Plasmon-enhanced photostimulated diffusion in a thin-layer Ag–GeSe2 structure

This work studies photostimulated diffusion of silver, enhanced by a plasmon field, into GeSe2 thin films. To ensure the excitation of surface plasmon polaritons (SPP) at the interface between Ag and GeSe2, silver diffraction gratings substrates were used, on which chalcogenide layers were deposited by thermal evaporation in vacuum. The samples were exposed to the p-polarized radiation of a He-Ne laser. The kinetics of photostimulated processes was studied by recording the changes in SPP characteristics with exposure. It has been established that at the initial stage of the photodiffusion process, SPP excitation at the Ag/GeSe2 interface during exposure results in a fourfold increase in the photostimulated flux of silver ions. The concentrations of photodissolved silver in the chalcogenide layer are estimated. The mechanism of photostimulated diffusion of Ag in GeSe2 and its features in such thin-layer structures, as well as a possible mechanism of plasmon-stimulated acceleration of this process, is discussed.