Investigation of the photovoltaic effect in dye-sensitized solar cells based on poly(ethylene glycol)-nanofiber electrolytes

Abstract

In this study, the effectiveness of electrospun poly(ethylene glycol) (PEG) nanofibers as polymer electrolytes for dye-sensitized solar cells (DSSCs) is evaluated. Regular PEG nanofibers are electrospun at an applied voltage of 15 kV, using a polymer concentration of 13 wt% and tip-to-collector distance of 20 cm. Subsequently, the photovoltaic effect in DSSCs containing PEG-nanofiber electrolytes with different I₂ concentrations is analyzed. On reducing the concentration of I₂ in the PEG-nanofiber electrolyte, the short-circuit photocurrent density (Jsc) of the corresponding DSSC increases significantly. A high power-conversion efficiency of 5.93% is recorded (by a solar simulator under AM 1.5 illumination) for a PEG-nanofiber-based DSSC containing an I₂/tetrabuthylammonium iodide (TBAI) molar ratio of 0.25. Additionally, electrochemical impedance spectroscopy is used to analyze the charge-transfer resistance of the TiO₂/PEG-nanofiber electrolyte interface in the fabricated DSSCs; the electrolyte uptake, ionic conductivity, and charge-transfer resistance values are investigated as a function of the molar ratio of I₂/TBAI.