Preparation of Antimony Tin Oxide Thin Film Using Green Synthesized Nanoparticles by E-Beam Technique for NO₂ Gas Sensing

This work delves into the preparation of ATO thin films and their characterization, fabrication, and calibration of a NO₂ gas sensor, as well as the development of the packaged sensor. ATO thin films were prepared by e-beam evaporation using green synthesized ATO nanomaterials on different substrates and annealed at 500 and 600 °C for one hour. The structural and morphological properties of the developed thin films were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. An orthorhombic SnO₂ crystal structure was recognized through XRD analysis. The granular-shaped nanoparticles were revealed through SEM and TEM images. The films annealed at 600 °C exhibited improved crystallinity. ATO films prepared on normal 5 µm interdigitated electrodes (IDEs) and annealed at 600 °C exhibited a response of 10.31 ± 0.25 with an optimum temperature of 200 °C for a 4.8 ppm NO₂ gas concentration. The packaged NO₂ gas sensor developed using IDEs with a microheater demonstrated an improved response of 16.20 ± 0.25 for 4.8 ppm of NO₂ gas.