Effect of Oxygen Flow Rate on Surface Morphology and Optical Properties of Reactive DC Magnetron Sputtered TiO2 Thin Films

Abstract

In the present work, reactive DC magnetron sputtering method is used to deposit TiO₂ thin films on glass substrates. The structural, surface morphology and optical studies of TiO₂ thin films were discussed by varying the oxygen flow rates from 1 to 4 sccm. X-ray diffraction patterns of TiO₂ thin films show amorphous nature. The surface morphological and elemental composition of TiO₂ thin films were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. From the optical absorption spectra, the shifting of absorption edge towards the longer wavelength leads to the decrement of optical bandgap from 3.48 to 3.19 eV with an increase of oxygen flow rate from 1 to 4 sccm.