Thin films were deposited by thermal evaporation, and thermally activated Ag diffusion into the films was studied. Visible UV transmission and Rutherford back-scattering spectrometry were used to characterize property changes during Ag incorporation. A straightforward analysis (Swanepoel), which permitted determination of the dispersion relation and the film thickness from optical transmission spectra, was here extended and applied to chalcogenide thin films. Rutherford back-scattering showed that the Ag diffusion mechanism depended strongly upon an annealing between the chalcogenide and Ag deposition steps. Without annealing, Ag diffusion took place via exchange between Ag and As atoms while S atoms remained stationary and As accumulation occurred at the surface. In annealed samples, the Ag diffused without changing the film stoichiometry. In this case, diffusion was much slower and the profile was more step-like.

Thermally Activated Silver Diffusion in Chalcogenide Thin Films. J.Fick, B.Nicolas, C.Rivero, K.Elshot, R.Irwin, K.A.Richardson, M.Fischer, R.Vallée: Thin Solid Films, 2002, 418[2], 215-21