Influence of doping level on the structure, texture, and nonlinear optical properties of graphene oxide/Au hybrids doped ORMOSIL gel glasses

Abstract

Graphene oxide (GO)/Au nanoparticle (NP) hybrids were introduced into nanostructured sol–gel organically modified silica (ORMOSIL) using a sol–gel technique. Scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, pore structure measurements, and UV–vis spectroscopy were performed to investigate the morphology, structure, texture, thermal stability and linear optical properties of the ORMOSIL gel glasses. The guest two-dimensional GO/Au NP hybrids maintained their own structures during the sol–gel procedure, confirming that the sol–gel technique can effectively produce graphene-based solid-state bulky composites. Increasing doping level would result in the formation of a highly porous structure, better thermal stability, and lower linear transmittance. The nonlinear optical (NLO) properties of GO/metal NP-doped ORMOSIL gel glasses were investigated using a nanosecond open-aperture Z-scan technique at 532nm. The nonlinear absorption coefficient of GO/Au NP-doped ORMOSIL gel glasses increases from 3.79cm/GW to 8.79cm/GW with increased doping level from 4.8×10−3 to 19.2×10−3. The result demonstrates that the NLO performance of the composite ORMOSIL gel glasses can be optimized by tuning the doping level of 2D GO/Au NP sheet in the matrices of the host gel glasses. The NLO behavior of GO/Au NP-doped ORMOSIL gel glasses were attributed to the combination of nonlinear absorption and nonlinear scattering.