Organic photovoltaic devices produced from conjugated polymer/methanofullerene bulk heterojunctions

Organic photovoltaic devices have been fabricated utilizing the photoinduced electron transfer with long-living charge separation in conjugated polymer/methanofullerene thin films. The performance of such "bulk heterojunction" photovoltaic devices is critically dependent on the charge transport properties of the interpenetrating network. Devices with power efficiencies higher than 2.5 % under AM1.5 have been realized. The physical properties of these bipolar devices are discussed with respect to the transport properties of the network. Further possible enhancement is discussed by analyzing the single parameters contributing to the AM 1.5 efficiency in plastic solar cells, namely, the open circuit voltage (Voc), the short circuit current (Isc), the fill factor (FF) as well as the absorption matching to the solar spectrum