Exploration on high-energy and high-dose rate X-ray detection with Bridgman-grown CsPbBr3 single crystal

Abstract

Perovskite-based semiconductors have emerged as promising candidates for next-generation radiation detectors due to their balanced carrier transport, high effective atomic number, and tunable electronic properties. In this study, we investigate the feasibility of Bridgman-grown CsPbBr₃ (CPB) single crystals for X-ray detection, particularly under high-energy and high-dose-rate conditions. Two types of planar devices, Au/CPB/Au and Ga/CPB/Au, were fabricated and evaluated. The asymmetric Ga/CPB/Au configuration, incorporating a low work function metal, exhibited significantly suppressed dark current and enhanced stability, attributed to Schottky barrier formation. Electrical characterization revealed comparable trap densities between both devices, confirming that performance differences resulted from electrode-induced interface effects rather than fabrication-causing effect such as thermal damage during deposition. The Ga/CPB/Au device demonstrated superior performance across a wide range of X-ray conditions from low dose-rate to diagnostic exposures, with high signal-to-noise ratio (SNR), high sensitivity, and low limit-of-detection (LoD). Notably, the device maintained stable photocurrent and high sensitivity even under harsh X-ray exposures (6 MeV and >1 Gy), validating its robustness and applicability for high energy X-ray dosimeter. This study demonstrates that CPB devices incorporating low work function electrodes are viable candidates for reliable and sensitive X-ray detection across a broad energy and dose range.