Poly(ethylene glycol) (PEG) was modified with a long alkyl acid to produce a self-organized amphiphilic polymer (amPEG). FT-IR and NMR spectroscopies confirmed the amPEG synthesis. This polymer was complexed with lithium iodide (LiI) and 1-methyl-3-propylimidazolium iodide (MPII) to prepare polymer electrolytes to be applied to dye-sensitized solar cells (DSSC). FT-IR studies showed that upon the addition of litium salt the free ether and ester carbonyl bands shifted towards lower wavenumbers, indicating the complexation of Li ions with oxygens on the amPEG. Alkylation and salt introduction reduced PEG crystallinity, as characterized by wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC). The ionic conductivities of the polymer electrolytes increased with increasing salt concentrations, and the energy conversion efficiency of DSSC reached 2.6% at 100 mW cm-2 for amPEG/MPII system which is higher than amPEG/LiI. This may be due to the higher mobility of MPII ion than the lithium ion in the polymer electrolyte. The interfacial properties between electrolytes and electrodes were investigated using field-emission scanning electron microscopy (FE-SEM) and electrochemical impedance spectroscopy (EIS).
|Number of pages
|Journal of Photochemistry and Photobiology A: Chemistry
|Published - 2011 Jan 1
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (NRF) grant funded by the Korea Government (MEST) through the Korea Center for Artificial Photosynthesis (KCAP) located at Sogang University (NRF-2009-C1AAA001-2009-0093879) and the Center for Next Generation Dye-sensitized Solar Cells (No. 2010-0001842).
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Chemical Engineering
- General Physics and Astronomy