Efficient orange light-emitting electrochemical cells

Abstract

We report the first bis-cyclometalated cationic iridium(III) complex with N-aryl-substituted 1H-imidazo[4,5-f][1,10]phenanthroline. The complex emits yellow-orange phosphorescence with a maximum at 583 nm, a quantum yield of 43%, and an excited-state lifetime of 910 ns in argon-saturated dichloromethane. Optimized orange light-emitting electrochemical cells with the new Ir(III) complex exhibit fast turn-on, a peak luminance of 684 cd m⁻² and a peak efficacy of 6.5 cd A⁻¹; in 850 h of continuous operation their luminance and efficacy decrease only by 20%.