Ultrafast fabrication of cavity-controlled perovskite-crystallites by a spin-coating method for microlasers

In recent years, organic-inorganic hybrid perovskite MAPbBr(3) has exhibited a broad application prospect in light-emitting diode and laser fields due to its excellent characteristics. In particular, single-crystal MAPbBr(3) microdisks can act as resonators and gain media, making them a good candidate for microlasers. In this work, we report a crystallization-manipulated spin-coating method to prepare single-crystal MAPbBr(3) microdisks in several minutes. The NMP additive is used and the ambient humidity is controlled to manipulate the crystallization of MAPbBr(3) microdisks. Attributed to the manipulation of crystallization, the prepared square and octagonal MAPbBr(3) microdisks have regular shapes and smooth end faces, which is beneficial to promoting laser performance. The obtained MAPbBr(3) microdisks can form whispering gallery mode (WGM) lasers and exhibit excellent laser performance with a low laser threshold and a high quality factor (Q). These results demonstrate that the MAPbBr(3) microdisks fabricated by this rapid growth approach could be promising materials for WGM microlasers.