Conjugated random copolymer of benzodithiophene-difluorobenzene-diketopyrrolopyrrole-benzothiadiazole with a broad absorption range of 300-900 nm for bulk heterojunction solar cells

摘要

A random donor-acceptor copolymer based on difluorobenzene (DFB), diketopyrrolo[3,4-c]pyrrole (DPP) and benzothiadiazole (BT) as co-electron acceptor units in conjugation with electron-donating benzodithiophene (BDT) unit has been synthesized and characterized. The copolymer exhibited a broad absorption from 300 nm to the near infrared region and a low optical bandgap of 1.51 eV. Preliminary studies of bulk heterojunction solar cells based on this polymer with PC_(60)BM showed a power conversion efficiency (PCE) of 1.56% without any processing additives.