High-color-temperature p-i-n white organic light-emitting devices based on the fluorescent RGB system

Abstract

P-i-n devices with 5% Cs doped Men as the n-type transporting layer and WO3 doped NPB as the p-type transporting layer are investigated for controlling the recombination zone (RZ) of carriers in WOLED based on three adjacent fluorescent red, green and blue emitters. Variation in while CIEx,y color-coordinates are closely related to the proportion of deep blue emission which serves as an indicator for the position of the RZ. By optimizing the concentration of the deep blue dopant, it is possible to enhance the color temperature of WOLED and boost the efficiency to 8 cd/A at 5.5 V (20 mA/cm2) with CIEx,y of (0.33, 0.34) which is among the best reported for the fluorescent RGB 3-emission WOLEDs.