Raman spectrum of graphene coated nano-holes

It was assumed in the past that aluminum is not a platform of choice for surface enhanced Raman scattering (SERS) experiments: this was in spite of its large negative permittivity value, larger than gold or silver at optical wavelength. It was also assumed that any oxide on top of metallic platform significantly hinders SERS signals. In addition, graphene has not been studied on perforated substrates. Here we use periodically perforated and oxidized aluminum surfaces to examine electrical and optical properties of multi layered graphene. Linear and nonlinear optical methods were used to characterize single and multi layered structures.