高压下碲化物基热电功能材料设计及输运性质研究

Seeking for high ZT-value thermoelectric materials is an important subject of condensed matter physics and materials science. High pressure can improve performance of thermoelectric materials through regulating the transport processes within them. Also, high pressure offers a new dimension for the discovery of new thermoelectric materials. For the materials system of tellurides that contains abundant high-performance thermoelectric materials, researchers take the advantage of the effect of high pressure on regulating the transport processes, and synthesize samples by high-pressure methods, making their thermoelectric performance exhibit a certain degree of improvement. But currently such research is still at the exploratory stage. In this project, we will firstly investigate via first-principles transport simulations the changes of thermoelectric relevant transport properties under the regulation of high pressure. This aims at gaining the regular knowledge of how high pressure affects performance of thermoelectric materials. At the same time, we will develop based on the idea of particle swarm optimization method the materials design method with the objective of optimizing the key thermoelectric relevant transport properties, forming a software with independent intellectual property right. Then guided by the regular knowledge gained, we will carry out the functional materials design study of new telluride-based thermoelectric materials by using the developed method. The aim is to find new-type high ZT-value metastable telluride-based thermoelectric materials at high pressures, providing valuable references to the experimental synthesis of these materials with high-pressure methods. This project has important scientific significance for the studies of improving the ZT-values of thermoelectric materials by means of high-pressure regulation and synthesizing new thermoelectric materials with high-pressure methods.

寻找高ZT值热电材料是凝聚态物理和材料科学的重要课题。高压可以通过调控热电材料中的输运过程改善其热电性能，并为新型热电材料的开发提供了一个新的维度。对于富含高性能热电材料的碲化物体系，人们利用高压对输运的调控、通过高压方法合成样品，使其热电性能得到了一定程度的提高，但目前研究仍处于探索尝试阶段。本项目拟先通过第一性原理输运性质模拟，系统研究碲化物的热电输运在高压调制下的变化，获取高压对热电材料性能的调控作用的规律性认知。同时，基于粒⼦群优化算法思想，开发以优化关键热电输运性质为目标的材料设计方法，编制具有自主知识产权的程序包。然后以获取的规律性认知为指导，利用发展的材料设计方法，开展高压下碲化物基热电功能材料优化设计，寻找新型高ZT值的亚稳相热电材料，为实验上高压合成新型热电材料提供有价值的参考。本项目对以高压为手段提升热电材料的ZT值、通过高压方法合成新型热电材料的研究有重要科学意义。

寻找高ZT值热电材料是凝聚态物理和材料科学的重要课题。高压可以通过调控热电材料中的输运过程改善其热电性能，并为新型热电材料的开发提供了一个新的维度。对于富含高性能热电材料的碲化物体系，人们利用高压对输运的调控、通过高压方法合成样品，使其热电性能得到了一定程度的提高。本项目主要基于第一性原理输运性质模拟，系统研究碲化物及其相关材料（如硫/硒化物）的热电输运在高压调制下的变化，从而获取高压对热电材料性能调控作用的规律性认知，同时开展新型热电材料的优化设计，获得了系列创新结果：1）因高压下的新材料设计研究的成果积累，受Nature Reviews Materials邀请撰写了高压下新材料发现的综述论文；2）针对高电负性元素填充方钴矿体系，提出高电负性元素的偏离中心行为导致体系具有超低声子频率的“Goldstone”声子模式，能够显著降低材料的晶格热导率；3）首次在二维层状材料中确定，热电功率因子显著增强的临界条件：量子限域长度小于热德布罗意波长；4）提出优化介电屏蔽的材料设计新视角，开展新型热电材料的优化设计。.项目执行期间，项目负责人作为第一或通讯（含共同）作者共发表了高水平的SCI学术论文45篇，包括Nature Reviews Materials 1篇、Nature Photonics 1篇、Nature Communications 4篇、Advanced Materials 1篇、Advanced Functional Materials 2篇、Journal of the American Chemical Society 4篇、Nano Letters 2篇、Joule 1篇。项目负责人获中国材料研究学会“计算材料学青年奖”（2018, 每次授予1人）、吉林省青年科技奖—特别奖（2018, 每次授予3人）。项目负责人受邀在国际会议上做特邀报告21次，指导毕业博士生2019年入选“博新计划”。