Abstract

Polycrystalline CuInSe₂- based thin films have exhibited very promising performance for thin film photovoltaic (PV) applications, now exceeding 20% conversion efficiencies at the laboratory scale. CuInSe₂-based thin-film solar cells technology is being used for terrestrial applications, however they are considered the main competitor candidate of the traditional crystalline solar cells, to provide the electrical power needed for space applications, especially when the CuInSe₂-based film deposition is considered on flexible-lightweight substrates. The overall advantages of CuInSe₂-based thin-film solar cells technology include low mass and storage volume, high power, lower production cost, high radiation resistance and stability, very important criteria to fulfill when their use is considered for space applications. The best quality CuInSe₂-based PV devices have been processed using high vacuum techniques. However, there is an interest in developing deposition techniques that avoid the use of high vacuum, especially when considering scale-up to industrial processing levels. Electrodeposition offers a number of advantages over high-vacuum deposition techniques, requiring a low cost equipment, allows deposition over large areas at low temperature and atmospheric pressure conditions, good control of film thickness, and it is a self-purifying process, allowing thus the use of low purity precursor materials. All these features are translated into reduction of production costs. In this paper, we described an approach to grow CuInSe₂- based thin films by the electrodeposition technique onto soda-lime glass substrates with a sputtered Mo layer. We discussed some aspects of the patent “Post deposition treatments of electrodeposited CuInSe₂-based thin films”, regarding the control of the chemical composition and the morphology of the film growth over rigid substrates. Finally, we discussed the advantages of using these CuInSe₂-based thin films for terrestrial and space applications, and a brief review of other patents that deal with some issues regarding their deposition on flexible-lightweight substrate.

Keywords: Electrodeposition, CuInSe₂-based thin films, solar cells.