Thermoelectric phenomena provide an alternative for power generation and refrigeration, which could be the best solution to the energy crisis by utilizing waste heat energy in the near future. In ...this study, we have investigated the structural, elastic, electronic, and thermoelectric properties of 18-valence electron count rhodium-based half-Heusler alloys focusing on RhTiP, RhTiAs, RhTiSb, and RhTiBi. The non-existence of imaginary frequencies in the phonon dispersion curve for these systems verifies that they are structurally stable. RhTiP is ductile, while others are brittle. The alloys are semiconducting with indirect band gaps ranging from 0.94 to 1.01 eV. While considering thermoelectricity, we discovered that p-type doping is more favorable in improving the thermoelectric properties. The calculated power factor values with p-type doping are comparable to some of the reported half-Heusler materials. The optimum figure of merit
ZT
is ∼1 for RhTiBi, and in between ∼(0.38-0.67) for RhTiP, RhTiAs, and RhTiSb. The low thermal conductivities and sufficiently large value of power factor of these alloys suggest that they are promising thermoelectric materials for use in thermoelectric applications.
Thermoelectric phenomena provides an alternative for power generation and refrigeration. Half-Heusler are excellent candidates for use in thermoelectric devices.
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.
We have investigated the electronic and thermoelectric properties of half-Heusler alloys NiTZ (T = Sc, and Ti; Z = P, As, Sn, and Sb) having 18 valence electron. Calculations are performed by means ...of density functional theory and Boltzmann transport equation with constant relaxation time approximation, validated by NiTiSn. The chosen half-Heuslers are found to be an indirect band gap semiconductor, and the lattice thermal conductivity is comparable with the state-of-the-art thermoelectric materials. The estimated power factor for NiScP, NiScAs, and NiScSb reveals that their thermoelectric performance can be enhanced by appropriate doping rate. The value of ZT found for NiScP, NiScAs, and NiScSb are 0.46, 0.35, and 0.29, respectively at 1200 K.
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