| 초록 |
A series of new semiconducting polymers based on 4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b’]dithiophene, 2,2-dihexyl-2H-benzimidazole, and thiophene units was synthesized. The polymers show good solubility at room temperature in organic solvents owing to long alkyl chain in new acceptor, 2,2-dihexyl-2H-benzimidazole. The advantage of dihexyl-2H-benzimidazole compared to the benzothiadiazole is to improve the solubility of the polymer. The spectra of the solid films show absorption bands with maximum peaks in the range of 421577 nm and the absorption onsets at 588683 nm, corresponding to band gaps of 2.111.82 eV. The devices with PCPDTDTHBI-1:PC71BM layers showed a VOC of 0.46 V, a JSC of 3.83 mA/cm2, and a FF of 0.36, giving a PCE of 0.64%.Decrease of the dihexyl-2H-benzimidazole contents in the polymers induced red-shift of the UV absorptions, and increased VOC and JSC values, to improve the efficiency of organic photovoltaics. |
