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

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（14）
• 页码范围: 1024-1030
• 页数: 7页
• 语种: 英文

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-1 K-1 at 773 K,close to the theoretical minimum of the lattice thermal conductivity (～0.50 W m-1 K-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 773 K for Sno.79Sb0.15Mg0.06Te,suggesting this SnTe-based composition has a promising potential in intermediate temperature thermoelectric applications.