Terpolymerization strategy to achieve high-efficiency organic solar cells construction of D1-A-D1-D2-type polymer donors

Novel terpolymers were developed with ester group incorporation (BDT-2EST). DM1 with 5% BDT-2EST possesses suitable crystallinity and miscibility matching with Y6 acceptor to offer an excellent power conversation efficiency up to 17.21%. Moreover, the intertwined random features in DM1 offer robust photovoltaic performances with a broad molecular weight tolerance. Terpolymerization provides a new approach to improve device efficiency (PCE) by simultaneously increasing fill factor and batch-to-batch reproducibility in OSCs.