High efficiency quasi-solid-state dye-sensitized solar cell based on polyvinyidene fluoride-co-hexafluoro propylene containing propylene carbonate and acetonitrile as plasticizers

Quasi-solid-state dye-sensitized solar cells (DSSCs) with different weight ratios of polyvinyidene fluoride-co-hexafluoro propylene (PVDF-HFP) containing two different plasticizers such as propylene carbonate (PC) and acetonitrile (AN) were fabricated and the effects of TiO2 morphology, light intensities as well as different organic iodides on the solar cell performance were studied. Two TiO2 photoelectrodes were designed by the coating of low (P1) and high molecular weight poly(ethylene glycol) (P2) incorporated into the TiO2 suspension. The DSSCs fabricated with the P2 TiO2 electrode show better performance in terms of short-circuit current densities (JSC) and conversion efficiencies than the P1 for all the weight percentages of PVDF-HFP containing both plasticizers. Further, the maximum current density (JSC) and conversion efficiency of PVDF-HFP containing different organic iodides follow the order: TBAI > TPAI > NH4I irrespective of the solvents and light intensity. A good conversion efficiency of 6.74% with JSC of 16.04 mA/cm2, an open-circuit voltage (VOC) of 0.657 V and a fill factor of 0.64 under illumination of 100 mW/cm2 was obtained for the DSSC with 10% of PVDF-HFP containing 0.4 M of TBAI and 0.04 M of I2 in PVDF-HFP/AN system.