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arXiv · 2111.13874

Giant thermoelectric figure of merit in multivalley high-complexity-factor LaSO

Roberta Farris·Francesco Ricci·Giulio Casu·Diana Dahliah·Geoffroy Hautier·Gian-Marco Rignanese·Vincenzo Fiorentini
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Abstract

We report a giant thermoelectric figure of merit $ZT$ (up to 6 at 1100 K) in $n$-doped lanthanum oxysulphate LaSO. Thermoelectric coefficients are computed from ab initio bands within Bloch-Boltzmann theory in an energy-, chemical potential- and temperature-dependent relaxation time approximation. The lattice thermal conductivity is estimated from a model employing the ab initio phonon and Gr\"uneisen-parameter spectrum. The main source of the large $ZT$ is the significant power factor which correlates with a large band complexity factor. We also suggest a possible $n$-type dopant for the material based on ab initio calculations.

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Roberta Farris, Francesco Ricci, Giulio Casu, Diana Dahliah, Geoffroy Hautier, Gian-Marco Rignanese, Vincenzo Fiorentini. 2021-11-27. Giant thermoelectric figure of merit in multivalley high-complexity-factor LaSO. https://doi.org/10.1103/physrevmaterials.5.125406

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