APS Logo

Near field study of twisted transition metal dichalcogenide bilayers

ORAL

Abstract

Twistronics has recently emerged as a novel tuning knob to engineer the properties of electrons and excitons in two dimensional van der Waals heterostructures. However, directly probing the properties of vdW heterostructures within a single moiré unit cell remains elusive. In this talk, we utilize near-field optical microscopy to explore twisted transition metal dichalcogenides (TMD) bilayers. The atomically thin vertical p-n junction of WSe2/MoSe2 bilayer is fabricated by mechanical exfoliation and stacking. The type-II band alignment of the WSe2/MoSe2 facilitates electron-hole separation permitting photocurrent measurements at the nanoscale. Features with ~100 nm periodicity are observed and show systematic evolution under electro-static gating. More experiments are carrying out to conclusively assign these features to the moiré. Our study demonstrates a viable pathway towards probing and manipulating moiré patterned TMD heterostructures at the nanoscale.

–

Presenters

  • Shuai Zhang

    Columbia Univ, Columbia University, Department of Physics, Columbia University

Authors

  • Shuai Zhang

    Columbia Univ, Columbia University, Department of Physics, Columbia University

  • Aaron Sternbach

    Columbia Univ, Department of Physics, Columbia University, Physics, Columbia University

  • Baichang Li

    Department of Mechanical Engineering, Columbia University

  • Lin Zhou

    Nanjing University, Department of Chemistry, Columbia University

  • Wenjing Wu

    Columbia University, Department of Chemistry, Columbia University

  • Lin Xiong

    Columbia Univ, Columbia University, Department of Physics, Columbia University, Physics, Columbia University

  • Essance Ray

    University of Washington, Department of Physics, University of Washington

  • Nathan P Wilson

    Department of Physics, University of Washington, University of Washington

  • Xiaodong Xu

    Department of Physics, University of Washington

  • Xiaoyang Zhu

    Columbia Univ, Chemistry, Columbia University, Columbia University, Chemistry, Columbia University, Department of Chemistry, Columbia University

  • James C Hone

    Columbia University, Mechanical Engineering, Columbia University, Columbia Univ, Physics, Columbia University, Columbia University, NY, USA, Department of Mechanical Engineering, Columbia University

  • Dmitri Basov

    Columbia University, The Department of Physics, Columbia University, Physics, Columbia University, Columbia Univ, Department of Physics, Columbia University