Perovskite Intermediate Phase FAPbBr3·DMSO Assisted In-Situ Growth of FAPbBr3 Polycrystalline Wafer for X-ray Detection and Imaging

Polycrystalline perovskite wafers featured in customizable in dimensions and thickness, represent a frontier in mass production of X-ray detectors. Nevertheless, inherent low crystallinity, elevated defect density, and grain boundaries in polycrystalline wafers typically impair the detection performance. Herein, a novel hot-pressing approach employing the perovskite intermediate phase FAPbBr3·DMSO was demonstrated to improve the quality and X-ray detection performance of polycrystalline perovskite wafers. The in-situ growth of FAPbBr3 wafers were promoted via dimethyl sulfoxide (DMSO) vapor released from the decomposition of FAPbBr3·DMSO phase during the hot-pressing process, resulting in compact morphology, large grain size, superior crystallinity and diminished defect density. The resulted wafers exhibit a high ion activation energy (Ea) of 0.45 eV and a substantial mobility-lifetime product (μτ) of 7.41 × 10−4 cm2 V−1. These advancements equip FAPbBr3 wafer-based detectors with remarkable sensitivity of 3694.6 μC Gyair−1 cm−2, low detection limit (LoD) of 43.8 nGyair s−1, and stable operational performance, comparable to that of single-crystal alternatives. Moreover, the detectors exhibit exceptional X-ray imaging capabilities with a spatial resolution of 4.41 lp mm−1. Thus, the thermally induced decomposition characteristic of perovskite intermediate phase presents a novel avenue for the amelioration of polycrystalline perovskite wafers, heralding a leap forward in X-ray detection performance.