近日，华南理工大学的夏志国及其研究团队取得一项新进展。经过不懈努力，他们研制出用于X射线成像的具有高效5d-4f带隙跃迁的Eu(II)-溴化物杂化闪烁体。相关研究成果已于2024年8月29日在国际知名学术期刊《光：科学与应用》上发表。

本文介绍了一种全新的混合Eu(II)-溴化物闪烁体，即一维型[Et₄N]EuBr₃·MeOH和零维型[Me₄N]₆Eu5Br₁₆·MeOH，它们在闪烁过程中具有自旋允许的5d-4f带隙跃迁发射，从而简化了载流子传输。

一维/零维结构中的边/面共享[EuBr₆]^4-八面体有助于降低带隙并增强量子限制效应，从而实现高效的闪烁性能（光产额约为73100±800 Ph MeV^-1，检测极限约为18.6 nGy s^-1，X射线余晖约为1%（@9.6 μs））。通过将Eu(II)基闪烁体嵌入AAO薄膜中，研究人员实现了27.3 lp mm^-1分辨率的X射线成像。本研究结果为闪烁体及相关光电子应用领域创造了新的低维稀土卤化物家族。

据悉，发光金属卤化物作为X射线成像闪烁体，在安全检查、医疗诊断等领域日益受到关注。

附：英文原文

Title: Hybrid Eu(II)-bromide scintillators with efficient 5d-4f bandgap transition for X-ray imaging

Author: Han, Kai, Jin, Jiance, Wang, Yuzhen, Zhou, Xinquan, Sun, Yongsheng, Chen, Lihan, Xia, Zhiguo

Issue&Volume: 2024-08-29

Abstract: Luminescent metal halides are attracting growing attention as scintillators for X-ray imaging in safety inspection, medical diagnosis, etc. Here we present brand-new hybrid Eu(II)-bromide scintillators, 1D type [Et₄N]EuBr₃·MeOH and 0D type [Me₄N]₆Eu₅Br₁₆·MeOH, with spin-allowed 5d-4f bandgap transition emission toward simplified carrier transport during scintillation process. The 1D/0D structures with edge/face -sharing [EuBr₆]^4- octahedra further contribute to lowing bandgaps and enhancing quantum confinement effect, enabling efficient scintillation performance (light yield ~73100±800 Ph MeV^-1, detect limit ~18.6 nGy s^-1, X-ray afterglow ~ 1% @ 9.6 μs). We demonstrate the X-ray imaging with 27.3 lp mm^-1 resolution by embedding Eu(II)-based scintillators into AAO film. Our results create the new family of low-dimensional rare-earth-based halides for scintillation and related optoelectronic applications.

DOI: 10.1038/s41377-024-01589-w

Source: https://www.nature.com/articles/s41377-024-01589-w