Selective Assembly of Perylene Diimide into Donor-Acceptor Interface in Polymer Solar Cells by Junction-Functionalized Block Copolymer

Novel block copolymers consisting of poly (3-hexylthiophene) (P3HT)/ poly (dimethylsiloxane) (PDMS) or P3HT / poly (ethylene glycol) (PEO) with a perylenediimide (PDI) unit at the junction between the segments were synthesized and utilized for donor materials in polymer solar cells. In the blend film of junction-modified block copolymer and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), the PDI unit introduced at the junction of block copolymers assembled at the interface of donor/acceptor domains. A distinctive phase-separated morphology was created in the block copolymer blend film, which provided higher device performance compared with a conventional polymer blend system.