Graphene Properties by Functionalization with Organic Molecules

We review first the unique band structure of graphene and explain how the linear dispersion near the Fermi level determines the so called Dirac cones and relativistic effects. Then we will deal with simple organic moieties on graphene and discuss the modification of the electronic structure of the pristine graphene by donor and acceptor chemisorbed radicals and physisorbed molecules. The peculiar magnetism induced by functionalization with chemisorbed molecules is accounted for. For excited organic molecules we will outline the charge transfer process to graphene. Electron core-level excitations to the valence shell will be considered as in the measurements of transfer times by resonant spectroscopies. The lifetimes for charge transfer are considered and possible applications outlined. Femtomagnetism in graphene with core-excited adsorbates is presented together with its implications for magnetic ordering. The electric conduction in single molecular switches with graphene electrodes is analyzed. Finally, the properties of functionalized graphene as sensor are summarized.