Deposition, optical and structural characterization of SnO2:F/CdS and ZnO/CdS structures used as optical windows in solar cells

The purpose of this work is to find the conditions for fabricating SnO2:F/CdS and ZnO/CdS bilayer structures with adequate properties to be used as optical windows in solar cells based on CdTe and CuInSe2 thin films. In both types of structures the CdS layer is deposited by chemical bath deposition (CBD) and by the evaporation method; the SnO2:F and ZnO layers are deposited by spray pyrolysis and reactive evaporation, respectively. The influence of the preparation methods on the optical and structural properties of each of the layers constituting the bilayer structures, was studied through spectral transmittance and X-ray diffraction (XRD) measurements. The studies revealed that the spectral transmittance of the ZnO/CdS system is significantly greater than that of the SnO2:F/CdS structure, indicating that the first type of structure is more suitable for using as optical window in solar cell fabrication.