Buffer layer control for solution processing of white organic light-emitting diodes

Abstract

Inverted structure white organic light-emitting diodes were fabricated via full solution processing with a functional buffer layer. The single emissive layer was composed of a blend of host and transporting materials (both hole and electron) doped with blends of blue and red phosphors. A mixed-host system was used to improve the device performances by lowering the energy barriers of the transporting layer to the emissive layer. The effect of the composition of transporting materials on the performance of solution processed organic light-emitting diodes was investigated. An ultra-thin physisorbed buffer layer was used for charge injection balance. A PEDOT layer was blended with polyvinyl alcohol and other additives in order to prevent penetration by silver paste into the emissive layer. White organic light-emitting diodes were fabricated with a luminance efficiency of 0.016 lm/W and balanced white light with CIE coordinates of (0.31, 0.33).