Rational design on D–A conjugated P(BDT–DTBT) polymers for polymer solar cells

Solution-processable D–A conjugated polymers are proving particularly promising in bulk heterojunction solar cells. Among these, P(BDT–DTBT) and their derivatives with benzodithiophene (BDT) as the donor unit and benzothiadiazole (DTBT) as the acceptor unit are the most commonly studied conjugated polymers due to their excellent photovoltaic properties. There have been a lot of reports recently on the design and structural organization of P(BDT–DTBT) for solar cells, and it has been demonstrated that one of the critical issues for achieving high performance is the rational molecular design of P(BDT–DTBT) polymers. In this review, we focus on the various structural modifications and photovoltaic properties of the resulting P(BDT–DTBT) polymers. We hope that this review will give some inspirations for high-performance P(BDT–DTBT) polymers and be an important guideline for the design of photovoltaic conjugated polymers.