Hydrothermal growth of one-dimensional Ce-doped TiO.sub.2 nanostructures for solid-state DSSCs comprising Mg-doped CuCrO.sub.2

In this work, hydrothermal method was used to grow the one-dimensional Ce-doped TiO.sub.2 nanostructures on the fluorine-doped tin oxide glass. The incorporation of cerium atoms into the TiO.sub.2 lattice was investigated by structural and electrical analyses. The results showed that TiO.sub.2 nanorod arrays had maximum electrical conductivity for 3 % of Ce dopant. The increase in the electrical conductivity can be ascribed to the formation of oxygen vacancy in TiO.sub.2 nanostructures with Ce doping. The morphology of the as-grown nanorods revealed that the diameter of the TiO.sub.2 nanorods increased with Ce doping concentration. Hydrothermal etching treatment was performed on the as-grown 3 % Ce-doped TiO.sub.2 nanorod arrays in hydrochloric acid solution at 160 °C for different time durations. The obtained results clearly showed that the morphology change from the nanorods to the nanotubes occurred after 4 h of etching during hydrothermal treatment. In addition, sol-gel process was employed to synthesize 5 % Mg-doped CuCrO.sub.2 nanoparticles with p-type conductivity as solid-state electrolyte. The solid-state DSSCs fabricated using hydrothermally treated 3 % Ce-doped TiO.sub.2 nanorods displayed better photovoltaic performance than those made from the untreated ones. This is attributed to the larger specific surface of the hydrothermally treated nanorods compared with the untreated ones. The dye-loading measurement confirmed that the amounts of adsorbed dye on the surface of hydrothermally treated nanorods were higher than that of the untreated ones.