Thermoelectric response of Lanthanum-doped SrTiO$_{3}$ thin-films grown under various oxygen partial pressures

ORAL

Abstract

Doped strontium titanate is a strong candidate for the next-generation high-$Z$ bulk thermoelectric material due to both its wide tunability in transport properties and very large carrier effective mass. Thermoelectric thin-films of Sr$_{1-x}$La$_{x}$TiO$_{3-\delta }$ with various La content were grown via pulsed-laser deposition (PLD) on (001)-oriented LSAT substrates under various oxygen partial pressures. We find that electron transport is dominated by carriers from oxygen vacancies in samples grown at low $p_{O2} \quad <$ 10$^{-6}$ Torr, and that thermopower as high as 1000 \textit{$\mu $}V/K can be achieved even in heavily La-doped samples. Doping combinations that yield resistivities as low as 5 m$\Omega $-cm yield power factors @ 300K as high as 0.7 W/m-K, implying \textit{ZT} $>$ 0.1.

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Authors

  • Matthew L. Scullin

    • Dept. of Materials Science and Engineering, University of California, Berkeley, CA 94720

  • Jayakanth Ravichandran

    • Dept. of Mechanical Engineering, University of California, Berkeley, CA 94720

  • Mark Huijben

    • Dept. of Physics, University of California, Berkeley, CA 94720

  • Choongho Yu

    • Lawrence Berkeley National Labs, Berkeley, CA, 94720

  • Subroto Mukerjee

    • Dept. of Physics, University of California, Berkeley, CA 94720

  • Joel Moore

    • Dept. of Physics, University of California, Berkeley, CA 94720

  • Arun Majumdar

    • Lawrence Berkeley National Labs, Berkeley, CA, 94720

  • R. Ramesh

    • Dept. of Materials Science and Engineering, University of California, Berkeley, CA 94720