Determination of the gate-tunable band gap and tight-binding parameters in bilayer graphene using infrared spectroscopy

By A. Kuzmenko, I. Crassee, D. van der Marel, P. Blake, K. Novoselov. 2009

228 citations recorded by the source corpus.

We present a compelling evidence for the opening of a bandgap in exfoliated bottom-gated bilayer graphene by fitting the gate-voltage-modulated infrared reflectivity spectra in a large range of doping levels with a tight-binding model and the Kubo formula. A close quantitative agreement between the experimental and calculated spectra is achieved, allowing us to determine self-consistently the full set of Slonczewski-Weiss-McClure tight-binding parameters together with the gate-voltage-dependent bandgap. The doping dependence of the bandgap shows a good agreement with the existing calculations that take the effects of self-screening into account. We also identify certain mismatches between the tight-binding model and the data, which can be related to electron-electron and electron-phonon interactions.

Subfields: Biomedical Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/7f750500c74137716b36bff134c0ed46653220fb

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Citations in the corpus

Nobel Lecture: Graphene: Materials in the Flatland (2011, background): “…energy (the position of the Fermi level in undoped bilayer graphene) is exactly 1, so these subbands do not contribute to electronic transport unless a very high level of doping is achieved [though these subbands can easily be observed in optical experiments (Kuzmenko et al., 2009a, 2009b)] (Fig.”
Colloquium: Graphene spectroscopy (2014, background): “16d by arrows (Kuzmenko et al., 2009b; Mak et al., 2009; Zhang et al., 2009b).”
Topological origin of subgap conductance in insulating bilayer graphene (2010, background): “In real devices this condition is satisfied when the gap is sufficiently larger than the root mean square of potential fluctuations in the bulk, which for samples on SiO2 substrate has been measured to be approximately 20 meV [25, 26].”
Colloquium: The transport properties of graphene: An introduction (2010, background): “This fact effectively smears the chemical potential and such an effect can be accounted for by considering an effective higher temperature, as was shown to be the case in the interpretation of the optical response of graphene’s bilayer (Kuzmenko et al., 2009).”
Electronic properties of graphene-based bilayer systems (2015, methodology): “The bands are calculated for non-zero t3, whose value was extracted from experiment [51] and DFT calculations [52]:”
Dirac electronic states in graphene systems: optical spectroscopy studies (2010, background): “als. These methods are likely to be of particular importance with respect to intense eﬀorts of band gap engineering in diﬀerent graphene systems [20] (e.g., graphene bilayer under the applied voltage [116, 117, 121, 115] or chemically functionalised graphene [152, 153, 154]). The problem of the spec”