Zhu Ziyao, Chen Huiwen, Huang Weixiong, Zhao Bo, Gao Sheng, He Yang, Zhong Gaokuo, Yang Xueqing, Wang Xingzhu, Li Yunlong
Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
School of Integrated Circuits, Anhui University, Hefei 230039, China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):53177-53185. doi: 10.1021/acsami.4c10707. Epub 2024 Sep 18.
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 MAPbICl 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/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.
金属卤化物钙钛矿因其高X射线衰减系数、缺陷耐受性以及适用于大面积、低温制造等特性，已成为X射线探测领域颇具潜力的材料。然而，这些材料固有的高离子导电性带来了诸如高暗电流密度和电流漂移等挑战，这会损害钙钛矿X射线探测器的稳定性和灵敏度。本研究介绍了一种通过使用一步刮涂法将2,2,3,3,3-五氟丙胺盐酸盐（PFH）掺入多晶MAPbICl薄膜中来缓解这些问题的方法。PFH在晶界处聚集，提高局部真空能级并钝化表面缺陷，从而在不影响电子导电性的情况下降低离子导电性。结果，该方法显著降低了暗电流并提高了灵敏度，实现了14.7 nGy/s的低检测限。此外，它还提高了探测器的信号稳定性、一致性和响应速度。这些发现表明，PFH是一种有前途的添加剂，可用于提升基于多晶金属卤化物钙钛矿的X射线探测器的性能和实际应用。
