Organic Light Emitting Diode

1. OLED TECHNOLOGY

2. INTRODUCTION
 Uses organic light emitting diode(OLED).
 Emerging Technology for displays in devices.
 Main principle behind OLED technology is
electroluminescence.
 Offers brighter, thinner, high contrast, flexible
displays.

3. WHAT IS AN OLED?
 OLEDs are solid state devices composed of thin
films of organic molecules that is100 to 500
nanometres thick.
 They emits light with the application of electricity.
 They doesn’t require any backlight. i.e., they are
self emitting.
 They are made from carbon and hydrogen.

4. 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.

5. HISTORY (CONTD.)
 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.

6. FEATURES
 Flexibility.
 Emissive Technology.
 Light weight and thin.
 Low power consumption.
 High contrast, brighter and perfect display from all
angles.

7. STRUCTURE OF OLED
 Substrate.
 Anode.
 Organic layer.
-Conductive layer (Hole Transport Layer).
made up of polyaniline or metal-phthalocyanine.
-Emissive layer( Electron Transport Layer).
made up of polyfluorene or metal chelates.
 Cathode.

8. STRUCTURE OF OLED(FIGURE)

9. OLED FABRICATION
 Substrate preparation.
 Device deposition
 Deposit and pattern anode.
 Pattern organic layers.
 Vacuum deposit and pattern cathode.
 Encapsulation.
 Also involves making backplane.

10. OLED DEPOSITION
 Organic layers can be applied to the substrate
using the following methods.
- Evaporation and shadow masking.
- Inkjet printing.
- Organic vapor phase deposition.

11. EVAPORATION AND SHADOW MASKING

12. INKJET PRINTING

13. ORGANIC VAPOR PHASE DEPOSITION

14. COLOUR GENERATION
 Different approaches for fabricating red, green and
blue pixels.
- Red, green and blue individual pixels.
- White emitter and colour filters.
- Blue emitter and colour converters.
- Stacked OLED

15. COLOUR GENERATION(FIGURE)

16. WORKING PRINCIPLE
 A voltage is applied across the anode and cathode.
 Current flows from cathode to anode through the
organic layers.
 Electrons flow to emissive layer from the cathode.
 Electrons are removed from conductive layer
leaving holes.
 Holes jump into emissive layer .
 Electron and hole combine and light emitted.

17. WORKING PRINCIPLE(FIGURE)

18. OLED DEVICE OPERATION
Transparent
substrate
Anode
(ITO)
Conductive
layer
Emissive
layer
Cathode
LUMO
LUMO
HOMO
HOMO
eˉeˉ
h+
h+h+
Light

19. TYPES OF OLED
Six types of OLEDs
 Passive matrix OLED(PMOLED).
 Active matrix OLED(AMOLED).
 Transparent OLED(TOLED).
 Top emitting OLED.
 Flexible OLED(FOLED).
 White OLED(WOLED).

20. PASSIVE MATRIX OLED

21. ACTIVE MATRIX OLED

22. TRANSPARENT OLED

23. TOP EMITTING OLED

24. FLEXIBLE OLED

25. WHITE OLED

26. OLED ADVANTAGES
 Thinner, lighter and more flexible.
 Do not require backlighting like LCDs.
 Can be made to larger sizes.
 Large fields of view, about 170 degrees.
 Faster response time.
 Brighter.
 High resolution, <5μm pixel size.

27. OLED DISADVANTAGES
 Expensive.
 Lifespan.
 Water damage.
 Colour balance issues .

28. OLED VS. LCD
 Greater view angle.
 High contrast.
 Faster response time.
 Do not require
backlighting.
 Temperature(~50°C –
80°C).
 Limited view angle.
 Low contrast.
 Slow response time.
 Require backlighting.
 Temperature(~0°C-
100°C).
OLED LCD

29. APPLICATIONS
Major applications of OLED technology are
 OLED TV.
 Mobile phones with OLED screens.
 Rolltop Laptop.

30. OLED TV

31. MOBILE PHONES WITH OLED SCREEN

32. ROLLTOP LAPTOP

33. 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.