Degradation of bulk heterojunction organic photovoltaics (OPV) based on poly (3-hexylthio-phene) (P3HT) and (6,6)-
phenyl-C61- butyric acid methyl ester (PCBM) as photo-active material has been investigated. In this manuscript, we
present the degradation studies on organic solar cells under different experimental conditions: <i>(i)</i> stored and encapsulated
under ambient condition and <i>(ii</i>) stored in vacuum and encapsulated under nitrogen (N<sub>2</sub>) atmosphere. The dark current
density-voltage (<i>J-V</i>) characteristic of the diode is used to understand the mechanism of degradation.