To minimize shading when interconnecting single solar cells to solar modules the shingling technique can be used. Having an electrically conductive substrate this interconnection technique can be applied without any modification of the single solar cells itself. In case of electrically isolating substrates a contacting of the back metal electrode from the backside is in general not possible without modification of the substrate. Within this paper we present a possibility to interconnect flexible CIGS thin film solar cells on polyimide substrate using the shingling technique. To expose the molybdenum layer from the backside the polyimide substrate has been removed locally with a pulsed Excimer laser (248 nm wavelength, 20 ns pulse duration). To interconnect the exposed back contact with the front contact of the next solar cell the blind vias can be filled with a conductive adhesive. The surface of the exposed back contact of the CIGS solar cells has been characterized using optical microscope and SEM to acquire information on the completeness of the polymer etching and possible damages of the thin films. To characterize the exposed thin films electrically conductive-AFM images were made. First solar cells have been contacted from backside and electrically characterized.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 3414-3417