硅材料微纳结构的载能离子束调控及其声子传输特性研究

This project focus on the micro/nanostructure adjustment and the modification of thermal properties，such as thermal diffusivity, specific heat capacity, thermal conductivity, Seebeck coefficient, in silicon materials during the ion implantation. In this project, different ions with different energy and dosage will be adopted to implant into the silicon materials. Effect of the material system, implanted ions and process, heat treatment process on the micro/nanostructure and thermal properties of Si materials will be comprehensively studied. Based on experimental results, we plan to systematically investigate the relationship between ultra-fine micro/nanostructures and ion implantation and heat treatment process, study the phonon transport properties in Si materials, investigate the influence of micro/nano structure on phonon transport mechanism in Si matetials, and master the method to modify the thermal properties in Si materials with the assistance of the energetic ion beam. Based on these researches, novel Si thermal functional materials will be developed with the help of ion implantation. To carry out this project, the research area of ion implantation technique will be extended, and the interdisciplinary study in nuclear science, material science, physics and chemistry will be promoted, which is helpful for the development of new materials and novel energy.

本课题围绕离子注入和后续加工过程中，硅材料微纳结构的变化对其热扩散系数、比热、热导、Seebeck系数等热物理性能的调控这一主题，在不同种类硅材料中注入不同能量、剂量和元素种类的离子；全面分析硅材料体系、注入离子和工艺选择以及后续热处理工艺对硅材料中微纳结构的影响；系统探讨微观结构与声子传输特性的关联性，研究硅材料中热物理特性的变化的微观机理，建立载能离子束硅材料声子传输特性的调制理论；掌握载能离子束对硅材料热物理特性的调控方法，发展离子注入热功能硅材料制备工艺。本课题的开展将极大的拓展离子注入材料改性的研究领域，有力地促进核科学、材料科学、物理学、化学等学科交叉的发展，对于推动新能源和新材料技术的发展具有重要意义。

采用He离子，研究了不同温度、剂量、能量的离子的可控注入工艺；探讨了注入工艺对硅材料内部微观结构的影响；分析了离子注入温度对于硅片内部多孔层微观结构和热传导性能的影响，建立了针对均匀分布的硅纳米孔结构好性能的具有良好可控性的离子注入工艺体系。研究了电化学腐蚀过程中单晶硅材料内部显微结构的形态、尺寸、占空比及元素组成和各种缺陷的分布与热物理性能的关联性；探讨了微观结构变化导致的热扩散系数、热导率等各个热物理参数之间的协同变化及竞争关系。分析了硅材料中纳米多孔层微观结构尺寸和分布效应对于其声子散射、热导率变化等微观物理特性的影响，探讨了降低热导率的结构调控方法及最优的硅热功能材料加工工艺。