Achieving Ultralong Room-Temperature Phosphorescence Via Single-Bond Locking Planarization Strategy

Ultralong room-temperature phosphorescence (URTP) materials have been widely studied due to their broad applications. However, achieving phosphorescent materials with ultralong lifetimes is engaging and challenging. In this work, the indolo[3,2,1-j,k]carbazole (ICZ) with excellent planarity is obtained through twice single-bond locking on triphenylamine (TPA). Doping ICZ into a rigid matrix, URTP materials with a lifetime of 3.24 s and a photoluminescence quantum yield of 37.37% is successfully prepared.. The analysis of single-crystal, temperature-dependent photophysical characterization, Huang–Rhys factor, and theoretical calculations demonstrates that it is possible to make the molecules more planar and rigid by single-bond locking, which can inhibit the structural relaxation of the excited state and thus reduce the nonradiative transition to generate URTP. In addition, we achieve full-color afterglow by energy transfer. The potential applications of anticounterfeiting and optoelectronic information display of these URTP materials have been conducted. This work is an important reference for the construction of URTP materials.