Unconventional increase of mesoporosity order in titanium dioxide thin film due to calcinations and investigation of its optical properties

In this research, a titanium dioxide thin film with average particles size of 8 nm was prepared on glass surface and then it's crystalline and optic properties before and after calcinations was investigated. Low angle XRD analyses showed that prepared thin film has mesoporous structured prior to calcination and a further increase in the meso-scale order has been made by calcination. Low angle XRD analyses revealed three peaks related to hexagonal symmetry before and after calcination. Lattice constant of the prepared titanium dioxide before and after calcination, using miller indices of (100) crystal plane calculated to be 147.57 and 143.47 Å, respectively. Transmission spectra of titanium dioxide coating exhibit a significant blue shift in absorption edge and increasing of its transparency after calcination. Indirect band gap of prepared coating estimated from UV-Vis spectra to be 3.69 eV and refractive index of the film and its porosity percentage was calculated to be 1.54 and 67%, respectively.