Degradation of bulk heterojunction solar cells operated in an inert gas atmosphere: a systematic study

We present a systematic study on the degradation of polymer/fullerene bulk heterojunction solar cells. Degradation behavior of photovoltaic devices based on poly [2-methoxy, 5-(3 ' ,7 ' -dimethyl-octyloxy)]-p-phenylene vinylene (MDMO-PPV) mixed with the soluble methanofullerene derivative [6,6]-Phenyl C-61-butyric acid methyl ester (PCBM) were investigated under inert gas atmosphere in the dark at room temperature, under enhanced temperature and under enhanced temperature together with illumination by white light at 80 mW/cm(2) light intensity. The influence on the degradation for exchanging the top electrode (Au instead of Al) was also investigated. Photothermal defect localization was performed on sealed polymer/fullerene photovoltaic devices.