A host material consisting of a phosphinic amide directly linked donor-acceptor structure for efficient blue phosphorescent organic light-emitting diodes

A host material with a high triplet excited-state energy level and a deep HOMO energy level has been developed by directly linking the donor and acceptor units through a phosphinic amide. Phosphorescent organic light-emitting diodes containing this material and a deep-blue dopant achieved an external quantum efficiency of 19.7%.