Electron transport properties of TiO2 shell on Al2O3 core in dye-sensitized solar cells

The performance of dye-sensitized solar cells (DSSCs) is strongly affected by the properties of semiconductor nanoparticles. In this work, we used TiO2 particles prepared by TiCl4 hydrolysis n times on Al2O3 films (A/T(n)), and investigated morphology, photoelectric, and electron transport properties of A/T (n). The TiO2 shell was composed of 10-20 nm nanoparticles and the number of nanoparticles increased with increasing TiCl4 treatment times. The highest photoelectric conversion efficiency of 3.23% was obtained as A/T(4). IMPS results indicated that electron transport rate was high enough to conduct current, and was not the dominating effect to limit the J(sc). J(sc) was mainly determined by dye loading on TiO2 and the interconnection of TiO2. These may provide a new strategy for preparing semiconductor working electrodes for DSSC.