Self-assembly and photoactivation of blue luminescent CsPbBr3 mesocrystals synthesized at ambient temperature

Mesocrystals, which are ordered superstructures composed of crystalline nanoparticles aligned along well-defined crystallographic directions, have recently been investigated for their novel or improved properties for different applications. All-inorganic halide perovskite CsPbX3 materials are believed to be promising materials for next generation optoelectronic devices. In this study, a facile and rapid synthesis of all-inorganic halide perovskite CsPbBr3 mesocrystals at ambient temperature in air is presented, which does not employ dimethylformamide (DMF). The results indicate that ligands have great influences on the growth kinetics and morphologies of CsPbBr3 mesocrystals with standard cubic structure and high luminescense. The destabilization of ligand matrix is responsible for the self-assembly of mesocrystals through oriented attachment into larger monocrystals because of mutual crystallographic orientations of individual building blocks with a defined long-range order on the atomic scale. Furthermore, photoactivation phenomenon was observed in CsPbBr3 mesocrystals and these intrinsic properties may help to understand the nucleation and growth mechanisms of metal-halide perovskites.