Influence of Polymer Concentration on Polysaccharide Electrolyte for Quasi-solid-state Dye-sensitized Solar Cell

A series of polymer electrolytes was synthesized to fabricate dye-sensitized solar cells by a novel polysaccharide agarose as polymer matrix, 1-methyl-2-pyrrolidinone (NMP) as plasticizers, lithium iodide (LiI)/iodine (I-2) as redox couple and titania nanoparticles as an absorber. The agarose polymer electrolytes with different agarose concentrations (1-5 wt %) were systematically studied by differential scanning calorimetry (DSC) and the AC impedance spectra. The photoelectric performances of the DSSCs with different agarose content were investigated. Increasing polymer concentration led to a decrease in T-g of electrolyte in the low content range (1-2 wt %), which results in relative high conductivity in these content ranles. The 1.5 wt % agarose contained electrolyte showed the maximum conductivity of 3.94 x 10(-4) S cm(-1). After optimization, the energy conversion efficiency of 4.14 % was obtained in the cell with 2 wt % agarose.