X-ray Detectors Using Inorganic Perovskite Thin Film Deposited by Close-Space Sublimation

Metal halide perovskites are emerging as robust alternatives to traditional radiation detection materials such as amorphous selenium (a-Se) and cadmium zinc telluride (CZT). This emergence is attributed to their high atomic number, excellent X-ray attenuation, remarkable optoelectronic properties, and low cost. While organic-inorganic perovskites exhibit high sensitivity, they are prone to degradation under moisture and heat. In contrast, inorganic perovskites offer enhanced environmental and thermal stability. This study presents high-sensitivity X-ray detectors utilizing thin-film inorganic CsPbX₃ perovskites, which are deposited via close-space sublimation with engineered solid-state precursors. The band structures were characterized using Scanning Kelvin Probe, Photoelectron Spectroscopy, and UV-Vis analysis. The devices were fabricated in the form of PN heterojunction diodes (ITO/a-Ga₂O₃/CsPbX₃/Au) and assessed through I-V curves, dark current reproducibility, and photoresponse evaluations. Among the various halide compositions, orthorhombic CsPbBr₃ and mixed-halide CsPbBr₂I exhibited superior electrical and environmental stability when compared to cubic CsPbCl₃ or CsPbCl₂Br. CsPbBr₃ achieved an X-ray sensitivity of 130 µC Gy_air⁻¹ cm⁻² at −4 V under 60 keV exposure, which is five times higher than the sensitivity exhibited by commercial a-Se detectors (20 µC Gy_air⁻¹ cm⁻²). These findings validate CsPbBr₃ as a leading candidate for low-voltage, high-performance, and stable X-ray detection.