Laser-induced crystal growth observed in CsPbBr₃ perovskite nanoplatelets

Benefiting from the easily adjustable optical properties of perovskite, CsPbBr₃ nanocrystals (NCs) are considered to show their advantages in the field of display. Here, we report that a selective laser irradiation is used to induce CsPbBr₃ nanostructural reshaping and then yielding a morphological change. Under 360 or 405 nm laser irradiation, a hierarchical crystal growth process occurs for the fabricated CsPbBr₃ nanoplatelets (NPLs), which are first arranged in a side-by-side manner and reshaped into nanorods (NRs), and then NRs are arranged in the face-to-face manner to reshape into NCs. The entire process is monitored optically and microscopically, which showed that crystal growth relies on seeking a dynamic balance between heat dissipation and accumulation under laser irradiation. The heat on NPLs generated by laser irradiation dissipated with a low dissipation rate and thus led to temperature rising and lattice breaking, which turned out to be the driving force for the crystal growth in CsPbBr₃ NPLs. This feasible laser irradiation-assisted method provides for crystal growth a reliable and scalable route toward the preparation of perovskite functional materials.