Quasi‐One‐Dimensional Perovskite Single Crystals Enabling Decoupled Ionic–Electronic Transport for Sensitive and Stable X‐ray Detection

Metal halide perovskites are promising candidates for low‐cost and sensitive x‐ray detection. However, the existing perovskite materials with diverse composition and dimensionality encounter an intrinsictrade‐off between carrier collection and ion migration, posing a critical challenge for high‐energy x‐ray detection. Here, we demonstrated that the quasi‐one‐dimensional perovskite of cystamine lead iodide featuring corner‐sharing [Pb 5 I 22 ] chains chain and small interchain spacing along edge‐on orientation enables efficient carrier collection and blocked ion migration simultaneously, and thus largely decouple the electronic and ionic transport pathways. The as‐grown single crystals yield a large mobility‐lifetime product of 4.35 × 10 −4 cm 2 V −1 , and a high activation energy for ion migration of 0.94 eV. Therefore, an impressive x‐ray sensitivity of 1.42 × 10 5 µC Gy −1 cm −2 (average x‐ray energy 42.7 keV) are obtained in quasi‐one‐dimensional perovskite. Under harsh conditions, such as continuous radiation, high electric fields, and high temperatures, the device exhibits excellent operational stability. As a proof of concept, the robust integration of a quasi‐one‐dimensional perovskite with a thin‐film transistor backplane for x‐ray imaging was achieved. This study offers innovative insights into the regulate the structural dimensions of materials for sensitive and stable x‐ray detection.