Study On Structure And Optical Properties Of Nanoparticles(NPs)-CuSiO₂ Multilayers Films Prepared By Magnetron Sputtering

As a new material with optical performance,the composite film is consist of nanometer-sized metal particles embedded in dielectric matrices.The nanometer-sized metal particles show several optical properties,such as surface plasmon resonance(SPR),photoluminescence performance and surface enhanced Raman spectroscopy(SERS),among which the SPR is the main optical response characteristic.Since the SPR and the local field enhancement effect of the nanometer-sized metal particles,the film presents quite strong non-linear optical effect with high nonlinear optical susceptibility,rapid time response and so on.That characteristic brings the film wide applications in optical communication domain such as wave separator,optical switch and optical sensor.Nanoparticles(NPs)-Cu/SiO₂ multilayers films were deposited by RF and DC magnetron sputtering technique in alternating deposition method with different Cu target power and substrate temperature.The microstructure and optical properties of the NPs-Cu/SiO₂ multilayers films were characterized and analyzed by X-ray diffraction(XRD);Transmission Electron Microscop(TEM)and ultraviolet-visible spectrophotometer(UV-VIS).The influences of Cu target power,substrate temperature and the number of Cu layers on phase structure,microstructure and optical properties were studied.After that,NPs-CuO/SiO₂ multilayers films were prepared by in-situ oxidized NPs-Cu/SiO₂ multilayers films.The influences of Cu target power,heat treatment temperature and the number of CuO layers on phase structure,microstructure and optical properties were studied.The results showed that the films of layered configuration are formed by alternately stacking amorphous SiO₂ and copper phases.It is vertified that the particle shape is almost spherical in the substrate normal direction when deposited the films at 400?.The optical absorption peak due to the surface plasmon resonance of Cu nanoparticles was observed at the wavelength range from 590 to 660 nm.With increasing the Cu target power,the mean diameter of particles increased,the space among nanoparticles decreased,the SPR peak enhanced and showed a red-shift trend.On the contrary,with increasing the substrate temperature,the SPR peak showed a blue-shift trend.Besides,due to the effect of interlayer coupling interaction of Cu nanoparticles,the SPR peak showed a blue-shift trend with increasing the number of Cu layers.The main phase of NPs-CuO/SiO₂ multilayer films was monoclinic CuO phase and the absorption peak of CuO nanoparticles was observed at 380 nm.With the increase of Cu target power,the size of CuO nanoparticals grown,the absorption peak showed blue-shift due to the presence of CuO surface defects.With the number of CuO layers increase,the intensity of absorption peaks increased but the position did not move.Besides,CuO films have great photocatalytic property.The results of NPs-Cu/SiO₂ films and NPs-CuO/SiO₂ films indicate that the size and distribution of Cu nanoparticles can be controlled,which will in turn further control the SPR peak.