Influence of Thermal Treatment on the Optical Properties of Zinc Oxide and Titanium Oxide for Dye-Sensitized Solar Cell Application

Abstract

The optical properties of one of the components of a Dye-sensitized solar cell (DSSC) were reported using a photoanode prepared with zinc oxide (ZnO) and titanium oxide (TiO₂) in conformity with Doctor Blade’s technique. The prepared photoanodes were characterized with UV-vis spectroscopy. The ZnO and TiO₂ photoanode exhibits high transparency (≥ 60 %) to photons. The modified photoanode, with ZnO-TiO₂(ZTO) composite, revealed an improved light transmittance over TiO₂. The energy band gaps obtained for ZnO thin films as-prepared and annealed are 3.93 eV and 3.98 eV, respectively, and 4.08 eV and 4.14 eV, respectively, for the TiO₂ as-prepared film and the annealed film. The ZTO composite lowers the absorption in the visible region. The results obtained provide improved photoanode for DSSC application, compared to using unannealed semiconductors.