PA2PbBr4/MAPbBr3 Heterojunction X-Ray Detector with Enhanced Sensitivity and Excellent Self-Powered Functionality

Heterojunctions combining 2D and 3D perovskites have caused a surge in the research on X-ray detectors. The enhanced charge transport facilitated by the built-in electric field further amplifies the potential of this material system, paving the way for highly sensitive and efficient X-ray detectors. In this study, PA 2 PbBr 4 single-crystal film with a thickness of 10 µm is successfully grown on the surface of MAPbBr 3 substrate via liquid phase epitaxial method, forming a 2D/3D heterojunction. This innovative detector exhibits a dramatically enhanced sensitivity of 3.81 × 10 4 µC Gy −1 cm −2 at an X-ray tube voltage of 70 keV and a bias of 50 V mm −1 , along with an ultra-low detection limit of 11.84 nGy s −1 , surpassing the performance of the conventional MAPbBr 3 X-ray detectors by a factor of four and 2 × 10 3 times higher than that of commercialized α -Se detectors. Furthermore, the 2D/3D heterojunction exhibits exceptional self-powered X-ray detection capabilities, achieving a remarkable sensitivity of 3562.26 µC Gy −1 cm −2 at 70 keV X-ray tube voltage. This superior performance implies reduced energy consumption, high portability, decreased ion migration, and provides inspiration for the next generation of high-performance X-ray detectors.