High-performance dye-sensitized solar cell based on an electrospun poly(vinylidene fluoride-co-hexafluoropropylene)/cobalt sulfide nanocomposite membrane electrolyte

Electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanocomposite membranes incorporated with different weight percentages (1, 2 and 3 wt%) of cobalt sulfide (CoS) were prepared by an electrospinning technique. The surface morphology, crystallinity, porosity and electrolyte uptake of the electrospun nanocomposite membranes were examined. The prepared electrospun PVdF-HFP/CoS nanocomposite membranes (esCPM) were activated by an ionic liquid electrolyte containing 0.5 M LiI, 0.05 M I-2, 0.5 M 4-tert-butylpyridine and 0.5 M 1-butyl-3-methylimidazolium iodide in acetonitrile to obtain electrospun PVdF-HFP/CoS nanocomposite membrane electrolytes (esCPMEs). The uniformly dispersed CoS nanoparticles increased charge transport and facilitated the diffusion of the redox couple in the electrolyte system. The electrochemical characteristics of the dye-sensitized solar cells depended on the amount of CoS incorporated into the esCPMEs. The photovoltaic performance of the dye-sensitized solar cell assembled using the esCPME incorporated with 1 wt% of CoS was measured and found to be 7.34%, which is higher than that of the dye-sensitized solar cell assembled using the esPME without CoS (6.42%).