Approaching the minimum lattice thermal conductivity of p-type SnTe thermoelectric materials by Sb and Mg alloying

作     者：Tiezheng Fu Jiazhan Xin Tiejun Zhu Jiajun Shen Teng Fang Xinbing Zhao 

作者机构：State Key Laboratory of Silicon Materialsand School of Materials Science and EngineeringZhejiang University 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2019年第64卷第14期

页      面：1024-1030页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：supported by the National Key Research and Development Program of China (2018YFB0703600) the National Science Fund for Distinguished Young Scholars (51725102) the National Natural Science Foundation of China (51861145305, 51761135127, and 51871199) 

主　　题：Tin telluride Thermoelectric materials Point defect scattering Band convergence 

摘      要：SnTe, as the nontoxic analogue to high-performance PbTe thermoelectric material, has captured the worldwide interest recently. Many triumphant instances focus on the strategies of band convergence, resonant doping, and nano-precipitates phonon scattering. Herein, the p-type SnTe-based materials Sn0.85-xSb0.15MgxTe (x=0-0.10) are fabricated and a combined effect of Sb and Mg is investigated. Sb alloying tunes the hole carrier concentration of SnTe and decreases the lattice thermal conductivity. Mg alloying leads to a nearly hundredfold rise of disorder parameter due to the large mass and strain fluctuations, and as a consequence the lattice thermal conductivity decreases further down to ~0.64Wm^-1K^-1 at 773K, close to the theoretical minimum of the lattice thermal conductivity (~0.50Wm^-1K^-1) of SnTe. In conjunction with the enhancement of the Seebeck coefficient caused by band convergence due to Mg alloying, the maximum zTmax reaches ~1.02 and the device zTdevice of ~0.50 at 773K for Sn0.79Sb0.15Mg0.06Te, suggesting this SnTe-based composition has a promising potential in intermediate temperature thermoelectric applications.