Prakash m

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Prakash m

  1. 1. PRAKASH M 4SF10EC073 Organic light-emitting diodes(OLED) Presented by: 1
  2. 2. CONTENTS  INTRODUCTION  HISTORY  FEATURES OF OLED  COMPONENTS OF OLED  OPERATION  MAKING OF OLED  TYPES OF OLED  ADVANTAGES & DISADVANTAGES  APPLICATION  CONCLUSION  REFERENCE 2
  3. 3. 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 3
  4. 4. 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 4
  5. 5. 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 5
  6. 6. COMPONENTS OF OLED  Cathode  Emissive Layer  Conductive Layer  Anode  Substrate 6
  7. 7. OPERATION 1. Voltage applied across Cathode and Anode 1. Typically 2V-10V 2. Current flows from cathode to anode 1. Electrons flow to emissive layer 2. Electrons removed from conductive layer leaving holes 3. Holes jump into emissive layer 3. Electron and hole combine and light emitted 7
  8. 8. Different Colors ‐type of organic molecule in the emissive layer ‐Three molecules used RGB  Intensity/brightness ‐amount of current 8
  9. 9. MAKING OF OLED  VACUUMTHERMAL EVAPORATION  ORGANICVAPOUR PHASE DEPOSITION ‐Uses inert carrier gases to transform films of organic materials ‐Deposited onto cooled substrate 9
  10. 10. Advantages of OVPD Higher deposition rate Higher material utilization Better device perf0rmance Large substrate size  INKJET PRINTING ‐OLEDs are sprayed onto substrates just like inks are sprayed onto paper during printing 10
  11. 11. 1. Passive-matrix OLED 2. Active-matrix OLED 3. Transparent OLED 4. Top-emitting OLED 5. Flexible/Foldable OLED 6. White OLED TYPES OF OLEDs 11
  12. 12. 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 12
  13. 13. Transparent OLED Top-emittingOLED • 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 13
  14. 14. FoldableOLED 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 14
  15. 15. ADVANTAGES  Brightness  Flexible  Viewing angles  Power consumption  Light weight  High resolution 15
  16. 16. 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 16
  17. 17. APPLICATIONS Display sources Mobile phones Keyboards Digital watches Light sources 17
  18. 18. 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 18
  19. 19. 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. 19
  20. 20. REFERENCES  Bardsley, James. "International OLEDTechnology Roadmap." IEEE JOURNAL OF SELECTEDTOPICS IN QUANTUM ELECTRONICS. Jan. 2004. IEEE.  Freud enrich, Craig, Ph.D. "How OLEDsWork." s Howstuffworks. 2008. <http://electronics.howstuffworks.com/oled.htm>.  Organic LightingTechnologies. "Technology." Organic LightingTechnologies LLC. 2006. <http://www.o- lite.com/technology.htm>. 20
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