Chemical bath deposition and characterization of Cu2O–CuxS thin films

Cu2 O-Cux S thin films have been deposited on glass substrate by chemical bath deposition technique. The films were obtained by depositing Copper Sulphide (Cux S) on Copper (I) Oxide (Cu2 O) and then Cu2O on Cux S. The peak solar transmittance across the thin films were found to be 40% and as low as 10%, and falls with energy into the infra-red region. The absorbance is higher near the UV and IR regions. Reflectance is 20%. The band gap of both respective combinations is in the range of 2.19–2.32 eV and with film thickness 0.54 μm–1.30 μm. The extinction coefficient and refractive index are in the ranges of 5.41×10^−2 – 20.11×10^−2 and 1.60–2.60, respectively. Since the absorbance increases as one goes towards the IR region, the films could be useful in solar control (providing cool interior) in tropical regions.