Physico-chemical properties of spin-coated Ag–As–Sb–S films

We have prepared amorphous chalcogenide films with composition of Agx(As0.27Sb0.06S0.67)100−x, where x = 0, 5, 10 and 15 at.%, using spin-coating technique from butylamine solution. The films were heated in vacuum furnace at 90 °C and 5 Pa. The compositions of the films have been established by Energy-Dispersive X-ray analysis and they were similar to the composition of glass used for solutions preparation. Raman spectroscopy showed the films structure with typical vibration bands connected with As–S bonds at 327 cm−1, S-rings fragments and S-rings at 474 and 495 cm−1 and appearance of AsS3 linked by S–Ag–S linkage at 374 cm−1 with increasing Ag-content in the films. The temperature regions of glass transformation of prepared films at 120–160 °C and crystallization at 160–230 °C were determined by Differential Scanning Calorimetry. The temperature regions of butylamine evaporation and melting processes of prepared films at 75–90 and 370–430 °C, respectively were found by means of Thermogravimetric Analysis. The optical transmission measurements proved the optical band gap (Egopt) decrease with increasing Ag-content. The MIR transmission spectra revealed solvent residua evaporation from as-coated films as result of annealing at 80, 120 and 160 °C for 1 h. The films surface observation using Scanning Electron Microscopy confirmed the expectation that films containing Sb have dramatically decrease of surface oxidation opposite to As–S films.