Thermoelectric high-entropy alloys with low lattice thermal conductivity

• Published in: RSC advances Vol. 6; no. 57; pp. 52164 - 5217
• Main Authors: Fan, Z, Wang, H, Wu, Y, Liu, X. J, Lu, Z. P
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• Subjects: alloys; silver; thermal conductivity
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c5ra28088e

Reducing lattice thermal conductivity is one of the most effective routes for improving the performance of thermoelectric materials. Herein, a novel alloy design concept, i.e. , the high-entropy alloy concept, is introduced as a new strategy to reduce lattice thermal conductivity and the BiSbTe 1.5 Se 1.5 high-entropy alloy was chosen as a paradigm to demonstrate the applicability of this new approach. It was found that the lattice thermal conductivity of this high-entropy alloy is quite low, i.e. , 0.47 W m 1 K 1 at 400 K, which results from its severe lattice-distortion. In addition, the minor addition of Ag could improve the absolute value of its Seebeck coefficient and further reduce its lattice thermal conductivity. Consequently, a peak ZT value of 0.63 was observed at 450 K for this alloy with the addition of 0.9 at% Ag. Our current results suggest that the revolutionary alloy design concept is a promising strategy for developing novel thermoelectric materials with desirable properties. Reducing lattice thermal conductivity is one of the most effective routes for improving the performance of thermoelectric materials.