Parametric Optimization for Highly Sensitive ZnO Based NO_X Gas Sensor

NO_X (NO, NO₂) is one of the most hazardous gases for the environment as well as human health. In this research, NO_X (NO, NO₂) gas sensor is fabricated by using a zinc oxide (ZnO) thin film. The study explored the impact of sensing layer thickness variations on gas sensing. In this work sensing response is analyzed at different thicknesses and the optimum thickness for better response. For the given samples with 355 nm optimum thickness at 180 °C optimal operating temperature, it is discovered that the sensing response with bare ZnO thin film increased dramatically from 0.1 to 8.6. The analysis has been carried out at different detecting surface thicknesses for the gas concentration of 500 ppm. In this study, the impacts of varying the ZnO-based thin film thickness are investigated through optical, structural, and gas-sensing characterizations.