A new donor-acceptor structured conjugated polymer (PDODTBI) with trifluoromethylated benzimidazole and benzo[1,2-b;3,4-b']dithiophene (BDT) unit have been designed and synthesized using Stille coupling polymerization reaction. The polymer is highly soluble in common organic solvents such as chloroform, tetrahydrofuran and chlorobenzene with good film forming properties. The structure of the polymer is elucidated by 1H NMR and FTIR spectroscopic techniques. The introduction of a trifluoromethyl group at 4th position of the benzimidazole unit has significantly altered the optical and electrochemical properties of polymer. Polymer film showed broad absorption band in the range of 400-680 nm. Optical band gap of the polymer estimated from the absorption band edge and is found to be ∼1.88 eV. Polymer exhibited deeper HOMO (-5.0 eV) and the LUMO (-3.12 eV) energy levels. Bulk heterojunction (BHJ) solar cell device with PDODTBI as a donor and PC61BM as an acceptor were evaluated.