Journal ArticleDOI
Edge state in graphene ribbons: Nanometer size effect and edge shape dependence.
TLDR
It is found that a non-negligible edge state survives even in graphene ribbons with less developed zigzag edges, when the system size is on a nanometer scale.Abstract:
Finite graphite systems having a zigzag edge exhibit a special edge state. The corresponding energy bands are almost flat at the Fermi level and thereby give a sharp peak in the density of states. The charge density in the edge state is strongly localized on the zigzag edge sites. No such localized state appears in graphite systems having an armchair edge. By utilizing the graphene ribbon model, we discuss the effect of the system size and edge shape on the special edge state. By varying the width of the graphene ribbons, we find that the nanometer size effect is crucial for determining the relative importance of the edge state. We also have extended the graphene ribbon to have edges of a general shape, which is defined as a mixture of zigzag and armchair sites. Examining the relative importance of the edge state for graphene ribbons with general edges, we find that a non-negligible edge state survives even in graphene ribbons with less developed zigzag edges. We demonstrate that such an edge shape with three or four zigzag sites per sequence is sufficient to show an edge state, when the system size is on a nanometer scale. The special characteristics of the edge state play a large role in determining the density of states near the Fermi level for graphite networks on a nanometer scale.read more
Citations
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The rise of graphene
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TL;DR: In this paper, the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations, are discussed.
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Energy band-gap engineering of graphene nanoribbons.
TL;DR: It is found that the energy gap scales inversely with the ribbon width, thus demonstrating the ability to engineer the band gap of graphene nanostructures by lithographic processes.
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Raman spectroscopy in graphene
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Journal ArticleDOI
Electronic Confinement and Coherence in Patterned Epitaxial Graphene
Claire Berger,Claire Berger,Zhimin Song,Xuebin Li,Xiaosong Wu,Nate Brown,Cécile Naud,Didier Mayou,Tianbo Li,J. Hass,Alexei Marchenkov,Edward H. Conrad,Phillip N. First,Walt A. de Heer,Walt A. de Heer +14 more
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