Influence of CdS thin films growth related with the substrate properties and conditions used on CBD technique

CdS polycrystalline thin films have been used as window layer in solar cells; the quality of the CdS-partner plays an important role in the photovoltaic device performance. CdS thin films were deposited using Chemical Bath Deposition (CBD) and photoassisted-CBD technique. The SnO₂:F substrates used in this work were treated with HCl (0.1 M) and some of themwere annealed in different atmospheres (Ar and O₂). The properties of CdS thin films were influenced by the HCl treatment, position and the movement of substrates inside the reactor glass. CdS samples were deposited in areas of 4 cm², 50 cm² and 100 cm²; obtaining thin films with thickness of 35 - 300 nm with good crystalline quality and uniform morphology. All samplespresented optical transmittance around of 85 - 91% and average gap energy of 2.5 eV.