Simple bipolar molecules constructed from biphenyl moieties as host materials for deep-blue phosphorescent organic light-emitting diodes.

Simple is good! Based on biphenyl molecules, two bipolar host materials with high triplet energies have been rationally designed, synthesized, and fully characterized. Deep blue phosphorescent organic light-emitting diodes, which employ the new hosts and an iridium(III) complex as triplet emitter, show a maximum current efficiency of 40 cd A(-1), a maximum power efficiency of 36 lm W(-1), and a maximum external quantum efficiency of 19.5 %.