Effect of 2,2’-bipyridine-4,4’-dicarboxylic acid-doped PVDF/KI/I2 based polymer electrolyte for dye sensitized solar cell applications

Solar energy transformation is a sustainable and dependable solution for rising energy demands and depleting fossil fuels. Dye-sensitized solar cells (DSSC) are one of the most popular solar energies conversions devices because of their simple fabrication, affordability, dependability, and high efficiency. Electrolytes are an essential component of DSSCs. They transfer electrons from the working electrode to the counter electrode and then return them to the photoanode via the polymer electrolyte. The performance of the 2,2’-Bipyridine-4,4’-dicarboxylic acid (2,2’-Bp-4,4’-dca)-doped Poly Vinylidene Fluoride (PVDF)/KI/I₂ polymer electrolyte was investigated to make an effective DSSC, using N, N-Dimethylformamide (DMF) as a solvent. The solution casting method were used to make 2,2’-Bp-4,4’-dca-doped PVDF/KI/I₂ electrolyte films with various weight percentages (0%, 10%, 20%, 30%, 40%, and 50%). The synthesized polymer electrolyte films were characterized using a variety of analyzing techniques including scanning electron microscopy (SEM), powdered X-ray diffractometer (PXRD), and AC-impedance analysis. PXRD studies verified that the strength of the peak gradually lowered up to 30% and then gradually increased. SEM analysis revealed that the size of spherical particles gradually decreased up to 30% of the 2,2’-Bp-4,4’-dca-doped PVDF/KI/I₂ polymer electrolyte. Ionic conductivity of the polymer electrolytes was calculated using AC-impedance analysis. The ionic conductivity of the 2,2’-Bp-4,4’-dca-undoped PVDF /KI /I₂ polymer electrolyte was 8.13x10^-8 S cm^-1, this increased to 4.94x10^-4 S cm^-1 for the 30% 2,2’-Bp-4,4’-dca-doped PVDF/KI/I₂ electrolyte. It was proved to achieve the highest electrolytic conductivity compared with other weight percentages. The photovoltaic measurements were measured using fabricated DSSC. The maximum efficiency (η) (3.68%) was measured for 30% 2,2’-Bp-4,4’-dca-doped PVDF/KI/I₂. Therefore the 30% 2,2’-Bp-4,4’-dca-doped PVDF/KI/I₂ electrolyte was suitable for DSSC applications.