NO2 gas sensor properties of In2O3-CuO Nanocomposite thin films prepared by chemical spray pyrolysis

Abstract

Abstract The NO2 gas sensor was synthesized from In2O3-CuO Nanocomposite thin films, deposited on glass substrate, with different mixing ratios (5, 15)Vol% of copper oxide, by chemical spray pyrolysis technique, at 400°C. The X-ray diffraction results showed that all the prepared films are polycrystalline, crystalline size in the range of (27.9 - 13.79 nm) with mixed ratio from 0 -15 Vol% of CuO respectively. From atomic force microscopy (AFM), the grain size ranged from (107.5 - 52.35 nm), and the prepared films have average roughness of (3.13-17.7 nm). The results of (UV-visible spectrometer) showed that the prepared films have high transmittance, and direct energy gap (3.5 -3.15) eV. The prepared films showed a high sensitivity to NO2 with a concentration of 193ppm. For the unmixed films, the sensitivity reached (89.77%) with an equal response and recovery times of (24s), at 200°C operating temperature. The mixture thin films gave less sensitivity than unmixed indium oxide thin films.