Screening Quinoxaline-Type Donor Polymers for Roll-to-Roll Processing Compatible Organic Photovoltaics

We demonstrate, by screening a library of four derivatives of benzodithiophene–quinoxaline (BDT-QX)-based polymer, that BDT-QX are donor polymer candidates for large-scale coating of organic photovoltaic (OPV) active layers. Our study shows that pairing them with a twisted N-annulated perylene diimide (PDI) dimer, which solid-state aggregation can be induced via diphenyl ether (DPE) solvent additive, yields OPV devices with power conversion efficiency (PCE) over 5%. The active layers, both spin-coated (from o-xylenes and o-methylanisole) and slot-die-coated (from o-xylenes), maintain a high open-circuit voltage (Voc) over 1 V and a fill factor (FF) of ca. 60%, with a maximum PCE of respectively 6.07 and 4.11%, which show promise for compatibility with roll-to-roll, non-halogenated processing of OPV devices.