Browsing by Author "Kunstmann, Jens"

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Citation Count: Quandt, Alexander; Ozdogan, Cem; Kunstmann, Jens, "Functionalizing graphene by embedded boron clusters", Nanotechnology, Vol.19, No.33, (2008).
Functionalizing graphene by embedded boron clusters
(IOP Publishing LTD, 2008) Quandt, Alexander; Özdoğan, Cem; Kunstmann, Jens; Fehske, Holger; 40569
We present a model system that might serve as a blueprint for the controlled layout of graphene based nanodevices. The systems consists of chains of B-7 clusters implanted in a graphene matrix, where the boron clusters are not directly connected. We show that the graphene matrix easily accepts these alternating B-7-C-6 chains and that the implanted boron components may dramatically modify the electronic properties of graphene based nanomaterials. This suggests a functionalization of graphene nanomaterials, where the semiconducting properties might be supplemented by parts of the graphene matrix itself, but the basic wiring will be provided by alternating chains of implanted boron clusters that connect these areas.
Citation Count: Özdoğan, Cem; Kunstmann, Jens; Quandt, A., "Localization of metallicity and magnetic properties of graphene and of graphene nanoribbons doped with boron clusters" Philosophical Magazine, Vol.94, No.16, pp.1841-1858, (2014).
Localization of metallicity and magnetic properties of graphene and of graphene nanoribbons doped with boron clusters
(Taylor&Francis INC, 2014) Özdoğan, Cem; Kunstmann, Jens; Quandt, A; 40569
As a possible way of modifying the intrinsic properties of graphene, we study the doping of graphene by embedded boron clusters with density functional theory. Cluster doping is technologically relevant as the cluster implantation technique can be readily applied to graphene. We find that B-7 clusters embedded into graphene and graphene nanoribbons are structurally stable and locally metallize the system. This is done both by the reduction of the Fermi energy and by the introduction of boron states near the Fermi level. A linear chain of boron clusters forms a metallic "wire" inside the graphene matrix. In a zigzag edge graphene nanoribbon, the cluster-related states tend to hybridize with the edge and bulk states. The magnetism in boron-doped graphene systems is generally very weak. The presence of boron clusters weakens the edge magnetism in zigzag edge graphene nanoribbon, rather than making the system appropriate for spintronics. Thus, the doping of graphene with the cluster implantation technique might be a viable technique to locally metallize graphene without destroying its attractive bulk properties.