Low‐Dose and Stable X‐Ray Imaging Enabled by Low‐Dimensional Dion‐Jacobson Perovskites

Abstract Metal halide perovskites have emerged as highly promising candidates for next‐generation X‐ray detectors due to their facile and low‐cost processability, high attenuation coefficient, and tunable optoelectrical properties. In this work, quasi‐2D Dion‐Jacobson (DJ) perovskites are introduced in a flat panel X‐ray imager (FPXI) for X‐ray imaging. This study demonstrates that the diammonium interlayers in DJ perovskites play a key role in enhancing structural stability, suppressing ion migration, and improving charge transport. As a result, DJ perovskite‐based X‐ray FPXIs achieve a sensitivity of 18000 µC Gy_air⁻¹ cm⁻², a low detection limit of 5.7 nGy_air s⁻¹, representing performance comparable to that of state‐of‐the‐art 3D perovskite FPXIs. Thanks to the decrease in the signal crosstalk effect of the FPXIs, a high spatial resolution of 0.54 line‐pair‐per‐pixel is achieved, which is higher than that of 3D perovskite FPXIs. Remarkably, high‐quality X‐ray imaging is achieved at a total dose of 20 µGy_air, which is only 1/5 of the dose typically used in commercial equipment. This work not only provides valuable insights and guidance for the fabrication of 2D DJ perovskite X‐ray detectors but also lays the groundwork for the adoption of high‐performance, stable DJ perovskite imagers as novel flat‐panel X‐ray detectors.