Enhanced photovoltaic properties of TiO2 film prepared by polycondensation in sol reaction

Abstract

A TiO₂ film of dye-sensitized solar cells was fabricated using a TiO₂ sol prepared from titanium isopropoxide as a starting material. The effect of polycondensation time and temperature on physical and chemical properties of TiO₂ film shows that the crystallinity, particle size, roughness, and surface area of TiO₂ film can be successfully controlled by adjusting the polycondensation time and temperature in the synthesis process of the TiO₂ sol. Adsorption properties (adsorption equilibrium, isosteric enthalpies of adsorption, and adsorption energy distributions) of N719 dye molecules on the prepared TiO₂ film revealed that the short circuit current (I_sc) and overall conversion efficiency (η_eff) are highly dependent on the crystallite size and the N719 dye adsorption properties. The TiO₂ film has a pure anatase phase, high surface area including pore volume, and large anatase crystallite size and is capable of enhancing the photovoltaic performance. The energy conversion efficiency of the dye sensitized solar cells is highly dependent on the physical and chemical properties of TiO₂ films.