Self‐Powered Photodetector Based on Perovskite/NiOx 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 FAPbBr3/NiOx heterostructure is demonstrated. The built‐in field of FAPbBr3/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 × 1011 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 × 10−3 cm2 V−1, which enable a superior X‐ray sensitivity of 402 µC Gyair−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. [ABSTRACT FROM AUTHOR]