However, regular planar D-A moieties experience an aggregation-caused quenching (ACQ) effect in the solid state, due to the π-π stacking . Tang et al. proposed the aggregation-induced emission (AIE) concept in 2001 and extended the study of the aggregated luminescence behavior of tremendous molecules since then . AIE molecules exhibit enhanced quantum yield while aggregate or in solid state, which is a desired feature for the emitter layers of organic light-emitting diodes (OLEDs) applications .