Electronic structure and high thermoelectric properties of a new material Ba3Cu20Te13

Abstract

The electronic structure and high thermoelectric properties of Ba3Cu20Te13 are studied using first principles calculations and the semiclassical Boltzmann theory. The coexistence of ionic and covalent bonding in Ba3Cu20Te13 indicates that it is a Zintl phase compound. The calculated band structure shows that the compound is a semiconductor with an indirect band gap ∼0.45 eV, which is an appropriate band for the high thermoelectric performance. The transport calculations based on the electronic structure indicate that it exhibits relatively large Seebeck coefficients, high electrical conductivities, and high power factor. For Ba3Cu20Te13, the n-type doping may achieve a higher thermoelectric performance than that of p-type doping. It is worth noting that the thermoelectric parameters of Ba3Cu20Te13 are comparable or larger than that of Ca5Al2Sb6, a typical Zintl compound representative with high thermoelectric performance.