Electronic structure and thermoelectric properties of half-Heusler alloys NiTZ

• Published in: AIP advances Vol. 11; no. 2; pp. 025304 - 025304-9
• Main Authors: Jaishi, Dhurba R., Sharma, Nileema, Karki, Bishnu, Belbase, Bishnu P., Adhikari, Rajendra P., Ghimire, Madhav P.
• Format: Journal Article
• Language: English
• Published: AIP Publishing LLC 01-02-2021
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/5.0031512

We investigated the electronic and thermoelectric properties of half-Heusler alloys NiTZ
(T = Sc and Ti; Z = P, As, Sn, and Sb) having an 18 valence electron count. Calculations
were performed by means of density functional theory and the Boltzmann transport equation
with constant relaxation time approximation, validated by NiTiSn. The chosen half-Heuslers
were found to be indirect bandgap semiconductors, and the lattice thermal conductivity was
comparable with the state-of-the-art thermoelectric materials. The estimated power factor
for NiScP, NiScAs, and NiScSb revealed that their thermoelectric performance can be
enhanced by an appropriate doping rate. The value of ZT found for NiScP,
NiScAs, and NiScSb is 0.46, 0.35, and 0.29, respectively, at 1200 K.