Graphene-metal interfaces: a new playground for nanoscience
Privatdoz. Dipl.-Ing. Dr.techn. Florian Mittendorfer
Computational Materials Science, Institut für Angewandte Physik,Technische Universität Wien
17:00 - 18:00 Tuesday 17 December 2013 KFU HS 5.01 The experimental isolation of a single layer of graphite, graphene, and the discovery of its unique electronic properties have led to a surge of experimental and theoretical studies. While numerous promising graphene-based applications have been suggested, ranging from novel sensors to materials for spintronics or energy applications, the fundamental understanding of the interaction of a graphene sheet with a substrate are still lacking.
In this talk, I will briefly discuss the shortcomings of the present workhorse of materials modeling, density functional theory (DFT), for the description of the graphene-metal interface, and show that a many-body (RPA) approach [1] allows to recapture the relevant non-local (van der Waals) contributions. On the basis of these calculations, we find that even in the case of graphene/Ni(111), where a “strong” interaction has been proposed, the adsorption is driven by subtle electronic effects [2].
By mapping the many-body calculations on a computationally cheaper approach we could also investigate several applied aspects of the graphene-metal interfaces. While the growth of a high-quality graphene film on Ni substrate is indeed facilitated by low barriers for the healing of defects [3], it is often preceded by the formation of a Ni2C surface carbide [4]. In the final part, I will show how the interaction strength can be tuned by the intercalation of metallic adlayers, leading to the formation of nanostructured templates.
[1]L. Schimka, et al., Nature Materials 9, (2010) 741.
[2] F. Mittendorfer, et al., Phys. Rev. B 84, (2011) 201401.
[3] P. Jacobson, et al., J. Phys. Chem. Lett. 3 (2012) 136.
[4] P. Jacobson, et al., ACS Nano 6 (2012) 3564.
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