High-Quality MAPbCl3 Polycrystalline Wafers for High-Performance Photodetectors and X-ray Detectors

Polycrystalline perovskite-type MAPbCl3, which exhibits a low grain-boundary trap state and high carrier mobility, is believed to achieve the highest performance of perovskite-based photoelectric and X-ray detection devices. However, the correlation between the carrier transport properties of MAPbCl3 polycrystalline wafers and their performance in photodetection and X-ray detection is still unclear. In this work, high-quality MAPbCl3 polycrystalline wafers were prepared by the hot-pressing method, and their photoelectric and X-ray response performance were investigated. It is found that the MAPbCl3 polycrystalline wafer photodetector exhibits a responsivity of 130 mA W– 1, an external quantum efficiency of 38%, and a specific detectivity of 3.35 × 1011 Jones under a 15 V bias. Moreover, the X-ray detector demonstrates a sensitivity of 761.04 μC Gyair–1 cm–2 at a 15 V bias, significantly surpassing the performance of commercial amorphous selenium detectors (20 μC Gyair–1 cm–2). The reason may be that reduced intergranular defects in MAPbCl3 polycrystals enhance the efficient generation of photogenerated electron–hole pairs and lower the carrier recombination probability at grain boundaries. These findings highlight the promising application prospects of MAPbCl3 polycrystalline wafers in photodetection and X-ray detection, providing research directions for the development of high-performance detectors.