FDTD Simulation Of Al Nanostructures And Their Applications In The Ultraviolet Range

With the rapid development of Nanotechnology, metallic nanostructures have gained much attention and related reasearch gradually formed a hot research subject-- Plasmonics. Plasmonic applications include biological and chemical sensing, spectroscopy, photovoltaic, optoelectronics and so on. However, most of the research in this area is limited to precious metals(such as Au and Ag), which can only suppose the visible and near-infrared plasmon resonance. There remains a gap in this activity in the ultraviolet.Firstly, a brief description of the research background and development situation of plasmonics is briefly described in this dissertation. In particular, Al material is highlighted, which can suppose surface plasmon resonance in the ultraviolet; Secondly the finite difference time domain method is introduced; Finally, two Al-based nanostructures are simulated by the software FDTD Solutions, namely Al triangular nanoparticles and triangular-lattice hole arrays in aluminum films. In addition, we have fabricated Al triangular nanoparticle arrays, about 50 nm in lateral size, on sapphire substrate through the nanosphere lithography(NSL) method. The main contents are as follows:(1) We have made a systematic study the effect of the structural parameters and the dielectric environment of Al nanoparticles on its localized surface plasmon resonance(LSPR) properties by FDTD simulation. To further study the effect of the sapphire substrate, we have fabricated Al triangular nanoparticle arrays experimentally. And we find that the extinction spectra in the ultraviolet range are similar both in the experimental measurement and the numerical simulation.(2) Utilizing the hybridization concept and simulated electric field distribution of the Al triangular nanoparticle, we conclude that the sapphire substrate not only changes local dielectric properties of the Al nanoparticle but also acts as a medium to support the interaction between the different plasmon modes in the Al nanoparticle.(3) We have also study the effect of the Al thin film structure parameters of nanostructure holes on EOT phenomenon. On the basis of this, a new style solar blind ultraviolet band-pass filtering structure is designed, which can effectively filter the incident light whose wavelength beyond 280 nm.