High-efficiency non-fullerene organic solar cells enabled by a difluorobenzothiadiazole-based donor polymer combined with a properly matched small molecule acceptor

Here we report high-performance small molecule acceptor (SMA)-based organic solar cells (OSCs) enabled by the combination of a difluorobenzothiadiazole donor polymer named PffBT4T-2DT and a SMA named SF-PDI₂. It is found that SF-PDI₂ matches particularly well with PffBT4T-2DT and non-fullerene OSCs with an impressive V_OC of 0.98 V, and a high power conversion efficiency of 6.3% is achieved. Our study shows that PffBT4T-2DT is a promising donor material for SMA-based OSCs, and the selection of a matching SMA is also important to achieve the best OSC performance.