Heterogeneity of Molecular Structure of Ag Photo-Diffused Ge₃₀Se₇₀ Thin Films

Silver photodiffusion in thin Ge ₃₀ Se ₇₀ films is investigated in order to understand the structure forming in the Ge-Se host after introduction of Ag in it. Optical micrographs point towards formation of homogeneous films after deposition of the Ge-Se material on glass substrate. This structure changes and occurrence of heterogeneous regions is imaged after Ag is introduced into the Ge-Se host. Raman spectroscopy provides data about the development of the structural organization in the host in depth. It confirms that while the initial non-doped films are organized in a structure corresponding to the bulk material with analogous composition, after Ag photodiffusion, the structure on the interface Ag/Ge ₃₀ Se ₇₀ film is identified as being amorphous Ag ₈ GeSe ₆ which continuously changes in depth to structure of Ge-rich material. Raman spectra testify that Ag distribution reaches the bottom of the hosting Ge ₃₀ Se ₇₀ films.