Journal Article polymer solar cells conjugated polymers nonfullerene acceptors ternary blends 4-bis(2-thienyl)pyrrole-2 5-dione B←N bonds Organic Chemicals Parkinson's disease therapy Published Erratum Y6-type all-polymer solar cells asymmetric design batch-to-batch reproducibility benzo[d]thiazole benzobisthiazole bulk charge transport charge extraction and recombination cyclohexane side chains dithienophthalimide donor terpolymers dopaminergic neuronal differentiation electrical conductivity electrical conductivity reducing additives end group stacking extracellular electrical stimulation general applicability green solvents high efficiency