Airflow-Controlled Crystallization for a Multi- Inch 2D Halide Perovskite Single-Crystal Scintillator for Fast High-Resolution X-ray Imaging

Theoretical analyses indicate that a two-dimensional (2D) layered metal halide perovskite, with its unique quantum-well structure and large exciton binding energy, should render both fast and strong fluorescence, making it ideal for fast X-ray imaging. Herein, an airflow-controlled solvent evaporation system is designed to grow an inch-sized 2D (PEA)2PbBr4 single crystal (SC) at low temperature (30 degrees C). Under X-rays, the (PEA)2PbBr4 SC exhibits a high light yield of 73226 photons/MeV and a fast response time of 14 ns, which is approximately 1.4 times higher and 75 times faster than those of the commercial CsI:Tl scintillator (54000 photons/MeV and 1049 ns), respectively. With such significant merits, an X-ray imager is assembled by integrating a (PEA)2PbBr4 SC with dimensions of 57 x 41 mm2 for X-ray imaging, and a high spatial resolution of 11.1 lp/mm is achieved, which demonstrates the application prospect of the large-size (PEA)2PbBr4 SC in high-speed nondestructive medical diagnosis.