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

We report a giant thermoelectric figure of merit ZT (up to six 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. Th...

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Detalles Bibliográficos
Autores: Farris, Roberta, Ricci, Francesco, Casu, Giulio, Dahliah, Diana, Hautier, Geoffroy, Rignanese, Gian-Marco, Fiorentini, Vincenzo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/264877
Acceso en línea:http://hdl.handle.net/10261/264877
Access Level:acceso abierto
Palabra clave:Electronic structure
Thermal conductivity
Thermopower
Transport phenomena
Ab initio calculations
Boltzmann theory
Descripción
Sumario:We report a giant thermoelectric figure of merit ZT (up to six 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 Grüneisen-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.