Gas Sensor Applications of Tungsten Doped ZnO Thin Films in Low Hydrogen Gas Concentration

Recently, studies have been conducted to apply hydrogen gas as an alternative energy source that can replace energy from fossil sources such as diesel, gasoline, and propane gas. Therefore, hydrogen gas is regarded as one of the major energy sources it has gone beyond just a promise alternative energy source of energy. However, hydrogen gas is explosive, and it can cause a massive conflagration. Since this gas has no color, smell, and taste, highly sensitive gas sensor that can detect a minimal amounts of hydrogen gas must be installed for safety. An explosion can occur when the gas concentration is above 4%; for this reason, sensors that can detect ppm scale hydrogen gas must be developed. In this study, 1% and 2% Tungten (W) doped ZnO thin films were grown by chemical bathing technique and Hydrogen gas (H2) sensing properties were investigated. Electrical characterization of the samples at different temperatures (30 degrees C-160 degrees C) and different gas concentrations (5 ppm-100 ppm) was performed. The operating temperature was found at 100 vertical bar vertical bar C. The sensors exhibited acceptable sensitivity to 5 ppm H2 gas. 1% W-doped ZnO thin film showed higher sensing performance than other thin films at 100 degrees C. 1 % W-doped ZnO thin film exhibited 28.56 % sensitivity to 5 ppm H2 gas, while the 2 % W-doped ZnO thin film exhibited 7% sensitivity. The results showed that the gas sensing properties of the samples varied depending on the doping.