强磁场辅助生长对SnSe热电性能的调控研究

项目名称： 强磁场辅助生长对SnSe热电性能的调控研究

项目编号： No.11504380

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： 黄亚楠

作者单位： 中国科学院合肥物质科学研究院

项目金额： 24万元

中文摘要： 热电材料可实现热能和电能之间的直接转换，热电优值ZT通常被用来衡量一种材料热电性能的好坏，单一块体材料的ZT值一般都在2.5以下。最近实验发现SnSe单晶沿特定晶轴方向的ZT值在923K可达2.6左右，是目前为止ZT值最高的单一块体材料，具有很大的热电应用潜力。SnSe单晶的高ZT值主要源于极低的晶格热导率，但其功率因子并不优越。若能找到调控该材料功率因子的有效途径，它将拥有广泛的热电应用前景。本项目拟采用“磁性离子掺杂+强磁场辅助生长”的调控方案，系统研究层状SnSe材料的结构、磁、电和热输运等性质，通过电荷和自旋两个自由度的协同作用实现对该材料功率因子的有效调控，从而优化其热电性能，同时获得磁性离子掺杂和强磁场辅助生长对层状SnSe热电性能调控的一般规律。结合理论计算，理解SnSe窄带半导体材料热电性质的微观物理机制，希望为相似体系材料的热电性能优化提供数据积累和理论指导。

中文关键词： SnSe；热电性能；强磁场辅助生长；自旋调控

英文摘要： Thermoelectric materials can be utilized to convert thermal energy and electrical energy directly in a single thermoelectric generation system. Thermoelectric figure of merit ZT is defined to determine the thermoelectric performance of the material. The ZT value of a single bulk material is always below 2.5. Recent experiment showed that the ZT value along the specific crystallographic axis direction could reach about 2.6 for SnSe single crystal. So far, it has been the single bulk material with the highest ZT value and has great potential for thermoelectric application. The high ZT value of SnSe single crystal is original from the ultra-low lattice thermal conductivity. However, the power factor of SnSe is not high enough. If we could find an effective method to enhance the power factor of SnSe, it will possess extensive thermoelectric application prospect. In this project, we will use a combined scheme of magnetic ions doping and high-magnetic-field assisted growth to investigate the structure, magnetic, electrical and thermal transport properties of SnSe thermoelectric material. The power factor of SnSe will be enhanced by the combined tunning of charge and spin degree of freedom to optimize its thermoelectric performance. At the same time, we could obtain the universal law of thermoelectric performance tunning by magnetic ions doping and high-magnetic-field assisted growth for the layered SnSe compound. Combining with the theoretical calculation, we will provide some information for the physical origin of thermoelectric performance of SnSe narrow band semiconductors. We hope to provide some guide to optimize thermoelectric performance for the similar system materials.

英文关键词： SnSe;Thermoelectric performance;High-magnetic-field assisted growth;Spin tunning