Simultaneous optimization of power factor and thermal conductivity via Te and Se double substitution in Cu12Sb4S13 tetrahedrite

[摘要] The present study reports the structural, electronic, elastic, and thermoelectric properties of Cu12Sb3.9Te0.1S13-xSex (x = 0, 0.1, 0.5, 0.75 and 1) tetrahedrite. The thermal conductivity was reduced due to charge carrier compensation (by Te), weakening of the Sb-S bond and local chemical disorder (induced by Se), resulting in a low mean sound velocity. Simultaneously, the power-factor was maintained high from an enhancement of the density of states near the Fermi level due to Se. Consequently, a maximum figure of merit similar to 0.84 at 673 K was achieved for the Cu12Sb3.9Te0.1S12.5Se0.5 sample due to concomitant optimisation of the power-factor and thermal conductivity. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

[发布日期] 2020-11-01

[关键词] Tetrahedrite;Raman spectroscopy;Density functional theory (DFT);Electrical properties;Mechanical properties