Efficient wide-band-gap copolymer donors for organic solar cells with perpendicularly placed benzodithiophene units

The working horses for the drastically improved power conversion efficiency (PCE) of organic solar cells (OSCs) were the small-band-gap molecular non-fullerene acceptors. This development not only removed the low performance obstacle for OSCs but also raised needs for wide-band-gap polymers for donor/acceptor mix with complimentary absorptions. Benzodithiophene (BDT) is one of the mostly used unit for constructing donor polymers. Here, we...