Effective interfacial layer to enhance efficiency of polymer solar cells via solution-processed fullerene-surfactants

Two methanol-soluble fullerene surfactants have been developed as interfacial layers for cathodes in polymer solar cells. These surfactants facilitate the tuning of cathode work function and extraction of electrons that significantly enhance open-circuit voltage and photocurrent generation. The performance of bulk heterojunction solar cells based on using these surfactant-modified cathodes improved significantly to afford high power conversion efficiencies (as high as 6.63% for a Ag cathode).