A highly efficient universal bipolar host for blue, green, and red phosphorescent OLEDs

Abstract

The bipolar host material BCPO (bis-4(N-carbazolyl)phenylphosphine oxide) containing a phosphine oxide and two carbazole groups, synthesized in three steps, shows a high triplet energy gap of 3.01 eV. The material can be used as a universal host for blue, green, and red phosphorescent devices, all giving extremely high efficiencies with turn-on voltages within 3 V. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.