Ultrafast Antisolvent Growth of Single-Crystalline CsPbCl₃ Microcavity for Low-Threshold Room Temperature Blue Lasing

All-inorganic perovskite CsPbCl₃ has recently attracted considerable attention due to its great potentials for the development of high-efficiency, deep-blue optoelectronic devices. Particularly, single-crystalline CsPbCl₃ planar microstructures provide good platforms for both fundamental studies and nanophotonics applications from lasers and detectors to amplifiers. In this study, we report an ultrafast antisolvent deposition route to fabricate single-crystalline CsPbCl₃ microplatelets (MPs). The as-grown MPs exhibit uniform morphology, strong emission, and outstanding gain property. Room temperature photoluminescence lasing is realized at 428 nm with a low threshold of 11.5 μJ cm^-2 and high net optical gain up to 720 cm^-1. These findings advance fundamental understanding on the fabrication and optoelectronic applications of low-dimensional CsPbCl₃ perovskite structures.