Substrate-induced bandgap opening in epitaxial graphene.

By Shuyun Zhou, G. Gweon, A. Fedorov, P. First, W. D. Heer, D. Lee, Francisco Guinea, A. C. Castro Neto, Alessandra Lanzara. Nature Materials, 2007

2,096 citations recorded by the source corpus.

Graphene has shown great application potential as the host material for next-generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is the lack of an energy gap in its electronic spectra. This, for example, prevents the use of graphene in making transistors. Although several proposals have been made to open a gap in graphene's electronic spectra, they all require complex engineering of the graphene layer. Here, we show that when graphene is epitaxially grown on SiC substrate, a gap of approximately 0.26 eV is produced. This gap decreases as the sample thickness increases and eventually approaches zero when the number of layers exceeds four. We propose that the origin of this gap is the breaking of sublattice symmetry owing to the graphene-substrate interaction. We believe that our results highlight a promising direction for bandgap engineering of graphene.

Subfields: Biomedical Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/5790254951d588d493a7a22a300cdff48cc24967

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Citations in the corpus

The formation of an energy gap in graphene on ruthenium by controlling the interface (2010, background): ““kinking”) of the bands due to electron-plasmon scattering[12, 13, 14, 15, 16, 17, 18] or else due to symmetry breaking due to substrate bonding as outlined above[19, 20].”
A topological Dirac insulator in a quantum spin Hall phase (2008, background): “1, but its spin-orbit coupling is several orders of magnitude weaker [3], and the only known method of inducing a gap in the Dirac spectrum of graphene is by coupling to an external chemical substrate [20].”
Colloquium: Graphene spectroscopy (2014, background): “An alternative interpretation of the apparent nonlinearity of the Dirac spectrum of graphene on SiC invokes a substrate-induced band gap (Zhou et al., 2007; Benfatto and Cappelluti, 2008; Kim et al., 2008; Zhou, Siegel, Fedorov, Gabaly et al., 2008; Zhou, Siegel, Fedorov, and Lanzara, 2008b); see Se”
Dirac electronic states in graphene systems: optical spectroscopy studies (2010, background): “ well-known and the basis of the graphene physics is pretty well established. Despite relevant advances in various experimental techniques, such as angular resolved photoemission spectroscopy (ARPES) [23, 24, 25, 26] or scanning tunnelling spectroscopy (STS) [27, 28, 29], a large part of our knowled”