Preparation and characterization of Cu-In-Ga-Se thin films by the electrodeposition technique using different metal salts and substrates

Abstract

Cu(In, Ga)Se2 thin films possess important optoelectronic properties desirable for their application in devices such as solar cells. Solar cells based on this material have reached higher efficiencies than 23%. However, the commercialization of these cells has been restricted due to the use of thin film deposition methods involving costly high vacuum and cost. To reduce costs, it is necessary to use methods that do not use a high vacuum, among which electrodeposition stands out. Unfortunately, solar cells produced with this technique have yet to achieve high conversion efficiencies. Several authors attribute the lower efficiencies in such cells to the use of chemical additives in the preparation, different substrates, different deposition temperatures, etc. Nevertheless, there are very few reports on the influence of other metal salts in electrolytic baths. This work aims to use three different types of metal salts and voltages to produce Cu(In, Ga)Se2 (CIGS) absorber thin films by co-electrodeposition technique. The effect of nucleation type with two different substrates is studied, also report the studies carried out on the atomic composition and structural, morphological, and electrochemical characterization to understand the formation, growth, and morphology of CIGS films and, in this way, to obtain a suitable stoichiometry of thin film solar cells using this absorber.