Experimental determination of the valence band of Bi$_2$Se$_3$

ORAL

Abstract

P-type Bi$_2$Se$_3$ is predicted theoretically to have good thermoelectric properties[1], because its valence band has a high calculated density of states (DOS). In this presentation, p-type Bi$_2$Se$_3$ samples are prepared both as single crystals and as polycrystals. Shubnikov - de Haas (SdH) measurements are carried out in a rotating stage on single crystals to obtain the Fermi surface cross-sections and the cyclotron effective masses. Thermoelectric transport measurements are done on polycrystals, and used to construct Pisarenko plots of Seebeck coefficient versus hole concentration. The Fermi surface cross-section measurements confirm the theoretically predicted [1] shape of the Fermi surface.Both cyclotron masses and Pisarenko plotsare in good agreement and show that p-type Bi$_2$Se$_3$ has a hole effective mass smaller than the theoretically predicted value. The reason for the discrepancy is not yet understood at this time. Reference: [1] Phys. Rev. X 1, 021005 (2011)

*This work is supported by Gentherm Inc., 1321 Mountain View Circle, Azusa, CA 91702, USA and the U.S. Department of Energy, EERE, Vehicle Technologies, Propulsion Materials Program (DP)

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Authors

  • Yi-Bin Gao

    • 1 Department of Mechanical Engineering, The Ohio State University, Columbus, OH
    • Department of Mechanical and Aerospace Engineering, Ohio State University

  • Bin He

    • Department of Mechanical and Aerospace Engineering, Ohio State University

  • Ioannis Androulakis

    • Gentherm Inc., 1321 Mountain View Circle, Azusa, CA 91702

  • Joseph P. Heremans

    • 1 Department of Mechanical Engineering, The Ohio State University, Columbus, OH; 2 Department of Physics, The Ohio State University, Columbus OH
    • Ohio State University
    • Department of Mechanical and Aerospace Engineering, Department of Physics, Ohio State University, Columbus, Ohio 43210
    • The Ohio State University
    • Department of Mechanical and Aerospace Engineering, Department of Physics. Ohio State University