Methylammonium-Based Quasi-Two-Dimensional Perovskite Single Crystals for Highly Sensitive X-ray Detection and Imaging.

The strategy of introducing large organic cations into three-dimensional perovskites could reduce the dimensionality of perovskites to form quasi-two-dimensional (quasi-2D) perovskites, resulting in increased stability and reduced detection limits due to less ion migration. Herein, a quasi-2D perovskite single crystal (BDA)(MA) 2 Pb 3 Br 10 (BDA = NH 3 C 4 H 8 NH 3 , MA = CH 3 NH 3 ) with a layered structure was grown by the temperature-cooling solution method. The X-ray detector based on the (BDA)(MA) 2 Pb 3 Br 10 single crystal has a sensitivity as high as 1984 μC Gy -1 cm -2 at 55.6 V/mm, and it could detect X-rays as low as 28.12 nGy s -1 at 22.2 V/mm. In addition, the X-ray imaging system based on the single-crystal device easily distinguishes between metals and plastics and exhibits a spatial resolution estimated as 250 μm, indicating the feasibility of (BDA)(MA) 2 Pb 3 Br 10 crystals for X-ray imaging. This research offers a method for the design of quasi-2D layered perovskites and enhances photoelectronic applications in X-ray inspection and imaging.