Optical and Structural Properties of Titanium Dioxide Papered by DC Magneto-Sputtering as a NO2 Gas Sensor

Abstract

In this work, a reactive DC magnetron sputtering technique was used to prepare TiO2 thin films. The variation in argon and oxygen gases mixing ratios (4:1, 2:1, 1:1, 1:2, 1:4) was used to achieve optimal properties for gas sensing. In addition, an analysis of the optical XRD properties of TiO2 thin films is presented. High-quality and uniform nanocrystalline films were obtained at a working gas pressure of 0.25 mbar and 1:4 (Ar/O2) gas mixture. The optical properties showed a transparent thin film with uniform adherence to the substrate. The average transmission of the TiO2 films deposited on the glass substrates was higher than 95% over the range of 400 to 800 nm. The optical band gap varied from 3.84 eV to 3.93 eV as a function of oxygen/argon ratios. The XRD pattern showed that the films have an amorphous structure, which is shifted to polycrystalline with increasing oxygen to argon ratio. The sensitivity, response time, and recovery time were measured for TiO2 thin films using NO2 oxidizing gas.

Improving the Performance of Titanium Oxide Nanocomposites as NO2 Gas Sensors for Optimum Sensitivity

“…The flow rate of NO2 gas was (80-100) ppm since the gas concentration was a key component of the sensing process [9]. As reaction and recovery durations are influenced by temperature, several temperatures have been used [10]. The redox interaction between the gas and the surface of the nanocomposites (sensor) was triggered when NO2 gas was pumped into the detecting chamber [11].…”

Enhancing Gas Sensing Performance of TiO2-ZnO nanostructures: Effect of ZnO Concentration

“…By fabricating gas sensors from semiconductor oxides with highly sensitive to gases, these limitations can be overcome [4][5][6]. Metal oxide semiconductors including TiO2 and ZnO are important materials and have been widely studied [7,8]. Because of their chemical stability, low cost, non-toxic semiconductor material, and photocatalytic efficiency properties [9][10][11].…”