High-brightness organic light-emitting diodes based on a simplified hybrid structure

High-brightness green phosphorescent hybrid inorganic-organic light-emitting diodes (HyLEDs) based on a simplified WO3/organic layer structure have been demonstrated. The WO3 layer greatly improved hole injection and enabled facile hole transport, leading to balanced charge injection and significant performance enhancement. The HyLEDs reached a luminance of 104 cd/m2 at 7.3 V. At this brightness level, their current efficiency was 55.2 cd/A, 57% higher than that of all-organic LEDs with a N,N-bis-(1-naphthyl)-N,N’-diphenyl-1,1′-biphenyl-4,4′-diamine hole transport layer. The HyLEDs also exhibited markedly improved reliability under constant-current stressing due to the stable indium-tin-oxide/WO3 interface.