Enhanced O-phenylenediamine-doped PVDF/LiI/I₂ polymer electrolytes for dye-sensitized solar cells in adaptive portable assistive power device applications

Dye-sensitized solar cells (DSSCs) represent a promising solution to global energy demands owing to their cost-effectiveness, facile fabrication, and compatibility with sustainable materials. In this study, we investigate the impact of o-phenylenediamine doping on the structural and electrochemical properties of PVDF/LiI/I₂-based polymer electrolytes and the corresponding photovoltaic performance in DSSCs. A series of doped polymer electrolytes were synthesized via solution casting using N, N-dimethylformamide (DMF) as the solvent, with o-phenylenediamine incorporated at varying weight percentages (0–50 wt%). The structural modifications were characterized by SEM and XRD, revealing a significant reduction in crystallinity and the formation of uniformly dispersed, spherical particles at 40% wt. doping. This composition exhibited the highest ionic conductivity of 4.44 × 10−5 S cm−1, attributed to enhanced ionic mobility facilitated by increased amorphous content. When employed in DSSC fabrication, the 40% wt. o-phenylenediamine–doped PVDF/LiI/I₂ electrolyte yielded the highest power conversion efficiency (PCE) of 3.1% under standard illumination (AM 1.5G, 100 mW cm−2). These findings underscore the effectiveness of molecular doping strategies in tuning polymer electrolyte properties and highlight the potential of o-phenylenediamine modified PVDF systems for next-generation DSSCs. In addition, the developed polymer electrolyte system demonstrates potential for integration into flexible, low-cost, solar-driven power modules for adaptive portable assistive power devices.