Crystallization effects in annealed thin GeS₂ films photodiffused with Ag

We have investigated the diffusion products occurring after photodiffusion of Ag in GeS₂ films at room temperature and after annealing up to 430 °C. Quantitative data regarding the host film composition and the amount of diffused silver has been gathered using Rutherford backscattering spectrometry. The structure of the glassy host and the changes appearing after silver photodiffusion and annealing are characterized using Raman spectroscopy. The crystalline diffusion products are depicted and their size calculated using X-ray diffraction. We have found that silver reacts with the host to form Ag₂S and Ag₂GeS₃ and this leads to formation of Ge-rich backbone and overall nanostructured heterogeneous medium. Annealing at temperatures close to the glass transition temperature affects the backbone and brings about the appearance of a new diffusion product - Ag₈GeS₆.