Electronic band dispersion of graphene nanoribbons via Fourier-transformed scanning tunneling spectroscopy

Soede H, Talirz L, Groning O, Pignedoli CA, Berger R, Feng X, Muellen K, Fasel R, Ruffieux P (2015)

Publication Type: Journal article

Publication year: 2015

Journal

Physical Review B - Condensed Matter and Materials Physics American Physical Society (APS)

Book Volume: 91

Article Number: 045429

Journal Issue: 4

DOI: 10.1103/PhysRevB.91.045429

Abstract

The electronic structure of atomically precise armchair graphene nanoribbons of width N=7 (7-AGNRs) are investigated by scanning tunneling spectroscopy (STS) on Au(111). We record the standing waves in the local density of states of finite ribbons as a function of sample bias and extract the dispersion relation of frontier electronic states by Fourier transformation. The wave-vector-dependent contributions from these states agree with density functional theory calculations, thus enabling the unambiguous assignment of the states to the valence band, the conduction band, and the next empty band with effective masses of 0.41±0.08me,0.40±0.18me, and 0.20±0.03me, respectively. By comparing the extracted dispersion relation for the conduction band to corresponding height-dependent tunneling spectra, we find that the conduction band edge can be resolved only at small tip-sample separations and has not been observed before. As a result, we report a band gap of 2.37±0.06 eV for 7-AGNRs adsorbed on Au(111).

Involved external institutions

Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology CH Switzerland (CH) Max-Planck-Institut für Polymerforschung (MPI-P) / Max Planck Institute for Polymer Research DE Germany (DE)

How to cite

APA:

Soede, H., Talirz, L., Groning, O., Pignedoli, C.A., Berger, R., Feng, X.,... Ruffieux, P. (2015). Electronic band dispersion of graphene nanoribbons via Fourier-transformed scanning tunneling spectroscopy. Physical Review B - Condensed Matter and Materials Physics, 91(4). https://doi.org/10.1103/PhysRevB.91.045429

MLA:

Soede, Hajo, et al. "Electronic band dispersion of graphene nanoribbons via Fourier-transformed scanning tunneling spectroscopy." Physical Review B - Condensed Matter and Materials Physics 91.4 (2015).

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