Recent progress in wide bandgap conjugated polymer donors for high-performance nonfullerene organic photovoltaics

In the last five years, the tremendous progress achieved in the field of polymer solar cells (PSCs) has attracted extensive attention to this emerging technology for exploiting renewable energy. Owing to their excellent optoelectronic features and outstanding manufacturability for film deposition, wide bandgap (WBG) polymer donors have become a leading component in bulk heterojunction layers and thus, a correlative review focusing on their molecular design, aggregation behavior and photovoltaic properties is necessary. In this feature article, we summarize our recent efforts in developing WBG polymer donors and understanding the charge separation and non-radiative recombination energy loss in high-performance non-fullerene (NF) PSCs. We also discuss the opportunities and challenges towards the realization of the commercialization of NF PSCs based on WBG polymer donors.