Bulk heterojunction (BHJ)-type polymer solar cells (PSCs) have attracted attention as potential competitors to silicon solar cells for its light weight, low cost, mechanical flexibility, ease of fabrication and processibility to large area. The photoactive layers in BHJ-PSCs consist of a blend of an electron donor conjugated polymer and an electron acceptor fullerene derivative and play a central role in generating photocurrents. A key requirement for efficient charge separation and collection is the formation of interconnected phase-separated domains structured on the sub-20 nm length-scale. However, for some polymer/fullerene blend systems, if there is sufficient space between the side-chains along the polymer backbone the fullerene molecules can intercalate into the spaces to form an intercalated structure, which would inhibit phase separation, lower the purity of donor or acceptor domains. It is not benefit for dissociation of excitons and the charge transfer.
© 2014 Optical Society of AmericaPDF Article