Effects of Electrolytes on the Photoelectric Properties of TiO2-Based Dye-Sensitized Solar Cells

The unique photoelectric properties of TiO₂, which make it a better choice of dye-sensitized solar cells with high efficiency, have attracted a lot of interest in recent years. Especially, single-crystal rutile TiO₂ nanorod arrays have been extensively investigated. In this study, in order to improve the photoelectric properties of TiO₂ and analyze the effects of different electrolytes on the performance of TiO₂ based dye-sensitized solar cells, the solar cells were fabricated with iodine base electrolyte, sulfur based electrolyte and inorganic solid state electrolyte, CsSnI_2.95F_0.05, as electrolyte respectively, and Pt deposited on the conductive face of fluorine-doped tin oxide (FTO) glass as the counter-electrode. TiO₂ nanorod arrays were treated with ethanol solution of cis-diisothiocyanato-bis-(2,2^,-bipyridyl-4,4^,-dicaboxylato)-ruthenium()bis(tetrabutyl-ammonium) (N719, DYESOL) for 18h before the cell assembly. Open-circuit voltage (V_OC), short-circuit current density (J_SC) and impedance of the solar cells with these three kinds of electrolytes were measured respectively, and then their conversion efficiencies were calculated. The TiO₂ based solar cell fabricated with CsSnI_2.95F_0.05 showed the highest conversion efficiency of about 8.9%, which was much higher than those of the solar cells fabricated with the other two kinds of electrolytes.