A new strategy for designing polymer electron acceptors: electronrich conjugated backbone with electron-deficient side units

Three “double-cable” conjugated polymers with thienopyrroledione-based backbone and perylene bisimide as side units were designed as electron acceptor for polymer-polymer solar cells. The polymers show broad absorption spectra and low-lying frontier energy levels due to both aromatic backbone and side units. The new double-cable polymers can be used as electron acceptor to combine with several electron donors, in which power conversion efficiencies above 3% could be achieved.