Morphological studies of vertical arrays TiO[sub 2] nanotubes by electrochemical anodization technique for dye sensitized solar cell application

A vertical array titanium dioxide nanotube (n-TiO2) for photovoltaic materials in dye sensitized solar cell has been synthesized by electrochemical anodization technique in NH4F aqueous solution. The morphological observation performed by SEM analysis on the scratch film showed that the distribution growths of TiO2 nanotubes on Ti subtract were uniform. The duration of growth is varied up to 12 h, with tubes length approximately 1 mu m. However, at the maximum duration, a compact TiO2 layers were formed. This phenomenon is due to the field-assisted anodic oxidation at the interfaces of Ti/TiO2 is at equal rate with the field-assisted dissolution rate of the top TiO2 nanotube's surface, resulting from the decreased quantity of F(-)ions to form fluoro complexes, [TiF6](2-). A slight increase in the rate of the chemical dissolution reaction produced a precipitated TiO2. Hence, [TiF6](2-). complexes which are required for tubes formation are difficult to exist.