Synthesis of 3-substituted carbazole derivative as a host material for deep blue phosphorescent organic light-emitting diodes

A high triplet energy material with carbazole and phosphine oxide, phenylbis(9-phenyl-9H-carbazol-3-yl)phosphine oxide (3DCPO), was synthesized as a bipolar host material for deep blue phosphorescent organic light emitting diodes. The 3DCPO host material showed a high triplet energy of 3.01 eV, which was high enough for deep blue phosphorescent organic light-emitting diodes. Deep blue phosphorescent organic light-emitting diodes with the 3DCPO host material exhibited high external quantum efficiency of 18.8% at 3% doping concentration.