Nanofiber (NF) based gel polymer electrolytes were prepared by soaking electrospun polyacrylonitrile (PAN) nanofiber membranes of different thicknesses in an optimized liquid electrolyte having the composition of 0.8 g PC: 0.17 g Pr4NI : 0.0139 g I-2. Dye Sensitized Solar Cells (DSSCs) of configuration FTO/TiO2/dye/PAN NF:Pr4NI:PC:I-2/Pt/FTO were fabricated using gel electrolyte films of different thicknesses and characterized using I-V measurements. The DSSC fabricated with the gel electrolyte with optimized nanofiber membrane thickness showed an efficiency of 5.44% with an open circuit voltage of 735.0 mV, short circuit current density of 14.49 mA cm(-2) and a fill factor of 51.06%. (C) 2016 The Authors. Published by Elsevier Ltd.