PbI(2)‐DMSO Assisted In Situ Growth of Perovskite Wafers for Sensitive Direct X‐Ray Detection

Although perovskite wafers with a scalable size and thickness are suitable for direct X‐ray detection, polycrystalline perovskite wafers have drawbacks such as the high defect density, defective grain boundaries, and low crystallinity. Herein, PbI(2)‐DMSO powders are introduced into the MAPbI(3) wafer to facilitate crystal growth. The PbI(2) powders absorb a certain amount of DMSO to form the PbI(2)‐DMSO powders and PbI(2)‐DMSO is converted back into PbI(2) under heating while releasing DMSO vapor. During isostatic pressing of the MAPbI(3) wafer with the PbI(2)‐DMSO solid additive, the released DMSO vapor facilitates in situ growth in the MAPbI(3) wafer with enhanced crystallinity and reduced defect density. A dense and compact MAPbI(3) wafer with a high mobility‐lifetime (µτ) product of 8.70 × 10(−4) cm(2) V(−1) is produced. The MAPbI(3)‐based direct X‐ray detector fabricated for demonstration shows a high sensitivity of 1.58 × 10(4) µC Gyair(−1) cm(−2) and a low detection limit of 410 nGy(air) s(−1).