Polymer gel matrix based quasi-solid electrolytes for stable Dye-Sensitized Solar Cells (DSSCs) /

Abstract

Sun is a great source of energy which needs to be harnessed and to be converted into a utilizable form of energy. Dye-sensitized solar cell is a next generation solar energy conversion device, which is currently facing performance degradation losses due to use of liquid electrolytes in its structure. In this work, an effort has been carried out to study effects of concentration of Cobalt complex redox ions on liquid electrolyte and on quasi-solid electrolyte with addition of 15wt% Polyethylene Oxide (PEO). First, three liquid electrolytes(LEs) of Co (II) and Co (III) TFSI in Acetonitrile solvent were synthesized by varying concentrations in the range of 20mM and 50mM. Then, 15wt% of PEO was added to each liquid electrolyte to form quasi-electrolytes(QEs). UV/Vis spectroscopy of bare FTO and Platinum coated FTO was performed to study absorbance as well as transmittance which showed that both of the samples were transparent with low absorption in visible region of spectra. Viscometry showed that viscosity of electrolyte is increased with increasing molar concentrations and then further increased with addition of PEO and thus, the highest viscosity of 2.49cP at 44rpm was obtained for 50mM QE. EIS measurements showed the highest conductivity of 83mS cm-1 for 50mM LE. Zinc Oxide was deposited on FTO glass substrates by Doctor Blade Technique and was used as photoanodes in fabrication of DSSC. ZnO rice grain like structure morphology was confirmed by SEM with film thickness of 16.4μm measured by Optical Profilometer. DSSCs were fabricated with different electrolytes and ZnO based photoanodes along with other DSSC components. IV testing was performed for all cells which showed the highest efficiency of 0.25% for DSSCs with liquid electrolyte of 50mM concentration.