Performance degradation is one of the crucial difficulties for the market of organic solar cell (OSC) devices. These deteriorative characteristics can be attributed to many factors, mainly to the chemical reactivity of the device multiple layers with the environment. Here, we investigate
the performance of a standard OSC device made of the polymer poly(3-hexylthiophene-2,5-diyl) and the fullerene [6,6]-phenyl-C61-butyric-acid-methyl-ester (P3HT:PCBM) as a photoactive layer in a high humidity environment (53%) within 100 days divided into three periods. The results confirm
that the OSC devices’ encapsulations should be completed immediately after the fabrication due to fast chemical degradation of the photoactive layer, which reduces the Jsc by 15% after 40 mins of fabrication. We also found that the FF has been reduced by 17.36% from its initial value
after 1152 hours due to a deficiency of the interfacial charge transfer between the multiple layers of the device. Finally, the performance of the device’s decays to zero after 2400 hours.