A simple carbazole-N-benzimidazole bipolar host material for highly efficient blue and single layer white phosphorescent organic light-emitting diodes

A new simple carbazole-N-benzimidazole bipolar luminogen mNBICz was constructed and utilized as a host for an FIrpic-doped blue device, and exhibited high efficiencies with a eta(EQE,max) of 26.2%, a eta(C,max) of 54.5 cd A(-1) and a eta(P,max) of 52.2 lm W-1. Furthermore, a two-color, all-phosphor single layer white device displayed a eta(EQE,max) of 22.9%, a eta(C,max) of 62.5 cd A(-1) and a eta(P,max) of 60.4 lm W-1.