铈掺杂硅酸镥晶体的微结构与闪烁性能研究

项目名称： 铈掺杂硅酸镥晶体的微结构与闪烁性能研究

项目编号： No.11475241

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 丁栋舟

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 82万元

中文摘要： 新型闪烁晶体硅酸镥Lu2SiO5:Ce (LSO:Ce)和焦硅酸镥Lu2Si2O7:Ce (LPS:Ce)具有高光输出、快衰减、不潮解、密度大等优异性能。在核医学成像、安全检查及高能物理领域应用前景广阔，具有重大的经济和社会价值。但晶体发光不均匀且实际光输出远低于理论光输出，LSO:Ce有余辉、双成分发光机理存在学术争论。这些问题的存在以及作用机理不明，严重制约了该晶体的实际应用。 本项目拟从微结构特性研究入手，阐明LSO:Ce余辉及双成分发光的机理；从发光中心离子价态、分凝、猝灭效应等出发，分析导致晶体发光不均匀、光输出低于理论光输出的主要原因。为调制晶体微结构以改性晶体,制备高光输出、高均匀性的LSO:Ce、LPS:Ce晶体提供理论依据,为该晶体在探测技术中的应用和研究奠定良好的基础。 本项目拟解决的关键科学问题是阐明铈掺杂硅酸镥晶体的微结构特点以及它与闪烁性能的关联性。

中文关键词： 闪烁晶体；铈掺杂硅酸镥；微结构；闪烁性能；晶体制备

英文摘要： Owing to their excellent scintillation properties, such as high light output, short decay time, nonhygroscopic and high density, new scintillation crystals lutetium silicate Lu2SiO5:Ce (LSO:Ce) and Lu2Si2O7:Ce (LPS:Ce) have wide application prospect in the fields of nuclear medicine, security check and high-energy physics, thus having great economic and scocial value. However, there are still some problems in the crystals such as: the actual light output is much lower than the theoretical value; LSO:Ce has afterglow; there exists academic debate on the origin of double luminescence composition of LSO:Ce between different crystalography occupation and interstice occupation of Ce3+ .The mechanisms and contributing factors for these problems are not clear yet. The existing problems seriously restrict the application of these two crystals. This project plans to carry out the research on the basis of microstructure study, in order to expound the mechanism of afterglow and double luminescence composition of LSO:Ce; to explore the main causes of luminescence nonuniformity and the actual light output being much lower than the theoretical value on the basis of the study of the valence state of luminescence center, segregation and quenching effect.This project helps to provide a theory basis for modulating crystals' microstructure, modifying crystals' performance and for improving the crystals luminescence uniformity and light output. This project can lay a good foundation for application and research of lutetium silicate single crystals in the field of detection technology. The key problems that this project plans to solve are: expounding the microstructure characteristics of lutetium silicate single crystals and exploring the relationship with their scintillation properties.

英文关键词： scintillation crystal;LSO:Ce;microstructure;scintillation properties;crystal growth