Comparison of the photovoltaic efficiency on DSSC for nanometer sized TiO2 using a conventional sol-gel and solvothermal methods

When the two types of TiO2 coatings prepared by sol-gel and solvothermal methods were applied to dye-sensitized solar cell (DSSC) in this study, the energy conversion efficiency of the solvothermal-modified TiO2 was considerably higher than that on the sol-gel modified TiO2; approximately 8.51 (solvothermal) and 5.93% (sol-gel) with the N719 dye under 100 mW/cm(2) of simulated sunlight, respectively. These results are in agreement with an electrostatic force microscopy (EFM) study showing that the electrons were transferred rapidly to the surface of the solvothermal-modified TiO2 film, compared with that on a sol-gel modified TiO2 film. Furthermore, FT-IR analysis of the films after N719 dye adsorption showed that the solvothermal-modified TiO2 had a strong band at 500 cm(-1), which was assigned to metal-O, due to a new Ti-O bond between the O of COO- and a Ti atom. This peak was considerably weaker in the sol-gel modified TiO2. (C) 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.