Design Growth of Triangular Pyramid MAPbBr3 Single Crystal and Its Photoelectric Anisotropy between (100) and (111) Facets

CH3NH3PbBr3 (MAPbBr3), one of the classical members in organic-inorganic hybrid perovskite family presents excellent advantages in high photon absorption efficiency and long carrier transport distance, is expected to break the responsiveness and efficiency as photo-detectors, because single crystal is superior to its thin films, nanowires and other counterparts. Moreover, single crystal provides an adequate media to reveal the intrinsic photoelectric properties, such as defect-related dark current, mixed-ionic conductivities etc. The mixed-ionic conductivities in MAPbBr3 single crystal is considered to be associated with the atomic packing densities, which is deemed as crystalline oriented or anisotropy. In this study, a series of large-size MAPbBr3 single crystals with (100) and (111) facets exposed were successfully grown through a crystal limiting method. By fabricating metal-semiconductor-metal (MSM) planner photo-detectors on both (100) and (111) facets with Au interdigital electrodes in only a MAPbB...