Electronic structure and thermoelectric properties of CoAsSb with post-DFT approaches

Journal Article · 29 January 2020 · Applied Physics A - Materials Science & Processing

DOI: https://doi.org/10.1007/s00339-020-3304-3 · OSTI ID:1583113

Kutepov, Andrey L.  ^[1]; Ruth, Anthony ^[2]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Univ. of Notre Dame, IN (United States)

Here, we study the electronic structure and thermoelectric properties of recently synthesized CoAsSb. The calculated bandgap becomes more accurate for increasingly-complex electronic structure methods: generalized gradient approximation, hybrid functionals, selfconsistent linearized quasiparticle GW method (LQSGW), and LQSGW with simplified vertex corrections. By equating the bandgaps of each method from a rigid shift of the bands, we evaluate the contributions made to thermoelectric properties beyond the bandgap. In doing so, we evaluate the efficacy of a commonpractice: a rigid shift applied to less-costly electronic structure methods in order to gain some accuracy of the more-costly methods. We find that while the shift made the Seebeck coefficients much closer to one another than from the original electronic structures, there remain differences in the Goldsmid-Sharp (thermoelectric) bandgap between the methods and from the intended electronic bandgap. Additionally, some lasting differences in temperature dependence remain between the methods.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1583113
• Report Number(s): BNL--213537-2020-JAAM
• Journal Information: Applied Physics A - Materials Science & Processing, Journal Name: Applied Physics A - Materials Science & Processing Journal Issue: 2 Vol. 126; ISSN 0947-8396
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English