We perform first-principles investigations of two-dimensional, triangular lattices of ${\text{Au}}_{38}$ 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 $\left(\approx 0.2{\text{nm}}^{-2}\right)$, 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.

• Received 28 March 2009

DOI:https://doi.org/10.1103/PhysRevB.80.115435