Size effect of synthetic saponite-clay in quasi-solid electrolyte for dye-sensititized solar cells

The use of a synthetic saponite-clay with different morphological features is proposed in this work as additive for DSSC solar cells electrolyte. The dilution of the synthesis gel allowed to decrease the saponite particle size from ca. 200 nm to ca. 50 nm and to obtain samples with different lamellae organization. The influence of these parameters on solar cell performances have been tested by dispersing 5 wt% of the clay in Z-946 liquid electrolyte and using the dispersion as non-liquid electrolyte. The stability of saponite dispersions in methoxyproprionitrile solvent has been studied by Dynamic Light Scattering (DLS). The electrochemical characterization showed that the addition of the saponite sample with the largest particles does not influence the solar cell efficiency, whereas the use of electrolyte having saponite suspension with the smallest particle size led to an increase of solar cell efficiencies of 8% with respect to the reference cell. Finally, tests devoted to investigate the stability over the time of DSSC prepared by using quasi-solid saponite-based electrolytes have been carried out.