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

Abstract 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 CsPbX 3 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‐Ga 2 O 3 /CsPbX 3 /Au) and assessed through I‐V curves, dark current reproducibility, and photoresponse evaluations. Among the various halide compositions, orthorhombic CsPbBr 3 and mixed‐halide CsPbBr 2 I exhibited superior electrical and environmental stability when compared to cubic CsPbCl 3 or CsPbCl 2 Br. CsPbBr 3 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 CsPbBr 3 as a leading candidate for low‐voltage, high‐performance, and stable X‐ray detection.