Spectroscopic and morphological study of graphene nanoplatelets thin films on Si/SiO2 substrates

In recent years, graphene nanoplatelets (GNPs) have emerged as innovative materials to be exploited for several applications. Nevertheless, the optical properties of GNPs thin films have not been studied yet. In this study, an exfoliation synthesized GNPs dispersion was dip-coated on Si/SiO substrates and GNPs thin films were studied by means of Variable Angle Spectroscopic Ellipsometry (VASE) in the [300-1000] nm wavelength range. Ellipsometry data was analyzed using a set of Gaussian oscillators. Moreover, the morphological and structural properties were investigated by Scanning Transmission Electron Microscopy (STEM), Scanning Electron Microscopy (SEM) and Micro-Raman Spectroscopy. Our results indicate that GNPs thin films have a lower optical density in comparison to other graphene related materials films.