Development of Nanostructured CuO Films Using DC Magnetron Sputtering for Ammonia Gas Sensing Applications

Abstract

In this study, nanostructured copper oxide (CuO) thin films were prepared using DC magnetron sputtering for application as an ammonia (NH₃) gas sensor. The films were deposited on glass substrates under different Ar:O₂ gas ratios (1:1 and 2:1), and the effect of post-deposition thermal treatment on structural and morphological properties was investigated. XRD analysis revealed that the films were polycrystalline with a clear preferred orientation, while FE-SEM images showed uniform nanosized grains with average sizes ranging from 35 to 44 nm, depending on the gas mixture ratio, indicating controlled crystal growth. FT-IR spectroscopy confirmed the presence of chemical bonds characteristic of copper oxide, verifying the formation of the desired. Gas sensing tests demonstrated effective NH₃ detection, with sensitivity directly influenced by grain size, surface roughness, and surface area, which facilitated efficient gas adsorption and rapid response and recovery these results indicate that DC magnetron sputtered nanostructured CuO films are promising candidates for high-performance ammonia gas sensors. Furthermore, sensor performance can be optimized by carefully controlling gas ratios and thermal treatment conditions, providing potential for practical applications in industrial and environmental NH₃ monitoring.