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

Abstract

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, PA₂PbBr₄ single-crystal film with a thickness of 10 µm is successfully grown on the surface of MAPbBr₃ substrate via liquid phase epitaxial method, forming a 2D/3D heterojunction. This innovative detector exhibits a dramatically enhanced sensitivity of 3.81 × 10⁴ 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 MAPbBr₃ X-ray detectors by a factor of four and 2 × 10³ 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.