| 초록 |
A new donor-acceptor random copolymers (PBDT-DFBI) based on the 4,7-dibromo-5,6-difluoro-2,2-dimethyl-2H-benzo[d]imidazole acceptor unit, a alkyloxyl-substituted benzodithiophene (BDT) donor unit and Thiophene were designed and synthesized for application as the donor material in polymer solar cells (PSCs), changing the ratio of these monomers. Thiophene bridge was introduced in the polymers to act as molecular spacer between donor and acceptor unit. The resulting copolymers were characterized by TGA, GPC, UV-vis absorption spectroscopy and cyclic voltammetry measurements. Their 5% weight-loss temperatures(Td) were all above 289℃ and it means PBDT-DFBI has good thermal stability. The highest occupied molecular orbital (HOMO) energy level of the polymers exhibited -5.17eV to -5.63eV and these polymers had narrow band gap of 1.75eV to 1.87eV. |
