Influence of iodide source on the performance of liquid and silica nanoparticle-loaded quasi-solid electrolyte-based dye-sensitized solar cells

Presence of cations from iodide source in liquid electrolyte has strong influence on photoelectrochemical characteristics of dye-sensitized solar cells (DSSCs). The present work shows the effect of different cations in liquid and silica-loaded gel electrolyte on the photovoltaic properties of DSSCs. Zeta potential measurements have been carried out to probe into the adsorption behavior of ions. It has been found out that lithium ions being smaller in size as compared to 1-methyl-3-propylimidazolium and tetrabutylammonium ions effectively get adsorbed onto the surface of silica nanopowder. Liquid and gel electrolytes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. In DSSCs, it was found that silica nanopowder addition to lithium ions-based liquid electrolyte significantly increases the open-circuit voltage as compared to the other two ions used in the study. This is due to adsorption of lithium ions onto silica surface which retards such ions to intercalate into or adsorb onto titania.