Solvothermal growth of high surface area mesoporous anatase TiO2 nanospheres and investigation of dye-sensitized solar cell properties

Abstract

Mesoporous anatase TiO2 nanospheres are successfully synthesized via a simple solvothermal method without the aid of templates. The effects of systematic growth periods on the morphological, structural and optical properties of the mesoporous TiO2 nanospheres are investigated. It was found that the samples prepared with a 25 h growth period yielded good interparticle connection with a well-defined sphere-like morphology when compared with the samples with the 15 and 20 h growth periods. High surface area of 188 m2 g−1 is obtained from the BET analysis for the 25 h grown TiO2 mesoporous nanospheres. Mesoporous TiO2 nanospheres with different growth periods are used to prepare a photoanode layer by spray pyrolysis deposition for dye-sensitized solar cell (DSSC) fabrication. The ruthenium dye (N719) and indoline dye (D205) are used as sensitizers in the devices. The effect of the photoanode active layer thickness on the DSSC conversion efficiency is investigated. It is found that the maximum efficiency (η) of 7.02 (N719) and 6.97% (D205) are achieved for a layer thickness of 16 μm.TiO2 mesoporous nanospheres is used as a scattering layer for standard P25 titania coated DSSC and the enhanced efficiency of 5.92 (N719) and 5.12% (D205) are obtained.