Cu(In,Ga)(S,Se) 2 solar cells and modules by electrodeposition

The CIS by electrodeposition (CISEL) project between Electricité de France (EDF), Centre National de la Recherche Scientifique (CNRS)/Ecole Nationale Supérieure de Chimie de Paris (ENSCP) and Saint-Gobain Recherche (SGR) aims at developing a low-cost electrodeposition process for Cu(In,Ga)(S,Se) 2 (CIGS) solar cells. The process is characterized by two main steps: (i) deposition of the precursor film and (ii) thermal annealing. This process enables the preparation of a large range of sulfur containing absorbers, with S/(S+Se) atomic ratio from 0% to more than 90%. The films are single phase over the whole composition range. The influence of Sulfur content on the microstructure has been shown with grain sizes decreasing with increasing sulfur content. Efficient solar cells can be obtained from all the different precursor compositions, with efficiencies of over 10% on lab cells on sulfur-rich absorbers, and 6–7% on 30×30 cm 2 devices. The homogeneity of 15×15 cm 2 substrates is also discussed.