title: Förster-Induced Energy Transfer in Functionalized Graphene.
abstract: Carbon nanostructures are ideal substrates for functionalization with molecules since they consist of a single atomic layer giving rise to an extraordinary sensitivity to changes in their surrounding. The functionalization opens a new research field of hybrid nanostructures with tailored properties. Here, we present a microscopic view on the substrate-molecule interaction in the exemplary hybrid material consisting of graphene functionalized with perylene molecules. First experiments on similar systems have been recently realized illustrating an extremely efficient transfer of excitation energy from adsorbed molecules to the carbon substrate, a process with a large application potential for high-efficiency photovoltaic devices and biomedical imaging and sensing. So far, there has been no microscopically founded explanation for the observed energy transfer. Based on first-principle calculations, we have explicitly investigated the different transfer mechanisms revealing the crucial importance of Förster coupling. Due to the efficient Coulomb interaction in graphene, we obtain strong Förster rates in the range of 1/fs. We investigate its dependence on the substrate-molecule distanceRand describe the impact of the momentum transferqfor an efficient energy transfer. Furthermore, we find that the Dexter transfer mechanism is negligibly small due to the vanishing overlap between the involved strongly localized orbital functions. The gained insights are applicable to a variety of carbon-based hybrid nanostructures.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Ermin
authors.initials: E
authors.lastname: Malic
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Appel
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Oliver T
authors.initials: OT
authors.lastname: Hofmann
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany ; Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Universidad del Pais Vasco , Avenida de Tolosa 72, E-20018 Donostia, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Rubio