Nano Research ( IF 9.9 ) Pub Date : 2021-09-09 , DOI: 10.1007/s12274-021-3808-y Zhaofen Wang 1 , Hong Liu 1, 2 , Ruijia Sun 2 , Depeng Shen 2 , Yuhai Zhang 2 , Nianqiao Liu 3 , Huailin Fan 4 , Xun Hu 4
Spatial resolution is an important criterion to evaluate the performance of a scintillation screen for X-ray imaging. Perovskite-based X-ray screen, usually made of powders or polycrystalline films, suffers from low spatial resolution (∼ 200 µm) due to the large thickness of scintillation layer despite of their compelling sensitivity to X-ray dose. In this work, a concentrated colloid of CsPbBr3 nanosheets was synthesized via a co-precipitation method at ambient condition. By drop casting, smooth scintillation screens of varied thickness were formed through self-assembly, which exhibited both high internal and external photoluminescence quantum yield (PL QY) (84.5% and 75.1%, respectively). The screen-based X-ray detector showed a high sensitivity down to 27 nGy/s, two orders of magnitude lower than the regular dose for medical diagnostics. Importantly, the screen of optimal thickness of 15 µm showcased an unprecedented spatial resolution (26 µm) when used for X-ray radiography, representing one order of magnitude improvement in perovskite community.
中文翻译:
通过钙钛矿组装实现 26 µm 分辨率的 X 射线成像仪
空间分辨率是评价闪烁屏 X 射线成像性能的重要标准。基于钙钛矿的 X 射线屏幕通常由粉末或多晶薄膜制成,尽管它们对 X 射线剂量具有强烈的敏感性,但由于闪烁层的厚度很大,因此空间分辨率低(~200 µm)。在这项工作中,CsPbBr 3的浓缩胶体纳米片是在环境条件下通过共沉淀法合成的。通过滴铸,通过自组装形成不同厚度的光滑闪烁屏幕,其表现出高的内部和外部光致发光量子产率(PL QY)(分别为 84.5% 和 75.1%)。基于屏幕的 X 射线探测器显示出低至 27 nGy/s 的高灵敏度,比医疗诊断的常规剂量低两个数量级。重要的是,当用于 X 射线照相时,最佳厚度为 15 µm 的屏幕显示出前所未有的空间分辨率(26 µm),代表钙钛矿群落的一个数量级改进。