EFFECT OF RADIO FREQUENCY POWER ON MAGNETRON SPUTTERED TIO2 THIN FILMS

Thin films of titanium dioxide (TiO2) were synthesized using radio frequency (RF) magnetron sputtering. Structural and microstructural studies were performed on TiO2 films deposited at different deposition powers. Films exhibited a transformation from amorphous to anatase phase and to anatase-rutile mixed phase with increase in deposition power. X-ray diffraction showed an increase in crystallite size with deposition power in support with scanning electron micrograph. Films exhibited good transmittance in the visible region and the spectra were oscillatory in nature. Band gap exhibited a decrease with increase in sputtering power. A band gap of 3.2 eV was obtained for anatase film, which coincides with its bulk value. The variation of refractive index with wavelength is used in the calculation of dispersion energy parameters in single oscillator model (i.e., Wemble and Didomenico model). The band gap of films calculated from dispersion energy parameter showed good agreement with the values calculated from transmittance spectra.