| 초록 |
A novel solid-state polymerizable monomer at 25oC, i.e. 2,5-dibromo-3,4-propylenedioxythiophene (DBProDOT) is designed and synthesized to produce a conducting polymer, poly(3,4-propylenedioxythiophene) (PProDOT). Crystalographic studies reveal a lower activation energy, higher exothermic reaction and closer interplane distance of the DBProDOT crystal, which are responsible for polymerization at low temperautre. Upon solid-state polymerization (SSP) at 25 oC, PProDOT is at self-doped state with tribromide ions, having an electron conductivity of 0.05 S cm-1, which is much higher than that of chemically polymerized PProDOT (2 × 10-6 S/cm). The PProDOT deeply penetrates into the nanocrystalline TiO2 photoelectrode and functions as a hole transporting material (HTM) for iodine(I2)-free solid-state dye-sensitized solar cells (ssDSSCs). Upon the introduction of an organized mesoporous TiO2 (OM-TiO2) layer, an energy conversion efficiency reaches 3.5 % at 100 mW/cm2, which is quite stable at least up to 2,000 h. |
