초록 |
Recently, to obtain longer conjugation lengths and backbone coplanarity of the polymers, various kinds of electrondeficient aromatic heterocycles have been widely investigated in OPVs. 2,1,3 Benzothiadiazole and its derivatives, particularly 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DTBT), are the electrondeficient comonomers for the intramolecular charge transfer, which results in the lower band gap of the polymers. We report new conjugated polymers, PCBBTHBI-5, PFBBTHBI-5, PCPPBBTHBI-5 and PEHOPBBTHBI-5 containing electron donor-acceptor pairs for OPV device utilizing a new type of acceptor, dihexyl-2H-benzimidazole to provide better solubility than PCDTBT at room temperature in organic solvents. The device with PEHOPBBTHBI-5:PC71BM blend demonstrated a VOC value of 0.59 V, a JSC value of 6.43 mA/cm2, and a FF of 0.39, leading to the efficiency of 1.46%. |