Out-of-plane Piezoelectricity and Ferroelectricity in Layered <i>α</i>-In<sub>2</sub>Se<sub>3 </sub>Nano-flakes

ORAL

Abstract

Piezoelectric and ferroelectric properties in the two dimensional (2D) limit are nontrivial and they are highly desired for nanoelectronic, electromechanical, and optoelectronic applications. Here we present the experimental observation of out-of-plane piezoelectricity and ferroelectricity in van der Waals layered α-In2Se3 nano-flakes. The non-centrosymmetric R3m symmetry of the α-In2Se3 samples is confirmed by scanning transmission electron microscopy, second-harmonic generation, and Raman spectroscopy measurements. Ferroelectric domains with opposite polarizations are visualized by piezo-response force microscopy and the polarization can be switched for α-In2Se3 nano-flakes with thicknesses down to ~ 10 nm. The piezotronic effect is demonstrated in two-terminal devices, where the Schottky barrier can be modulated by the strain-induced piezopotential. Our work on polar α-In2Se3, one of the model 2D piezoelectrics and ferroelectrics with simple crystal structures, shows its great potential in nanoelectronic applications.

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Presenters

  • Di Wu

    • University of Texas at Austin
    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin

Authors

  • Di Wu

    • University of Texas at Austin
    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin

  • Yu Zhou

    • Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University

  • Yihan Zhu

    • Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Yujin Cho

    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin

  • Qing He

    • Durham University

  • Xiao Yang

    • Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University

  • Kevin Herrera

    • Department of Physics, University of Texas at Austin

  • Zhaodong Chu

    • University of Texas at Austin
    • Department of Physics, University of Texas at Austin

  • Yu Han

    • Physical Sciences and Engineering Division, King Abdullah University of Science and Technology

  • Michael Downer

    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin
    • Physics, University of Texas
    • Physics, Univ of Texas

  • Hailin Peng

    • Center for Nanochemistry, College of Chemistry and Molecular Engineering, Peking University
    • Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University
    • Peking University

  • Keji Lai

    • University of Texas at Austin
    • Univ of Texas, Austin
    • Department of Physics, University of Texas at Austin