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, an...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.展开更多
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)
文摘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.
