Optical Properties Of Nickel And Zinc-oxide Microstructures Based On Two-dimensional Colloidal Crystal Template

In this thesis, two-dimensional metallic half shell structures were first prepared by physically depositing a thin film of metal layer onto the self-assembled two-dimensional colloidal crystals. We investigated surface plasmons supported on the half shell arrays and the effect of refractive index of environment medium on the plasmonic properties. Furthermore, the as-prepared metallic half shell arrays were used as electrodes to electrochemically grow morphology-controllable zinc-oxide shell arrays. We also experimentally characterized photoluminescence properties of the prepared zinc-oxide shell arrays. The main results of this work are described as follows:1. We successfully prepared large-area highly-ordered two-dimensional colloidal crystals by micro-channel self-organization techniques. Metallic half shell arrays were obtained by vacuum sputtering a thin film of gold layer onto the silica colloidal crystal templates and subsequently removing silica colloidal crystals in hydrofluoric acid solutions. The plasmonic resonance frequencies are very sensitive to the refractive index of environment medium. It was found that the refractive index sensitivity of such half shell arrays could be as high as1026nm/RIU. Therefore, we hope such metallic half-shell arrays have potential applications such as trace detection and analysis in biological and chemical fields.2. We employed a flat ITO glass substrate as working electrode to electrochemically grow nickel within the pores of the colloidal crystals. The height of the inversed nickel opal microstructures could be precisely controlled by controlling the electrochemical deposition time. Furthermore, we employed two-dimensional metallic half-shell arrays as working electrodes to electrochemically grow zinc oxides within the spherical voids of polymer matrix. By tuning the electrochemical deposition time, zinc oxides half-shell and complete-shell microstructures have been obtained. As an initial step, we also experimentally characterized the photoluminescence spectra of the prepared zinc oxide microstructures. We hope such morphology, size and composition controllable metal and metal oxide microstructures prepared by the combination of template method and electrochemical method could provide variant research platforms for studying the magnetic and photoluminescence related properties.