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Evaluating the Thermoelectric Properties of BaTiS3 by Density Functional Theory
journal contribution
posted on 2020-05-22, 11:34 authored by Tula R. Paudel, Evgeny Y. TsymbalBaTiS3 is a semiconductor
with a small bandgap of ∼0.5
eV and strong transport anisotropy caused primarily by structural
anisotropy; it contains well-separated octahedral columns along the
[0001] direction and low lattice thermal conductivity, appealing for
thermoelectric applications. Here, we evaluate the prospect of BaTiS3 as a thermoelectric material by using the linearized electron
and phonon Boltzmann transport theory based on the first-principles
density functional band structure calculations. We find sizable values
of the key thermoelectric parameters, such as the maximum power factor
PF = 928 μW K–2 and the maximum figure of
merit ZT = 0.48 for an electron-doped sample and PF = 74 μW
K–2 and ZT = 0.17 for a hole-doped sample at room
temperature, and a small doping level of ±0.25e per unit cell.
The increase in temperature yields an increase in both the power factor
and the figure of merit, reaching large values of PF = 3078 μW
K–2 and ZT = 0.77 for the electron-doped sample
and PF = 650 μW K–2 and ZT = 0.62 for the
hole-doped sample at 800 K. Our results elucidate the promise of BaTiS3 as a material for the thermoelectric power generator.