Optically pumped lasing in single crystals of organometal halide perovskites prepared by cast-capping method

A simple cast-capping method is adopted to prepare single-crystal perovskites of methyl ammonium lead bromide (CH3NH3PbBr3). By capping a CH3NH3PbBr3 solution casted on one substrate with another substrate such as glass, mica, and distributed Bragg reflector (DBR), the slow evaporation of solvent enables large-size cubic crystals to grow between the two substrates. Under optical pumping, edge-emitting lasing is observed based on Fabry-Perot resonation between parallel side facets of a strip-shaped crystal typically with a lateral cavity length of a few tens of mu m. On the other hand, vertical-cavity surface-emitting lasing (VCSEL) is obtained from a planar crystal grown between two DBRs with a cavity thickness of a few mu m. Simultaneous detection of those edge-and surface-emissions reveals that the threshold excitation fluence of VCSEL is higher than that of the edge-emitting lasing due to thickness gradient in the planar crystal. Published by AIP Publishing.