초록 |
The novel series of random copolymers and alternating copolymer using fluorene and fluorinated quinoxaline were synthesized by Suzuki and Stille coupling reactions. In these polymers, it was changed the ratio of fluorene and fluorinated quinoxaline. The polymers showed good solubility in organic solvent such as benzene derivative (toluene, chlorobenzene and o-dichlorobenzene). All polymer showed good thermal stability with 5% weight loss temperature over 410℃. These polymer observed a narrow bandgap 1.93 to 2.14eV. A highest occupied molecular orbital (HOMO) energy level showed at -5.59 to -5.67 eV. Under optimized condition{copolymer:PC¬¬70BM(1:1.5 wt%) + 3 vol% DIO}, the best efficiency among the polymers was achieved in random copolymer (ratio of 1:4) with 3.98% of power conversion efficiencies (PCE), Voc of 0.95 V, Jsc of 6.37 mA/cm2, FF of 0.66%. |