A self-power photodetector based on controlled growth of single crystal MAPbBr3/WO3 heterojunction

Compared with polycrystalline films, perovskite single crystal is considered as a promising photoelectric material due to its unique advantages in quantum efficiency and carrier diffusion length. In this work, the micron-thickness MAPbBr3 single crystal was prepared through a highly repeatable process based on the crystal seed dissolution-growth method. A heterojunction of MAPbBr3/WO3 single crystal was realized through a simple thermal evaporation process, and the integrated C/MAPbBr3/WO3/C device demonstrated self-powered characteristics and high photoelectric performance, which showed good responsivity of about 111 mA/W, detectivity of 9.64×1011 Jones and fast response speed (0.11/0.56 ms). Meanwhile, the device exhibited good rectification performance (ratio of 125 at ±2 V) and reduced dark current due to the built-in electric field formed in the heterojunction. This study provides a facile, flexible, and highly repeatable method for the preparation of high-performance photodetectors based on MAPbBr3 single crystals with micrometer thickness.