| Noble metal nanoarrays are widely used in sensing,catalysis,fluorescence imaging,biomedicine,solar cells,surface-enhanced Raman scattering and many other fields due to their regular periodic structure arrangement and unique optical properties of local surface plasmon,it has been a research hotspot in many fields and an important frontier subject in modern material chemistry and physics for a long time.A number of studies have found that it's of great application value to modulating the local surface plasmon resonance absorption peak and bandwidth of noble metal nanoarrays.In this paper,silver nanoshpere arrays with controllable spacing were prepared by vacuum evaporation deposition and anodic oxidation,furthermore,we studied the light absorption characteristics of arrays.The main research contents are as follows:1.Preparation and optical properties of silver nanoparticles array.In this thesis,we report an assembly technology using anodic oxidation method to prepare nanobowl array as template assistant,then the fabrication of silver nanosphere array with spacing adjustable by depositing nanoparticles into the nanobowl array with vacuum evaporation method,and we discussed the influence of technological parameters on the properties of the arrays in detail.This method can be used to obtain large scale and highly ordered periodic arrays with small spacing.Next,the diameter and spacing of silver nanosphere in the arrays are adjusted just by controlling the thickness of evaporation.Furthermore,the measurement results of absorption spectra show that the nano-arrays have obvious electromagnetic wave absorption characteristics in the ultraviolet,visible and near-infrared bands.This can effectively modulate the absorption peaks and bandwidths of the silver spherical nanoarray by changing the size of nanoparticles.The finite-difference time-domain method is used to analyze the physical mechanism of light absorption characteristics in different wavebands.Experiments and numerical simulations confirm that the ultraviolet strong absorption is due to the Fano resonance induced by asymmetric dielectric environment of silver and aluminum;the visible absorption originates from local surface plasmon resonance of silver nanoparticles;the near-infrared strong absorption is attributed to the surface lattice resonance of silver nanosphere arrays.2.The response of optical properties of silver nanosphere arrays to temperature.we studied the influence of aluminum-based silver nanoarray and optical properties with different temperature by heating.The experimental results show that the shape of nanoarrays can be improved by heating at a certain temperature.In addation,the resonance peak is sensitive to the temperature in the near infrared band.When the temperature is 80?260 ?,the absorption peak moves to the short-wavelength direction;and the temperature reached about 290 ?,the absorption peak is red shifted,because the form of silver nanoparticles changed from solid to solid and liquid temporarily after being heated;we keep raising the temperature,the resonance peak is blue shifted and the peak is slightly enhanced due to silver particles melt into a sphere.However,with the appearance of particle clusters,the peak strength is also suppressed. |
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