The effect of Al2O3 nanolayers on the efficiency of organic light-emitting devices
We report the effect of Al2O3 nanolayers on the efficiency of organic light-emitting devices. Several different Al2O3 nanolayers were introduced between 8-hydroxyquinoline aluminum (Alq3) and N, N'-bis-(1-naphthyl)-N, N'-diphenyl-1, 1'-biphenyl-4, 4'-diamine (NPB) layers, and their influence on the device performance was investigated. When a 1.0 nm thick Al2O3 film was inserted, for an unoptimized device composed of indium–tin oxide (ITO)/NPB/Al2O3/Alq3/LiF/Al, the current efficiency was as high as 3.75 cd A−1. It was much higher than that of conventional devices. The mechanism of performance enhancement is discussed.