Quantum-Confined Electronic States arising from Moir\'e Pattern of MoS2-WSe2 Hetero-bilayers
Abstract
A two-dimensional (2D) hetero-bilayer system consisting of MoS2 on WSe2, deposited on epitaxial graphene, is studied by scanning tunneling microscopy and spectroscopy at temperatures of 5 and 80 K. A moir\'e pattern is observed, arising from lattice mismatch of 3.7% between the MoS2 and WSe2. Significant energy shifts are observed in tunneling spectra observed at the maxima of the moir\'e corrugation, as compared with spectra obtained at corrugation minima, consistent with prior work. Furthermore, at the minima of the moir\'e 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 moir\'e 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.
Keywords
Cite
@article{arxiv.1712.00116,
title = {Quantum-Confined Electronic States arising from Moir\'e Pattern of MoS2-WSe2 Hetero-bilayers},
author = {Yi Pan and Stefan Fölsch and Yifan Nie and Dacen Waters and Yu-Chuan Lin and Bhakti Jariwala and Kehao Zhang and Kyeongjae Cho and Joshua A. Robinson and Randall M. Feenstra},
journal= {arXiv preprint arXiv:1712.00116},
year = {2018}
}
Comments
10 page (5 figures) in main manuscript, with 9 pages (7 figures) of supplementary information; in v2, refs 8,9,24,25,34,40,41 are added, refs 27-30 are moved from supplementary info to main manuscript, and minor revisions to the text are made in connection with these changes