Tunable Multicolor Electroluminescent Polymer Devices for Full Color Displays

摘要

Efficient light emitting diodes (LEDs) of various colors and suitable methods of their pixelation are essential to incorporating polymer LEDs into full color display systems. We have developed polymer/polymer heterojunction LEDs that exhibit multicolor emission which is tunable by the bias voltage. These LEDs are based on poly(p-phenylenevinylene) (PPV)/n-type polymer structures. ITO/PPV/polyquinoiine/Al diodes fabricated under ambient air environment had a turn-on voltage of 3.5 V, luminance levels of over 800 cd/sq m, and efficiencies of up to 1%. Such devices, for example, reversibly switch colors (red -- yellow --green) in the 5-12 V range, facilitating easy pixelation. Origin of the color tunability will be discussed.