Ideal Bipolar Host Materials with Bis-benzimidazole Unit for Highly Efficient Solution-Processed Green Electrophosphorescent Devices

摘要

An ideal host material with high triplet energy, suitable HOMO energy level, excellent thermal and electrochemical stability, and bipolar charge carrier transport ability was synthesized. A high external quantum efficiency of 13.7% and a luminance efficiency of 48.2 cd A~(-1) with low efficiency roll-off were achieved in solution-processed green electrophosphorescent devices.