Non-edible oil based polyurethane acrylate with tetrabutylammonium iodide gel polymer electrolytes for dye-sensitized solar cells

Abstract Polyurethane acrylate (PUA) gel polymer electrolytes were prepared with tetrabutylammonium iodide (TBAI) as the complex salt. Fourier transform infrared spectroscopy results confirmed that the N H, C O, C N and C O C polar functional groups formed the coordination with TBA+ cations of salt observed from the bands shift. The maximum ionic conductivity of (1.88 ± 0.02) × 10-4 S cm−1 was obtained for the electrolyte with composition of 67.94 wt% PUA–30.00 wt% TBAI–2.06 wt% I2 (S3 electrolyte) which influenced by the highest charge mobility of (6.24 ± 0.12) × 10-7 cm2 V−1 s−1 and number density of (1.93 ± 0.04) × 1021 cm−3 estimated from fitting the Nyquist plots. The S3 electrolyte was electrochemically stable up to 1.64 V and capable of performing up to 2000 cycles steadily. Triiodide ion diffusivity obtained was 1.70 × 10-8 cm2 s−1. The electrolyte performance in dye-sensitized solar cells (DSSCs) was tested and cell with S3 electrolyte showed the highest solar conversion efficiency of (1.97 ± 0.21)% with short-circuit current density ( J sc ) of (7.15 ± 0.74) mA cm−2 and open-circuit voltage ( V oc ) of (0.55 ± 0.01) V when exposed under 1000 W m−2 light illumination. The highest efficiency obtained was influenced by the high electrons driving force in DSSCs. Low reduction resistance ( R pt ) of (2.46 ± 0.08) Ω at the electrolyte/counter electrode interface along with low charge transfer resistance ( R ct ) of (24.97 ± 0.14) Ω at TiO2/dye/electrolyte interface and charge diffusion resistance ( R d ) of (34.14 ± 0.11) Ω in redox electrolyte increase the electrons dynamic, thus resulting high J sc and hence high DSSC efficiency. This work shows that PUA-based electrolytes have potential for DSSC applications.