PbI2-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, PbI2-DMSO powders are introduced into the MAPbI(3) 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 MAPbI(3) wafer with the PbI2-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 (mu tau) product of 8.70 x 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 x 10(4) mu C Gyair(-1) cm(-2) and a low detection limit of 410 nGy(air) s(-1).