xSyOz thin flms with various thicknesses were prepared by thermal evaporation. The structural, morphological, electrical
and optical characteristics are examined for possible usage as solar control coatings on cars and architectural windows. The
efect of thermal annealing on Cu
xSyOz flms was examined for the thick flm of 734 nm at 550 °C. The annealing was done
for various annealing times of 2, 4 and 6 h. Energy-dispersive analysis of X-ray (EDAX) was used to evaluate the chemical
composition of the as-prepared and annealed flms. X-ray difraction (XRD) elucidated the presence of hexagonal CuS and
orthorhombic Cu
2S together with a small contribution of the orthorhombic CuSO4 phase for the thicker flms ( ≥ 241 nm).
With increase in the annealing time, the hexagonal CuS and orthorhombic Cu
2S peaks disappeared. The morphology of the
flms is strongly dependent on both thickness and annealing time. By controlling the flm thickness, the transmission of the
NIR region can be brought to zero, whereas adequate transmission, 6–27%, in the visible spectral region was maintained.
After annealing, the transmittance increased while the refection decreased. The optical band gap and the optical constants of
the annealed flms were also studied. It was found that the values can difer depending on the annealing time. The as-prepared
xSyOz flms behaves as metallic materials. It is found that room temperature resistivity decreased as the flm thickness
increased, while it increased with annealing.