REGN NO:- 14304018
DEPT. OF ELECTRONICS ENGG.
• Organic Light Emitting Diode(OLED).
• Emerging Technology for displays in devices.
• Main principle behind OLED technology is
• Offers brighter, thinner, high contrast, flexible
• OLEDs are solid state devices composed of thin films
of organic molecules that is 100 to 500 nanometres
• They emits light with the application of electricity.
• They doesn’t require any backlight. i.e., they are self
• They are made from carbon and hydrogen.
• The discovery of the electroluminescence property in organic
materials in 1950s is considered to be the stepping stone of
• The first OLED device was developed by Eastman Kodak in
• In 1996, pioneer produces the world’s first commercial
• In 2000, many companies like Motorola, LG etc developed
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
Many developments had take place in the year 2012.
Architecture of OLED
• Substrate (clear plastic, glass, foil) - The substrate supports
• 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.
A voltage is applied across the anode and cathode.
Current flows from cathode to anode through the organic
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.
Types of OLEDs
• The organic layer is
between strips of cathode
and anode that run
• The intersections form the
• Easy to make
• Use more power
• Best for small screens
• Full layers of cathode
• Anode over lays a
thin film transistor
• Requires less power
• Higher refresh rates
• Suitable for large
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.
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.
OLED vs. LED
• Picture clarity is good.
• High contrast.
• Faster response time.
• Do not require
• Colour space is good.
• Viewing angles are
• Picture clarity is comparatively
• Low contrast.
• Slow response time.
• Require backlighting
• Colour space is bad
• Viewing angles are less
Current Research for OLEDs
• Manufacturers focusing on finding
a cheap way to produce
o "Roll-to-Roll" Manufacturing
• Increasing efficiency of blue
• Boosting overall lifespan
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.
• High resolution, <5μm pixel size.
Disadvantages of OLED
• Lifespan .
• Water damage.
• Colour balance issues.
• 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
Future Uses for OLED
Flexible / bendable lighting
Wallpaper lighting defining new ways to light a space
Transparent lighting doubles as a window