Enhanced Low-Temperature Thermoelectric Performance in (PbSe)<sub>1+δ</sub>(VSe<sub>2</sub>)<sub>1</sub> Heterostructures due to Highly Correlated Electrons in Charge Density Waves

ORAL

Abstract

We explore the effect of charge density wave (CDW) on the in-plane thermoelectric transport properties of (PbSe)1+δ(VSe2)1 and (PbSe)1+δ(VSe2)2 heterostructures. In (PbSe)1+δ(VSe2)1 we observe an abrupt 86% increase in the Seebeck coefficient, 245% increase in the power factor, and a slight decrease in resistivity over the CDW transition. This behavior is not observed in (PbSe)1+δ(VSe2)2 and is rather unusual compared to the general trend observed in other materials. The abrupt transition causes a deviation from the Mott relationship through correlated electron states. Raman spectra of the (PbSe)1+δ(VSe2)1 material show the emergence of additional peaks below the CDW transition temperature associated with VSe2 material. Temperature-dependent in-plane X-ray diffraction (XRD) spectra show a change in the in-plane thermal expansion of VSe2 in (PbSe)1+δ(VSe2)1 due to lattice distortion. The increase in the power factor and decrease in the resistivity due to CDW suggest a potential mechanism for enhancing the thermoelectric performance at the low temperature region.

*DOE [DE-FG02-07ER46376 (Y.W.), DE-FG02-07ER46377 (L.S.)] and NSF [CBET2012845 (Z.C.) and CBET-1905357 (J.C.)]. NSF Graduate Research Fellowship Program grant no. 1309047. National Science Foundation DMR-1710214.

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Presenters

  • Yu Wang

    • Materials Science, Univ of Southern California

Authors

  • Yu Wang

    • Materials Science, Univ of Southern California

  • Danielle M. Hamann

    • Chemistry, University of Oregon

  • Dmitri Leo M. Cordova

    • Chemistry, University of Oregon

  • Jihan Chen

    • Electrical Engineering, University of Southern California

  • Bo Wang

    • Physics, University of Southern California

  • Lang Shen

    • Materials Science, Univ of Southern California

  • Zhi Cai

    • Materials Science, Univ of Southern California

  • Haotian Shi

    • Chemistry, University of Southern California

  • Evguenia Karapetrova

    • Advanced Photon Source, Argonne National Laboratory
    • Argonne National Laboratory

  • Indu Aravind

    • Physics, University of Southern California

  • Li Shi

    • University of Texas at Austin
    • Mechanical Engineering, University of Texas at Austin

  • David C. Johnson

    • Chemistry, University of Oregon

  • Steve Cronin

    • Electrical Engineering, University of Southern California