High efficiency of 9.61% has been produced for dye sensitized solar cell using a phthaloylchitosan based gel polymer electrolyte. The gel polymer electrolytes have been optimized by varying the amount of tetrapropylammonium iodide (TPAI) and 1-butyl-3-methylimidazolium iodide (BMII) ionic liquid (IL). The highest ionic conductivity of gel polymer electrolyte containing 8 wt.% IL was obtained with the value of 13.5 mS cm(-1). The temperature dependence ionic conductivity follows Arrhenius rule. The highest conducting electrolyte also exhibits the highest diffusion coefficient of triiodide ion which is 3.9 X 10(-7) cm(-2) s(-1). The optimized gel polymer electrolyte exhibits the highest short circuit current density of 19.68 mA cm(-2). (C) 2017 Elsevier Ltd. All rights reserved.