Solution‐Phase Synthesis of Cesium Lead Halide Perovskite Microrods for High‐Quality Microlasers and Photodetectors

Recently, due to broad wavelength tunability and high material stability, cesium lead halide perovskite nanorods have been intensively studied as potential candidates for microlasers and photodetectors. However, the current CsPbX 3 perovskite nanorods can only support low quality ( Q ) Fabry–Perot lasers and the response time of CsPbX 3 nanorod photodetector is extremely long. Here, CsPbBr 3 microrods with larger cross‐sectional sizes and almost uniform aspect ratio are successfully synthesized with a solution processed one‐step precipitation method and their applications in microlasers and photodetectors are reported. Due to the larger cross‐sectional size, whispering‐gallery‐mode lasers can be formed in the transverse plane of CsPbBr 3 microrod under both of one‐photon and two‐photon excitation. The highest Q factor can reach around 7000. Besides, the synthesized CsPbBr 3 perovskite lasers have shown much better photostability and thermal stability. The single‐crystalline CsPbBr 3 microrods also provide a stable platform for photodetectors. The rise and decay time of CsPbBr 3 microrod based photodetectors are around 8 ms, which are almost two orders of magnitude smaller than the previously reported CsPbX 3 microrod photodetector. Such findings can pave new route on all‐inorganic CsPbX 3 based optoelectronic devices.