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Author Hiebel, F. ♦ Mallet, P. ♦ Magaud, L. ♦ Veuillen, J. -Y
Source arXiv.org
Content type Text
File Format PDF
Date of Submission 2009-12-04
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Natural sciences & mathematics ♦ Physics
Subject Keyword Condensed Matter - Materials Science ♦ physics:cond-mat
Abstract We present an investigation of the atomic and electronic structure of graphene monolayer islands on the 6H-SiC(000-1)(3x3) (SiC(3x3)) surface reconstruction using scanning tunneling microscopy (STM) and spectroscopy (STS). The orientation of the graphene lattice changes from one island to the other. In the STM images, this rotational disorder gives rise to various superlattices with periods in the nm range. We show that those superlattices are moir\'e patterns (MPs) and we correlate their apparent height with the stacking at the graphene/SiC(3x3) interface. The contrast of the MP in STM images corresponds to a small topographic modulation of the graphene layer. From STS measurements we find that the substrate surface presents a 1,5 eV wide bandgap encompassing the Fermi level. This substrate surface bandgap subsists below the graphene plane. The tunneling spectra are spatially homogeneous on the islands within the substrate surface gap, which shows that the MPs do not impact the low energy electronic structure of graphene. We conclude that the SiC(3 x 3) reconstruction efficiently passivates the substrate surface and that the properties of the graphene layer which grows on top of it should be similar to those of the ideal material.
Description Reference: Physical Review B 80, 235429 (2009)
Educational Use Research
Learning Resource Type Article
Page Count 24


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