Fluorine substitution enhanced photovoltaic performance of a D–A1–D–A2 copolymer

Abstract

A new alternating donor–acceptor (D–A₁–D–A₂) copolymer containing two electron-deficient moieties, isoindigo and quinoxaline, was synthesized. The photovoltaic performance of this polymer could be improved by incorporating fluorine atoms into the quinoxaline units, resulting in an efficiency of 6.32%. This result highlights the attractive promise of D–A₁–D–A₂ copolymers for high-performance bulk heterojunction solar cells.