Highly efficient white organic light-emitting diode

We present a highly efficient white electroluminescence device by the combination of a solution processed blue organic phosphorescence light-emitting diode with appropriate down-conversion phosphor system. The use of this down-conversion system produced an extraordinary enhancement on device performance, resulting in a white electroluminescence device with luminance efficacy of 25 lm/W at luminance efficiency reaching 39 cd/A. The extraordinary enhancement on device performance is attributed to isotropic radiation pattern of the excited phosphor particles, leading to high light extraction properties. (c) 2006 American Institute of Physics.