Effects of Residual Oxygen in the Degradation of the Performance of Organic Bulk Heterojunction Solar Cells: Stability, Role of the Encapsulation

We have shown in our first articles [1] [2] that even after encapsulation, the first rapid phase of degradation mechanism observed has been attributed to oxidation of interfaces and an alteration of the charges collection process. A second phase slower is induced by the oxidation of the active film, namely a decrease in the absorption and a degradation of the charge transport process. We revealed that another decrease in power conversion efficiency which has been induced by a possible interfacial passivation occurred at the organic/cathode interface, owing to the presence of residual oxygen, moisture and other impurities. This is in reality the real cause of the first rapid phase of degradation mechanism observed.