Dithienocarbazole and isoindigo based amorphous low bandgap conjugated polymers for efficient polymer solar cells.

Three highly rigid and planar low-bandgap conjugated polymers comprising alternate isoindigo and dithienocarbazole groups are synthesized for the fabrication of high performance polymer solar cells. Power conversion efficiencies of up to 7.2% for conventional devices and 8.2% for inverted devices are demonstrated.