Ma Wenbo, Su Yirong, Zhang Qisheng, Deng Chao, Pasquali Luca, Zhu Wenjuan, Tian Yue, Ran Peng, Chen Zeng, Yang Gaoyuan, Liang Guijie, Liu Tianyu, Zhu Haiming, Huang Peng, Zhong Haizheng, Wang Kangwei, Peng Shaoqian, Xia Jianlong, Liu Huafeng, Liu Xu, Yang Yang Michael
State Key Laboratory of Modern Optical Instrumentation, Institute for Advanced Photonics, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.
Intelligent Optics & Photonics Research Center, Jiaxing Institute of Zhejiang University, Jiaxing, China.
Nat Mater. 2022 Feb;21(2):210-216. doi: 10.1038/s41563-021-01132-x. Epub 2021 Nov 11.
X-ray detection, which plays an important role in medical and industrial fields, usually relies on inorganic scintillators to convert X-rays to visible photons; although several high-quantum-yield fluorescent molecules have been tested as scintillators, they are generally less efficient. High-energy radiation can ionize molecules and create secondary electrons and ions. As a result, a high fraction of triplet states is generated, which act as scintillation loss channels. Here we found that X-ray-induced triplet excitons can be exploited for emission through very rapid, thermally activated up-conversion. We report scintillators based on three thermally activated delayed fluorescence molecules with different emission bands, which showed significantly higher efficiency than conventional anthracene-based scintillators. X-ray imaging with 16.6 line pairs mm resolution was also demonstrated. These results highlight the importance of efficient and prompt harvesting of triplet excitons for efficient X-ray scintillation and radiation detection.
X射线检测在医学和工业领域发挥着重要作用，通常依靠无机闪烁体将X射线转换为可见光光子；尽管已经测试了几种高量子产率的荧光分子作为闪烁体，但它们的效率一般较低。高能辐射可使分子电离并产生二次电子和离子。因此，会产生很大一部分三重态，这些三重态充当闪烁损失通道。在此，我们发现X射线诱导的三重态激子可通过非常快速的热激活上转换用于发光。我们报告了基于三种具有不同发射带的热激活延迟荧光分子的闪烁体，其效率比传统的基于蒽的闪烁体显著更高。还展示了分辨率为16.6线对毫米的X射线成像。这些结果突出了有效且迅速捕获三重态激子对于高效X射线闪烁和辐射检测的重要性。
