Rational design and elucidation of interfacial dynamics in PMMA/PVDF compatibilized blends through solution blending for stable quasi-solid-state dye-sensitized solar cells

In the photovoltaic market, the widespread adoption of traditional dye-sensitized solar cells (DSSCs) faces obstacles due to inherent stability challenges. The solution to these issues involves replacing liquid electrolytes with quasi-solid electrolytes. In this work, quasi-solid state electrolytes were synthesized by employing a polymer blend and inorganic salt. The polymeric blends, comprising polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF), were meticulously prepared through the solution blending technique. The investigation of blend compatibility, crystallinity, and stability involved analyses through differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-degradation assessments, respectively. The findings indicated that the concentration of ingredients significantly influenced the compatibility, crystallinity, and stability of the blends. The compatibilized blend was employed in crafting polymer gel electrolytes (PEGs), demonstrating that both the concentration and type of salts significantly influence the ionic conductivity of PEGs. The highest conductivity, reaching 2 mS/cm, was achieved with a mixed salt concentration of 50w%/50w% (NH₄I/KI). Subsequently, this electrolyte was incorporated into the fabrication of quasi-solid state DSSC. The results showed that the DSSC with PEG achieved 2.81 % efficiency, while the traditional DSSC had 4.11 % efficiency. Notably, after fifteen days, the efficiency of the traditional DSSC dropped to 0.20 %, while the PEG-based DSSC remained stable (2.58 %).