Dark Current Suppression in Two‐dimensional Histamine Lead Iodine Perovskite Single Crystal for X‐ray Detection and Imaging

Abstract Lead halide perovskites have emerged as attractive X‐ray detector materials, owing to properties such as strong X‐ray stopping power, excellent carrier transport, and high sensitivity. Additionally, they can be easily prepared by using solution‐based synthesis approaches. However, traditional 3D (three‐dimensional) perovskites X‐ray detectors have shown limited application due to high dark currents generated under bias voltage as a result of strong ion migration. In this work, an X‐ray detector with a vertical structure device is demonstrated using 2D (two‐dimensional) histamine lead halide perovskite single crystal HAPbI 4 (HPI, HA = histamine). Due to the dielectric screening effect of diamine and the vertical structure of the HPI device, the fabricated detector shows a sensitivity of 7737 µC Gy air −1 cm −2 under a bias voltage of 30 V. Furthermore, the detector shows a sensitivity of 293 µC Gy air −1 cm −2 and detection limit of 51.38 nGy air s −1 without bias voltage, wherein the dark current is almost completely suppressed. All of these properties indicate the X‐ray detection device is a promising candidate for next‐generation optoelectronic applications.