Cu基类金刚石结构新型热电化合物的设计与优化

项目名称： Cu基类金刚石结构新型热电化合物的设计与优化

项目编号： No.11204333

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 席丽丽

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 25万元

中文摘要： 本项目围绕Cu基类金刚石结构热电化合物电热输运机制研究，探索新型高性能热电化合物设计与优化原则，并尝试理解"声子玻璃-电子晶体"(PGEC)概念在非笼状化合物中的物理内涵。初步研究表明，若干Cu基类金刚石结构如Cu2SnSe3等表现较好的热电性能，是一类潜在的新型高性能热电材料体系。Cu基类金刚石种类繁多，本项目以三元Cu2-Ⅳ-Ⅵ3，Cu-Ⅲ-Ⅵ2，Cu3-Ⅴ-Ⅵ4(其中Ⅲ=Al, Ga, In;Ⅳ=Si, Ge, Sn; V=As, Sb, Bi, Ⅵ=S,Se,Te)化合物为研究对象，结合第一原理电子结构计算研究该化合物的晶体结构、电子结构、晶格振动与电热输运等性质，理解化合物中Cu-VI三维网络与电子结构和电热输运性能之间的关系及规律，揭示该类化合物中电热输运规律与调控机制，阐明PGEC概念在非笼状化合物中的物理内涵，凝练热电化合物设计原则，密切结合实验，开展新型热电化合物设计。

中文关键词： 类金刚石热电材料；电热输运机制；导电通道；第一性原理；

英文摘要： In this project, we investigate the thermoelectric (TE) properties of Cu-based diamond-like semiconductors, and try to understand the meaning of concept "phonon glass and electron crystal" (PGEC) in cage free thermoelectric compounds. Based on the concept, we systematically investigate thermoelectric transport mechanism of a series of diamond-like compounds. Previous results have shown that Cu2SnSe3 of diamond-like structure has the potential to be good TE materials. There are various of diamond-like compounds, here, we study the crystal structures, electronic structures, lattice vibration, and thermoelectric transport properties of ternary compounds such as Cu2-Ⅳ-Ⅵ3，Cu-Ⅲ-Ⅵ2，and Cu3-Ⅴ-Ⅵ4(where Ⅲ=Al, Ga, In;Ⅳ=Si, Ge, Sn; Ⅴ= As, Sb, Bi; Ⅵ=S, Se,Te). The purpose of this project is to understand the relationship between the Cu-VI electrically conductive channels and electronic structures, transport properties in these diamond-like compounds, predict the composition of materials with good TE performance, revise the rules of controlling transport of electrons and phonons independently, and figure out the in-depth physical meaning of PGEC in cage free compounds. As a result, our work will give support and guidance for experimental designing and searching for novel thermoelectric material system.

英文关键词： Diamond-like thermoelectric materials；electrical and thermal transport mechanism；Conductive network；Ab initio calculations；