Wavelength-Dependent Nonlinear Optical Absorption and Broadband Optical Limiting in Au-Fe2O3-rGO Nanocomposites

Abstract

Broadband optical limiting and wavelength-dependent nonlinear absorption studies of Au-Fe2O3-(15, 25, 40 wt %)rGO (reduced graphene oxide) nanocomposites were investigated using the Z-scan technique and excited with femtosecond (700–900 nm, 80 MHz, 150 fs) laser pulses. A reduction in the graphene perfect (La) domain and ID/IG ratio observed in the Raman data and the appearance of a Au 4f and Fe 2p singlet along with a shift in the C 1s state toward higher energy in the XPS data, peak broadening in the XRD data, and different mass residues left out with respect to content of rGO in the TG-DTA data strongly indicated the incorporation of Au-Fe2O3 nanostructures on solar exfoliated reduced graphene oxide. Selected aread electron diffraction data ascertained the presence of Au and Fe2O3 as a composite, and transmission electron microscopy (TEM) data revealed that the nano-octahedra Au-Fe2O3 turned themselves into nanospindles during incorporation of rGO. Ground state absorption spectra illustrated a pure and...