Mechanism of the dissolution of As–S chalcogenide glass in n-butylamine and its influence on the structure of spin coated layers

• The structure of prepared As–S glass aliphatic amine solutions was studied by Raman spectroscopy.
• The dissolution mechanism of As–S glasses involving amine–sulfur reaction was proposed.
• The structure of as-prepared and annealed spin-coated thin layers was studied.
• New As–S salt Raman band was assigned in Raman spectra of deposited thin layers.

Chalcogenide glass thin layers are useful to many practical applications especially for the fabrication of infrared (IR) optical elements. In comparison to the conventional vacuum deposition methods of their preparation, recently chemical methods such as spin coating are gaining attention. They involve dissolution of the source bulk glass in appropriate solvent and then depositing its thin layer. Chemical processes occurring during the glass dissolution and thin layer deposition determine the physico-chemical properties of deposited thin layers. The structure of chalcogenide bulk glasses (AsxS100 − x, where 30 ≤ × ≤ 40) and their solutions in n-butylamine have been studied in this work by Raman spectroscopy. From the composition and time dependence of Raman spectra of solutions the mechanism of arsenic–sulfur glass dissolution involving the reaction of aliphatic amine solvent with homopolar SS bonds is proposed and the presence of alkyl ammonium arsenic sulfide salts in thin layers is established.