Essay - Organic Light Emitting Diode (Oled) I. Executive Summary the Development...

Organic Light Emitting Diode (OLED)

*****. Executive Summary

The development of Organic ***** Emitting *****s (OLEDs) is a m*****jor technological breakthrough since the invention of liquid crystal displays (LCDs) in providing digital lighting and display. These components can display brighter colors, produce faster refresh rates, consume less power, ***** costs less to manufacture. ***** are now being used in *****r electronics such as cellular phones, personal ***** organizers (PDAs), and flat-screen televisions. In the future, these can be ***** in virtual reality, heads-up display (HUDs), ***** ***** military applications. The technology looks very promising, and may provide us a cheaper and *****tter alternative than current LCDs and LEDs in displaying bright and crisp digital images.

II. Introduction ***** topic

OLEDs differ from traditional ***** ***** LEDs mainly beca*****e they use organic molecules and polymers for the emissive layer (***** part that emits light). The ***** of organic materials instead of ***** crystals is much cheaper. The fabrication of polymer light emitting diodes (PLED), for example, only involves "printing" on a substrate using techniques currently provided by inkjet printers. Because of this low manufacturing cost, it is possible to create large and flexible OLED sheets that can be used ***** a wide r*****nge ***** products. O***** operate on the principle of organic electro-luminescence. This involves ***** use ***** electric current on a material in order ***** stimulate electr*****s and produce *****. Like LCDs, The emissive material is still semiconductor but an organic one.

One important advantage of OLEDs over ***** is the absence of a b*****cklight. LCDs require a constant light source that is selectively blocked in order to produce images. OLEDs, on the other h*****, do not ***** a backlight but *****stead ***** activates light ***** the ***** layer. This al*****s OLEDs to use less power (about 20% less ***** LCDs) and last longer on battery-powered devices such as ***** ph*****s ***** digital cameras. Also, OLEDs ***** not require diff*****rs and polarizers ***** are used ***** LCDs.

*****. History / Background

OLEDs were first developed by Eastman-Kodak in 1979 and subsequently patented in 1987. Through a *****nership with S*****nyo called "SK Display," they were able to develop an active-matrix, full-color 2.4-inch display. Kodak used "small-molecule" OLED which is m*****ufactured through the condensation of organic materials on a sheet inside a v*****cuum. ***** process ***** expensive and in*****.

An***** company ***** Cambridge Display Technologies (CDT) ***** another approach in 1996 ***** called their product LEP (Light Emitting Polymer). Instead of creating ***** by ***** of ***** inside a vacuum, they just "printed" the layers ***** the same technology used by commercial inkjet *****. This process proved to be cheap and flexible. However, this method is not yet mature as compared ***** "small-molecule" technology by Kodak (Organic Light-***** Diode, 2005). Because ***** the patents held by these companies, the ***** development and improvement of OLEDs ***** still slow and restricted due to licensing issues.

OLED ***** is very promising, and various industries expect that it will eventually replace LCD. This is due