Efficient extraction of singlet-triplet excitons for high-efficient white organic light-emitting diode with a multilayer emission region

摘要

We reported a highly efficient white organic light-emitting diode (WOLED) with a multilayer emission region made of sequentially evaporated host and guest layers. The singlet and triplet excitons were harvested in two separate channels. An external quantum efficiency of 16.3% photons/electron (~41 cd/A) was achieved with a good color rendering index (CRI) of 76, and a Commission Internationale de l'eclairage (CIE) coordinate of (x = 0.38, y = 0.46). At brightness of 100 and 500 cd/m~2, the external quantum efficiencies reached 11% and W%, respectively. The performance of the WOLED is better than that fabricated by co-evaporation method due to an improved exciton capture and emission efficiencies. This work presents an alternative way of fabricating WOLED.