Synthesis and photovoltaic properties of a phenylenevinylene copolymer with dithienylbenzothiadiazole and bis(di(p-tolyl)phenylamino)phenylene units

A novel phenylenevinylene copolymer (JP) with 4,7-dithien-5-yl-2,1,3-benzodiathiazole (DTBT) moiety along the backbone and di(p-tolyl)phenylamine (p-TPA) unit as side groups was synthesized and applied in polymer solar cells (PSCs). Introduction of DTBT and p-TPA moieties is beneficial to lowering the band gap, broadening the absorption spectrum and improving the photovoltaic properties of the copolymer. The effects of DTBT and p-TPA moieties on the thermal, photophysical, electrochemical and photovoltaic properties of the copolymer are investigated. The bulk heterojunction polymer solar cells based on JP and PC61BM (1:3, w/w) showed a maximum power conversion efficiency of 1.09% with an open-circuit voltage of 0.75 V, a short-circuit current of 3.69 mA cm−2, and a fill factor of 0.50.