Advancements in Metal Halide Perovskites and their Derivatives for Direct‐Type X‐Ray Detectors

Metal halide perovskites and their derivatives have emerged as promising candidates for direct-conversion X-ray detectors owing to their strong X-ray attenuation ability, remarkable defect tolerance, large electric resistivity, and cost-effective solution processability. Existing reviews have predominantly focused on device performance breakthroughs in perovskite X-ray detectors, yet critical gaps persist in addressing material optimization strategies and structural derivative exploration. This review first summarizes the research progress of the X-ray detector and the applications of perovskites, as well as their derivatives in detection technologies. Subsequently, it introduces fundamental properties and X-ray detection performance of halide materials with different crystal structures, including ABX₃, A₂BB'X₆, A₃B₂X₉, Ruddlesden-Popper (R_mA_n-1B_nX_3n+1), and metal-free perovskites. The performance-limiting mechanism and corresponding defect-mediated optimization are further analyzed, establishing a material design framework for developing highly sensitive metal halide perovskite-based detectors. The last part envisions strategic domains spanning charge transport engineering, biocompatibility and eco-friendliness considerations, flexible and self-powered perovskite system design, high-quality and efficient preparation methods, and high operational stability enhancements, constructing a comprehensive framework for advancing perovskite-based detection technologies. This review provides insightful inspiration for the development of novel X-ray detectors.