Composition and the thermoelectric performance of β-Zn4Sb3

• Published in: Journal of materials chemistry 2010-01, Vol.2 (44), p.9877-9885
• Main Authors: Toberer, Eric S, Rauwel, Protima, Gariel, Sylvain, Taftø, J, Jeffrey Snyder, G
• Format: Article
• Language: English
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c0jm02011g

β -Zn 4 Sb 3 is a promising thermoelectric material due to the abundance of zinc and antimony and reports of high efficiency in bulk samples. This work establishes the high temperature properties of β -Zn 4 Sb 3 across the phase stability window. By controlling the stoichiometry, the Hall carrier concentration can be tuned from 6-9 × 10 19 cm −3 without requiring extrinsic dopants. The trend in Seebeck coefficient on carrier concentration is rationalized with a single, parabolic band model. Extremely low lattice thermal conductivity (0.4-0.6 W m −1 K −1 ) coupled with a moderate effective mass (1.2 m e ) and mobility leads to a large figure of merit ( zT of 0.8 by 550 K). The single parabolic band model is used to obtain the carrier concentration dependence of the figure of merit and an optimum carrier concentration near 5 × 10 19 cm −3 is predicted. High temperature thermoelectric properties of Zn 4 Sb 3 are reported within the phase stability window, revealing the potential for improved performance at lower carrier concentrations.