| As the nonlinear optical technology is applied in daily life, the nonlinear opticalmaterials are of great interest. G/ZnO nanocomposites have attracted much attention due tonot only excellent electrical and optical properties of ZnO, but also new popular researchmaterial for graphene-based hybrids. At present, the research of G/ZnO nanocomposites hasmainly focused on photocatalytic, photoelectric response and super capacitor, etc. However,nonlinear optical (NLO) properties about G/ZnO nanocomposites have been seldom studied.The overall topic idea in this thesis is nonlinear optical character of G/ZnO organic glass, andthe specific work about this thesis is as follows:1. First, G/ZnO nanocomposites were synthesized by a chemical wet method, and itsstructure and morphology were analysised by XRD， SEM and TEM. Then G/ZnOnanocomposites were dispersed in polymethyl methacrylate (PMMA) to prepare G/ZnO/PMMA，ZnO/PMMA and G/PMMA organic glass with different concentrations were alsofabricated by a casting method.2. UV-vis absorption spectra for three different kinds of organic glass were measuredwith spectrometer, their nonlinear optical(NOL) characters and optical limiting(OL)properties were investigated by the open-aperture Z-scan technique. Finally, the performanceof the three kinds organic glass was compared.3. The obtained experimental data was analyzed, and it was found that G/ZnO/PMMAorganic glass exhibits enhanced reverse saturable absorption(RSA) and optical limiting (OL)properties compared to the ZnO/PMMA and G/PMMA organic glass.As the experimental results were further analyzed, it was found that the enhancement ofRSA and of OL properties of G/ZnO/PMMA organic glass are attributed to the excellenttwo-photon absorption (TPA) properties. On the basis of the energy levels of graphere andZnO, the enhanced TPA are attributed to interfacial charge transfer between ZnO andgraphene, two-dimensional (2D) π-electron conjugated structure of graphene, and small sizeeffect of ZnO nanoparticles. |
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