| 초록 |
Thermal, optical, electrochemical, electrical properties of four different carbazole based conjugated polymers, P(2,7C-DTBT), P(3,6C-DTBT), P(2,7C-HDTBT) and P(3,6C-HDTBT) were investigated. Thermal studies revealed that all the copolymers were stable up to 400℃ and Tg of the copolymers were strongly dependant on the direction of conjugation as well as alkyl substitutents of thiophene units, respectively. Photophysical studies confirmed that the bandgap of the copolymers was lower at longer effective conjugation length which was enhanced at more planar structure. While delocalization and stabilization of exciton were observed at shorter effective conjugation length. An electrochemical characterization determined the HOMO/LUMO levels of the copolymers and HDTBT based polymers showed deepest HOMO energy levels promising superior oxidation stability. Finally, hole mobility determined by hole only devices showed better charge carrier ability in 3,6-carbazole based polymers than others. |
