Thermoelectric properties of doubly doped Strontium Titanate thin films

ORAL

Abstract

Lanthanum doped Strontium Titanate (SrTiO$_{3})$ is amongst the most promising n-type thermoelectric materials for power generation. We report a double doping method for thin films of SrTiO$_{3}$, grown on (001) oriented LSAT substrates by Pulsed Laser Deposition (PLD), where doping of SrTiO$_{3}$ in the A-site by Lanthanum is accompanied by doping with oxygen vacancies. Based on careful transport measurements, we show that it is possible to obtain enhanced thermoelectric power factor in the limit of high effective mass and large carrier concentration in these thin films. The presence of oxygen vacancies also serves to decrease the thermal conductivity due to effective phonon scattering. The optimized doping concentration leads to a thermoelectric figure of merit, zT $>$ 0.2 at room temperature.

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Authors

  • Jayakanth Ravichandran

    Applied Science and Technology Graduate Group, University of California, Berkeley, CA 94720

  • Matthew L. Scullin

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

  • Subroto Mukerjee

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

  • Joel Moore

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

  • R. Ramesh

    University of California at Berkeley, University of California, Berkeley, CA, 94720, University of California-Berkeley, Department of Physics, and Material Science and Engineering, University of California, Berkeley, CA 94720, USA., Department of Physics, UC Berkeley, Dept. of Materials Science and Engineering, University of California, Berkeley, CA 94720

  • Arun Majumdar

    Deptartment of Mechanical Engineering, University of California - Berkeley, Dept of Mech Eng, UC Berkeley, University of California at Berkeley, Dept. of Mechanical Engineering, University of California, Berkeley, CA 94720