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

Abstract

This study examines the kinetics of thermal diffusion of silver in Ag-GeSe₂ and Ag- As₁₀Ge₃₀S₆₀ 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 As₁₀Ge₃₀S₆₀ 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 GeSe₂ is significantly higher than into As₁₀Ge₃₀S₆₀. For Ag– As₁₀Ge₃₀S₆₀, photostimulated silver diffusion coefficients were measured with and without SPP excitation. SPP excitation triples the photostimulated Ag flux into As₁₀Ge₃₀S₆₀. Although photosensitivity decreases over time, the plasmon-stimulated increase in Ag flux remains stable. Additionally, As₁₀Ge₃₀S₆₀ 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.