Applying porous polyimide films in fibrous dye-sensitized solar cells

Fibrous dye-sensitized solar cells (DSSCs) were fabricated using porous polyimide films prepared by the phase inversion technique and their photovoltaic characteristics were investigated. A titanium wire was used as the photoelectrode substrate and a platinum wire as the counter electrode. The platinum wire was coated with a porous polyimide film to prevent direct contact between the two electrodes while facilitating electrolyte penetration through the pores. The pore size and pore size distribution of the porous polyimide films were controlled by varying the immersion time in nonsolvent. With increased immersion time, the pore size distribution gradually broadened as the pore size increased, enhancing electrolyte penetration. Increased electron transport owing to the enhanced electrolyte penetration resulted in enhanced photovoltaic performances of the fibrous DSSC. The fibrous DSSC with 60 min immersion time had a short-circuit current density (Jsc) of 0.0372 mA/cm2, an open-circuit voltage (Voc) of 0.182 V, and a fill factor (FF) of 0.33.

► Fibrous dye-sensitized solar cells were fabricated using porous polyimide films.
► The porous film was applied to the counter electrode by the phase inversion method.
► Pores of various sizes were generated by immersing the film in water, a nonsolvent.
► The increase in pore size facilitated the electrolyte penetration.
► The photovoltaic performances enhanced with increased immersion time.