高压诱导热电材料能带简并机制及对电、热输运性能的影响

镁硅基热电材料是我国和国际上高度重视发展的中温域热电材料之一。本项目以发展环境友好型的高性能镁硅基热电材料为研究目标，基于申请者团队最新发现的压力诱导Al掺杂镁硅材料能带简并的现象，拟采用高温高压工艺设计并制备具有特殊电子结构的新型高性能Mg2Si和Mg2(Si,Sn)基热电材料。研究并揭示高压诱导镁硅基新型热电材料能带简并机理及形成条件，探索和发展新型镁硅基热电材料可控制备方法，实现新型镁硅基材料中电、热输运行为的协同调控，阐明压力在材料合成和输运过程中的作用机制，揭示高压诱导跨尺度微结构的形成和演化机理，为实现稳定的高性能绿色镁硅基热电材料的设计和制备奠定基础。

Magnesium-silicon-based thermoelectric material is one of most important medium-temperature thermoelectric materials that are highly developed in China and internationally. The project aims to develop environmentally-friendly high-performance magnesium-silicon-based thermoelectric materials. Based on our recently findings of band convergence in Al doped Mg2Si induced by pressure, this project will design and prepare new high-performance Mg2Si and Mg2(Si,Sn) based thermoelectric materials with desired electronic structure through high temperature and high pressure (HTHP) process. We will explore the underlying mechanism of high-pressure induced band degeneracy of magnesium-silicon-based thermoelectric materials, as well as its experimental control conditions. We will develop a new HTHP control and preparation method, realizing the synergistic optimization of the electrical and thermal transport characteristics in new magnesium-silicon based materials. Then, we will clarify the mechanism of pressure in the synthesis and transport of materials, revealing the formation and evolution mechanism of high-pressure induced cross-scale microstructures. The research results will lay the foundation for the design and preparation of green high-performance magnesium-silicon thermoelectric materials with high stability.