Influence of Argon Flow Rate on Structural and Optical Properties of TiO_2 Thin Films Deposited by RF Sputtering

摘要

Structural and optical properties of Titanium Oxide (TiO_2) thin films deposited by RF magnetron sputtering with variation in argon (Ar) flow rate (20-40 sccm) have been studied. The film structure, optical transmission and band gap was studied using Raman spectroscopy, X-ray diffraction (XRD) and UV-Vis-NIR spectroscopy. In the as-deposited films, mixed phase i.e. rutile and anatase phase of TiO_2 was obtained. Effect of annealing on the deposited film was also studied. Phase transformation from mixed phase in as deposited films to pure anatase phase of TiO_2 after annealing at 500 °C for 2 hours was observed. Band gap of the as deposited film at Ar flow rate of 35 sccm is around 3.01eV and for the annealed film it is 2.92eV. The optical transmission in the visible range for as deposited film at Ar flow rate of 35 sccm is between 70-90% and for annealed film it is 64-85%.