Bilayer Graphene - WSe<sub>2</sub> Resonant Tunneling Heterostructures With Large Current Densities

ORAL

Abstract

Two-dimensional (2D) materials offer an exciting avenue to explore novel electronic devices and properties, and can be easily stacked to create designer heterostructures. We present here a study of resonant tunneling heterostructures consisting of two rotationally aligned bilayer graphene electrodes separated by a bilayer WSe2 tunnel barrier. Rotational alignment of the graphene bilayers aligns their respective band structures in momentum-space, which allows for momentum and energy conserving tunneling between the two layers. This behavior is manifested through a pronounced resonance peak in the interlayer current-voltage characteristic, and gate-tunable negative differential resistance. The studied samples show current densities exceeding 60 μA/μm2 and peak-to-valley ratios over 5 at room temperature. Theoretical calculations using a Lorentzian spectral function for the 2D quasiparticle states match closely with the experimental data. In-plane magnetotunneling measurements show a splitting of the resonance peak and suppression of the conductance, consistent with momentum conserving tunneling.

*This work was supported by the National Science Foundation Grant EECS-1610008, Semiconductor Research Corp. Nanoelectronics Research Initiative SWAN center, and Samsung Corp.

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Presenters

  • Gregory Burg

    • The University of Texas at Austin
    • Department of Electrical and Computer Engineering, The University of Texas at Austin
    • Electrical and Computer Engineering, The University of Texas at Austin

Authors

  • Gregory Burg

    • The University of Texas at Austin
    • Department of Electrical and Computer Engineering, The University of Texas at Austin
    • Electrical and Computer Engineering, The University of Texas at Austin

  • Nitin Prasad

    • Electrical and Computer Engineering, The University of Texas at Austin

  • Babak Fallahazad

    • Univ of Texas, Austin
    • Electrical and Computer Engineering, The University of Texas at Austin

  • Kyounghwan Kim

    • The University of Texas at Austin
    • Univ of Texas, Austin
    • Electrical and Computer Engineering, The University of Texas at Austin

  • Leonard Register

    • The University of Texas at Austin
    • Electrical and Computer Engineering, The University of Texas at Austin

  • Emanuel Tutuc

    • The University of Texas at Austin
    • Department of Electrical and Computer Engineering, The University of Texas at Austin
    • Univ of Texas, Austin
    • Electrical and Computer Engineering, The University of Texas at Austin