Fabrication And Optical Properties Of Au Nanoparticle Array

The most unique optical property of noble metal nanoparticle is the strong absorption band that is absent in bulk metal, which is due to the collective resonance of the conductive electrons in response to an incident light. The surface plasmon resonance spectrum is strongly dependent on the size, shape, distribution of metal nanoparticles and dielectric environment. In this dissertation, some theoretical and experimental studies on Au periodical array are presented:(1) Combined Nanosphere Lithography with pulsed laser deposition technique, Au nanoparticles with different height have been fabricated on quartz substrates. From scanning electron microscopy image, the closed-packed nanosphere mask and periodical array of Au triangular-shaped nanoprisms can be observed. After the annealing treatment, the particles height increases and the shape turns round.(2) By measuring UV-visible absorption spectroscopy, the strong absorption band in the visible range caused by surface plasmon resonance of Au particles can be found. The effect of the annealing treatment is also investigated. Furthermore, theoretical calculation based on the discrete dipole approximation was performed. The experimental and theoretical results showed that the absorption peaks of the Au nanoparticles shift to the blue as the out-of-plane height increases. The annealing treatment leads to the blue shift of the absorption peaks of the Au nanoparticles, and the absorption peak become sharper and stronger.(3) The elementary results on the third order nonlinear property of Au nanoparticles and the effect of the removal of copper oxides are presented.