ELECTROLUMINESCENCE INVESTIGATION ON THIN FILM MODULES

The fast market growth during the recent years led to huge amounts of production capacities and a large variety of module types. The increasing need for cost reductions obliges the manufacturers to maximize production and module efficiencies. Electroluminescence investigation is a powerful tool to reveal failures of thin film photovoltaic modules during the production stage and within test sequences. We use it to identify failures after reliability tests included in the IEC 61646 or beyond such as bias damp heat assessments. In an earlier stage, the manufacturer could use it to sort and optimize his products directly after frontend production. The results presented here aim to pave the way for such an inline electroluminescence analysis. In this paper we also present spectral analysis of electroluminescence signals to simplify the choice of cameras and filters as a set-up for an EL testing station. Furthermore, we compiled a failure catalogue for all thin-film modules, applying electroluminescence. We developed a brightness-evaluation sheet to describe the analogies between power losses and lowering of brightness. Finally, we investigated the effect of the shunt resistance of CIGS modules on their weak light behavior.