Determination of the gate-tunable band gap and tight-binding parameters in bilayer graphene using infrared spectroscopy
- Departement de Physique de la Matiere Condensee, Universite de Geneve, CH-1211 Geneve 4 (Switzerland)
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.
- OSTI ID:
- 21287095
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 80, Issue 16; Other Information: DOI: 10.1103/PhysRevB.80.165406; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
Similar Records
Gate-tunable bandgap in bilayer graphene
Infrared spectroscopy of electronic bands in bilayer graphene