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arXiv · 0808.2283

Structure, Stability, Edge States and Aromaticity of Graphene Ribbons

Tobias Wassmann·Ari P. Seitsonen·A. Marco Saitta·Michele Lazzeri·Francesco Mauri
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Abstract

We determine the stability, the geometry, the electronic and magnetic structure of hydrogen-terminated graphene-nanoribbons edges as a function of the hydrogen content of the environment by means of density functional theory. Antiferromagnetic zigzag ribbons are stable only at extremely-low ultra-vacuum pressures. Under more standard conditions, the most stable structures are the mono- and di-hydrogenated armchair edges and a zigzag edge reconstruction with one di- and two mono-hydrogenated sites. At high hydrogen-concentration ``bulk'' graphene is not stable and spontaneously breaks to form ribbons, in analogy to the spontaneous breaking of graphene into small-width nanoribbons observed experimentally in solution. The stability and the existence of exotic edge electronic-states and/or magnetism is rationalized in terms of simple concepts from organic chemistry (Clar's rule)

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Tobias Wassmann, Ari P. Seitsonen, A. Marco Saitta, Michele Lazzeri, Francesco Mauri. 2008-08-17. Structure, Stability, Edge States and Aromaticity of Graphene Ribbons. https://doi.org/10.1103/physrevlett.101.096402

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