Quantum-Confined Electronic States Arising from the Moiré Pattern of MoS2–WSe2 Heterobilayers
Year: 2018
Type: article
Abstract: A two-dimensional (2D) heterobilayer system consisting of MoS 2 on WSe 2, deposited on epitaxial graphene, is studied by scanning tunneling microscopy and spectroscopy at temperatures of 5 and 80 K. A moiré pattern is observed, arising from lattice mismatch of 3.7% between the MoS 2 and WSe 2 . Significant energy shifts are observed in tunneling spectra observed at the maxima of the moiré corrugation, as compared with spectra obtained at corrugation minima, consistent with prior work. Furthermore, at the minima of the moiré corrugation, sharp peaks in the spectra at energies near the band edges are observed for spectra acquired at 5 K. The peaks correspond to discrete states that are confined within the moiré unit cells. Conductance mapping is employed to reveal the detailed structure of the wave functions of the states. For measurements at 80 K, the sharp peaks in the spectra are absent, and conductance maps of the band edges reveal little structure.
Source: Nano Letters
Authors: Yi Pan, Stefan Fölsch, Yifan Nie, Dacen Waters, Yu-Chuan Lin, Bhakti Jariwala, Kehao Zhang, Kyeongjae Cho, Joshua A. Robinson, Randall M. Feenstra
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2773673828