Mixed low-dimensional metal halide perovskite single crystal for low-detection-limit x-ray detection via oriented ion migration

Abstract

Low-dimensional metal halide perovskites exhibit exceptional photoelectronic properties and intrinsic stability, positioning them as a promising class of semiconductor materials for light-emitting devices and photodetectors. In this work, we present a millimeter-scale single crystal of mixed low-dimensional (one-dimensional–zero-dimensional [1D–0D]) organic lead iodide with well-defined crystallinity. The fabricated single-crystal devices demonstrate high-sensitivity photoresponse and x-ray detection performance. By spatially isolating organic molecules to form the mixed 1D–0D crystal structure, ion migrations is effectively suppressed, resulting in a remarkable three orders of magnitude reduction in the dark current (56.4 pA @200 V) of the single-crystal devices. Furthermore, by enhancing the background characteristics, we achieved an impressive low x-ray detection limit of 154.5 nGys⁻¹ in the single-crystal device. These findings highlight that the mixed 1D–0D organic lead iodide configuration efficiently controls ion migration within the crystal structure, offering a promising avenue for realizing high-performance perovskite-based photodetectors and x-ray detectors.