Preparation of solution-processed thin films of As-S-Se system from As40S60 solution modified by amorphous selenium

This work presents the possibility of As-S-Se chalcogenide glass thin film preparation from a solution of commercially available As40S60 glass by modification of the solution composition with elemental selenium. We studied the dissolution of elemental selenium in n-butylamine and ethylenediamine based chalcogenide glass solutions. Samples of four compositions ranging from 0% selenium content (pure As40S60) to 30% selenium content (As28S42Se30) were prepared by spin-coating in specular optical quality with low surface roughness (below 1 nm). Structure, refractive index, optical band gap, organic residua content, and chemical resistance were studied in dependence on the annealing temperature. The structure was studied using Raman spectroscopy, and the data suggest incorporation of selenium into the glass structure already in the solution, which resulted in an increased refractive index and reduced optical band gap of deposited thin films. Due to chalcogen over-stoichiometry, modified thin films have lower organic residua content.