探测器级高纯锗的深能级瞬态谱晶体缺陷分析研究

High-purity germanium (HPGe) detectors play an important role in nuclear science and technology. HPGe single crystal must have a high purity and a low dislocation density to meet the requirement of detector grade crystals, which makes it very difficult to prepare. Until now all of the HPGe single crystals are imported from abroad. The preparation of HPGe crystals requires not only the development of special zone melting purification technology and single crystal growing technology, but also the detection and analysis of impurities and crystal defects. On the basis of the existing high purity germanium preparation technology and several basic detection technologies, in order to improve the sample detection skills, the deep level transient spectroscopy (DLTS) analysis of the trap impurities is developed, the types and sources of impurities are identified, and the law of impurity enrichment is found out. Accordingly, corresponding methods are adopted to reduce impurity concentration and dislocation density according to impurity types. The influence of crystal defects on the energy resolution of the detector was further investigated by DLTS spectroscopy, and the preparation technology of single crystal and detector will be improved, which will lay a foundation for the further industrialization development.

高纯锗探测器在核科学技术领域具有重要作用，探测器级锗单晶中净杂质浓度和位错密度的要求使得其制备难度极高，目前国内所有的高纯锗晶体完全依赖进口。高纯锗晶体的制备不仅需要发展特殊的区熔提纯技术和单晶拉制工艺，杂质成分和晶体缺陷的检测分析也同样重要。在现有高纯锗制备技术及几种基本检测技术基础上，为完善样品的检测技术，发展深能级瞬态谱（DLTS）测试分析主要陷阱杂质，提升对杂质种类和来源的识别，并找出杂质富集规律，由此针对杂质类型采用相应的方法降低杂质浓度和位错密度。进一步通过DLTS谱测试晶体缺陷对探测器能量分辨率的影响，改进单晶和探测器制备工艺，为下一步产业化发展奠定基础。

高纯锗探测器在核科学技术领域具有重要作用，探测器级锗单晶中净杂质浓度和位错密度的要求使得其制备难度极高，目前国内所有的高纯锗晶体完全依赖进口。高纯锗晶体的制备不仅需要发展特殊的区熔提纯技术和单晶拉制工艺，杂质成分和晶体缺陷的检测分析也同样重要。在现有高纯锗制备技术及基本检测技术基础上，开发了第二代籽晶，籽晶同轴性得以保证，由其生长的晶体位错密度满足探测器制备要求；为完善样品的检测技术，完善位错密度检测方法和深能级瞬态谱测试分析主要陷阱杂质，提升对杂质种类和来源的识别，并找出杂质富集规律，由此针对杂质类型采用相应的方法降低杂质浓度和位错密度。进一步通过测试晶体缺陷对探测器能量分辨率的影响，改进单晶和探测器制备工艺，为下一步产业化发展奠定基础。