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

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 e T for low carrier concentrations at a given temperature, and n-type CuAlTe2 appears to be a particularly promising thermoelectric material.