Ultrafast Antisolvent Growth of Single-Crystal CsPbBr 3 Microcavity for Whispering-Gallery-Mode Lasing.

In recent years, all-inorganic cesium lead bromide (CsPbBr 3 ) perovskites have garnered considerable attention for their prospective applications in green photonics and optoelectronic devices. However, the development of efficient and economical methods to obtain high-quality micron-sized single-crystalline CsPbBr 3 microplatelets (MPs) has become a challenge. Here, we report the synthesis of CsPbBr 3 MPs on Si/SiO 2 substrate by optimizing the ultrafast antisolvent method (FAS). This technique is able to produce well-dispersed, uniformly sized, and morphologically regular tetragonal phase single crystals, which can give strong green emission at room temperature, with excellent stability and excitonic character. Moreover, the crystals demonstrated lasing with a whispering gallery mode with a low threshold. These results suggest that the single-crystalline CsPbBr 3 MPs synthesized by this method are of high optical quality, holding vast potential for future applications in photonic devices.