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.

Perovskite solar cells (PSCs) have attracted much attention due to their rapidly increased power conversion efficiencies, however, their inherent poor long-term stability hinders their commercialization. The degradation of PSCs first comes from the degradation of hole transport materials (HTMs). Here, we report the construction of periodic π-columnar arrays and ionic interfaces over the skeletons by introducing cationic covalent organic frameworks (C-COFs) to the HTM. Periodic π-columnar arrays can optimize the charge transport ability and energy levels of the hole transport layer and suppress the degradation of HTM, and ionic interfaces over the skeletons can produce stronger electric dipole and electrostatic interactions, as well as higher charge densities. The C-COFs were designed and synthesized via Schiff base reaction by using 1,3,5-triformylphloroglucinol as a neutral knot and dimidium bromide as cationic linker. The neutral COFs (N-COFs) were also synthesized as a reference by using 3,8-diamino-6-phenylphenanthridine as neutral linker. PSCs with cationic COF exhibit the highest efficiency of 23.4% with excellent humidity and thermal stability. To the best of our knowledge, this is the highest efficiency among the meso-structured PSCs fabricated by a sequential process.