Guar gum-based polymer gel electrolyte for dye-sensitized solar cell applications

A Guar Gum-based biopolymer (GG), a characteristic non-ionic polysaccharide extracted from guar beans, is utilized in this work as a cost-effective polymer gel electrolyte towards the fabrication of dye-sensitized solar cells (DSSC). A redox electrolyte is prepared by stirring Guar Gum biopolymer with a known amount of LiI/I, 4-tert-butylpyrdine, 1-methyl-3-propylimidazolium iodide, and polyethylene glycol for 24 hrs. The polymer gel electrolyte is carefully characterized through Fourier transform infrared spectra, UV-visible spectrum, Field-emission scanning electron microscopy and Differential Scanning Calorimetry. Using this polymer gel electrolyte, dye-sensitized solar cells are fabricated by sandwiching metal-free organic MK-2 dye coated TiO photoanode and Pt counter electrode as a photocathode. The photoelectrochemical characterization of the fabricated device shows maximum power conversion efficiency of 4.96% instead of 2.13% obtained with the liquid electrolyte without Guar Gum. The electrolyte containing Guar Gum polymer gel shows ionic conductivity (?) of 1.46 S [cm] while the liquid electrolyte show 2.44 S [cm].