A Study of thermoelectric properties of Hf-doped RhTiP Half-Heusler alloy

Abstract

In this work, we present a first-principles based investigation to analyse the effect of Hafnium (Hf) doping on thermoelectric properties of half-Heusler alloy RhTiP. In recent times, Hf based Heuser alloys are proved to be good thermoelectric (TE) materials. So, its interesting to see the effect of Hf, as dopant, on the newly propsed RhTiP. The energy bandgap of pure RhTiP is 0.810 eV. As we start doping, the bandgap first decrease for RhTi0.75Hf0.25P and then increase liearly for higher doping concentrations. We find that the material shows the high thermoelectric performance at 100% doping of Hf in place of Ti (RhHfP) at room temperature. The maximum value of power factor and electrical conductivity at room temperature are estimated, respectively, as 0.19688x1012WK-2m-1s-1 and 3.2058x1018Ω-1m-1s-1 which belong to RhHfP . The maximum ZT value at room temperature is found to be 0.7950 at room and it is too for RhHfP. We estimate that RhHfP can become a good thermoelectric material amongst all the studied concentrations for room temperature applications.