Quasi-One-Dimensional Perovskite Single Crystals Enabling Decoupled Ionic-Electronic Transport for Sensitive and...

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 [Pb₅I₂₂] 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 cm² V^-1, and a high activation energy for ion migration of 0.94 eV. Therefore, an impressive x-ray sensitivity of 1.42 × 10⁵ 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.