PRAKASH M 4SF10EC073

Organic light-emitting diodes(OLED)

Presented by:

CONTENTS INTRODUCTION HISTORY FEATURES OF OLED COMPONENTS OF OLED OPERATION MAKING OF OLED TYPES OF OLED ADVANTAGES & DISADVANTAGES APPLICATION CONCLUSION REFERENCE

INTRODUCTION

 An OLED is a solid state device or electronic device that typically consists of organic thin films sandwiched between two thin film conductive electrodes.

electro phosphorescence. produces self-luminous displays that do not

require backlighting and hence more energy efficient.

OLED materials present bright, clear video and images that are easy to see at almost any angle

HISTORY First developed in the early 1950’s in France by

applying a high-voltage alternating current field to crystalline thin films of acridine orange

1960’s – AC – driven electroluminescent cells using doped anthracene was developed

Electroluminescence from polymer films was first observed by Roger Partridge

FEATURES OF OLED

High brightness is achieved at low drive voltages/current densities.

Materials do not need to be crystalline, so easy to fabricate.

Self luminescent so no requirement of backlighting

A flexible, thin and lightweight Broader operating temperature ranges Low power consumption

COMPONENTS OF OLED

Cathode Emissive Layer Conductive Layer Anode Substrate

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OPERATION

1. Voltage applied across Cathode and Anode

1. Typically 2V-10V2. Current flows from

cathode to anode1. Electrons flow to

emissive layer2. Electrons removed

from conductive layer leaving holes

3. Holes jump into emissive layer

3. Electron and hole combine and light emitted

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Different Colors ‐ type of organic molecule in the emissive layer

‐ Three molecules used RGB

Intensity/brightness‐ amount of current

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MAKING OF OLED

VACUUM THERMAL EVAPORATION

ORGANIC VAPOUR PHASE DEPOSITION

‐Uses inert carrier gases to transform films of organic materials ‐Deposited onto cooled substrate

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Advantages of OVPD

Higher deposition rateHigher material utilizationBetter device perf0rmanceLarge substrate size INKJET PRINTING

‐OLEDs are sprayed onto substrates just like inks are sprayed onto paper during printing

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1. Passive-matrix OLED2. Active-matrix OLED3. Transparent OLED4. Top-emitting OLED5. Flexible/Foldable OLED6. White OLED

TYPES OF OLEDs

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Passive matrix OLED

Active matrix OLED• Perpendicular

cathode/anode strip orientation

• Light emitted at intersection (pixels)

• Large power consumption

• Used on 1-3 inch screens

• Full layers of cathode, anode, organic molecules

• Thin Film Transistor matrix (TFT) on top of anode

• Less power consumed then PMOLED

• Used for larger displays

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Transparent OLED Top-emitting OLED• Transparent substrate,

cathode and anode• Bi-direction light emission• Passive or Active Matrix

OLED • Useful for heads-up display

i. Transparent projector screen

ii. glasses

• Non-transparent

• Transparent Cathode

• Used with Active Matrix Device

• Smart card displays

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Foldable OLED White OLED

• Flexible metallic foil or plastic substrate

• Light weight and ultra thin

• Reduce display breaking

• Emits bright white light

• Replace fluorescent lights

• Reduce energy cost for lighting

• True Color Qualities

• Environmental friendly

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ADVANTAGES

Brightness Flexible Viewing angles Power consumption Light weight High resolution

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DISADVANTAGES

Cost to manufacture is high

Constraints with lifespan

Easily damaged by water

Limited market availability

OLED Lighting Vs. Incandescent and Fluorescent

Not as easy as changing a light bulb

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APPLICATIONS

Display sources

Mobile phones

Keyboards

Digital watches

Light sources

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Lighting• Flexible / bendable lighting

• Wallpaper lighting defining new ways to light a space

• Transparent lighting doubles as a window

Cell Phones

Future uses of oled

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CONCLUSION

•OLEDs offer many advantages over both LEDs and LCDs. They are thinner, lighter and more flexible than the crystalline layers in an LED or LCD. They have large fields of view as they produce their own light.

•Video images much more realistic and constantly updated.

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REFERENCES

  Bardsley, James. "International OLED Technology

Roadmap." IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS. Jan. 2004. IEEE.

  Freud enrich, Craig, Ph.D. "How OLEDs Work." s

Howstuffworks. 2008. <http://electronics.howstuffworks.com/oled.htm>.

  Organic Lighting Technologies. "Technology."

Organic Lighting Technologies LLC. 2006. <http://www.o-lite.com/technology.htm>.

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Thank you