Abstract
In this study, the effect of the synthesis parameters on the structure of the porous titanium dioxide thin films were investigated by Grazing-Incident Small-Angle X-ray Scattering(GISAXS). Sol-gel method was employed in this study to synthesize the porous titanium dioxide thin films using the polymer Pluronic P123 as the soft template. The hydrolysis and condensation rate of the precursor used in the sol-gel method play very important roles in controlling the synthesized structure. It is necessary to control these rates to allow the formation of ordered template structure. It is often need to use the evaporation-induced self-assembly method (EISA method) to successfully synthesize ordered porous titanium dioxide thin films. The factors affecting the hydrolysis and condensation reaction, such as the type of precursors, the concentration of hydrochloric acid, the humidity, and the Pluronic P123 concentration, were varied in this study. At Pluronic P123 concentration 10 wt%, and HCl/TTIP molar ratio 0.5, it was found that the synthesized titanium dioxide thin film possess hexagonal stacking structure, lying parallel to the silicon substrate surface with a unit cell constant of 11 nm. At higher P123 concentrations or higher acid conditions, it was found that the hexagonal structure is replaced by the lamellar structure. These findings suggest that the synthesized structures follow closely with the phase diagram of P123.