Controlled Synthesis And Nonlinear Optical Properties Of Graphene/CdS Organic Glass

As the laser technology, optical communication and data storage technology areexpanding, and the nonlinear optics has attracted much attention. Due to the deepingunderstanding of science and the increasing demands of novel optical devices, the nonlinearoptical properties of nanomaterials are of great interest. In the thesis, Graphene/CdS (G/CdS)nanocomposite was first fabricated by a hydrothermal method. G/CdS nanocomposite wasthen dispersed in polymethyl methacrylate (PMMA) for preparation of organic glass by acasting method. Finally, the nonlinear optical properties of the organic glass were studied. Thecontents of the thesis are as follows:1. Synthesis of G/CdS nanocompositeG/CdS nanocomposite was fabricated by a hydrothermal method, and its structure andmorphology were characterized. It was obvious that CdS nanoparticles were deposited on thesurface of graphene uniformly, and both sides of the graphene were coated with CdSnanoparticles. HRTEM method showed the single crystal nature of CdS nanoparticles. XPSanalysis revealed a charge transfer process may occur between CdS and graphene. The resultsabove demonstrated that G/CdS nanocomposite could be successfully synthesized by thepresent method.2. Fabrication of G/CdS/PMMA organic glassG/CdSnanocomposite was dispersed in polymethyl methacrylate (PMMA) forpreparation of organic glass by a casting method. And its transparency and uniformity wereobserved. The G/PMMA and CdS/PMMA organic glass were also fabricated according to thesame method as comparisons.3. The nonlinear optical properties of G/CdS/PMMAThe nonlinear optical properties of G/CdS/polymethyl methacrylate (G/CdS/PMMA)organic class were studied. It was found that G/CdS/PMMA organic class exhibited betternonlinear optical properties than those of G/PMMA and CdS/PMMA organic glass. Moreover,NLO properties of the G/CdS/PMMA organic glass can be controlled by adjusting the addition amount of G/CdS nanocomposite in PMMA. It was proved that (G/CdS)7.8/PMMAorganic glass had the best nonlinear optical properties among these glasses via UV-vis methodand Z-scan technique.