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Rajesh panigrahi

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Rajesh panigrahi

  1. 1. ORGANIC LIGHT EMITTING DIODE BY RAJESH PANIGRAHI REGN NO:- 14304018 DEPT. OF ELECTRONICS ENGG.
  2. 2. • 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. INTRODUCTION
  3. 3. Contd.. • OLEDs are solid state devices composed of thin films of organic molecules that is 100 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. 4. HISTORY • The discovery of the electroluminescence property in organic materials in 1950s is considered to be the stepping stone of OLED • 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.
  5. 5. Contd..  In 2001, Sony developed world’s largest full colour 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.
  6. 6. Structure of OLED
  7. 7. Architecture of OLED • 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. • Organic layer: o Conducting layer - This layer is made of organic plastic molecules that transport "holes" from the anode. o Emissive layer - This layer is made of organic plastic molecules that transport electrons from the cathode; this is where light is made. • Cathode (may or may not be transparent depending on the type of OLED) - The cathode injects electrons when a current flows through the device.
  8. 8. 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.
  9. 9. Working Principle (Diagram)
  10. 10. OLED DEVICE OPERATION Transparent substrate Anode (ITO) Conductive layer Emissive layer Cathode LUMO LUMO HOMO HOMO eˉeˉ h+ h+h+ Light
  11. 11. Types of OLEDs 1.Passive OLEDs • The organic layer is between strips of cathode and anode that run perpendicular • The intersections form the pixels • Easy to make • Use more power • Best for small screens
  12. 12. Contd.. 2.Active OLEDs • Full layers of cathode and anode • Anode over lays a thin film transistor (TFT) • Requires less power • Higher refresh rates • Suitable for large screens
  13. 13. Contd.. 3.Transparent OLED
  14. 14. Contd.. 4.Top Emitting OLED
  15. 15. Contd.. 5. FLEXIBLE OLED
  16. 16. FLEXIBLE OLED  It incorporates a flexible plastic substrate on which organic semiconductor is deposited.  Works on the principle of electroluminescence.  Generally OLEDS are fabricated on glass substrate whereas flexible OLEDS are fabricated using flexible plastic such as polyethylene terephthalate.
  17. 17. Contd..  Flexible OLED devices can be fabricated by deposition of the organic layer onto the substrate using a method derived from inkjet printing, allowing the inexpensive and roll-to-roll fabrication of printed electronics.  Flexible OLEDs may be used in the production of rollable displays, electronic paper, or bendable displays which can be integrated into clothing, wallpaper or other curved surfaces.
  18. 18. OLED vs. LCD OLED • Greater view angle. • High contrast. • Faster response time. • Do not require backlighting. • Temperature(~50°C – 80°C). LCD • Limited view angle. • Low contrast. • Slow response time. • Require backlighting. • Temperature(~0°C- 100°C).
  19. 19. OLED vs. LED OLED • Picture clarity is good. • High contrast. • Faster response time. • Do not require backlighting • Colour space is good. • Viewing angles are more(170) • Expensive LED • Picture clarity is comparatively bad. • Low contrast. • Slow response time. • Require backlighting • Colour space is bad • Viewing angles are less • Cheap
  20. 20. Current Research for OLEDs • Manufacturers focusing on finding a cheap way to produce o "Roll-to-Roll" Manufacturing • Increasing efficiency of blue luminance • Boosting overall lifespan
  21. 21. Advantages of OLED • 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.
  22. 22. Disadvantages of OLED • Expensive. • Lifespan . • Water damage. • Colour balance issues.
  23. 23. Applications of OLEDs  TVs  Cell Phone screens  Computer Screens  Keyboards (Optimus Maximus)  Lights  Portable Divice displays
  24. 24. OLED Televisions  OLED TELEVISIONS • Released XEL-1 in February 2009. • First OLED TV sold in stores. • 11'' screen, 3mm thin • $2,500 MSRP • Weighs approximately 1.9 kg • Wide 178 degree viewing angle • 1,000,000:1 Contrast ratio
  25. 25. Future Uses for OLED LIGHTING:  Flexible / bendable lighting  Wallpaper lighting defining new ways to light a space  Transparent lighting doubles as a window
  26. 26. Contd.. Cell Phones:  Nokia 888
  27. 27. REFERENCES • http://impnerd.com/the-history-and-future-of-oled • http://en.wikipedia.org/wiki/Organic_light-emitting_diode • http://www.oled-research.com/oleds/oleds-history.html • http://www.voidspace.org.uk/technology/top_ten_phone_tech s.shtml#keep-your-eye-on-flexible-displays-coming-soon • http://www.pocket- lint.com/news/news.phtml/23150/24174/samsung-say-oled- not-ready.phtml • http://www.cepro.com/article/study_future_bright_for_oled_l ighting_market/ • http://www.technologyreview.com/energy/21116/page1/ • http://optics.org/cws/article/industry/37032 • http://jalopnik.com/5154953/samsung-transparent-oled- display-pitched-as-automotive-hud

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