Improved Efficiency of Dye-Sensitized Solar Cells Based on a Double Layered TiO2 Photoanode

Abstract

A dye-sensitized solar cell (DSSC) consists of a TiO₂ nanocrystalline photoanode, electrolyte and a counter electrode. In this work, spray pyrolysis deposition technique was used to construct the nanocrystalline TiO₂ film. We found that repetitive spraying and sintering processes assists to decrease the number of cracks in the TiO₂ film. The TiO₂ electrodes were constructed by varying the bottom layer thickness with keeping total thickness of the film. The highest conversion efficiency of 8.5 % was obtained with the double-layered electrode (top layer: 6 μm, bottom layer: 9 μm). Short-circuit current was obviously improved from 10.51 mA/cm² of the single-layered electrode (15 μm thick) to 15.37 mA/cm² of this double-layered electrode.