大尺寸高纯锗晶体关键技术研究

Large High-purity germanium (HPGe) crystal is the core material to fabricate the HPGe detector. The combination of high-efficiency and excellent energy resolution make the HPGe detectors represent the gold standard in detecting gamma radiation. The HPGe detectors have a range of applications in research of the fundamental physics such as particle physics and nuclear physics, in the environmental monitoring and nuclear safety monitoring. In recent years, with the rise of big scientific projects, the demand for tons of high purity germanium crystals has been put forward. In order to meet these need, in this project, we proposed to research the technology of crystal impurity level control, crystal defect level control, large diameter crystal growth and automatic diameter control technology. The project will achieve the core technique needed to prepare large size high purity germanium crystals from the germanium ingot from the domestic supplier, will break the international monopoly as soon as possible and achieve localization, so as to create the necessary conditions for the domestic nuclear technology innovation and the upgrading of high purity germanium industry.

大尺寸高纯锗晶体是制造高纯锗探测器的核心材料。高纯锗探测器具有极高的能量分辨率和优秀的探测效率，在粒子物理、核物理等基础研究以及环境监测、核安全监控等领域都取得了广泛的应用，迄今为止仍是探测伽马射线能谱的金标准。近年来随着国际上大科学项目的兴起，提出了吨级规模高纯锗晶体的需求。为了满足这些需求，本项目提出研发高纯锗晶体制备过程中的晶体杂质水平控制技术、晶体缺陷水平控制技术和大晶体生长等径控制技术等大尺寸高纯锗晶体关键技术，以期实现从国内区熔锗锭制备大尺寸高纯锗晶体所必需的核心能力，尽早打破国际垄断，实现国产化，为国内核技术领域的自主创新和高纯锗产业的升级创造必要条件。

大尺寸高纯锗晶体关键技术研究项目主要是针对高纯锗制备过程中的技术问题开展了一系列的研究工作。其中包括：高纯锗晶体杂质和缺陷对晶体性能的影响；区熔提纯和晶体生长工艺对晶体性能的影响；晶体测试方法对测试指标的影响；区熔提纯和晶体生长设备的温场改进设计、气路改进设计、测温方法改进设计、原料处理工艺改进设计，同时开展了大尺寸高纯锗晶体生长实验并取得显著成果：国内首次实现净载流子浓度109cm-3量级的高纯锗测试样片，用直径80mm厚度13mm晶体样品制造的高纯锗晶体探测器钴-60能量分辨率达到2‰，达到国际同类产品水品，为国内首次。由于疫情原因深能级测试和晶体生长等径控制没有达到预期，后续还将继续开展相关工作，同时持续改进晶体制造工艺水平，争取尽快实现技术到产品的转化。