Synthesis and characterization of donor–acceptor semiconducting polymers containing 4-(4-((2-ethylhexyl)oxy)phenyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrole for organic solar cells

Abstract

In this study, new donor–acceptor (D–A) conjugated polymers based on 4-(4-((2-ethylhexyl)oxy)phenyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrole (EPDP) and 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-ethylhexyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (BTBP) or 4,7-bis(5-bromothiophen-2-yl)benzo[c][1,2,5]thiadiazole (BT) have been synthesized successfully via direct (hetero)arylation polymerization using Pd(OAc)₂ and PCy₃·HBF₄ as a catalyst system. The obtained D–A conjugated polymers have been characterized via¹H NMR, GPC, FTIR, DSC, XRD, PL and UV-Vis methods. Afterward, the D–A conjugated polymers have been applied for the fabrication of organic solar cells based on bulk-heterojunction (BHJ) structures.