卤化铅钙钛矿闪烁体的X射线成像性能模拟  

Simulation of X-ray imaging property of halide lead perovskite scintillators

作　　者：张育育 杨智[1,2] 盛亮 段宝军[3] 严维鹏[3] 宋岩 汪敏强[1] ZHANG Yuyu;YANG Zhi;SHENG Liang;DUAN Baojun;YANWeipeng;SONG Yan;WANG Minqiang(Electronic Materials Research Laboratory(EMRL),Key Laboratory of Education Ministry,International Center for Dielectric Research(ICDR),Shaanxi Engineering Research Center of Advanced Energy Materials and Devices,School of Electronic and Information Engineering,Xi'an Jiaotong University,Xi'an 710049,China;Key Laboratory of Materials Physics,Ministry of Education,School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450052,China;State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi'an 710024,China)

机构地区：[1]西安交通大学电子科学与工程学院电子陶瓷与器件教育部重点实验室国际电介质中心陕西省先进储能电子材料与器件工程研究中心,西安710049 [2]郑州大学物理学院材料物理教育部重点实验室,郑州450052 [3]西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室,西安710024

出　　处：《核技术》2022年第12期25-32,共8页Nuclear Techniques

基　　金：国家自然科学基金(No.61604122);高功率微波技术重点实验室基金(No.6142605190202)资助。

摘　　要：近年来,卤化铅钙钛矿闪烁体在X射线成像领域受到广泛关注。20~120 keV硬X射线医学成像使用闪烁体探测器,其灵敏度和成像空间分辨率是重要指标。利用Geant4模拟卤化铅钙钛矿量子点/聚合物复合闪烁体的X射线相对探测效率和成像空间分辨率,并利用次级电子运动解释能量与钙钛矿量子点占比对分辨率的影响。结果表明:增大复合闪烁体厚度和钙钛矿量子点占比可提高相对探测效率;降低厚度和增加钙钛矿量子点占比都可以提高空间分辨率;当吸收效率达到99.5%时计算得到20 keV X射线激发下钙钛矿闪烁体空间分辨率可与商用CsI闪烁体相媲美,而50 keV X射线激发下空间分辨率则有所下降。表明卤化铅钙钛矿在20 keV低能X射线医疗成像中具有一定应用潜力。[Background]In recent years,lead halide perovskite scintillators have received extensive attention in the field of X-ray imaging.Hard X-ray medical imaging in energy range of 20~120 keV using scintillator detectors,sensitivity and imaging spatial resolution are important performance indicators.[Purpose]This study aims to explore X-ray imaging property of halide lead perovskite scintillators by simulation.[Methods]First of all,3D MAPbBr3 quantum dots/polystyrene and 2D PEA2PbBr4 quantum dots/polystyrene scintillators were taken as research objects.Then,simulation code Geant4 was employed to establish detector model and simulate the X-ray relative detection efficiency and imaging spatial resolution of lead halide perovskite quantum dots/polymer composite scintillators.Finally,the effect of energy and the ratio of perovskite quantum dot occupation on the resolution were explained by secondary electron motion.[Results]The results show that increasing the thickness of the composite scintillator and the proportion of perovskite quantum dots can improve the relative detection efficiency whilst reducing the thickness and increasing the proportion of perovskite quantum dots can improve the spatial resolution.When the absorption efficiency reaches 99.5%,80%of 3D MAPbBr3 quantum dots/polystyrene excited by 20 keV X ray obtain the same spatial resolution of 10 lp·mm^(−1) as CsI.When the incident energy increases to 50 keV,the spatial resolution of CsI is 8 lp·mm^(−1),while that of lead halide perovskite scintillators is less than 4 lp·mm−1.[Conclusions]It is shown by this study that lead halide perovskites have certain application potential in 20 keV low-energy X-ray medical imaging.

关 键 词：钙钛矿 X射线闪烁体 GEANT4 相对探测效率 空间分辨率 

分 类 号：TL99[核科学技术—核技术及应用]