Indolo Acridine-Based Hole-Transport Materials for Phosphorescent OLEDs with Over 20% External Quantum Efficiency in Deep Blue and Green

Thermally stable high-triplet-energy hole transport materials based on 8H-indolo[3,2,1-de]acridine core (FPC) were synthesized and the device performances of FPC-based investigated. The FPC-based hole transport materials showed a phosphorescent organic light-emitting diodes (OLEDs) were high triplet energy (above 2.90 eV) and high glass-transition temperature (above 140 degrees C). The FPC-based hole-transport materials (HTMs) were effective as the HTMs for green and deep-blue phosphorescent OLEDs, and a high quantum efficiency (over 20%) was achieved in both devices.