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 

机构地区：[1]State Key Laboratory of Silicon Materials,and School of Materials Science and Engineering,Zhejiang University

出　　处：《Science Bulletin》2019年第14期1024-1030,共7页科学通报（英文版）

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)

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.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$0.64 W m-1K-1at 773 K,close to the theoretical minimum of the lattice thermal conductivity($0.50 W m-1K-1)of SnTe.In conjunction with the enhancement of the Seebeck coefficient caused by band convergence due to Mg alloying,the maximum zTmaxreaches$1.02 and the device zTdeviceof$0.50 at 773 K for Sn0.79Sb0.15Mg0.06Te,suggesting this SnTe-based composition has a promising potential in intermediate temperature thermoelectric applications.

关 键 词：Tin TELLURIDE THERMOELECTRIC materials Point defect scattering Band CONVERGENCE 

分 类 号：N[自然科学总论]