Corrosion and charge transfer dynamics of ITO-coated-PET/graphite-substrates with polyaniline/PMMA gel-electrolytes

Abstract

This study reports the charge transfer process and the corrosion behavior across the interface between the Counter Electrode (CE) and Polymer Gel Electrolytes (PGEs) of Flexible Dye-Sensitized Solar Cells. The Counter Electrode (CE) consists of ITO-coated PET/Graphite substrates, while the polymer gel electrolyte thin film was prepared using Polyaniline and Polymethylmethacrylate. ITO-coated-PET/Graphite substrates were selected for their flexibility and optical transparency, which enhances the device's light absorption. Impedance Spectroscopy was employed to analyze the charge transfer resistance, electron recombination dynamics, and enhanced electron mobility of PANI/PMMA-based PGEs. Two PANI/PMMA-based PGEs were studied: one with added salt and the other without. The highest ionic conductivity, 5.2 × 10⁻⁴ S/cm, was observed in the sample having salt, indicating stable charge transport within the polymeric matrix. A one-month corrosion study and galvanostatic-charge-discharge test evaluated the stability of the counter electrode-gel electrolyte interface, confirming long-term performance. The highest efficiency of 1.71% was observed in the sample having salt. This work highlights the potential of advanced materials in FDSSCs, where the distinct role of the ITO-coated-PET/Graphite and PANI/PMMA-based PGEs results in a synergistic enhancement of FDSSC performance.