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.