Dual-energy X-ray imaging (DEXI) has a wide range of applications in various fields such as medical diagnostics and security. However, existing DEXI systems face significant challenges that require immediate resolution, including high preparation costs, excessive cumulative radiation doses and low resolution. In this study, we developed a soft X-ray film detector based on lead thioantimony (Pb₂SbS₂I₃) using the spin-coating technique. This method not only reduces fabrication costs but also achieves high sensitivity (9669 μC·Gy_air⁻¹·cm⁻²) and a low detection limit (71 nGy_air·s⁻¹), making it one of the top-performing soft X-ray detectors reported to date. By simply placing the film in front of a normal X-ray detector, we constructed a novel DEXI system that enables dual-energy detection within a single exposure, thereby enhancing material discrimination while reducing the cumulative radiation dose. Additionally, it provides imaging resolution (7.2 lp·mm⁻¹) comparable to commercial products, and its compact thickness (20 μm) does not compromise the resolution of other detectors. This work opens new applications for metal chalcohalides in X-ray detection, enabling precise soft X-ray imaging within a single exposure for the first time. These advancements are expected to have significant implications for cutting-edge applications such as bone density measurement, energy-dispersive computed tomography, intelligent security screening, and space exploration.

In this work, we demonstrate that an organometallic perovskite (OP) single crystal for effective photodetection can be grown on a gold (Au)-decorated substrate using liquid phase epitaxy. The covered gold could both control the shape of the epitaxial layer and act as its electrodes. An MAPbCl₃ single crystal and an MAPbBr_1.5Cl_1.5 single crystal were used as the substrate and the epitaxial layer, respectively. The device, with an Au-perovskite-Au structure, can be fully characterized. Due to the high-quality epitaxial layer, the maximum external quantum efficiency (EQE) value is over 60% under the voltage of −20 V. In addition, the response speed can reach 200 and 500 ns (ns) rise and fall, respectively. Our work provides an effective and promising method to fabricate efficient perovskite-based photodetectors.