09:45 〜 10:00
▲ [17a-A408-2] Controlling the defect states formation in anatase TiO2 thin film by rf magnetron sputtering and its role on photocatalytic performance
キーワード：Thin film, TiO2
The photocatalytic activity of TiO2 is limited by the structure and the band gap of TiO2. As several factors are being considered to dictate the photocatalytic activity, recent studies show that engineering defects in TiO2 could be one possible solution to address the above-mentioned limitations. It has been demonstrated that defect-rich TiO2 has a superior activity than defect-free TiO2. Among many approaches to preparing TiO2 thin films, radio frequency (rf) magnetron sputtering allows for better control of the composition and the morphology of products, as well as making uniform thickness over a large area with strong adhesion and high reproducibility. However, controlling defects state formation in TiO2 thin films by sputtering has not been studied. Herein, we report that sputtering parameters such as magnetic field strength, oxygen partial pressure, substrate-target (S-T) etc. plays important role in defect state formation in TiO2 thin films. Figure 1(a), shows the XRD spectra of TiO2 thin films prepared at different oxygen partial pressure and S-T. It can be noted that all the films show pure anatase phase of TiO2. However, defects states, as seen in figure 1(b), is found to be different for each case. It was observed that, with the decrease in the partial pressure of oxygen, F, F+ and surface defect (Vo @ 4-coord.) states start to disappear. Further, the photocatalytic property of TiO2 thin films is found to be influenced by different defect states.