Comparison of 3D non-fullerene acceptors for organic photovoltaics based on naphthalene diimide and perylene diimide-substituted 9,9′-bifluorenylidene

Tetra(PDI) derivatives of non-planar cores have previously been used as acceptors in OPVs; here a tetra(NDI) is shown to be a viable alternative, although, for the pair of acceptors and the donor polymers used here, the PDI species performs better.