Organic light-emitting diodes (OLED) are LEDs with an emissive electroluminescent layer composed of a film of organic compounds, which usually contains a polymer substance that allows suitable organic compounds to be deposited by a simple "printing" process. The resulting matrix of pixels can emit light of different colors.
OLEDs do not require a backlight to function, and require low levels power and operate longer. This also allows OLED displays to be quite thin. OLEDs can be printed onto any suitable substrate including flexible substrates, allowing such applications such as roll-up displays and displays embedded in fabrics or clothing. Because OLED pixels directly emit light, pixel colors appear correct and unshifted, even as the viewing angle approaches 90 degrees from normal. Typical response time is less than 0.01 millisecond. OLEDs used for flat-panel displays, are usually rated for about 750,000 hours of sustained 400 cd/mē of luminance, depending on manufacturer.
The intrusion of water into displays can damage or destroy the organic materials. Therefore, improved sealing processes are important for practical manufacturing and may limit the longevity of more flexible displays.
OLEDs are used in a variety ways, including telecom screens, computer displays, portable system screens, advertising, information, and indicators. They are also used as general light sources for space illumination, and large-area light-emitting elements.