Synthesis of novel benzothiophene derivative as a host material for blue phosphorescent organic light-emitting diodes

Abstract

An organic compound having carbazole, benzothiophene, and phosphine oxide moieties, (5-(9H-carbazol-9-yl)benzo[b]thiophen-2-yl)diphenylphosphine oxide (CBTPO), was synthesized and employed as a blue host material to harvest triplet excitons from blue triplet emitters. The CBTPO material is a bipolar host material because it includes carbazole and diphenylphosphine oxide charge transport units with both a high triplet energy of 2.76 eV and a high quantum efficiency of 19.1% in blue phosphorescent device.