TiO2 nanorods as additive to TiO2 film for improvement in the performance of dye-sensitized solar cells

Anatase TiO2 nanorods and nanotubes were produced from hydrolyzed TiCl4 using an anodic alumina membrane (AAM) as template. SEM analysis indicated that the form of nanostructures depends on the pore size of the membrane, and their diameters are almost same regardless of nominal pore sizes. When the nanorods were incorporated at about 10 wt% level in a P25 TiO2 film electrode of a dye-sensitized solar cell, its solar energy conversion efficiency was enhanced by about 42% as a result of a higher short-circuit photocurrent, compared with that of a cell fabricated with bare P25. The nanostructures were characterized by SEM, energy dispersive X-ray spectroscopy and Raman spectroscopy. Reasons for the invariance of sizes of nanostructures, and for the enhancement of the solar energy conversion efficiency are discussed. These explanations are supported by SEM, dye-adsorption measurements and light scattering findings.