Highly efficient phosphorescent organic light-emitting diodes using a homoleptic iridium(III) complex as a sky-blue dopant

Abstract

Homoleptic triscyclometalated iridium(III) complex Ir(dbi)3 was used as a dopant for sky blue phosphorescent organic light-emitting diodes (PHOLEDs). Its photophysical, thermal, electrochemical properties as well as the device performances were investigated. Ir(dbi)3 exhibited high quantum yield of 0.52 in solution at room temperature. A maximum current efficiency and external quantum efficiency (EQE) of 61.5cdA−1 and 23.1% were obtained, which are the highest ever reported for blue homoleptic iridium complexes. High efficiencies of 53.5cdA−1 and 20.1% EQE were achieved even at the luminance of 1000cdm−2.