Double-cable Conjugated Polymers with Rigid Linkers for Single-component Organic Solar Cells

Two novel double-cable conjugated polymers,poly [2-(4-{3,3'-didodecyl-5'-[4-(1-{4-[5-(2-ethylhexyl)thiophen-2-yl]-8-[5-(heptan-3-yl)thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophen-2-yl}-4,6-dioxo-4H-thieno[3,4-c]pyrrol-5(6H)-yl)phenyl]-[2,2'-bithiophen]-5-yl}phenyl)-9-(tricosan-12-yl)anthra [2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone)](FLP7)and poly [2-(4-{4,4'-didodecyl-5'-[4-(1-{4-[5-(2-ethylhexyl)thiophen-2-yl]-8- [5-(heptan-3-yl)thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophen-2-yl}-4,6-dioxo-4H-thieno [3,4-c]pyrrol-5(6H)-yl)phenyl]-[2,2'-bithiophen]-5-yl}phenyl)-9-(tricosan-12-yl)anthra [2,1,9-def:6,5, 10-d'e'f']diisoquinoline-1,3,8,10(2H,9H)-tetraone](FLP8), have been developed with bithiophene-based rigid linkers. These polymers were synthesized by adopting a thiophenedicarboximide (TPD) donor backbone and perylene biimide (PBI) acceptor side units. By adjusting the position of alkyl chains on the rigid linkers from external to interior, the self-aggregation capacity, film morphology and photoelectric conversion efficiency of the polymers were improved. Finally, the FLP7 polymer demonstrated superior photoelectric performance parameters as compared to the FLP8 polymer and achieved a power conversion efficiency of 1.59%.