PbI2-DMSO Assisted In Situ Growth of Perovskite Wafers for Sensitive Direct X-Ray Detection

Abstract

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, PbI2-DMSO powders are introduced into the MAPbI3 wafer to facilitate crystal growth. The PbI2 powders absorb a certain amount of DMSO to form the PbI2-DMSO powders and PbI2-DMSO is converted back into PbI2 under heating while releasing DMSO vapor. During isostatic pressing of the MAPbI3 wafer with the PbI2-DMSO solid additive, the released DMSO vapor facilitates in situ growth in the MAPbI3 wafer with enhanced crystallinity and reduced defect density. A dense and compact MAPbI3 wafer with a high mobility-lifetime (µτ) product of 8.70 × 10−4 cm2 V−1 is produced. The MAPbI3-based direct X-ray detector fabricated for demonstration shows a high sensitivity of 1.58 × 104 µC Gyair−1 cm−2 and a low detection limit of 410 nGyair s−1.