovision-impaired users, in addition to otherapplications, notes subcommittee chair AdiAbileah. “The idea is that there is more thanone way to interact with displays,” saysAbileah. “We think this is a direction thatSID will head toward in the future.”

As is also usual for applications, there aretoo many interesting papers to cite here, butone of note in the Emerging Displays sessionis the invited paper “Optical and System Considerations for Mobile Touch-ScreenApplications,” by Steven Bathiche ofMicrosoft, which Abileah describes as anexcellent review presentation that will coverdifferent considerations for mobile-display

Plan Ahead for the 2013 SymposiumMake the most of Display Week 2013 with an advance look at this year’s technology sessions.

by Jenny Donelan

Jenny Donelan is the Managing Editor ofInformation Display Magazine. She can bereached at [email protected].


symposium preview

ID Preview Donelan p46-50_Layout 1 3/22/2013 10:10 PM Page 46


parameters including pixel density, opticaleffects, ambient-lighting influence, touch-screen weight, and power. The paper analyzesthe significance of these parameters based onthe human eye’s acuity, contrast sensitivity, and focusing ability in differentlighting conditions. The paper “Semi-Trans-parent Inverted Quantum-Dot Light-EmittingDiodes,” by Jin Jang of Kyung Hee Univer-sity, will describe a new display technology, asemi-transparent inverted quantum-dot light-emitting diode (QLED) that uses tri-layeredquantum dots. “Blur-Free Transparent LCDwith Hybrid Transparency,” by Chia-Wei Kuoof AU Optronics Corp., outlines a 65-in trans-parent LCD in which the author controlled LCorientation to suppress image blurring behindthe transparent LCD.

Applied Vision: Night-time TVWatching“This year there are a lot of Applied Visionpapers related to 3-D and lighting,” says sub-committee chair Yi-Pai Huang. “These arethe trends.” Two interesting invited papersfrom the joint session with lighting thataddress real practical marketplace issues are“Displays as Light Sources: Resolving theConflict between Gamut and Color Render-ing,” by Lorne Whitehead of the University ofBritish Columbia, and “Opportunities withLEDs for Increasing the Visual Benefits ofLighting,” by Mark Rea of the RensselaerPolytechnic Institute.

One slightly different paper that Huang recommends is “The Impact of Watching Tel-evision on Evening Melatonin Levels,” byMariana Figueiro of Rensselaer PolytechnicInstitute. For at least a decade, someresearchers (and the media) have suggestedthat night-time TV viewing suppresses humanmelatonin levels and thus interferes withsleep. Figueiro’s paper investigated whetherthe blue light from television does in fact sup-press melatonin. Readers will have to attendthe session to find out the answer, as well asthe author’s recommendation.

Display Electronics: OLED DriversLead the PackThe scope of papers in Display Electronicsthis year is diverse but very relevant, accord-ing to subcommittee chair Seung Woo Lee.“We do have many OLED-driving papers, butexcept for this area, the topics are widespread,”he says. One trend that Lee did note for 2013

is a larger number of papers from academiarather than private industry.

There is a full session focused on OLEDPixel and Driving as well as interesting papersin other areas include “Capacitively Coupled13.56-MHz Resonance-Controlled WirelessPower Transfer System for e-Paper Modules,”by Reiji Hattori of Kyushu University, and“ESD and EOS Impact During ModuleAssembly Processes of Display Panels,” byMing-Dou Ker of the National Chiao-TungUniversity, both from the advanced LCDElectronics session. Hattori’s paper describesa development that could enable electronicpaper that works without batteries. Ker’s presentation will address the phenomena ofelectrostatic discharge (ESD) and electricaloverstress (EOS) as they occur in productionprocesses, as well as their effect on productreliability. He will suggest ways to controlESD and EOS so as to improve overall yield.

Display Manufacturing: TimelyProblem SolvingManufacturing is an exciting R&D focus topicthese days. We are witnessing doubled-downefforts for solving manufacturing process andmaterials challenges to enable the long-heldpromise of OLED use in TVs, as well as toaccelerate the adoption of oxide-semiconduc-tor TFTs for high-performance display appli-

cations. With that in mind, the Display Man-ufacturing subcommittee is highlighting threepapers from this year’s impressive selection.The first, “Ink-Jet-Printed 17-in. AMOLEDDisplay with Amorphous-IGZO TFT Back-plane,” by Ze Liu of BOE Technology GroupCo., is an invited paper that reports on thesuccessful integration of ink-jet processedOLEDs with amorphous-oxide TFTs as a pathto cost-effective manufacturing of large-sizedpanels. “It is very exciting to see this technol-ogy at the manufacturing stage,” says Sub-committee Chair Ion Bita. “BOE is a relativenewcomer,” he says, “but their rapid advancesin technology development and manufacturingare very impressive.”

The paper “Advanced Glass Substrate forthe Enhancement of OLED Lighting Out-Coupling Efficiency,” by Nobuhiro Nakamuraof Asahi Glass Co., reports on a substratedesigned to improve efficiency in lighting andwith potential for display applications. Thissubstrate incorporates a glass-scattering layerthat greatly improves efficiency, as demon-strated by the paper’s author using OLEDlighting panels. “Roll-to-Roll Process onUltra-Thin Flexible Glass for Manufacturing aMulti-Touch Sensor Panel,” by Chia-ShengHuang of ITRI, demonstrates the advantagesof roll-to-roll manufacturing on thin-glasssubstrates, in which the set of processes andequipment developed by the authors enabledfabrication of ITO-pattern-based touch-sensor panels from 0.1-mm rollable thin glass.

Display Measurement: IDMS GainsTractionAs was the case for the last several years, 3-Dis a hot topic for Display Measurement in2013. This is because 2-D measurement justdoesn’t cover all of what needs to be meas-ured in 3-D, explains subcommittee chairFrank Rochow. What is new in measurementpapers this year is that authors have begunadopting the IDMS, the display measurementstandard released in 2012 by the ICDM (Inter-national Committee for Display Metrology).“The IDMS methods are definitely beingimplemented in the papers being presented,”says Rochow. “The IDMS is being seen as asuccess and is widely respected.”

A good paper to check out for the latest in3-D measurements is the invited “Techniquesand Challenges in the Measurement of Stereo-scopic Displays,” by Adi Abileah of Planar


Dr. Kinam Kim, President & CEO, Samsung Display Co., will give a Keynoteaddress on “Displays and Innovation:

An Exciting Future”


Systems. Another interesting paper that takeson the newest types of displays is “Viewing-Angle Measurements on Flexible Reflectivee-Paper Displays,” by Dirk Hertel of E InkCorp. Displays that are curved and reflectivemake it difficult for researchers to obtainrepeatable, consistent measurements, explainsRochow.

Display Systems: Deep ViewsWith nine separate sessions, Display Systemshas a lot going on this year. 3-D continues tobe a popular topic, but within 3-D the types ofdisplays have grown increasingly diverse.This year’s 3-D sessions include Autostereo-scopic and Multiview I and II, Holographicand Volumetric Displays, Lightfield Display,and 3-D Algorithms and Driving.

Other Display Systems sessions include Augmented Reality and Near-to-Eye Displays, Novel Backlighting Systems, Automotive andHead-Up Displays, and Energy-Efficient Dis-plays. Of special interest is the invited paper, “Augmented-Reality Head-Up Display for Car Navigation System,” by Toshiki Kaneko ofJapan Display, Inc., which uses a laser projec-tor and microlens array to create what the authors say is the first such display that creates augmented reality beyond the windshield.Another invited paper, “Extending BatteryLife of Ultrabook through Use of Panel Self-Refresh Technology,” by Kamal Shah of IntelCorp., describes an interesting new power-management technique for mobile devices.

Emissive Displays: Lots of Late-Newsfor Quantum Dots and PhosphorsProbably the most intriguing aspect of theEmissive Display sessions this year are thenumber of late-news papers in the Phosphorsand Quantum-Dot session – three out of atotal of six. These are “Development of Stable Alkaline-Earth-Sulfide LED Phosphorsfor LCD Backlights,” by Ravi Rao of Specialty Phosphors, Inc.; “High-Efficiencyand Long-Lifetime Quantum-Dot Light-Emit-ting Diodes for Flat-Panel-Display Applica-tion,” by Paul Holloway of the University ofFlorida; and “How to Fabricate Much BrighterAC Electroluminescent Lamps: Optimizingthe Alignment of the Emitting ZnS:Cu Phos-phor Particles to the AC Field,” by Jack Silverof Brunel University. According to the com-mittee, an exceptional paper in this session is“Characterization of Electron–Hole-PairMigration and Trapping in Rare-Earth-Doped

YBO3 under Vacuum-Ultraviolet Excitation,”by Anthony Diaz of Central Washington University, in which the author’s analysis suggests a correlation between electron-holetrapping efficiency and the energy of activatorelectronic states relative to the host conduc-tion band.

The other two emissive sessions aredevoted to plasma. An invited plasma paperof special interest is “Progress in LuminousArray Film with Plasma-Tube Technology forSeamless-Tiling Super-Large-Area Display,”by Terukazu Kosako of Shinoda Plasma Co.,which discusses a new flat-sealing processthat can enable extra-large curved displays.The late-news paper “New, Thinner PhosphorLayer Fabrication Process for ACPDPs,” byRyuichi Murai of Panasonic AVC NetworksCompany, describes a process for achieving a3-µm-thick phosphor layer in the PDP cells.

e-Paper and Flexible DisplaysThe six e-Paper and Flexible Displays sessionsthis year include one composed entirely of late-news papers on the topic of Flexible OLEDs and Printed Electronics. These five papers,covering topics such as barrier films, ink-jetprinting, and plastic substrates, will obviouslyprovide an exciting look at the state of the art.

A notable paper from AU Optronics is “A9-in. Flexible Color Electrophoretic Displaywith Projected-Capacitive Touch Panel and

Integrated a-Si Gate Driver,” by Yen Lai.This paper, highly recommended by the sub-commitee, describes how the authors devel-oped a prototype and concept design for whatthey describe as the next-stage e-reader: combining a flexible color electrophoretic display (EPD), flexible projected-capacitivetouch panel (TP), and amorphous-silicon gatedriver circuit on array (GOA) technologies.

Liquid-Crystal Technology: Meetingthe Challenges of a Changing LandscapeThe LCT subcommittee made a point of invit-ing what chair Philip Chen describes as themajor Asian companies to submit papers thisyear: Samsung, AUO, LG Display, Japan Dis-play, China Star, BOE, and others. The idea,says Chen, was to get these companies tocome to Display Week to share their latestdevelopments and plans for the future, thusproviding symposium goers with a completeview of the LC landscape.

Another subcommittee initiative was toorganize a session specifically on the topic ofOLEDs and LCDs. The three invited papersin the session titled LCDs or OLEDs? include“TFT-LCDs as the Future Leading Role inFPDs,” by Yasuhiro Ukai of Ukai DisplayDevice Institute;”AH-IPS, Superb Display forMobile Devices,” by Joun Ho Lee of LG Display Co.; and “LCD or OLED: WhoWins?,” by David Barnes of BizWitz. Thislast, possibly provocative paper will discusshistorical trends that point toward a future ofincreasing technical performance and decreas-ing financial performance for LCD producers,as well as the feasibility of creating an OLEDinfrastructure. “This will be a very attractivesession,” says Chen, “for students and foranyone else in the industry who wants toknow about the future direction of these technologies.”

Four more notable papers from the LC sessions are “High-Transmission VA-LCDwith a Three Dimensionally Shaped PixelElectrode for 4K × 2K Displays,” by MasashiMiyakawa of Sony Corp.;” “LC GRIN LensMode with Wide Viewing Angle for Rotatable2D/3D Tablet,” by Masako Kashiwagi ofToshiba Corp.; “Driving Method of FFS-Mode Oxide LCD for Reducing Eye Strain,”by Ryo Hatsumi of the Semiconductor EnergyLaboratory Co.; and “A Nematic LCD withSubmillisecond Gray-to-Gray ResponseTime,” by Daming Xu of the University ofCentral Florida.

symposium preview


Mr. Bill Buxton, Principal Researcher,Microsoft Research, Microsoft Corp.,

will give a keynote address on “The Social Life of Devices”


OLEDs: Big TVs and Better MaterialsOne trend is certain: OLED TVs, at leastOLED TV prototypes, keep getting larger. Themost exciting OLED paper this year, accord-ing to subcommittee chair Sven Murano, willbe “Large-Sized Amorphous-Oxide-TFTAMOLED-TV Using Side-by-Side and Fine-Metal-Mask Technology” by Jen-Yu Lee ofAU Optronics Corp. This paper describes a65-in. panel with a long-range threshold volt-age uniformity of 0.34 V. The dam and fillencapsulation process is simple and highlystable, according to the author. The AUOpaper is part of a special all OLED-TV session (jointly offered through the OLEDsand Active-Matrix Devices committees) thatMurano says may be among the hottest at thesymposium.

There is more to OLEDs than big TVs,though. This year has brought many improve-ments to OLED lighting technology (see theLighting section below), and also progress inOLED R&D in general. One of the hurdlesthat OLED technology needs to clear in orderto realize its full commercial potential is effi-ciency in both materials and devices. Twovery interesting papers that address this aspectare “Highly Efficient OLED Device withDevice Architecture for Reducing Drive Volt-age,” by Yoshiharu Hirakata of SemiconductorEnergy Laboratory, which describes how theauthor’s team developed phosphorescentOLEDs with high efficiency, a long lifetime,and low drive voltage using energy transferfrom an exciplex to an emitter; and “EfficiencyImprovement of Fluorescent Blue Device byMolecular Orientation of Blue Dopant,” byHitoshi Kuma of Idemitsu Kosan Co., Ltd.Kuma’s research suggests how phosphores-cent blue devices, which have lagged behindtheir red and green counterparts in terms ofefficiency, can be made to catch up.

Projection: Lasers Loom LargerLast year, subcommittee co-chair Alan Sobelpredicted that 2012 would be the year of thepico projector, in terms of commercial avail-ability. That seems to be true, based on aquick online search for the products, whichare numerous and available in some cases forless than $200. In terms of the symposium,however, the technology is mature. “Surpris-ingly, there are no [LED-based] pico-projectorpapers this year,” says Sobel. Instead, laser-light engines for projection are the focus ofseveral papers.

A standout invited paper in the Projectionsessions that Sobel recommends is “High-Efficiency Polarization Preserving CinemaProjection Screen,” by Dave Coleman ofRealD. This paper describes a polarization-preserving projection screen that addressesissues of conventional silver screens throughsubstantially increased efficiency (brightness),increased stereo contrast, larger viewingangle, and matte appearance. In addition, the screen enables vastly improved laser-speckle reduction. Says Sobel, “This is potentially a game changer, a big curvedscreen for digital cinema, with better perform-ance, wider angles, [reduced] ghosting. It will be more expensive than conventionalscreens.”

Special Topics: OLED TV, Oxide TFTs,3-D, Lighting, and Touch &InteractivityEach year, the Society for Information Displaydesignates special sessions to explore impor-tant and timely display topics. This year’ssessions are OLED TV, oxide TFTs, 3-D,lighting, and touch & interactivity. Here arehighlights from each:OLED TV: The four papers in this one

session, jointly sponsored by the Active-Matrix Devices and OLEDs subcommittees, will no

doubt be among the most popular at the sym-posium. AUO’s 65-in TV (described in theOLEDs section above) will certainly be anattention-getter, but the other three papers willbe fascinating as well. Certainly, no one willwant to miss “Technological Progress and Commercialization of AMOLED TV,” in which author Chang-Ho Oh of LG Display Co. talksabout the art and science behind getting thefirst mass-produced large-area OLED TVs off the factory floor and into people’s living rooms. Oxide TFTs:A mere four years ago, the

idea that oxide TFT could take the place ofsilicon in display devices was “very new andpromising,”according to Hyun Jae Kim, the2009 Active-Matrix subcommittee chair. In2013, oxide TFT is now a special topic withfive sessions devoted to it alone. Those are:

• Oxide TFT I and II• Oxide TFT Reliability• OLED and Oxide TFT Manufacturing• Oxide TFT ManufacturingSeveral of the outstanding oxide-TFT

papers have been described above in conjunc-tion with other technology topics such asActive-Matrix Devices and Display Manufac-turing. An additional paper to take note of is“Electrical Properties of Amorphous InGaZnOTFTs Prepared by Magnetron SputteringUsing Kr and Xe Gas,” by Tetsuya Goto ofTohoku University. Goto’s work explainshow the use of certain noble gases in the mag-netron-sputtering part of the manufacturingprocess can reduce film damage caused byion-bombardment, and thus improve overallthin-film quality.3-D: This technology area continues to be

extremely well-represented in terms of papersubmissions – there are 10 3-D sessions in thisyear’s symposium – but the subjects haveevolved over the past few years from discus-sions on passive vs. active glasses to a widerange of 3-D displays. The 3-D sessions are

• Autostereoscopic and Multi-View I andII

• LC Technology for 3D I and II• Holographic and Volumetric Displays• Light-field Display• Perception in 3D Display• 3D Algorithms and Driving• 3D Application• Projection ScreensSome of the outstanding 3-D papers are

outlined in the sections above, such asRealD’s curved cinema screen described


Professor John F. Wager, The Michael andJudith Gaulke Endowed Chair Professor ofElectrical Engineering, School of EECS,

Oregon State University, will give a keynoteaddress on “Exciting Developments

in Oxide-TFT Technology”


under Projection. Here are some additionalones to check out: “High-PerformanceAutostereoscopic 2D/3D Switchable DisplayUsing Liquid-Crystal Lens,” by ShinichiroOka of Japan Display, Inc., describes thedevelopment of a switchable 2D/3D displaywith higher luminance and reduced crosstalk.Late-news paper “Real-Time Up-Converterfrom HDTV to 4K with Super-High Resolu-tion,” by Seiichi Gohshi of Kogakuin Univer-sity, suggests a method for obtaininghigh-quality 4K resolution from HDTV video,a subject that will become increasingly rele-vant in the months and years to come. Lighting: There are four lighting sessions

this year, two of them devoted to OLEDs:

• Human Factors on Lighting• Lighting Design• OLED Lighting I and II

OLED lighting still has far to go in terms ofmanufacturing costs, efficiency, and lifetime,but progress is being made. One paper thatdescribes a good advance is the invited “80-lm/W White OLEDs for Solid-State Light-ing,” by Jaemin Moon of LG Chem. TheseOLEDs were realized by introducing a three-stacked tandem structure in conjunction with an internal light-extraction layer. Anotherexciting paper in terms of getting closer tocommercial viability is “Highly Efficient

White OLEDs with Over 100-lm/W for General Lighting,” by Kazuyuki Yamae ofPanasonic Eco Solutions. The author’s high-performance all-phosphorescent white deviceson a light-outcoupling substrate showed anefficacy of 114 lm/W at 1000 cd/m2 and 102lm/W at 3000 cd/m2.

According to Sven Murano, this year’sOLED subcommittee chair, “Now is the timewhen [lighting] companies are starting toinvest in manufacturing lines, and I am opti-mistic that in the coming years OLED lightingwill become cheaper and its efficacy will goup.”Touch and Interactivity: Tighter integra-

tion and reduction of cost are two major issuessurrounding touch in display design and man-ufacturing, according to Touch & Interactivitychair Jeff Han. (Earlier this year, Han gavethe keynote address for the Bay Area SIDChapter’s one-day technical conference, Display and Touch Technologies of theFuture.) “Touch is still expensive,” says Han,also noting that the touch user experience isalso increasingly crucial. This year there is asession devoted just to the user experience,and three others as well:

• Touch User Experience• Touch Integration and Controller• Touch Application

• Touch Sensors, Materials, and Manufac-turing

A touch paper of note is “12.2-in. 1920 ×RGBW × 720 IPS-LCD Integrating In-CellTouch Panel for Automotive Use,” by ChihiroTanaka of Japan Display, Inc., which suggestssolutions to some of the special issues sur-rounding the design of an in-cell touch panelspecifically for automotive use. An interest-ing paper that addresses the touch user experi-ence is “The Need for Speed in Touch Systems,”by Albert Ng of Microsoft. The author showsthe impact of touch-to-display latency, framerate, and motion blur on the touch-user experi-ence. He explains how by using a customdevice his team was able to achieve latenciesdown to ~1 msec, with frame rates up to 1000 Hz.

A Wealth of InformationIn sum total, there is no doubt that this collec-tion of symposium papers represents the mostimportant display industry information youwill find all year. Please join the DisplayWeek presenters as they share their researchwith their friends and colleagues in the dis-play industry. n

symposium preview





www.displayweek.org

J O I N S I DWe invite you to join SID to participate in shaping the future development of:

• Display technologies and display-relatedproducts

• Materials and components for displays anddisplay applications


• New markets and applications

In every specialty you will find SID members as leading contributors to their profession.





SID Bay Area Chapter Hosts aGlimpse into the Future ofDisplays

by Stephen P. Atwood

The flyer headline read: “SID Bay AreaAnnounces First One-Day Technical Confer-ence: Display and Touch Technologies of theFuture: Jan 16, 2013.” So, there I went toattend the first of what I sincerely hope willbe an annual event, held in one of the mostfertile technology innovation regions in theworld. The program was expertly arranged byconference co-chairs Jennifer Colegrove andRashmi Rao, and I was expecting a smallgathering of about 50 or so die-hard displayfolk. What I encountered instead were over160 attendees, a virtual sell-out, representing43 different technology companies and count-less different product and display-applicationinterests. What unfolded throughout the daywas a wonderful balance of speaker presenta-tions, audience questions, panel discussions,and informal interactions that surely sparkedsome fresh ideas and seeded some new energyback into our industry.

Keynote speaker Jeffrey Han (Fig. 1) talkedabout his background at Perceptive Pixel, thecompany he founded. He described how hiseffort to create new touch-screen hardwarequickly became an endeavor to expand thepotential of multi-touch through software ashe realized how little capability existed in userinterfaces at the time. Now that Jeff as wellas his company are part of the MicrosoftOffice organization, Perceptive Pixel remains

a hardware division with a mission to seedinteractive large-screen displays into everypossible application, not just conferencerooms and presentation arenas.

Repeating a mantra we all know well, Jeffstressed that there is no perfect touch technol-ogy for all applications. In fact, Jeffexplained that in his view, “Touch is not asgood at content creation [as other methods],”and he went on to show some great demon-strations of how the future will be focused onpen and touch working together. For example,in a large-screen application, you might useyour left hand for manipulation of the docu-ments and windows and your right hand todraw and write the content.

Modality is also a big problem for touchapplications – it’s challenging to program thecomputer to know what you intend when youuse your fingers. However, we can use toolsto define modality, such as pens for inkingcontent and hands for manipulation. In agood UI design, your hand should be able torest on the screen while you are inking andyou should be able to perform a variety ofcontent creation and context managementtasks with no modality switching involved.This is part of what Jeff is working on at theMicrosoft Research Center and it is surely aglimpse of what we’ll see in Microsoft prod-ucts someday soon.

In the LCD Technology session, we heardfrom three speakers whose endeavors andthose of their companies are all making funda-mental contributions to the field. CandiceBrown Elliott, founder of first Clairvoyantand now Nouvoyance, companies dedicated toinnovative ways of producing multi-primarycolor with improved power efficiency andvisual performance, presented her vision ofkey technology trends that are changing thelandscape of color displays. “Thank goodnesswe’re moving to 4K resolution displays,” shebegan, talking about all the experientialadvantages that users will gain from the ultra-high-definition formats. She then made acompelling case for the adoption of multi-primary display formats such as red-green-blue-yellow-cyan, which allow a variety ofcolor metamers and creative ways to processand render images with wider color gamutswhile avoiding increases in energy require-ments.

She then explained how local dimming –using segmented 2-D backlights that enhancedynamic range – can be augmented with field-

sequential color rendering to also greatlyexpand the boundaries on color and producehigh-dynamic-range displays. These methodsare much more achievable on consumer displays today due to the very low cost ofhigh-performance processors and the newstandards coming for digital-content distribu-tion. Of course, mentioning field-sequentialtopics invokes fear in technologists used todealing with color-breakup artifacts and pooruser response. Well, not to fear, because asCandice described, the display area can besegmented into small zones where each zonehas its own color map and usually much lowercolor-diversity requirements that, in turn, canbe met with virtual primaries (mixes of theactual primaries) that are much less saturatedand therefore less likely to produce colorbreakup in observers.

Professor John F. Wager from Oregon State University took the podium next andpresented the technical merits and futurepotential of oxide thin-film transistors (TFTs)for a variety of display applications, especiallywhere transparency is needed. This is newtechnology that is just beginning to appear inmainstream OLED and LCD panels, promis-ing a host of advantages and performanceimprovements. The first published work onoxide TFTs appeared in 2003 and seriousinterest developed around 2007. TFTs madefrom oxides are accumulation-mode devices,where electrons flow source to drain with positive gate voltage and positive drain voltage.

Making an oxide TFT with good mobility ischallenging because unlike silicon, you wantto discourage polycrystalline structures infavor of amorphous. This is because of aneffect called “carrier trapping,” which causesan overall reduction in mobility in polycrys-talline states. However, some combinationsof elements such as zinc-tin (ZnSn) can bemade amorphous rather than polycrystalline.Today, we see great success using InGaZnOx(IGZO,) which is now in commercial use andis described in several ID magazine articles oflate.

The key advantages of oxide TFTs for LCDmanufacturing include high mobility, fastrefresh, and easy insertion into already exist-ing a-Si plants. By contrast, poly-Si fabrica-tion requires a totally new plant, while oxidetechnology needs more of an upgrade. Oxide-TFT technology promises to spread intoAMLCDs, EPDs, and AMOLEDs. It’s not yetready to become part of flexible displays, but


Fig. 1: Conference organizer Rashmi Raoand Perceptive Pixel Founder Jeff Handemonstrate the large-area multi-touch Perceptive Pixel touch screen.

NEWSSOCIETY FORINFORMATION

DISPLAY

SID News Issue2 p51-54_Layout 1 3/22/2013 10:30 PM Page 51

to read about progress being made in this area,see the article “Oxide TFTs for AMOLEDTVs” in this issue. Also, see Fig. 2, for acomparison.

Rounding out this trio of speakers was SethCoe-Sullivan, CTO and co-founder of QDVision, a company well known for its work inquantum-dot research, especially by those ofus in the Northeast U.S. Seth discussed hiscompany’s newest innovation, which involvesLCD color-gamut-enhancing films with quantum-dot technology that can be installeddirectly into edge-lit backlights. This technol-ogy uses blue LEDs and then converts theblue-light energy into very specific spectrumsof red, green, and blue as desired. QD Visioncalls this technology “Color IQ,” and it wasjointly announced with Sony at CES as theinnovation behind Sony’s new “Triluminous”Displays. The result is what Seth describes as“LCDs with OLED color gamuts.” Seth wenton to explain that another advantage of quantumdots is that they have worldwide environmentalcompliance, containing no materials that areknown to be hazardous to the environment. Inthe first embodiment, Color IQ is packaged ina polymer film, but in the future quantum dotsmight be suitable for inclusion in the LEDpackage itself, eliminating the need for anadditional component. This could represent asub-$100 solution to the panel designer.

However, there are further developmentchallenges, including increasing total lightoutput, managing heat, and improving life-times. Earlier QD optical performance usedto degrade significantly at temperatures above80°C but now is within ±3% up to 140°C.The currently expected lifetimes are greaterthan 2500 hours at power densities up to 100sof W/cm2 with no measureable luminancedecay. Seth also believes that while the dotsthemselves are currently made in “batches,”the process itself is completely scalable tohigh-volume LCD manufacturing.

The next series of presentations focused onOLED technology, leading off with DennisKondakov, Principal Scientist at Dupont.Dennis, who compared two options for depo-sition of OLED materials onto backplanesduring OLED manufacturing – evaporationwith masks or solution printing and process-ing. Major considerations in selecting one ofthese processes include material waste andpanel size because OLED materials are veryexpensive and processes must scale effec-tively to very large substrate sizes. Dupont

believes that nozzle printing will be theapproach chosen most often in future becauseof inherent advantages with the nozzles’ highprinting rates of 2–5 m/sec and scalability.

Up next was Sean Xia, a research managerwith Universal Display Corp., who discussedthe short- and long-term potential for phos-phorescent OLEDs (PHOLEDs). Xia and histeam believe PHOLED materials hold the keyto a variety of new innovations in displays aswell as lighting applications, owing in largemeasure to the potential advantage in internalquantum efficiency (IQE) of up to 4× that offluorescent OLEDs. This higher optical effi-ciency naturally reduces heat dissipation inthe devices and allows many more creativedesign concepts than current lighting tech-nologies. Of course, there are numerousadvantages to both inorganic as well asorganic LEDs for lighting, including widecolor gamuts and high optical efficiency, butOLED and particularly PHOLED materialscan be printed in large sheets and on manytypes of flexible substrates while achievingtested performance up to 70 lm/w for 30,000hours or longer. OLED lighting has been

talked about before at conferences and in ID,but I was convinced that significant progressis being made, and it’s inevitable that we willsee this technology in lighting applications inthe not too distant future.

While UDC has been working on large-areaOLEDs, Amal Ghosh and his colleagues ateMagin Corp. have been working on OLEDmicrodisplays, packing more and more active-matrix RGB pixels onto silicon backplaneswith display diagonals in the range of from0.5 in. to about 0.9 in. Their most stunningachievement is a 0.86-in.-diagonal WUXGAmicrodisplay with an astounding 7,138,368RGB pixel elements on it. This translates intoa pixel pitch of about 9.6 µm, with each sub-pixel having dimensions of 3.45 × 8.5 µm.The application enables full HD 3-D glassesthat can be used to create a virtual displayexperience. With the prototype the peoplefrom eMagin discussed, the diagonal field ofview was 65°, creating a virtual image ofapproximately 212 in. on the diagonal at 12 ft.with a luminance of over150 cd/m2. Becauseit is OLED technology, it has a very fastintrinsic response time and therefore can


Fig. 2: John Wager presented this slide comparing the relevant properties of a-Si, low-tempera-ture polysilicon (LTPS), and IGZO for AMLCD TFT fabrication. Credit: John F. Wager,“Amorphous Oxide Semiconductor Thin-Film Transistors for Display Applications,” presentedat the Bay-Area SID Chapter’s One-Day Conference on “Displays and Touch Technologies ofthe Future,” Sunnyvale, CA, January 16, 2013.

sid news

AMLCDsProperty

Manufacturability

Microstructure

VT uniformity

VT stability

Mobility

Mobility uniformity

Device type

Process complexity low low

good

good

good...

proven,

CMOS

good

excellent

20–100 10–30

good

poor

1

NMOS NMOS

emerging

amorphous

scaling issues

polycrystalline

high

fair

fair

mature, proven

amorphous

a-Si:H LTPS IGZO


deliver full 3-D stereo images without flicker,motion blur, or image latency. And, of course,Ghosh promised they are also working on 2K× 2K imagers and beyond.

By this point, you might think we havealready covered a full day but, in fact, all theabove was presented before lunch! The after-noon sessions began with a keynote fromAchin Bhowmik, Intel’s Director of Percep-tual Computing, who characterized the majorweakness of computers today as their limitedability to interact with humans. Although thehuman brain has a much slower processingspeed than even the slowest computers, it canperform massive amounts of parallel process-ing on multiple sensor inputs at the same time,creating a much broader range of analyticalabilities than computers. Intel’s focus is tobridge that gap in a series of steps, starting byenabling touch interfaces in all forms oftablets and handheld devices.

As touch and Windows 8 become perva-sive, Intel envisions moving to the next levelwith a system it calls “Perceptual Computing,”which is powered by a multi-input 3-D camerasystem and an SDK that Intel is currentlyoffering for free in beta form. This SDK supports several perceptual modes, includingClose-Range Interactions, Hand and FingerLevel Tracking, Face Analysis, Tracking andRecognition, Speech Recognition, and 2-D/3-DObject Tracking. As Bhowmik said, this newapproach “opens a world to creating applica-tions without developing underlying controls.”You can see an interesting demo of these newconcepts at http://software.intel.com/en-us/vcsource/tools/perceptual-computing-sdk

These demos are more interesting than any-thing I can write about here in a short space.Clearly, we have seen for several yearsincreasing interest all over the industry in newtypes of 3-D and non-contact interactionmodes with computers. Many concepts haverecently been discussed at Display Week pre-sentations, some built on the Microsoft Kinectplatform. In fact, Intel’s product is compati-ble with the Kinect device as well as its stan-dard depth camera offering, but the Intel SDKfocuses on hands and faces rather than theentire body. “If we want computers to beinteractive with people, we need to give peoplethe tools to communicate with them,” saidBhowmik in closing.

Next, we heard from well-known industryexpert Geoff Walker, who spoke about thefuture of touch technology. Noting that early

sales of Windows 8 have not been encourag-ing, Geoff said there is a lack of hardware that fully enables the new features and thatWindows 8 will soon drive the consumer marketas hardware catches up. He also predictedthat by 2018, 95% of phones will be touchenabled – something I’m not at all surprisedabout. Recently, the concentration of touch insome notebook formats such as All-in-Ones(AiOs) actually went down due to fears ofpro-cap-only choices for Windows 8 – notbecause the market doesn’t exist. Similarly,with traditional “clamshell” notebooks,increasing touch penetration will require solu-tions that are easier or more convenient thanalternative input methods and, of course, Windows 8!

Meanwhile, Geoff said that large-formattouch has huge opportunities, and there are anumber of technology options on the marketor coming to market soon, including: camera-based, vision-based, FTIR, projected-capacitive(Pro-Cap), “traditional” infrared, and high-finger-count multi-touch infrared. All of these are in various stages of development or deploy-ment now. Not surprisingly, Pro-Cap is thebiggest show in town, capturing 83% of themarket for screen applications less than 15 in. and spawning a number of R&D effortson core materials such as metal mesh, silvernanowires, carbon nanotubes, and conductivepolymers. However, as Geoff explained, it’s really the process to manufacture these screens that determines cost and performance improve-ments. With the OEM cost of a 13.3-in Pro-Cap screen in the range of $55–85, there haveclearly been many improvements recently.

The other trend that Geoff emphasized wasrenewed interest in stylus input. Windows 7was finger-focused because of the perceivedfailure of stylus input on tablet PCs. How-ever, several recent products have broughtback the stylus, which is much better for con-tent creation such as drawing and writing, soWindow 8 will likely re-energize stylus input.In fact, the ideal embodiment on largerscreens may be just what Jeff Han discussedearlier: hand recognition for control of framesand windows and simultaneous stylus inputfor actual content creation.

Next in line was Joel Kent from Elo Touch-Systems to explain how surface-acoustic-wave (SAW) technology may be seeing arebirth. He explained his company’s newedge-to-edge SAW implementation, whichcan produce a virtually bezel-less design with

the sensors and transducers moved to the backof the glass. Until recently, the touch marketwas predominantly a commercial and indus-trial application space. As we know, begin-ning around 2000, the consumer touch marketbegan its expansion way beyond the commer-cial market. This is important because theuser’s learning curve in the two markets isvery different. Consumers will make theeffort to learn how to best optimize their personal devices, but commercial marketusers are transient and will not invest time tolearn; therefore, the touch interface and appli-cation experience must still be significantlydifferent. Examples Kent cited included anairport check-in kiosk vs. a smartphone.

Rounding out the trio of touch technologyspeakers was Zachi Baharav, Manager ofR&D from Corning. We’re all familiar withthe significant and highly innovative roleCorning has played in the LCD industry forthe last 30+ years, but it was interesting tohear how diverse and nuanced the company’sofferings are for touch-sensor development.The diversity in touch-application require-ments varies in strength, thickness, chemistry,tolerance to processing, surface texture, etc.,in much greater degrees than we might haverealized. Baharav brought with him some ofthe best Corning videos, including the famous“A Day Made of Glass.” Famous for theirimaginative depictions of transparent tabletdisplays and augmented reality, these videospose many interesting questions about userinteraction as well as future modalities forinformation devices. They are, incidentally,also available on youtube but they are morefun to watch on the big screens at a confer-ence like this one.

The final round of talks addressed flexibledisplays and emerging technologies. JenniferColegrove, President of Touch DisplayResearch, spoke about the opportunities forcontinued technical advances in technologiesand commented on the future potential. Shesaid that there are “currently over 10 differenttechnologies that can be made into flexibledisplays.” She went on to make a bold predic-tion that we will see a “…flexible AMOLEDfrom Samsung in 2013 that will be a phoneand a tablet combined, with a screen size >5 in.” That certainly got my attention! Themarket revenue for flexible displays in 2011was a modest $400 million (which is largerthan I would have even thought), but Jenniferpredicts by 2015 that it could be as much as



http://software.intel.com/en-us/vcsource/tools/perceptual-computing-sdk

$2.5 billion Some of the key technologyareas that are ripe for further developmentinclude OLED flexible barrier layers, colorfor e-Paper, ITO replacement materials, flexi-ble touch, and better/smaller batteries.

The last speaker was Jian Chen, VP of R&D for Nanosys, a former winner of SID’s pres-tigous Display Industry Awards. Dr. Chenexplained that green LED efficiency was oneof the factors limiting adoption of RGB LEDbacklights. Also, differential aging made ithard to maintain white balance over longproduct life cycles, which explains why phos-phor white LEDs have become the de-factostandard for most LED backlight designs.Nanosys provides a film for LCD backlights itcalls QDEF, which produces a secondary light emission with quantum-dot technology. These films can be tuned to very specific light wave-lengths based on stimulation from 365-nm blue LED sources. Nanosys has demonstrated its process to be very scalable with modest invest-ment, allowing it to partner with companies such as 3M to produce a roll-to-roll manufacturing process. This ensures the product can meet the demands of major LCD-manufacturing customers.

While a great many seemingly diverse top-ics were covered during the course of thisevent, it was clear that they all fit togetherwhen you step back and try to envision thecharacteristics of display technology severalyears into the future:

• More advanced and efficient interactionbetween people and their devices.

• A wider range of power-efficient, lower-cost, and even flexible devices goingway beyond what we have today.

• Displays becoming more fully integratedinto all our appliances and devices, withvirtual linkage creating a seamless envi-ronment for information exchange.

• And best of all, a wide range of newopportunities for invention, discovery,investment, and future careers.

I really enjoyed my trip to the future and itwas all due to the outstanding efforts of theBA chapter conference team pictured in Fig. 3. Congratulations to them all for a verysuccessful conference! n


sid news

Fig. 3: Bay Area SID Chapter Conference Organizers. From left to right in back row: JoelPollack, Steven Huang, and Cheng-Wei Pei; from left to right in front row: Carolyn Marsden, Jennifer Colegrove, Rashmi Rao, John Miller, and Geoff Walker.




www.displayweek.org

VISIT INFORMATION DISPLAY ON-LINE

www.informationdisplay.org




Thank You” for everything they haveachieved.Our lineup of technical articles was devel-

oped for us by our two outstanding guest editors this month. The OLED articles weresolicited by H. K. Chung, who led Samsung’sOLED R&D for over 10 years and now isChair Professor at Sungkyunkwan University.You can read his Guest Editor’s note to seewhat his thoughts are for the future of OLEDTVs and related developments. Our firstFrontline Technology article comes fromauthor Jang Hyuk Kwon from the Departmentof Information Display, Kyung Hee University,Seoul, Korea. All color flat-panel displaysutilize some form of color subpixel matrix toproduce mixed colors and Dr. Kwon describesthe prevailing methods for patterning the colorfilters and/or emitters for those subpixels inhis work titled “RGB Color Patterning forAMOLED TVs.” Next, we have our second Frontline Tech-

nology feature titled “Oxide TFTs forAMOLED TVs” by author Jin-Seong Park, aprofessor at Hanyang University. Dr. Parkexplains the reasons why oxide TFTs are sopotentially important for OLED TVs, as wellas the current state of the art and some of the remaining hurdles in the way of mass-producing oxide-TFT backplanes. OxideTFTs have turned out to be one of the big stories thus far this year, especially whenlinked to the future of OLED displays. GuestEditor Dr. Arokia Nathan brought us a greatarticle by Yan Ye from Applied Materialsdescribing the underlying physics and proper-ties of oxide TFTs. In his article, “ZincOxynitride TFT: Toward a New High-MobilityLow-Cost Thin-film Semiconductor,” welearn much about the different types of possi-ble oxide compounds that are candidates forTFTs and why the amorphous state is actuallybetter for mobility than the polycrystallinestate. This is a very detailed article that reallyfilled in the blanks for me about the currentstate and future potential of this technology. In this issue’s Display Marketplace feature

titled “AMOLED Production: Entering a NewEra” contributing editor Paul Semenza has puta great deal of effort into detailing the currentstate of AMOLED manufacturing, the varyingpixel architecture approaches companies arepursuing, and the likely forward paths thesesame companies will follow. Paul is notafraid to name names, and both his industryinsight and technical understanding are widely

respected for their accuracy. Needless to say,oxide-TFT technology plays a large role in hisview of the future.One application that Paul believes creates a

unique opportunity for OLED technology isflexible displays, and so we asked another frequent contributor, Dr. Jason Heikenfeld,Associate Professor at the University ofCincinnati, to look at the state of the art inflexible displays for our Enabling Technologyfeature that Jason decided to call “Flexing andStretching.” Looking back as well as lookingforward, Jason shows us where the mostpromising work is happening, the key oppor-tunities for future innovation, and also namescompanies to point out specific embodimentsof each key infrastructure component. FromJason’s description, which will also likely beupdated at his seminar at Display Week inMay, it’s clear organic electronics, specificallyOLEDs, will play a major role in the future offlexible displays.There were a lot of headlines from this

year’s Consumer Electronics Show, includinga dazzling keynote by Samsung incorporatinga new phone concept presented by our ownSID President Brian Berkeley. If you werenot one of the reported 150,000 people whowere there, worry not, because we askedindustry reporter Steve Sechrist to give us“Alpha and Omega: Most Exciting DisplayTechnologies at CES.” Not surprising, if youhave been following our recent issues of ID,was that the major themes were ultra-high-definition (UHD) TV, OLEDs, oxide TFTs, 3-D, and even transparent LCDs, which Ithink have a lot more potential than othersmay recognize. In any case, there is plentyfor everyone to get excited about in this showreview from Steve.And so, with this issue finally complete and

ready for your enjoyment, I hope I’ll see all ofyou in Vancouver in less than 2 months fromnow. I want to thank our tireless staff, ourguest editors, and all our authors for their dedicated work on this and every issue. n

support the idea of abrupt transition are theoptimists who believe that the current manu-facturing issues will be solved within 2–3years, as many companies shift to OLED-TVmanufacturing. The gradual transition sce-nario stems from the consideration that theLCD TV will continue to lead the marketbecause it will take more than 2–3 years forOLED TV to establish a manufacturing tech-nology with both low cost and high yield.Besides, the LCD-TV infrastructures havealready been well established. In my opinion,the entry of OLED TV into the marketplacewill be driven by the marketing strategy ofTV-set makers more than by the economy inthe early phase, and the transition could beswift because I believe the learning curve forlarge-OLED-panel manufacturing will bequicker than that for the small mobile display.

n

Ho Kyoon Chung led Samsung’s OLED R&Dfor over 10 years and is now Chair Professorat Sungkyunkwan University after retirementfrom Samsung. He is still continuing hisresearch on core-technology development forflexible AMOLED and OLED lighting on flexible substrates. He is a Fellow of SID and can be reached at [email protected].

continued from page 2


editorial

continued from page 4

guest editorial

J O I N S I DWe invite you to join SID to participate in shaping the future development of:

• Display technologies and display-relatedproducts

• Materials and components for displays anddisplay applications


• New markets and applications

In every specialty you will find SID members as leading contributors to their profession.


ID Editorial Issue2 p2,55_Layout 1 3/22/2013 2:51 PM Page 55



AGC Asahi Glass (Silver Member)AU Optronics Corp.

CDT, Ltd.Chimei InnoluxChunghwa Picture Tubes, Ltd.CLEARINK DisplaysCorning Holding Japan

Dawar Technologies, Inc.Dontech (Gold Member)

Elo TouchSystemseMagin Corp.Epoxy TechnologyEuroptec Holding AG

Henkel (China) Investment Co.,Ltd. (Silver Member)

IGNIS Innovation, Inc.Instruments Systems

(Gold Member)I-PEXITRI Display Technology Center

Japan Display, Inc.

Kuraray Co., Ltd.

Logic Technologies, Ltd.

Microvision Mitsubishi Chemical Corp.Mitsubishi Electric Corp.

Nano-Proprietary, Inc.NANOSYS

NEC Corp.NextWindowNoritake Itron Corp.Novaled AG (Silver Member)

OcularOptical Films

Panasonic Corp.Parker ChomericsPrime View International

Radiant Zemax (Silver Member)ROLIC Technologies, Ltd.

Sartomer USA LLCSharp Corp.Shenzhen Leaquer Optronics Co.,Ltd.Synape Product DevelopmentLLC

Tannas ElectronicsTatsuta Electric Wire & Cable Co.Teijin Dupont Films Japan Ltd.TLC International

Universal Display Corp.US Micro Products, Inc.

Vestal Electronics A.S.

Westar Display Technologies, Inc.WINTEK Corp.

Crystal International Corp. .......56Dawar ......................................10DELO Industrial Industries ......25Display Week 2013 ..................C3Dontech....................................29EuropTec USA ............................3Global Lighting ........................34Technologies (GLT)Henkel Corp. ...........................C4

Instrument Systems...................11Jaco Displays.............................15KOE Americas ..........................25Ocular.......................................40Pixelligent .................................11Radiant Zemax............................5TFD.........................................C2Xenon .........................................5


sustaining members index to advertisers

Sales Office

Joseph TomaszewskiAdvertising Sales ManagerWiley111 River StreetHoboken, NJ [email protected]

Advertising Sales Representative

Roland EspinosaWiley111 River StreetHoboken, NJ [email protected]

Sales Office – Europe

George Isaacs12 Park View CourtThe Paddock, Eaton FordSt. Neots, CambridgeshirePE19 7SD U.K.+44-(0)[email protected]

Technical Sales Representative for Display Products

European-based globally active glass manufacturerneeds sales representative to expand U.S. customerbase for processed float glass products with emphasis ondisplay screens.Responsibilities• Develop new relationships and opportunities whileestablishing credibility and rapport with existing customer base.

• Identify new strategic opportunitiesRequirements• Must have technical sales/marketing experience withdisplay industry

• Willing to travel in the U.S.Compensation• Reasonable base salary with a larger performancebased component

Please contact:Duo Seal LLC

500 Nordhoff PlaceEnglewood, NJ 07631 Fax: (201) 541-0555

500 NORDHOFF PLACE, ENGLEWOOD, NJ 07631-4815TEL (201) 227-9095 • FAX (201) 227-2500

e-mail [email protected]

ID Ad Index p56_Layout 1 3/28/2013 9:31 AM Page 56





Display Week pC3_Layout 1 3/22/2013 10:43 PM Page 1


When you choose Loctite® you’re choosing the best for you and your customers. Our solutions can increase contrast ratio by 400%, increase display ruggedness and extend battery life. Making you the hero of your shareholders, your customers and your customers’ customers.

Thinner. Lighter. Brighter.Loctite® Liquid Optically Clear Adhesives

www.loctite.com/loca • [email protected] • Telephone: China: +86-21-2891 8000 • Japan: +81-45-758 1800 • Korea: +82-2-3279 1700 • Taiwan: +886-2-2227 1988

Cover Lens

Touch Panel Sensor

LOCADirect Bonding

Display Module

LOCACover Lens Bonding

Henkel_LOCA_ADs_forSID_Thinner-Lighter-Brigher_Final_18Mar13.indd 1 3/22/2013 11:03:10 PM


http://www.loctite.com/loca


oleds, oxide tfts, and display week preview...

Documents