Extremely high thermoelectric performance of SnSe at optimal carrier densities

ORAL

Abstract

High-efficiency thermoelectric materials are desirable for their capability of functioning as all solid-state modules for electric power generation from waste heat or distributed spot-size refrigeration. Bulk tin selenide (SnSe) has received much attention since its excellent thermoelectric figure of merit (zT) was reported. Using extensive first-principles calculations of carrier-impurity and carrier-phonon scattering processes, we investigate the optimal carrier densities to maximize zT in p- and n-doped SnSe over a broad range of temperatures. We predict an ultrahigh zT > 4 for in-plane p-doped and out-of-plane n-doped SnSe at high temperatures, which is robust against variations in the concentration of ionized impurities. An extensive analysis of the transport properties as a function of the carrier density and temperature indicates that the Lorenz number reaches a minimum at the optimal conditions. Our results are motivation for improving the efficiency of doping in SnSe in order to attain optimal carrier densities.

*A.S.C and A.A. acknowledge support from the Brazilian agencies CNPq and FAPESP. D.T.L. is supported by NSF DMREF Grants No. 1922165 and No. DMR-1231319, and by DOE Basic Energy Science Award No. DE-SC0019300. The calculations were performed at CCJDR-IFGW-UNICAMP.

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Publication: 1) Chaves, Anderson S; Antonelli, Alex; Larson, Daniel T,; Kaxiras, Efthimios; Boosting the efficiency of ab initio electron-phonon coupling calculations through dual interpolation ; Physical Review B, 102 (12),125116, 2020.
2) Chaves, Anderson S.; Larson, Daniel T.; Kaxiras, Efthimios; Antonelli, Alex; Microscopic origin of the high thermoelectric figure of merit in n-doped SnSe; Physical Review B, 104, 115204, 2021.
3) Chaves, Anderson S.; Gonzalez-Romero, Robert L.; Meléndez, Juan J.; Antonelli, Alex; Investigating charge carrier scattering processes in anisotropic semiconductors through first-principles calculations: the case of p-type SnSe , PCCP, 2021, 23(2), 900-913.
4) Chaves, Anderson S; Larson, Daniel T,; Kaxiras, Efthimios; Antonelli, Alex; Carrier density optimization in SnSe: Robust zT > 4 due to low Lorenz numbers, to be submitted.
5) Chaves, Anderson S; Larson, Daniel T,; Kaxiras, Efthimios; Antonelli, Alex; Optimal doping prediction for out-of-plane p-doped GeSe thermoeletrics, to be submitted.

Presenters

  • Anderson S Chaves

    • Harvard University and University of Campinas

Authors

  • Anderson S Chaves

    • Harvard University and University of Campinas

  • Daniel T Larson

    • Harvard University

  • Efthimios Kaxiras

    • Harvard University

  • Alex Antonelli

    • UNICAMP-Univ de Campinas