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Enhancement of efficiency by using iodide mixture (Pr 4 NI and KI), instead of a single iodide salt, in N719 dye-sensitized solar cells with a polymethylmethacrylate (PMMA) based gel electrolyte is investigated. The salt ratio is varied to optimize efficiency. With 100 wt.% KI and 100 wt.% (Pr 4 NI) efficiencies under AM 1.5 illumination are 3.39% and 3.21%, while 22.2:77.8 wt.% ratio KI:Pr 4 NI shows the highest efficiency of 3.99 %. This is an efficiency enhancement of 18%. Variation of efficiency with salt composition appears to correspond to the change in short circuit photocurrent density ( J sc ) and the iodide ion conductivity. [ABSTRACT FROM AUTHOR]

Efficiency enhancement is achieved in dye sensitized solar cells (DSSCs) fabricated with polyethylene oxide (PEO) based gel electrolyte by optimizing the iodide ion conductivity using a binary iodide salt and TiO 2 nanofiller. The binary iodide salt system consists of K + as the small cation and Pr 4 N + as the large cation. The correlation between the efficiency variation and the short circuit current density variation with salt composition suggests that the improved iodide ion conductivity of the electrolyte plays a dominant role in enhancing the solar cell performance. The highest DSSC efficiency of 4.12% is obtained for the electrolyte with salt composition 25 wt% Pr 4 N + I − : 75 wt.% KI. The incorporation of 2.5 wt% TiO 2 nano fillers into the polymer electrolyte further enhances the solar cell efficiency to 5.31%, very likely due to the increased ionic mobility caused by the increased amorphous phase content of the PEO based polymer electrolyte. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the effect of using a mixed iodide salt system with two dissimilar cations to enhance the efficiency of dye-sensitized solar cells made with polyvinylidenefluoride (PVdF) based gel electrolyte. Instead of a single iodide salt, a mixture of potassium iodide (KI) with a small K+ cation and tetrapropylammonium iodide (Pr4NI) with a bulky Pr4N+ cation were used to provide the required iodide ion conductivity. Solar cells of configuration FTO/TiO2/Dye/electrolyte/Pt/FTO were fabricated using a mesoporous TiO2 electrode sensitized with a Ruthenium dye (N719). With identical electrolyte compositions, the cells with KI and Pr4NI alone gave efficiencies of 2.37% and 2.90% respectively. The cell with the mixed iodide system, KI:Pr4NI = 16.6:83.4 (% weight ratio), however, showed an enhanced efficiency of 3.92% with a short circuit current density of 9.16 mA cm−2, open circuit voltage of 674.4 mV and a fill factor of 63.4%. [Copyright &y& Elsevier]