Ion Leakage Current Control for Polycrystalline Metal Halide Perovskite Direct X-ray Detectors

作者：Ziyao Zhu, Huiwen Chen, Weixiong Huang, Bo Zhao, Sheng Gao, Yang He, Gaokuo Zhong, Xueqing Yang, Xingzhu Wang, Yunlong Li · 发表于：ACS Applied Materials & Interfaces · 年份：2024 · DOI：10.1021/acsami.4c10707 · 被引用次数：8 · 研究领域：Perovskite Materials and Applications、Magnetic and transport properties of perovskites and related materials、Luminescence Properties of Advanced Materials

Metal halide perovskites have emerged as promising materials for X-ray detection due to their high X-ray attenuation coefficients, defect tolerance, and suitability for large-area, low-temperature fabrication. However, the intrinsic high ion conductivity of these materials presents challenges, such as high dark current density and current drift, which impair the stability and sensitivity of perovskite X-ray detectors. This study introduces an approach to mitigating these issues by incorporating 2,2,3,3,3-pentafluoropropylamine hydrochloride (PFH) into polycrystalline MAPbI 3– x Cl x films using a one-step blade-coating method. PFH aggregates at grain boundaries, raising local vacuum energy levels and passivating surface defects, thereby reducing ion conductivity without affecting electron conductivity. As a result, this approach significantly reduces the dark current and enhances sensitivity, achieving a low detection limit of 14.7 nGy air /s. Additionally, it improves signal stability, consistency, and response speed of the detector. These findings suggest that PFH is a promising additive for advancing the performance and practical application of polycrystalline metal halide perovskite-based X-ray detectors.