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

Abstract

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.