High-performance self-powered broadband imaging photodetector based on single crystal-CsPbBr3/single crystal-β-Ga2O3 heterojunction

UV/visible light detection and imaging is a vibrant research field with broad application prospects in both civilian and military fields. Metal halide perovskite materials have been widely studied in the preparation of photodetectors for image sensing due to their excellent optoelectronic properties, tunable band gaps and low-cost preparation processes. At present, in order to further broaden the response of perovskite in the ultraviolet region (especially deep ultraviolet) and realize the self-powering function, it has been proposed to combine perovskite with wide-bandgap semiconductors to construct a heterojunction. However, existing reports are limited to some heterojunction detectors between polycrystalline and amorphous states. In this paper, we report a detector made of a heterojunction of single crystal CsPbBr3 and single crystal wide bandgap β-Ga2O3. The device has a responsivity of 7.9 mA/W and 6.5 mA/W at 250 nm and 450 nm, respectively, without an external bias, and a fast response speed (~102 μs), showing self-powered characteristics and broadband detection capabilities. Finally, the device was applied to an optical imaging system, effectively realizing image detection for solar-blind and visible light, demonstrating the practical application of single-crystal heterojunctions as signal receivers in the system. This study provides a noteworthy path for promoting the commercialization of all-single-crystal perovskite/wide-bandgap semiconductors in optical imaging systems.