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)

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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