Graphene oxide (GO) has emerged as a carbon-based nanomaterial providing an alternative pathway to graphene. One of its most notable features is the ability to partially reduce it, resulting in graphene-like sheets through the removal of oxygen-containing functional groups. Herein, the effect of localized interactions in a Ag/GO/Au multilayer system was studied to explore its potential for photonic applications. The Ag/GO/Au structure was fabricated through a sequential deposition process. First, silver thin films (10 nm) were deposited onto glass substrates using a DC magnetron sputtering system. Subsequently, graphene oxide (GO) layers (8 nm) were applied onto the silver films via a dip-coating technique. Finally, gold thin films (15 nm) were deposited over the GO/Ag/glass substrates using the same sputtering system. Micro-Raman Spectroscopy, SEM (Scanning electron microscopy) and Variable Angle Ellipsometry measurements were performed on the Ag/GO/Au structure.
Micro-Raman measurements confirmed that the atomic frame of sp2 carbon formed in RGO (reduced graphene oxide), thus indicating the transition from sp3 (oxidized regions) to sp2 (graphitic regions) hybridization.
An interesting behavior of the GO dip-coated on magnetron sputtered silver with the formation of Ag nanostructures on top of the GO layer was reported using SEM . Furthermore, the dispersion laws estimated for the glass/Ag/GO/Au structure by ellipsometry characterization seemed to confirm the morphological behavior observed with SEM measurements . The gold thin film adjusted elastically on the GO/Ag /glass sample, without modifying its overall optical behavior, whereas the interface GO/Ag was more complex. Additionally, calculations based on effective medium theory (EMT) highlighted the potential of Ag/GO structures in multilayer hyperbolic metamaterials for photonic applications.
