高能离子辐照诱导的硅锗合金热电性能演化机理研究

项目名称： 高能离子辐照诱导的硅锗合金热电性能演化机理研究

项目编号： No.11505247

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 朱亚滨

作者单位： 中国科学院近代物理研究所

项目金额： 23万元

中文摘要： 对于深空探测器来说，放射性同位素温差发电器是目前唯一的供电系统。硅锗合金具有优良的高温热电性能，是深空探测器上温差发电器件的首选热电材料。然而，空间环境中的高能离子会在硅锗合金中引起结构损伤，进而导致材料热电性能的恶化和温差发电器件性能的衰退。为了准确地评估温差发电器件的运行寿命，高能离子辐照下硅锗合金热电性能的演化机理研究势在必行。本项目选择P型和N型单晶Si0.8Ge0.2合金为研究对象，利用兰州重离子加速器HIRFL提供的高能Si和Ge离子进行辐照，结合多种分析手段研究高能离子辐照在硅锗合金中引起的缺陷的产生和结构损伤的形成，以及由此导致的硅锗合金电导率、热导率和Seebeck系数等热电性能的变化，建立样品热电性能与辐照参数之间的联系，探索高能离子辐照下硅锗合金热电性能的演化机理。

中文关键词： 高能离子辐照；硅锗合金；结构损伤；热电性能

英文摘要： Radioisotope thermoelectric generator is the only power supply system on the deep space probes so far. Silicon-germanium (SiGe) alloy is preferred thermoelectric material for thermoelectric generator on space probes due to its remarkable high-temperature thermoelectric properties. However, the high-energy ions in space environment induce structural damages in the SiGe alloy and then result in the performance degradation of SiGe material and thermoelectric generator. In order to accurately evaluate the operating life of thermoelectric generator, it is imperative to study the thermoelectric performance evolution mechanism of silicon-germanium alloy induced by high-energy ion irradiation. In this project, P-type and N-type monocrystalline Si0.8Ge0.2 samples will be taken as the research objects, and a variety of analysis methods will be used to study the irradiation effects on the SiGe samples induced by high-energy Si and Ge ions delivered by HIRFL (Heavy Ion Research Facility in Lanzhou). The generation of defects, formation of microstructural damages and variation in the thermoelectric properties, such as electrical conductivity, thermal conductivity and Seebeck coefficient will be studied in this project. The relationship between thermoelectric performance and irradiation parameters will be established. As a result, the thermoelectric performance evolution mechanism of silicon-germanium alloy induced by high-energy ion irradiation will be explored.

英文关键词： High-energy ion irradiation;Silicon-germanium alloy;Structural damages;Thermoelectric properties