Electronic structure and thermoelectric properties of half-Heusler Zr0.5Hf0.5NiSn by first-principles calculations

Abstract

The electronic structures of Zr0.5Hf0.5NiSn and the parent compounds ZrNiSn and HfNiSn are investigated by using first-principles calculations, and the thermoelectric properties are calculated on the base of the semi-classical Boltzmann transport theory and the empirical thermal conductivity model. The temperature dependence of thermoelectric transport properties of these three compounds is discussed and compared with experimental data, and good agreements are observed. To further optimize the thermoelectric performance of the Zr0.5Hf0.5NiSn compound, the chemical potential dependence of electrical transport properties at three different temperatures is investigated, and the maximum power factors and corresponding optimal p- or n-type doping levels are evaluated, suggesting that the compound has better thermoelectric performance when it is p-type doped.