Scanning tunnelling microscopy and spectroscopy of ultra-flat graphene on hexagonal boron nitride
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Jarillo-Herrero_STM spectroscopy.pdf
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2.35 MB
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Author(s)
Xue, Jiamin
Sanchez-Yamagishi, Javier
Bulmash, Daniel S.
Jacquod, Philippe
Deshpande, Aparna
Watanabe, K.
Taniguchi, T.
Jarillo-Herrero, Pablo
LeRoy, Brian J.
Date Issued
February 2011
Journal
Nature Materials
Publisher
Nature Publishing Group
Citation
Xue, Jiamin et al. “Scanning Tunnelling Microscopy and Spectroscopy of Ultra-flat Graphene on Hexagonal Boron Nitride.” Nature Materials 10.4 (2011): 282–285. Web.
Version
Author's final manuscript
Abstract
Graphene has demonstrated great promise for future electronics technology as well as fundamental physics applications because of its linear energy–momentum dispersion relations which cross at the Dirac point1, 2. However, accessing the physics of the low-density region at the Dirac point has been difficult because of disorder that leaves the graphene with local microscopic electron and hole puddles3, 4, 5. Efforts have been made to reduce the disorder by suspending graphene, leading to fabrication challenges and delicate devices which make local spectroscopic measurements difficult6, 7. Recently, it has been shown that placing graphene on hexagonal boron nitride (hBN) yields improved device performance8. Here we use scanning tunnelling microscopy to show that graphene conforms to hBN, as evidenced by the presence of Moiré patterns. However, contrary to predictions9, 10, this conformation does not lead to a sizeable band gap because of the misalignment of the lattices. Moreover, local spectroscopy measurements demonstrate that the electron–hole charge fluctuations are reduced by two orders of magnitude as compared with those on silicon oxide. This leads to charge fluctuations that are as small as in suspended graphene6, opening up Dirac point physics to more diverse experiments.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1038/nmat2968
