A photo-physical and electrochemical impedance spectroscopy study on the quasi-solid state dye-sensitized solar cells based on poly(vinylidene fluoride-co-hexafluoropropylene)

Quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated with poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) in methoxy propionitrile (MPN) as gel polymer electrolyte (GPE), tetrabutylammonium iodide (TBAI)/iodine (l(2)) as redox couple, 4-tertiary butyl pyridine (TBP) as additive and silica nanoparticles as fillers. The energy conversion efficiency of the cell with 5 wt% PVDF-HFP is comparable to that one obtained in liquid electrolyte system. Solar cell containing PVDF-HFP with 0.8 M of TBAI and 0.12 M of l(2) shows maximum short-circuit current density (J(sc)). Further, tertiary butyl pyridine (TBP) has little effect in improving the performance of the solar cell. Moreover, the addition of I wt% silica nanoparticles is found to improve the at-rest durability and the performance of the solarcell. The transient photovoltage and photocurrent measurements were employed to find out the electron lifetimes in TiO2 electrode with different weight percentages of PVDF-HFP, various concentrations of l(2) and durability of the cell storage at 70 degrees C. A photocurrent density of 14.04 mAcm(-2), an open-circuit voltage of 0.71 V, a fill factor of 0.598 and an overall conversion efficiency of 5.97% under 100Wcm(-2) was observed for the best performance of a solar cell in this work. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.