Nanoscale Phase Separation-Induced Suppression of Geminate Recombination in Low Bandgap Polymer-Fullerene Solar Cells
LIU Jian1, WU Jiang1, SHAO Shu-Yan1, XIE Zhi-Yuan1**, GUO Shi-Jie2**
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 2The First Bethune Hospital of Jilin University, Changchun 130021
Abstract：The short-circuit current of polymer solar cells based on a PCPDTBT:PC71BM blend is substantially increased by using a processing additive. It is found that the significant geminate recombination in the PCPDTBT:PC71BM blend film is dramatically suppressed by using a processing additive which can produce a nanoscale PCPDTBT and PC71BM phase separation. The processing additive-induced aggregation of PCPDTBT polymer chains and PC71BM molecules can give rise to a driving force for the separation of charge-transfer states at the donor/acceptor interfaces into the free charge carriers and thus geminate recombination is suppressed.
2014, Vol. 31 
