Electrical characterization of organic solar cell contact degradation resulting from ambient exposure

The electrical and photocurrent characteristics resulting from low light ambient degradation of organic bulk heterojunction solar cells are reported. The degradation is associated with the contacts and the active layer shows no evidence of any change in properties. Ambient exposure induces an exponential current-voltage characteristic in the contact region. An empirical model for the cell current-voltage characteristics shows how the cell properties may be corrected to recover the characteristics of the active layer. Modeling compares the effects of ohmic and exponential contact resistance on the solar cell response of a typical cell. (C) 2013 Elsevier B. V. All rights reserved.