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arXiv · 0908.0672

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

A. B. Kuzmenko·I. Crassee·D. van der Marel·P. Blake·K. S. Novoselov
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Abstract

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.

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A. B. Kuzmenko, I. Crassee, D. van der Marel, P. Blake, K. S. Novoselov. 2009-08-05. Determination of the gate-tunable bandgap and tight-binding parameters in bilayer graphene using infrared spectroscopy. https://doi.org/10.1103/physrevb.80.165406

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