Synergistic Effects of Precursor Reduction and Ion Migration Blocking Enable Highly Sensitive MAPbI₃ X-ray Detector with Low Detection Limit

Lead halide perovskites have emerged as promising materials for sensitive, low-dose-rate X-ray imaging. However, the dark current drift caused by ion migration poses challenges to their long-term operational stability and performances. To address this issue, we explored the synergistic effects of precursor reduction and ion migration blocking have been investigated. Reducing the precursor solution decreases the defect density, enhancing the carrier lifetime and mobility-lifetime product, thus boosting X-ray sensitivity. However, this approach alone does not effectively suppress dark current drift. By incorporating ion migration blocker, the optimized device exhibits a significantly reduced dark current drift of 3.62 × 10−4 nA  cm−1 s−1 V−1, an improved X-ray sensitivity of 1.22  105 μC Gyair−1 cm−2 and a low detection limit of 3 nGyair s-1 under 12.66 V mm-1 electrical field, positioning it among the best of polycrystalline perovskite X-ray detectors. Additionally, it can capture a clear X-ray image of a metal key at an X-ray dose of 2.85 μGyair s−1, highlighting its potential for low-dose X-ray imaging applications.