Local structural and sensing properties of TiO<sub>2</sub> thin films using the PVD method
Ankit Kumar Vishwakarma, Ashok Kumar Mishra, Chandra Kumar Dixit, Lallan Yadava
Abstract
This paper studied the structural, morphological, optical, near-edge X-ray absorption fine structure spectroscopy (XANES) and sensing properties of a titanium dioxide (TiO 2 ) thin film. The titanium dioxide thin film was prepared in a thin-film laboratory on a clean glass plate using a physical vapor deposition (PVD) method. The structural, morphological, optical and electronic properties of the fabricated samples were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet–visible spectroscopy and XANES. It was found from XRD that the crystallite size was ∼25.66 nm with a microstrain of ∼0.0064 using the Williamson–Hall plot. The fractal terms such as grain size, roughness, kurtosis and skewness were estimated using AFM. The grain size laid within the nanometric range and was found to be ∼77.21 nm. The band gap of the fabricated film was ∼3.23 eV. The XANES analysis was well supported by XRD measurement, and the results showed that the fabricated titanium dioxide thin film was in anatase phase. The sensing properties of titanium dioxide were studied for the detection of liquified petroleum gas (LPG) at concentrations of 0–5000 parts per million at room temperature. The results showed that the titanium dioxide film was highly sensitive and had a fast response as an LPG sensor with a maximum sensitivity of ∼198%.