Ag-photodoping in Ge-chalcogenide amorphous thin films—Reaction products and their characterization

We make a brief review on the effect of silver photodiffusion in Ge-chalcogenide glasses and report some of our recent results in this aspect. Using Raman spectroscopy and X-ray diffraction analysis we demonstrate that the hosting backbone undergoes depletion in chalcogen due to the specific conditions of photodiffusion and the diffusion products are silver chalcogenides. While in the Ge–Se system preliminary binary Ag—chalcogenides are forming, in the Ge–S system formation of Ag2GeS3 is evidenced. This effect is related to the ability of the Ge–S glasses to form ethane—like structure at much lower Ge concentration than the Ge–Se glasses. For this type of structures is known that Ag replaces Ge to form homogeneous material, hence formation of Ag-containing ternary occurs. r 2007 Elsevier Ltd. All rights reserved.