Study of color-conversion-materials in chromatic-stability white organic light-emitting diodes

Abstract

We have fabricated high efficiency white organic light-emitting diodes (WOLEDs) with red-dye doped hole injection layer (HIL) and blue emissive layer. We investigated the carrier transport and photoluminescence efficiency in the device of single-layer HIL with different red dye species, bis(4-diphneylamino-phenyl)-perylene-3-yl-amine, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9enyl)-4Hpyran and a dopant material of fused aromatic ring (P1) provided by Idemitsu Kosan in 4,4',4"-tris[2-naphthyl(phenyl)amino]triphenylamine with a varied concentration. It was found that 25-% wt P1 in HIL has better electro-optical characteristics. Furthermore, we have fabricated three WOLEDs of chromatic-stability with different thickness of HIL layer. High chromatic-stability CCM-WOLEDs have been achieved, which can be applied for lightening and backlight for flat panel display.