SEMINAR
The State Key Lab of
High Performance Ceramics and Superfine Microstructure
Shanghai Institute of Ceramics, Chinese Academy of Sciences

　　中 国 科 学 院 上 海 硅 酸 盐 研 究 所 高 性 能 陶 瓷 和 超 微 结 构 国 家 重 点 实 验 室

　　Theory-guided synthesis of an eco-friendly and low-cost copper-based sulfide thermoelectric material

　　Dr. Cedric Weber

　　Theory and Simulation of Condensed Matter,

　　King's College London

　　时间：2016年7月17日（星期日）下午2: 00

　　地点： 2号楼607会议室（国家重点实验室）

　　欢迎广大科研人员和研究生参与讨论！

　　联系人：史 迅（2803）

　　Abstract:

　　Cu3SbS4 is a copper-based sulfide composed of earth-abundant elements. We present a combined theoretical and experimental study of the thermoelectric properties of Ge-doped Cu3SbS4. Based on density functional theory, we found that the pristine compound is a semiconductor with a large density-of-state effective mass of 2.2 me for holes. Ge was predicted to be an effective p-type dopant that only slightly shifts the band structure of Cu3SbS4. The power factor was predicted to reach a maximum value with 10 15 mol% Ge-doping on the Sb site (n 6 9 1020 cm-3) at high temperature (up to 700 K). Theory was used to guide the synthesis of optimally doped Cu3SbS4 bulk samples. Experimentally, Cu3SbS4 bulk samples were prepared by mechanical alloying and spark plasma sintering. The samples had very fine microstructures, with grain size of 100 to 300 nm, which contributed to a much lower lattice thermal conductivity than reported in the literature. A maximum power factor of 1.08 mWK-2m-1 was achieved with an optimized carrier concentration of 4.79 1020 cm-3, which is in good agreement with theoretical prediction and a zT of 0.63 was obtained at 623 K.