ABSTRACT
Many nanostructures, in particular nanostructured metals, show very particular and interesting optical properties. One of the most promising phenomena encountered in these structures is the electromagnetic resonance, due to collective oscillations of the conduction electrons, said plasmons. Under special circumstances, plasmons are excited by light; this leads to strong light scattering and absorption and increase of the local electromagnetic field. Models concerning plasmonics simulate the extinction of the localised surface plasmons resonance by nanoparticles and nanoarrays. The Di Sia model, as a generalisation of the Drude formula based on linear response theory and resonant plasmonic mode, is able to accommodate many observed phenomena and to give a detailed description of the dynamic response of carriers. The results of the model can give an explanation of the ultra-short times and of high mobilities, with which charges spread in mesoporous systems that are of great interest in photocatalitic and photovoltaic systems.
