新型Eu2ZnSb2基Zintl相热电材料的晶体结构与电声输运

热电材料是一种可以在静态下实现电能和热能之间相互转换的新型能源材料，在温差发电与热电制冷领域具有很高的应用价值。我们近期针对ZrBeSi结构的Zintl相化合物Eu2ZnSb2的热电性质进行了初步研究。本课题以这一本征低晶格热导率的Zintl相热电材料为研究对象，通过精细的结构表征结合第一性原理计算，明确材料中[ZnSb2]阴离子框架的构型，揭示材料晶体结构和晶体缺陷对载流子和声子输运的影响及其物理机制，阐明其本征低晶格热导率的原因，并探索在低热导率的基础上进一步优化电输运性能的可行性和有效途径。通过对Eu2ZnSb2电声输运性质的调控，开发出具有高热电性能的Eu2ZnSb2基Zintl相热电材料，为Zintl相热电材料的性能优化提供新的技术基础，进而推动Zintl相热电材料的发展。

Thermoelectric materials are new energy materials that can convert electricity and heat. They have high application value in thermoelectric power generation and thermoelectric refrigeration. Recently, our group reported a promising Zintl-phase thermoelectric materials Eu2ZnSb2. This present proposal suggests to investigate the Eu2ZnSb2-based Zintl compounds with ultralow thermal conductivity. To clarify the structure of [ZnSb2] framework, the various microstructure analysis and first-principles calculation are conducted. The influence of structure and defects on the electron/phonon transports is investigated to reveal the reason of low lattice thermal conductivity. Furthermore, the electron/phonon regulating is conducted to develop high performance Eu2ZnSb2-based Zintl thermoelectric materials. This study will enrich the technology for refining the performance of Zintl-phase thermoelectric materials, and promote the development of Zintl-phase thermoelectric materials.