Synthesis of the 2H-benzimidazole-based conjugated polymers with various thiophene units and their application in photovoltaic

▶ New random copolymers, to broaden the absorption spectrum, were synthesized by Stille coupling reactions. ▶ The solid films of PFBBTMBIs are red-shifted about 20 nm as compared to PFDTMBIs. ▶ The long wavelength peaks exhibit a gradual red-shift with increased amounts of the MBI contents.