High-performance quasi-solid-state dye-sensitized solar cell based on an electrospun PVdF-HFP membrane electrolyte

An electrospun membrane was prepared from a 16 wt % solution of poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) in a mixture of acetone/N,N-dimethylacetamide (7:3 wt %) at an applied voltage of 12 kV. It was then activated by immersing it in 0.6 M 1-hexyl-2,3-dimethylimidazolium iodide. 0.1 M LiI 0.05 M I-2, and 0.5 M 4-tert-butylpyridine in ethylene carbonate/propylene carbonate (1:1 wt %) to obtain the corresponding membrane electrolyte with an ionic conductivity of 10(-5) S cm(-1) at 25 degrees C. On the basis of this electrospun membrane electrolyte, quasi-solid-state dye-sensitized solar cells were fabricated. which showed an open-circuit voltage (V-oc) of 0.76 V, a fill factor of 0.62. and a short-circuit current density (J(sc)) of 15.57 mA cm(-2) at an incident light intensity of 100 mW cm(-2). This yields a light-to-electricity conversion efficiency of 7.3%. Moreover, this cell possessed better long-term stability than that fabricated with conventional liquid electrolyte.