Highly efficient p-i-n white organic light emitting devices with tandem structure

Abstract

Highly efficient tandem p-i-n white organic light emitting devices have been fabricated. Utilizing an optical transparent bilayer with doped organic p-n junction that consists of 4,7-diphenyl-1,10-phenanthroline: 2% cesium carbonate (Cs2 C O3) N, N′ -bis(1-naphthyl)- N, N′ -diphenyl- 1, 1′ -biphenyl- 4, 4′ -diamine: 50% v/v tungsten oxide (W O3) as the connecting layer, the tandem p-i-n white device achieved an electroluminescence efficiency of 23.9 cdA and a power efficiency of 7.8 lmW at 20 mA cm2 with a Commission Internationale de l'Eclairage coordinates of (0.30, 0.43). The electroluminescent color of this tandem p-i-n white organic light-emitting diode device will not change significantly with respect to drive current variation and forward viewing angle. © 2007 American Institute of Physics.