prakash m
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PRAKASH M 4SF10EC073
Organic light-emitting diodes(OLED)
Presented by:
CONTENTS INTRODUCTION HISTORY FEATURES OF OLED COMPONENTS OF OLED OPERATION MAKING OF OLED TYPES OF OLED ADVANTAGES & DISADVANTAGES APPLICATION CONCLUSION REFERENCE
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
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
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
COMPONENTS OF OLED
Cathode Emissive Layer Conductive Layer Anode Substrate
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OPERATION
1. Voltage applied across Cathode and Anode
1. Typically 2V-10V2. Current flows from
cathode to anode1. Electrons flow to
emissive layer2. Electrons removed
from conductive layer leaving holes
3. Holes jump into emissive layer
3. Electron and hole combine and light emitted
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Different Colors ‐ type of organic molecule in the emissive layer
‐ Three molecules used RGB
Intensity/brightness‐ amount of current
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MAKING OF OLED
VACUUM THERMAL EVAPORATION
ORGANIC VAPOUR PHASE DEPOSITION
‐Uses inert carrier gases to transform films of organic materials ‐Deposited onto cooled substrate
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Advantages of OVPD
Higher deposition rateHigher material utilizationBetter device perf0rmanceLarge substrate size INKJET PRINTING
‐OLEDs are sprayed onto substrates just like inks are sprayed onto paper during printing
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1. Passive-matrix OLED2. Active-matrix OLED3. Transparent OLED4. Top-emitting OLED5. Flexible/Foldable OLED6. White OLED
TYPES OF OLEDs
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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
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Transparent OLED Top-emitting OLED• 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
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Foldable OLED 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
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ADVANTAGES
Brightness Flexible Viewing angles Power consumption Light weight High resolution
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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
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APPLICATIONS
Display sources
Mobile phones
Keyboards
Digital watches
Light sources
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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
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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.
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REFERENCES
Bardsley, James. "International OLED Technology
Roadmap." IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS. Jan. 2004. IEEE.
Freud enrich, Craig, Ph.D. "How OLEDs Work." s
Howstuffworks. 2008. <http://electronics.howstuffworks.com/oled.htm>.
Organic Lighting Technologies. "Technology."
Organic Lighting Technologies LLC. 2006. <http://www.o-lite.com/technology.htm>.
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Thank you