Modifications in graphene electron states due to a deposited lattice of Au nanoparticles: Density functional calculations

We perform first-principles investigations of two-dimensional, triangular lattices of Au-38 nanoparticles deposited on a graphene layer. We find that lattices of thiolate-covered nanoparticles cause electronic structure modifications in graphene such as minigaps, charge transfer, and new Dirac points, but graphene remains metallic. In contrast, for a moderate coverage of nanoparticles (approximate to 0.2 nm(-2)), a lattice of bare (noncovered) Au nanoparticles may induce periodic deformations on the graphene layer leading to the opening of a band gap of a few tens of meV at the Dirac point, in such a way that a properly charged system might become a semiconductor.