光致光辐射探测材料陷阱分布及控制技术研究

项目名称： 光致光辐射探测材料陷阱分布及控制技术研究

项目编号： No.U1330103

项目类型： 联合基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 向霞

作者单位： 电子科技大学

项目金额： 88万元

中文摘要： 作为一种新型辐射探测技术，光致光具有传统热释光技术无法比拟的优点，α-Al2O3:C晶体是一种良好的光致光材料，但浅陷阱的存在限制了测量精度和温度适用范围，如何控制浅陷阱成为提高其性能的关键。本项目拟利用基于密度泛函理论的第一性原理和VASP程序，研究α-Al2O3:C及掺杂和辐照后体系的电子结构、陷阱能级分布和发光性能，揭示各因素对陷阱形成机制的影响，得到浅陷阱缺陷控制的理论方案，为实验研究提供依据。参考理论结果，选择合适的掺杂元素并结合电子束、γ射线辐照制备改性的Al2O3:C晶体，引入不同类型点缺陷，改变陷阱能级分布，表征其微观结构、陷阱分布和（时间分辨）光致光特性。研究陷阱能级分布与发光特性之间的物理规律，获得浅陷阱控制方法和优化掺杂的晶体样品，并以此开展剂量监测实验，验证和改进浅陷阱控制方法，获得浅陷阱控制方法和工艺方案，为工程应用提供参考。

中文关键词： 浅陷阱；光释光；剂量计；掺碳氧化铝；第一性原理

英文摘要： As a new radiation detection technology, optically stimulated luminescence (OSL) has many advantages compared with the conventional thermoluminescence (TL). α-Al2O3:C single crystal is a good OSL material, but its shallow traps limit the measurement accuracy and application temperature range. How to control the shallow traps is critical to improve the OSL performance. In this proposal, the first-principles based on density functional theory (DFT) and VASP program will be used to study the electronic structure, trap energy level distribution, and luminescence of α-Al2O3:C and its doped and irradiated systems to understand the effects of various factors on the mechanism of trap formation. The theoretical protocol will be obtained to control the shallow traps of α-Al2O3:C systems, which will support the experimental investigations and parameter optimization. Based on the simulated results, the proper dopant elements will be selected and combined with the electron beam and γ-ray irradiations to prepare the modified α-Al2O3:C single crystals with different types of point defects and different trap distribution. The microstructure, trap distribution and (time-resolved) OSL will be characterized. The correlation between trap energy level distribution and OSL properties will be studied to obtain the control method of sh

英文关键词： shallow traps；optically stimulated luminesce；dosimetry；Al2O3:C；First-principles