All wet preparation of Ag-As33S67 thin films by silver ions photodiffusion from silver nitrate solution

Abstract

Amorphous As33S67 thin films were prepared by spin-coating method from n-butylamine based glass solution as well as by thermal evaporation. Thin films were doped by silver ions from a solution of silver nitrate in dimethylsulfoxide. The influence of illumination on the photodoping kinetics was studied in dependence on the deposition technique and thermal pre-history of solution processed As33S67 thin films. Doped thin films maintained good optical quality, decreased optical bandgap and increased refractive index were observed with increasing silver content. Highly doped thin films remained amorphous. A hypothesis explaining observed significant differences in doping mechanisms between solution processed and thermally evaporated samples was proposed based on structural differences and organic residua content. Described procedure simplifies the silver doping technique and our findings proved, that it is suitable for all wet processes, thus excluding the necessity for vacuum deposition of solid silver film.