this presentation is about OLED(organic light emitting diode) technology.It involves how oleds works,the types of oled and their mechanisms,advantages,disadvantages,applications

1. OLED
(Organic Light Emitting Diode)
TECHNOLOGY
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2. OLED (organic light-emitting diode) is a display
technology for use in mobile devices and televisions.
OLED describes a specific type of thin-film display
technology in which organic compounds form the
electroluminescent material.
Introduction

3. History of OLEDs
• First developed in the early 1950s in FRANCE.
• Early technology would emit a short burst of light when a
voltage was applied.
o In1960s – AC-driven electroluminescent cells using
doped anthracene was developed.
o In 1997 paper,Shirakawa et al.Reported high
conductivity in similarly oxidized and iodine doped
polyacetylene.
o In 1987 Chin Tang and Van Slyke introduced the first
light emitting diodes from thin organic layers.
o In 1990 electroluminescence in polymers was
discovered.

4. Architecture of OLEDs
• Organic Layer:
o Conducting layer-This layer is made of organic
plastic molecules that transport “holes” from the
anode.One conducting polymer used in OLEDs is
polyaniline.
o 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 polyflurene.

5. How OLED Works?
o Voltage applied across cathode and
anode(2v-20V).
o Current flows from cathode to anode.
o Electrons flow to emissive layer.
o Electrons removed from conductive
layer leaving holes.
o Holes jump into emissive layer.
o Electron and hole combine and light
emitted.

6. Types of OLEDs
o Passive Matrix OLEDs
o Active Matrix OLEDs
o Transparent OLEDs
o Top-Emitting OLEDs
o Foldable OLEDs
o White OLEDs

7. Passive Matrix OLEDs
o Perpendicular cathode/anode strip orientation.
o Light emitted at intersections(pixels).
o Easy to make.
o Large power consumption.
o Best for small screens.

8. Active Matrix OLEDs
o Full layers of cathode and anode.
o Anode overlays a Thin Film Transistor(TFT).
o Requires less power.
o Suitable for large screens.

9. Transparent OLEDs
o Transparent substrate,cathode and anode.
o Emits light bi-directionally.
o Passive or Active matrix OLED.
o Useful for head-up displays
• Transparent projector screens
• Glasses

10. Top-Emitting OLEDs
o Non Transparent or reflective substrate.
o Transparent cathode.
o Used with Active matrix device.
o Smart Card displays.

11. Foldable OLEDs
o Substrates made of very flexible metallic foils or
plastics.
o Very lightweight and durable reduces breakage.
o Attached to fabrics to create "smart" clothing, such
as outdoor survival clothing.

12. White OLEDs
o Emits bright white light.
o Replace fluorescent lights.
o Reduce energy cost for lighting.
o True Color Qualities.

13. Applications of OLEDs
o Manufacture of TELEVISION screens.
o Cell Phone Displays.
o Computer Displays.
o Lights.
o Portable device displays.

14. Advantages of OLEDs
o Thinner, lighter and more flexible.
o Plastic substrates rather then glass.
o High resolution (<5um pixel size) and fast switching (1-10um).
o Do not require backlight, light generated.
o Low voltage, low power and emissive source.
o Larger sized displays.
o Brighter- good day light visibility.
o Larger viewing angles -170o

15. Disadvantages of OLEDs
o Lifetime
 White, Red, Green  46,000-230,000 hours.
• About 5-25 years.
 Blue  14,000 hours.
• About 1.6 years.
o Expensive.
o Susceptible to water.
o Overcome multi-billion dollar LCD market.

16. Conclusions
o Flexibility and thinness will enable many applications.
o OLED will replace current LED and LCD technologies.
o Integrated touch OLED display will be potential competitive item.
o A good candidate of green solution for display.