Cu(In,Ga)(S,Se) 2 solar cells and modules by electrodeposition S. Taunier a , J. Sicx-Kurdi a , P.P. Grand a , A. Chomont a , O. Ramdani a , L. Parissi a , P. Panheleux a , N. Naghavi a , C. Hubert a , M. Ben-Farah a , J.P. Fauvarque a , J. Connolly a , O. Roussel a , P. Mogensen b , E. Mahe ´ b , J.F. Guillemoles a , D. Lincot a , O. Kerrec a, * a Laboratoire Commun EDF-CNRS/ENSCP, Plateau CISEL, 6 Quai Watier, 78401 Chatou cedex, France b Saint-Gobain Recherche, 39, Quai Lucien Lefranc, 93303 Aubervilliers Cedex, France Available online 22 January 2005 Abstract The CIS by electrodeposition (CISEL) project between Electricite ´ de France (EDF), Centre National de la Recherche Scientifique (CNRS)/Ecole Nationale Supe ´rieure 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. D 2004 Elsevier B.V. All rights reserved. Keywords: Cu(In,Ga)(S,Se) 2 solar cells; Electrodeposition; Sulfur 1. Introduction For the PV industry to reach a significant fraction of the electricity market, price per produced kWh must fall and the size of the industry must expand significantly. One of the most promising strategies for lowering PV costs is the use of thin-film technologies in which thin films of photo- active materials (typically b5 Am in thickness) are deposited on inexpensive large-area substrates like for example window glass [1,2]. Chalcopyrite compounds Cu(In,Ga)(Se,S) 2 (CIGS) have led to the highest laboratory efficiencies for thin film solar cells (N19%) [3] and CIGS modules have been successfully produced on an industrial scale [13–15]. Although CIGS compounds are comparable in perform- ance and stability to existing crystalline silicon devices, their market share is still very small (b1%) [4]. At present, high cost vacuum based techniques such as coevaporation and sputtering, are used to deposit the CIGS absorbers which is reducing the competitiveness of this technology. There is thus great interest in developing alternative, more cost effective, techniques based on low-temperature, non- vacuum techniques deposition processes such as electro- deposition. Electrodeposition is well suited for large-scale industrial processes, having a low energy consumption and low capital investment [2,5]. Electrodeposition has already been shown to be a promising approach for the production of efficient, low-cost CIGS solar cells. Efficiencies in the range of 6–7% had been reported for the so-called one-step electrodeposition route [6]. The CIS by electrodeposition (CISEL) project was launched in December 2000. The partners involved are Electricite ´ de France (EDF), the Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supe ´r- ieure de Chimie de Paris (ENSCP) and Saint-Gobain Recherche (SGR), with financial support from the Agence de l’Environnement et de la Maı ˆtrise de l’Energie (ADEME) 0040-6090/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.tsf.2004.11.200 * Corresponding author. Tel.: +33 1 3087 7135; fax: +33 1 3087 8565. E-mail address: o `livier.kerrec ´@edf.fr (O. Kerrec). Thin Solid Films 480–481 (2005) 526 – 531 www.elsevier.com/locate/tsf