Thermoelectric performance of chemically exfoliated n-Bi$_2$Te$_3$

ORAL

Abstract

Bi$_{2}$Te$_{3}$ based thermoelectric (TE) devices are of interest because of their high thermoelectric figure of merit (ZT) near room temperature, and ability to be utilized in both refrigeration and power generation modes. Recently, nano-structuring has shown promise in improving the TE performance of $p$-type Bi$_{2}$Te$_{3}$, however $n$-type counterparts are still lagging in this respect. Here, we display high ZT values ($\sim$ 0.9) in exfoliated $n$-Bi$_{2}$Te$_{3}$ at elevated temperatures (400-- 500 K). The chemically exfoliated samples were prepared by an ultra-sonication technique with subsequent spark plasma sintering to obtain dense pellets. Our transport results showed improved compatibility and a shift in the ZT maximum towards a higher temperature ($\sim$ 430 K) than commercially available ingots. The experimental details and transport data will be discussed within the frame work of exfoliation-induced structural modifications.

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Authors

  • Pooja Puneet

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634

  • Mehmet Karakaya

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634

  • R.S. Sai Siddhardha

    • Department of Physics, Clemson University, Clemson, SC 29634
    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Dept. of Physics and Astronomy, Clemson University, Clemson, SC USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634
    • Sri Sathya Sai Institute of Higher Learning, India
    • Department of Physics and Astronomy, Clemson University, Clemson, SC 29634
    • Sri Sathya Sai Institute of Higher Learning

  • Song Zhu

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634

  • Jian He

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634

  • Terry Tritt

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634

  • Malcolm Skove

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Clemson University
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634

  • Apparao M. Rao

    • Department of Physics and Astronomy, Clemson University, Clemson SC, USA 29634
    • Clemson University
    • Dept. of Physics and Astronomy, Clemson University, Clemson, SC USA 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC, United States 29634
    • Department of Physics and Astronomy, Clemson University, Clemson, SC 29634