| 초록 |
A series of low-bandgap alternating copolymers consisting of electron-accepting quinoxaline derivatives and electron-donating carbazole or fluorene were synthesized via the Suzuki coupling reaction. For the purpose to improve the molecular packing of polymer chains and to enhance the charge carrier mobility in the packing direction, a new quinoxaline derivative, 5,8-dithien-2-yl-dibenzophenazine which is expected to have planar polycyclic structure, was synthesized and introduced as a new building block of alternating copolymer instead of frequently-used 5,8-dithien-2-yl-2,3-diphenylquinoxaline. The copolymers with planar quinoxaline derivative exhibited better optical and structural properties as compared to the polymers with less planar quinoxaline derivative. The power conversion efficiency was achieved up to 3.8% when the copolymer with planar quinoxaline derivative was blended with [6,6]-phenyl-C71-butyric acid methyl ester as a active layer material in BHJ solar cells. |
