Crystallinity and orientation of solution deposited anatase TiO2 films

The crystallinity of anatase TiO2 material synthesized from an acidic fluoride-based solution at 60 to 200 degrees C was raised by increasing the growth temperature by an amount that was significantly lower than that required by postdeposition heat-treatment in air. As higher temperatures lead to more complete dehydration reactions and lower proton incorporation, the long- range attractive forces necessary for crystallinity are disrupted to a lesser degree. In addition, films grown on glass slides at 60 and 100 degrees C exhibited preferential c-axis orientation due to restricted lateral and off- normal growth of crystallites elongated along the c-axis. As the island nucleation density was higher at 100 degrees C, this resulted in even less lateral and off- normal crystallite growth compared to the film grown at 60 degrees C, giving rise to a greater degree of c-axis preferred orientation for the 100 S C film. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.1943590] All rights reserved.