Sunday, October 17, 2010

OLED

Today we are coming across new technologies, new mobiles with diff  features ,strange laptops  and many other  electronics  based inventions. Here I bring some info about  new success of engineers which is recieving lot of attension around the world....
OLED- Organic Light Emitting Diode

advantages over led:
you know now these days LED tv are on boom. every where there is a craze for led tv 
but this will not last long for many days , because OLED is here.
1.oled can be viewed from any angle 
2. Low [power consumption
3. screen can be made much thinner and flexible.
4. Response time
Video wallpaper - just a millimeter thick - could transform your living room wall into a flat screen and electronic film as thin as a sheet of paper could serve as your screen for the internet, the news, images or games.



TECHNOLOGY used:
A Layer of organic material is sandwiched between two conductors (an anode and a 
cathode), which in turn are sandwiched between a glass top plate (seal) and a glass bottom plate (substrate).The organic layers comprise a hole-injection layer, a hole-transport layer, an emissive layer and an electron-transport layer. When an appropriate voltage (typically a few volts) is applied to the cell, the injected positive and negative charges recombine in the emissive layer to produce light (electroluminescence). 
The thickness of the organic Layer is adjusted to produce the strongest light for each 
of the colors " red, green and blue - used to render the color picture. The three colors 
are further refined by a color filter, which purifies each color without the need for a 
polarizer, rendering outstanding color purity.


In the OLED technology, two different material groups have to be distinguished: OLED 
materials with low molecular weight called small-molecule (SM) OLED. SM-OLED were 
first introduced by the research group led by Dr. Ching Tang at the Kodak Laboratories 
in 1987. The deposition of SM-OLEDs is based on vacuum thermal evaporation. Polymer 
based OLED (PLEDs) are based on long polymer organic chains and are deposited by 
spin-cast or ink-jet principles