Thermoelectric Properties of LiYSi Half-Heusler Alloy

Half-Heusler compounds are a broad class of materials that have attracted attention as possible high-temperature thermoelectric materials due to their favourable electrical transport behaviour and other features useful for device manufacturing. Although half-Heusler compounds exhibit an incredibly wide range of thermal conductivities, these are nonetheless often higher than other cutting-edge thermoelectric materials, which present a unique difficulty. It was observed that the chosen half-Heuslers were direct bandgap semiconductor with high power factors equivalent to the art of thermoelectric materials. Since the computed phonon is positive, the substance is dynamically stable. The high power factor and high Seebeck coefficient of the half-Heusler alloy are also revealed by the density of states. The stability of the material is also revealed by the formation energy. The optimized structure of LiYSi has band gap of 0.70 eV. The calculated power factor of n-type LiYSi is 7.31 × 1011Wm−1 K−2 s−1 per relaxation time. The calculated power factor per relaxation time of p-type LiYSi is 1.44 × 1012Wm−1 K−2 s−1.The power factor increases with increase in temperature. High n-type thermoelectric performance is produced by the interaction of low lattice thermal conductivity and excellent electrical transport characteristics. This suggests that at high temperatures, LiYSi is a potential n-type half-Heusler thermoelectric material. It is clear that the electronic structure has high valence band degeneracy, which contributes for good transport properties and results good thermoelectric material.