**6. Conclusions**

We have found that CBD-CdS thin films grown under different conditions, like monolayers or bi-layers, using a standard bath configuration or a modified configuration, the principle for the deposition process is the same: a common precipitation reaction. Depending of the regime we decide to choose, we must perform an optimization of the deposition parameters in order to get the CdS film with the best physical and chemical properties. The quality of the CdS window partner and the absorber material like CdTe and Cu(In,Ga)Se2 will have a great impact on the conversion efficiencies when applied into thin film solar cells.
