Eur. Phys. J. B (2015) 88: 330
https://doi.org/10.1140/epjb/e2015-60398-4

Regular Article

Electronic structures and thermoelectric properties of CuMTe₂ (M = Al, Ga, In) copper chalcopyrites: a first-principles study

¹ School of Physics Science and Engineering, Tongji University, Shanghai 200092, P.R. China
² College of Physics and Electrical Engineering, Anyang Normal University, Anyang, Henan 455000, P.R. China
³ Department of Physics, Henan University of Technology, Zhengzhou, Henan 450001, P.R. China

^a e-mail: l001wf@gmail.com

Received: 19 May 2015
Received in final form: 22 September 2015
Published online: 9 December 2015

Abstract

We investigated the electronic structures and thermoelectric properties of CuMTe₂ (M = Al Ga, In) copper chalcopyrites based on first-principles calculations using the Tran-Blaha-modified Becke-Johnson potential, which yielded accurate band gaps for the semiconductors. The band structures show both light and heavy bands near the valence band maximum. Light bands improve mobility, and heavy bands often increase the Seebeck coefficient, so our results suggest that the chalcopyrites should have larger power factors. To calculate the thermoelectric properties of CuMTe₂ (M = Al, Ga, In), we used semi-classical Boltzmann transport theory. The results show relatively high Seebeck coefficients and Z_eT for low carrier concentrations at a given temperature, and n-type CuAlTe₂ appears to be a particularly promising thermoelectric material.