Synergetic effect of Ag/PVP on nonlinear optical characteristic of rGO transparent thin films

Reduced graphene oxide (rGO)-based transparent thin films including rGO, rGO/PVP and rGO/PVP/Ag (TFs) were prepared by drop casting method. The reduction process was performed using HI vapor. The physicochemical, morphological and structural characteristics of the prepared samples were studied using different characterization methods such as X-ray diffraction analysis, scanning electron microscopy and Raman spectroscopy. The linear and nonlinear optical properties of prepared samples were evaluated by Z-scan technique using a He–Ne laser (632 nm), respectively. Results showed that the nonlinear refraction index (n2) and nonlinear absorption coefficient (β) of the prepared rGO/PVP thin film are higher than that reported before. Adding Ag NPs caused a considerable improvement in the NLO characteristics of rGO/PVP.