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TT: Fachverband Tiefe Temperaturen

TT 29: Graphene: Structural Properties (organized by O)

TT 29.6: Vortrag

Montag, 31. März 2014, 17:15–17:30, WIL C107

Ab initio study of graphene on O-intercalated Ir(111) surface and its functionalization via molecular adsorption — •Vasile Caciuc, Nicolae Atodiresei, and Stefan Blügel — Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

To integrate graphene in molecular electronics and spintronics devices it is crucial to understand how the strength of the graphene–metal electrode interaction can be specifically tuned. One possibility to loose or strengthen this interaction is to intercalate adatoms with different chemical reactivity between graphene and the metal surface in question. We will analyse this approach from first principles by considering the case of the O-intercalated graphene on Ir(111) [1]. Another path is to analyse how the adsorption of π−conjugated organic molecules can affect the electronic structure of a quasi-freestanding graphene layer. We investigated this issue by performing spin-polarized density functional theory (DFT) for a trioxotriangulene-derivate molecule [2] on graphene. Importantly, as already demonstrated in [3], for such systems it is mandatory to include the dispersion interaction and in our ab initio study these long-range van der Waals interactions were considered at a semi-empirical [4] or first-principle [5] level.

[1] E. Grånäs et al., ACS Nano. 6, 9951 (2012).

[2] Y. Morita et al., Nat. Mater. 10, 946 (2011).

[3] C. Busse et al., Phys. Rev. Lett. 107, 036101 (2011).

[4] S. Grimme, J. Comput. Chem. 27, 1787 (2006).

[5] M. Dion et al., Phys. Rev. Lett. 92, 246401 (2004).