Quasi-solid state dye-sensitized solar cells (DSSCs) are fabricated with a novel polysaccharide gel electrolyte composed of agarose in 1-methyl-2-pyrrolidinone (NMP) as polymer matrix lithium iodide (LiI)/iodine (I-2) as redox couple and mania nanoparticles as fillers The polysaccharide electrolyte with different agarose concentrations (1-5 wt%) and various inorganic filler TiO2 concentrations (0-10 wt%) are studied systematically by differential scanning calorimetry (DSC) and the AC impedance spectra The electrochemical and photoelectric performances of DSSCs with these electrolytes are also investigated It is found that increasing agarose and inorganic filler concentration leads to a decrease in T-g in the range of 1-2 wt% for agarose and 0-2 5 wt% for TiO2 changed electrolytes which results in high conductivity in these electrolytes From the electrochemical analysis it is observed that the electron lifetime in TiO2 of DSSCs increases with agarose while decreases with inorganic filler contents The prolonged electron lifetime in DSSCs is advantageous to improve open-circuit voltage (V-oc) Based on these results the cell with the electrolyte of 2 wt% agarose shows the optimized energy conversion efficiency of 4 14% The optimized efficiency of the DSSC with added Mania is 4 74% at 2 5 wt% Mania concentration (C) 2010 Elsevier B V All rights reserved