Enhanced nonlinear optical properties of the Cu2Se/RGO composites

Abstract

Tuning the third-order nonlinear optical (NLO) properties of graphene (G) is of great significance in nonlinear optics. In this work, Cu2Se/reduced graphene oxide (RGO) composites with different Cu2Se contents were prepared via a solvothermal method. The structure and morphology indicated that the Cu2Se nanoparticles were uniformly dispersed on the surface of the graphene nanosheets. The NLO properties of the composites with different Cu2Se contents were investigated via the Z-scan technique with a picosecond-pulse laser at 532 nm. The results showed that the Cu2Se/RGO composites had the properties of reverse saturated absorption (RSA) and positive nonlinear refraction, and their NLO properties could be effectively regulated by controlling the Cu2Se contents. The third-order nonlinear susceptibility of the Cu2Se/RGO composite with a 1.5:1 mass ratio of Cu2Se to graphene oxide could reach 6.52 × 10−11 esu, which increased five-fold compared to G. The introduction of Cu2Se improved the NLO response of G, which might be attributed to the content effect of Cu2Se in the composites and the synergistic effects stemming from charge transfer between the Cu2Se and RGO This paper lays a foundation for the further study on the applications of the Cu2Se/RGO composite materials in NLO devices.