Li Fenghua, Wang Hu, Chen Zhilong, Liu Xin, Wang Pengxiang, Zhang Wenqing, Dong Hao, Fu Jie, Wang Zhiyuan, Shao Yuchuan
Laboratory of Thin Film Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2024 Feb 28;16(8):10344-10351. doi: 10.1021/acsami.3c16870. Epub 2024 Feb 13.
The outstanding photoelectric properties of perovskites demonstrate extreme promise for application in X-ray detection. However, the soft lattice of the perovskite results in severe ionic migration for three-dimensional materials, limiting the operation stability of perovskite X-ray detectors. Although ligand-decorated nanocrystals (NCs) exhibit significantly higher stability than three-dimensional perovskites, defects remaining on the interface of NCs could still trigger halide migration under a high bias due to the incomplete ligand decoration. Furthermore, it is still challenging to realize sufficient thickness of absorption layers based on NCs for X-ray detectors through traditional methods. Herein, we develop a centimeter-size and millimeter-thick wafer based on CsPbBr NCs through isostatic pressing for X-ray detectors, in which the interfacial defects of NCs are remedied by CsPbBr during aging of wafer in ambient humidity. The wafer shows outstanding sensitivity (200 μC Gy cm) and ultralow dark current drift (1.78 × 10 nA cm s V @ 400 V cm). Moreover, it shows storage stability with negligible performance degradation for 60 days in ambient humidity. Thus, aging perovskite NC wafers for X-ray detection holds huge potential for next-generation X-ray imaging plates.
钙钛矿优异的光电特性在X射线检测应用中展现出极大的前景。然而，钙钛矿的软晶格导致三维材料中存在严重的离子迁移现象，限制了钙钛矿X射线探测器的运行稳定性。尽管配体修饰的纳米晶体（NCs）表现出比三维钙钛矿更高的稳定性，但由于配体修饰不完全，NCs界面上残留的缺陷在高偏压下仍可能引发卤化物迁移。此外，通过传统方法为X射线探测器制备基于NCs的足够厚度的吸收层仍然具有挑战性。在此，我们通过等静压法开发了一种基于CsPbBr NCs的厘米尺寸、毫米厚的用于X射线探测器的晶片，其中在环境湿度下晶片老化过程中，CsPbBr对NCs的界面缺陷进行了修复。该晶片表现出出色的灵敏度（200 μC Gy cm）和超低暗电流漂移（在400 V cm下为1.78 × 10 nA cm s V）。此外，在环境湿度下放置60天，其性能退化可忽略不计，显示出存储稳定性。因此，用于X射线检测的钙钛矿NC晶片老化在下一代X射线成像板方面具有巨大潜力。
