Flexible direct‐conversion X‐ray detectors represent a transformative advance in X‐ray imaging, enabling conformal, low‐dose, and distortion‐free detection across medical, industrial, and wearable applications. This review comprehensively analyzes four emerging material systems for flexible direct‐conversion X‐ray detectors: organic semiconductors, perovskites, metal–organic frameworks (MOFs), and inorganic metal compounds, specifically examining their composition, fabrication strategies, and performance metrics such as sensitivity, detection limit, and mechanical flexibility. Perovskites exhibit superior sensitivity and charge transport, organic semiconductors present exceptional flexibility, MOFs demonstrate structural tunability, and inorganic composites ensure environmental stability. Critical challenges including the trade‐off between absorption and flexibility, environmental instability, and integration with readout electronics are discussed. Elaboration on the recent advancements in device architectures and imaging modalities for each material category is provided, along with a systematic comparison of their respective performances. Future directions emphasize hybrid materials, scalable fabrication, and system integration to achieve high‐resolution, robust, and biocompatible next‐generation flexible X‐ray detectors.
Di et al. (Wed,) studied this question.