Comparison between Cu(In,Ga)Se2 solar cells with different back contacts submitted to current stress

The main goal of this paper is to compare the stability over time of two different kinds of Cu(In,Ga)Se2 solar cells: the first is designed with a molybdenum back contact, the second has a semi-transparent back contact based on ITO (Indium Tin Oxide). To achieve this goal, we subjected two different samples to a forward pulse current stress during which the main electric cell parameters (i.e. Isc, Voc, PCE, IV characteristic) were monitored. Based on the collected results, we propose a physical interpretation to explain the different behaviours shown by the samples during degradation.