Structural Modification of Sol-Gel Derived TiO2 Nanostructured Films Using Microwave Irradiation

Thin films of TiO₂ have been deposited on Si (100) polished substrates at room temperature by sol-gel spin coating technique followed by two different annealing treatment methods. One set by conventional annealing at different temperatures ranging from 200°C to 1000°C for 3 h and second set by exposure to microwave (2.45 GHz) radiation at different powers ranging from 100W to 900W for 10 min. X-ray diffraction, scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy techniques have been employed to characterize structural, morphological as well as compositional properties of the microwave exposed and annealed films. Microwave exposed films have shown nanostructured growth of TiO₂ anatase phase at 300W and above, with grain size ranging from 8-12 nm compared to conventional annealing process, where the grain size of anatase phase of TiO₂ has 25-30 nm. Plausible mechanism for the formation of anatase phase of TiO₂ on Si substrates has also been discussed.