Plasmon-Induced Electric Effects in Plasmonic Surfaces

The project "Plasmon-Induced Electric Effects in Plasmonic Surfaces" has been devoted to the exploration of plasmon-induced electric effects in metal nanostructured systems, in order to better understand the nature of these effects and explore possible applications. The plasmon related enhancement in photoinduced electric currents has been studied in metal structures and metasurfaces with various profile geometries. It was found that 1D periodically modulated structures with relatively high amplitudes of profile modulation show a sharp switching in the photovoltage polarity around the surface plasmon polariton resonance conditions. This finding presents new opportunities for applications, in particular, in plasmonic-based sensing allowing one to use a compact electric detection instead of bulk optical setup. Itwas demonstrated that small changes in the refractive index (n=0.001) or a presence of a monolayer on the surface could be ultimately resolved with switching in photovoltage polarity, which is not possible with traditional optical detection. Systematic experimental data has been obtained on the photoinduced electric effects which take place in various materials (gold, silver, aluminum,copper, platinum and permalloy) under plasmon resonance conditions in the dependence on the wavelength of illumination and surface geometry (films or gratings).Experiments show that the photo responses exhibit a general decrease with an increase in the wavelength and strongly vary depending upon the material in the contrast to the theoretical predictions of the existing plasmonic pressure model.