IMF2017

Gel polymer electrolytes (GPEs) consisting of polyacrylonitrile (PAN) polymer, ethylene carbonate (EC) and propylene carbonate (PC) plasticizers and different compositions of tetrapropylamonium iodide (TPAI) salt have been prepared and investigated for the application in dye-sensitized solar cells (DSSCs). The electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy techniques have been utilized to characterize the GPEs. From the EIS study lowest bulk impedance, R_b (17 Ω) and highest ionic conductivity (4.72 × 10⁻³ S.cm⁻¹) have been observed for the GPE containing 30 wt. % TPAI. The highest apparent diffusion coefficient of triiodide ion is 5.5 × 10^-7cm² s^-1 at 0.051 (g) I₂ containing GPE with 30 wt. % of TPAI. Functional group interactions among PAN, EC, PC, and TPAI have been observed in FTIR spectra of the GPEs. An up-shift of XRD peak indicates the polymer-salt interaction and possible complexation of cation (TPA⁺ ion) with lone pair electron containing site (-CºN) in the host polymer matrix at the N atom. The DSSC with this GPE (30% TPAI) shows highest efficiency of 4.76% and short circuit current density of 19.74 mA.cm², open circuit voltage of 553.8 mV and fill factor 0.44.