Surface-plasmon resonance-wavelength control of graphene surfaces containing metal nanoparticles

Self-assembled silver nanoparticles were synthesized on a graphene surface to investigate the surface plasmon effect. Graphene films were synthesized on glass substrates by using a chemical vapor deposition method and transfer process. Various sizes of silver nanoparticles were formed using a thermal evaporator and a post-annealing process. The size of the silver nanoparticles was measured using a scanning electron microscope. The surface-plasmon resonance wavelength was measured using the absorbance spectrum, and we confirmed that the resonance wavelength could be controlled from 396 nm to 425 nm according to the size of the silver nanoparticles on the graphene surface. We confirmed a strong surface-plasmon resonance effect by using Raman spectroscopy. In addition, the surface-plasmon effect for graphene with aluminum was investigated in the same way, but the surface plasmon effect could not be observed. The results show that the surface-plasmon resonance wavelength of graphene films can be controlled by changing the size of the silver nanoparticles on the graphene surface.