Phosphorescent top-emitting organic light-emitting devices with improved light outcoupling

A study was performed on phosphorescent top-emitting organic light-emitting devices (OLED) with improved light outcoupling. The transmittance of the top electrode could be adjusted by controlling the thickness of the dielectric layer deposited on top of a thin metal cathode. It was found that OLED efficiency of 64 cd/A with pure green emission was achieved using the capping-layer concept.