MULTILAYER WHITE LIGHT-EMITTING ORGANIC ELECTROLUMINESCENT DEVICE

Organic electroluminescent devices are light-emitting diodes in which the active materials consist entirely of organic materials. Here, the fabrication of a white light-emitting organic electroluminescent devic e made from vacuum-deposited organic thin films is reported. In this d evice, three emitter layers with different carrier transport propertie s, each emitting blue, green, or red light, are used to generate white light. Bright white light, over 2000 candelas per square meter, nearl y as bright as a fluorescent lamp, was successfully obtained at low dr ive Voltages such as 15 to 16 volts. The applications of such a device include paper-thin light sources, which are particularly useful for p laces that require lightweight illumination devices, such as in aircra ft and space shuttles. Other uses are a backlight for liquid crystal d isplay as well as full color displays, achieved by combining the emitt ers with micropatterned color filters.