Pb-doped p-type Bi<sub>2</sub>Se<sub>3</sub> thin films via interfacial engineering

ORAL

Abstract

Due to high density of native defects, the prototypical topological insulator, Bi2Se3, is naturally n-type. Although Bi2Se3 can be converted into p-type by substituting 2+ ions for Bi, only light elements such as Ca have been so far effective as the compensation dopant. Considering that strong spin-orbit coupling (SOC) is essential for the topological surface states, a light element is undesirable as a dopant, because it weakens the strength of SOC. In this sense, Pb, which is the heaviest 2+ ion, located right next to Bi in the periodic table, is the most ideal p-type dopant for Bi2Se3. However, Pb-doping has so far failed to achieve p-type Bi2Se3 not only in thin films but also in bulk crystals. Here, by utilizing an interface engineering scheme, we have achieved the first Pb-doped p-type Bi2Se3 thin films. Furthermore, at heavy Pb-doping, the mobility turns out to be substantially higher than that of Ca-doped samples, indicating that Pb is a less disruptive dopant than Ca.

*This work was supported by the Gordon and Betty Moore Foundation’s EPiQS Initiative (GBMF4418) and National Science Foundation (NSF) grant EFMA-1542798.

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Presenters

  • Jisoo Moon

    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Rutgers University, New Brunswick
    • Department of Physics & Astronomy, Rutgers, The State University of New Jersey

Authors

  • Jisoo Moon

    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Rutgers University, New Brunswick
    • Department of Physics & Astronomy, Rutgers, The State University of New Jersey

  • Zengle Huang

    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey

  • Weida Wu

    • Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • Seongshik Oh

    • Physics, Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, the state university of New Jersey
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Rutgers University, New Brunswick
    • Department of Physics & Astronomy, Rutgers, The State University of New Jersey