Graphene-covered sandwich nanostructure for enhanced light absorption

At present, the combination of graphene and metal nanostructures is explored for strong light–matter interaction. In this study, the optical properties of a composite nanostructure are studied experimentally by simply coating a monolayer graphene on a sandwich nanostructure (Ag nanoparticles–SiO2 film–Ag nanoparticles) fabricated via oblique angle deposition. Results indicate that graphene coverage leads to enhanced light absorption in the visible range. The simulation results show that the interaction between graphene and nanoparticles plasmons increase the light absorption originating from the strong localized electric field of graphene. In addition, the light–graphene interaction can be tuned via plasmon resonance by changing the size of nanoparticles and the thickness of the SiO2 film. The simplicity of the fabrication process and the tunability of plasmon resonance makes the application of graphene-covered nanostructures in diverse areas promising.