| 초록 |
Synthesis of new D-A alternating copolymers (PBDT-DFQx, PBDT-FQx) having low band gap was implemented by Stille coupling reaction using palladium catalyst. Di-fluorinated quinoxaline(DFQx) or mono-fluorinated quinoxaline(FQx) was used as an electron-deficient unit, while alkoxyl substituted benzo[1,2-b:4,5-b']dithiophene (BDT) was used as an electron-rich unit. In order to look into effect of fluoro group, Qx unit’s hydrogen of backbone was substituted with fluorine atom on one side or both sides. The characterization of resulting copolymers was measured by TGA, GPC, UV-vis absorption spectroscopy and cyclic voltammetry measurements. The two copolymers showed good thermal stability through result of TGA that displayed 5% weight loss temperature (Td) over 300°C. Both of the polymers exhibited strong absorption in the range of 596 - 602 nm in solution state. Lowest unoccupied molecular orbital (LUMO) energy level of two polymers showed -3.40 eV and -3.44 eV respectively. |
