Kinetics of thermal and photoinduced diffusion of Ag into thin layers of chalcogenide glasses

This study examines the kinetics of thermal diffusion of silver in Ag-GeSe ₂ and Ag- As ₁₀Ge ₃₀S ₆₀ thin film structures during prolonged storage in the dark at room temperature, as well as the effects of plasmon-enhanced photostimulated diffusion of silver into As ₁₀Ge ₃₀S ₆₀ films. Ag diffraction gratings with a period of 519 nm were used to excite surface plasmon-polaritons (SPP) at the silver-chalcogenide glass interface. It was found that the thermal diffusion coefficient of silver into GeSe ₂ is significantly higher than into As ₁₀Ge ₃₀S ₆₀. For Ag– As ₁₀Ge ₃₀S ₆₀, photostimulated silver diffusion coefficients were measured with and without SPP excitation. SPP excitation triples the photostimulated Ag flux into As ₁₀Ge ₃₀S ₆₀. Although photosensitivity decreases over time, the plasmon-stimulated increase in Ag flux remains stable. Additionally, As ₁₀Ge ₃₀S ₆₀ thermally doped with silver shows much higher optical absorption at the probing wavelength compared to the photodoped layer with the same silver concentration. Possible mechanisms of these layers formation are discussed.