Effects of an Ultra-thin Green Phosphor on White Organic Light-emitting Devices With Double Doped Emissive Layers

Abstract

The phosphorescent white OLEDs were fabricated based on double doped emitting layers, and the effect of an ultrathin layer of non-doped green phosphor Ir(ppy)3 which was inserted between the doped EMLs on device performance was studied. By introduction of 0.3 nm Ir(ppy)3, the white OLED achieved maximum current efficiency of 24.3 cd/A and power efficiency 7.2 lm/W, showing a doubled efficiency compared to the white OLED without Ir(ppy)3. The experiment shows, When Ir(ppy)3 was added, the charge carrier was balanced and the recombination zone was broadened due to direct charge trapping effect, contributing to enhanced device performance.