oled technology
DESCRIPTION
Organic Light Emitting Diode or OLED An OLED is a solid state device or electronic device that typically consists of organic thin films sandwiched between two thin film conductive electrodes. When electrical current is applied, a bright light is emitted. OLED use a carbon-based designer molecule that emits light when an electric current passes through it. This is called electrophosphorescence. Even with the layered system, these systems are thin . usually less than 500 nm or about 200 times smaller than a human hair.TRANSCRIPT
WELCOME
OLEDOrganic Light Emitting Diode
Presented By
HAREESH KM S5 EPT 12190027
INTRODUCTION
o Uses organic light emitting
diode(OLED).
o Emerging Technology for displays in
devices.
o Main principle behind OLED
technology is electroluminescence.
o Offers brighter, thinner, high
contrast, flexible displays.
HISTORY
The first OLED device was developed by Eastman
Kodak in 1987.
In 1996, pioneer produces the world’s first
commercial PMOLED.
In 2000, many companies like Motorola, LG etc
developed various displays.
In 2001, Sony developed world’s largest fullcolor
OLED.
In 2002, approximately 3.5 million passive matrix
OLED sub-displays were sold, and over 10 million
were sold in 2003.
In 2010 and 2011, many companies announced
AMOLED displays.
Many developments had take place in the year
2012.
What is an OLED ?
• OLED - Organic Light Emitting Diode
• An OLED is an electronic device made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted.
• A device that is 100 to 500 nanometers thick or about 200 times smaller than a human hair.
.
What is OLED?
OLED - Organic Light Emitting Diode
An OLED is any light emitting diode (LED) which emissive electroluminescent layer is composed of a film of organic compounds.
FEATURES
Flexibility.
Emissive Technology.
Light weight and thin.
Low power consumption.
High contrast, brighter and perfect display from
all angles.
OLED STRUCTURE
Architecture of OLEDs Substrate (clear plastic, glass, foil) - The substrate supports
the OLED.
Anode (transparent) - The anode removes electrons (adds electron "holes") when a current flows through the device
Cathode (may or may not be transparent depending on the type of OLED) - The cathode injects electrons when a current flows through the device.
Organic layer:
Conducting layer - This layer is made of organic plastic molecules that transport "holes" from the anode. One conducting polymer used in OLEDs is polyaniline.
Emissive layer - This layer is made of organic plastic molecules (different ones from the conducting layer) that transport electrons from the cathode; this is where light is made. One polymer used in the emissive layer is polyfluorene.
Working Principle(figure)
WORKING PRINCIPLEo A voltage is applied across the anode and
cathode.
o Current flows from cathode to anode through
the organic layers.
o Electrons flow to emissive layer from the
cathode.
o Electrons are removed from conductive layer
leaving holes.
o Holes jump into emissive layer .
o Electron and hole combine and light emitted.
Sample Demonstration of OLED Device
Types of OLEDs
Passive-matrix OLED Active-matrix OLED
Top-emitting OLED
Transparent OLED
Foldable OLED
White OLED
Passive-Matrix OLED (PMOLED)
Passive-Matrix OLED (PMOLED)
PMOLEDs are easy to make, but they consume more power than other types of OLED, mainly due to the power needed for the external circuitry.
PMOLEDs are most efficient for text and icons and are best suited for small screens (2- to 3-inch diagonal) such as those you find in cell phones, PDAs and MP3 players.
Active-Matrix OLED (AMOLED)
AMOLEDs consume less power than PMOLEDs because the TFT array requires less power than external circuitry, so they are efficient for large displays.
AMOLEDs also have faster refresh rates suitable for video.
The best uses for AMOLEDs are computer monitors, large-screen TVs and electronic signs or billboards
Active-Matrix OLED (AMOLED)
Transparent OLED (TOLED)
Transparent OLED (TOLED)
When turned off, are up to 85 percent as transparent as their substrate.
When it is turned on, it allows light to pass in both directions.
They are either active- or passive-matrix. This technology can be used for heads-up displays.
Foldable OLED (FOLED)
Foldable OLED (FOLED) Foldable OLEDs have
substrates made of very flexible metallic foils or plastics.
Potentially, foldable OLED displays can be attached to fabrics to create "smart" clothing.
White OLED (WOLED)
White OLEDs emit white light that is brighter, more uniform and more energy efficient than that emitted by fluorescent lights.
White OLEDs also have the true-color qualities of incandescent lighting.
Because OLEDs can be made in large sheets, they can replace fluorescent lights
Advantages
Much faster response time Consume significantly less energy Able to display "True Black" picture Wider viewing angles Thinner display Better contrast ratio Safer for the environment Has potential to be mass produced
inexpensively OLEDs refresh almost 1,000 times
faster then LCDs
DISADVANTAGES
PROBLEMS WITH OLED
OLED seem to be the perfect technology for all types of displays, but they also have some problems:•Lifetime:- While red and green OLED films have long lifetimes (10000 to 40000 hours), blue organics currently have much shorter lifetimes (only about 10000 hours).•Manufacturing :- Manufacturing processes are expensive right now.•Water:- Water can easily damage OLEDs
Applications of OLEDs
TVs Cell Phone screens
Computer Screens Keyboards (Optimus Maximus)
Lights Portable Divice displays
FUTURE USES FOR OLED
Lighting• Flexible / bendable lighting
• Wallpaper lighting defining new ways
to light a space• Transparent lighting doubles as a
window
Cell Phones
• Nokia 888
Scroll Laptop
• Nokia concept OLED Laptop
CONCLUSION
• Organic Light Emitting Diodes are
evolving as the next generation
displays.
• As OLED display technology
matures, it will be better able to
improve upon certain existing
limitations of LCD including
• high power consumption
• limited viewing angles
• poor contrast ratios.