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arXiv · 1412.1954

Electronic Band Dispersion of Graphene Nanoribbons via Fourier-Transformed Scanning Tunneling Spectroscopy

Hajo Söde·Leopold Talirz·Oliver Gröning·Carlo Antonio Pignedoli·Reinhard Berger·Xinliang Feng·Klaus Müllen·Roman Fasel·Pascal Ruffieux
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Abstract

Atomically precise armchair graphene nanoribbons of width $N=7$ (7-AGNRs) are investigated by scanning tunneling spectroscopy (STS) on Au(111). The analysis of energy-dependent standing wave patterns of finite length ribbons allows, by Fourier transformation, the direct extraction of the dispersion relation of frontier electronic states. Aided by density functional theory calculations, we assign the states to the valence band, the conduction band and the next empty band of 7-AGNRs, determine effective masses of $0.42\pm 0.08\,m_e$, $0.40\pm 0.18\,m_e$ and $0.20\pm 0.03\,m_e$, respectively, and a band gap of $2.37\pm 0.06$ eV.

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Hajo Söde, Leopold Talirz, Oliver Gröning, Carlo Antonio Pignedoli, Reinhard Berger, Xinliang Feng, Klaus Müllen, Roman Fasel, Pascal Ruffieux. 2014-12-05. Electronic Band Dispersion of Graphene Nanoribbons via Fourier-Transformed Scanning Tunneling Spectroscopy. https://doi.org/10.1103/physrevb.91.045429

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