11,11-Dimethyl-11H-indeno[1,2-b]indolo[1,2,3-jk]carbazole: A rigid chromophore with novel amalgamation strategy for long lifetime blue fluorescent organic light-emitting diodes

Abstract

In this work, we report a novel chromophore, 11,11-dimethyl-11H-indeno[1,2-b]indolo[1,2,3-jk]carbazole (IDFL), developed from a indenocarbazole building block and a blue fluorescent emitter, 11,11-dimethylN2,N2,N8,N8-tetraphenyl-11H-indeno[1,2-b]indolo[1,2,3-lm]carbazole-2,8-diamine (IDFL-2DPA), derived from the IDFL by diphenylamine functionalization. The device fabricated using the IDFL-2DPA emitter offered blue emission with a very small full-width at half maximum of 32 nm in addition to high external quantum efficiency above 5% and 4 times longer lifetime than that of pyrene-based blue device. Therefore, the IDFL-2DPA emitter was appropriate as the pure blue emitter with high color purity, high efficiency, and long device lifetime.