Ionic liquid tributyl methylphosphonium iodide infused polyethylmethacrylate based polymer electrolyte for dye sensitized solar cell application

Abstract In this study, a polymer electrolyte—composed of poly(ethyl methacrylate) (PEMA) as the host polymer, doped with the ionic liquid tributylmethylphosphonium iodide (TMPI)—is synthesized for use as an electrolyte in dye-sensitized solar cells (DSSCs). The ionic conductivity of the PEMA:TMPI polymer electrolyte is determined using electrochemical impedance spectroscopy (EIS). It is observed that the conductivity of the polymer electrolyte increases in the presence of the ionic liquid, reaching a maximum value of 5.08 × 10 −4 S/cm with 20 wt.% TMPI under ambient conditions. Fourier transform infrared spectroscopy confirms the complexation between PEMA and TMPI. X-ray diffraction and polarized light microscopy studies confirm the alteration of the polymer's crystallinity. The photovoltaic performance of the DSSC fabricated with the optimized polymer electrolyte demonstrated a solar conversion efficiency of 1.45% under solar illumination.