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 CsPbX3 perovskite nanorods can only support low quality (Q) Fabry–Perot lasers and the response time of CsPbX3 nanorod photodetector is extremely long. Here, CsPbBr3 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 CsPbBr3 microrod under both of one‐photon and two‐photon excitation. The highest Q factor can reach around 7000. Besides, the synthesized CsPbBr3 perovskite lasers have shown much better photostability and thermal stability. The single‐crystalline CsPbBr3 microrods also provide a stable platform for photodetectors. The rise and decay time of CsPbBr3 microrod based photodetectors are around 8 ms, which are almost two orders of magnitude smaller than the previously reported CsPbX3 microrod photodetector. Such findings can pave new route on all‐inorganic CsPbX3 based optoelectronic devices.

Lead halide perovskites are intensively studied in past few years due to their potential applications in optoelectronic devices such as solar cells, photodetectors, light-emitting diodes (LED), and lasers. In addition to the rapid developments in material synthesis and device fabrication, it is also very interesting to postsynthetically control the optical properties with external irradiations. Here, the influences of very low energy (10-20 keV) electron beam of standard electron beam lithography are experimentally explored on the properties of lead halide perovskites. It is confirmed that the radiolysis process also happens and it can selectively change the photoluminescence, enabling the direct formation of nanolaser array, microsized light emitter array, and micropictures with an electron beam writer. Interestingly, it is found that discontinuous metallic lead layers are formed on the top and bottom surfaces of perovskite microplate during the radiolysis process, which can act as carrier conducting layers and significantly increase the photocurrent of perovskite photodetector by a factor of 217%. By using the electron beam with low energy to modify the perovskite, this method promises to shape the emission patterns for micro-LED with well-preserved optical properties and improves the photocurrent of photodetector.

Lead halide perovskites have recently attracted attention due to their outstanding photoelectric properties. Hence, perovskite-based optoelectronic devices are widely studied. Herein, a simple solution-based one-step anti-solvent method to produce well-controlled and uniform CH 3 NH 3 PbBr 3 -based micro-devices is reported. It is confirmed that the size and mode numbers of the self-assembled microdisk cavities can be well controlled by modifying the size of the SiO 2 microdisks on the substrate or changing the concentration of the perovskite precursor. With this simple and robust method, the produced CH 3 NH 3 PbBr 3 microdisk arrays are extremely uniform in both their size distribution and emission spectra. Moreover, a perovskite photodetector array with fast rise (<8.3 ms) and decay (<8.3 ms) times was fabricated by periodically patterning the substrate. Based on the high controllability and high reproducibility of the patterned CH 3 NH 3 PbBr 3 microdisk arrays, this cost-effective and mass-manufacturable approach significantly increases the production yield of lead halide perovskite microdevices and boosts their ability to be used in practical applications.