Self-Powered Photodetector Based on Perovskite/NiO_x Heterostructure for Sensitive Visible Light and X-Ray Detection

Self-powered halide perovskite X-ray detectors have evoked busting interests because they present outstanding properties such as low power consumption, high sensitivity, and integrability without external power source. Nevertheless, existing self-powered X-ray detectors exhibit low sensitivity due to the insufficient charge separation and transport. Herein, a self-powered photodetector for sensitive X-ray and photodetection based on single-crystalline perovskite FAPbBr(3)/NiOx heterostructure is demonstrated. The built-in field of FAPbBr(3)/NiOx heterojunction provides a driving force for separation and transport of photoexcited carriers. Without an external power supply, the photodetector presents excellent photoresponse performance under 450 nm light illumination, including high photoresponsivity (123.6 mA W-1), good detectivity (D = 7.1 x 10(11) Jones), and ultrafast response/recovery time (10/200 ns). Simultaneously, the device achieves photovoltaic effect of 0.80 V and a large mobility-lifetime product of 1.1 x 10(-3) cm(2) V-1, which enable a superior X-ray sensitivity of 402 mu C Gy(air)(-1) cm(-2) at zero bias voltage. These results imply that the simple combination of perovskite single crystal and a hole transporting layer provides a flexible platform for the realization of energy-saving self-powered photodetector in visible light and X-rays.