Influence of Ar:O2 Mixing Ratio on Characteristics of Tio2 Nanostructured Thin Films Deposited by DC Reactive Magnetron Sputtering Method

Abstract

In this paper, titanium dioxide nanostructured thin films TiO₂ were deposited on unheated glass substrates by applying the DC reactive magnetron sputtering method. Three TiO₂ films were deposited using argon sputtering gas with different oxygen ratios: 10%, 25%, and 50%. The resulting films had thicknesses of 200, 184, and 140 nm, respectively. The structural, morphological, optical, and electrical properties of deposited thin films were studied. X-ray diffraction (XRD) data showed that the samples exhibited an amorphous phase. It was found from atomic force microscopy (AFM) that the deposited thin films had a nanostructure, and the heights of their nanograins were 16, 24, and 30 nm, respectively. It was observed from the root-mean-square height RMS values that the films had low roughness. The UV-Vis-NIR spectroscopy showed that the films become more transparent with the increase in oxygen content. The direct band gap ranged between 3.68 and 3.88 eV, while the indirect band gap ranged from 3.3 to 3.66 eV. The highest intensity photoluminescence emission was obtained for the film deposited at 50% O₂. In addition, the impedance spectroscopy showed that the films’ resistance did not change with changing oxygen content.