【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。更多还原

【Abstract】 [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 MAPbBr3quantum dots/polystyrene and 2D PEA2PbBr4quantum 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 MAPbBr3quantum 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 is8 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.更多还原