Preparation of Nanorod-like Anatase TiO2 Nanocrystals and Their Photovoltaic Properties

Anatase TiO(2) nanocrystals with the specific surface area ranged from 100 to 220 m(2)/g were prepared by the hydrothermal treatment of anatase TiO(2) sols at the temperature of 110 degrees C and above. When TiO(2) sols with a lower content of TiO(2) and at a relatively high pH value were hydrothermal treated, the dispersible and nanorod-like TiO(2) nanocrystals were formed via the oriented attachment. The nanorod-like TiO(2) nanocrystals mixed with the original sol and were subsequently subjected to a further hydrothermal treatment; the branched and nanoring-like nanostructures in the anatase phase were obtained. The as-prepared TiO(2) nanocrystals were characterized with X-ray diffraction, FT-Raman spectrometry, UV-vis absorption spectrometry and transmission electron microscopy. The TiO(2) nanostructures were deposited on the FTO conductive glass as the anodic electrode for the dye-sensitized solar cell and assembled into solar cells. The derived solar cells showed a conversion efficiency of 6.12 % under 1 sun illumination of simulated sunlight and an external quantum efficiency (EQE) of more than 60% at the wavelength of 550 nm.