Studies and correlation among the structural, electrical and gas response properties of aerosol spray deposited self assembled nanocrystalline CuO

• Published in: Applied surface science 2011-06, Vol.257 (17), p.7592-7599
• Main Authors: Singh, Iqbal, Bedi, R.K.
• Format: Article
• Language: English
• Subjects: ACTIVATION ENERGY; Ammonia sensor; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; COPPER OXIDE; Correlation analysis; Cross-disciplinary physics: materials science; rheology; CRYSTAL STRUCTURE; CuO; DEPOSITION; Electrical properties of specific thin films; Electrical properties of specific thin films and layer structures (multilayers, superlattices, quantum wells, wires, and dots); Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Elovich equation; Exact sciences and technology; FRACTOGRAPHY; Materials science; Methods of nanofabrication; MICROSTRUCTURES; Nanostructure; NITRATES; Physics; Precursors; Self-assembly; Spray pyrolysis; SPRAYING; Structure and morphology; thickness; Surface chemistry; Surface layer; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Texture; TEXTURES; Thin film structure and morphology
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.03.133

[Display omitted] ► Deposition of CuO films by ultrasonic spray pyrolysis technique. ► Comparison of results with literature. ► Effect of substrate temperature on structural, morphological, electrical properties. ► CuO films as room temperature ammonia sensor. ► The kinetics of the ammonia gas adsorption by Elovich Model. Nanostructured CuO films have been grown on to the glass substrate by varying the deposition time from 10 to 30 min and substrate temperature from 300 to 400 °C by a simple ultrasonic spray pyrolysis technique, using aqueous a cupric nitrate solution as precursor. The effect of the substrate temperature on the textural, structural, electrical, and gas sensing properties of CuO films was studied and correlated. Thermal analysis of the dried precursor shows the elimination of physisorbed and chemisorbed water. It suggests the formation of CuO phase on substrate at temperature of 300 °C. X-ray diffractograms of the films indicate the formation of polycrystalline monoclinic CuO having monoclinic with crystallite size around 18 nm. The texture coefficient finds the (0 0 2) plane as the preferred orientation in films. The microstrain and dislocation densities have been calculated and found to decreases with increase in substrate temperature. The scanning electron micrographs indicate the formation of trapezium like facet structures on the film surface. AFM analysis shows uniform deposition of the CuO film over the entire substrate surface. Observations reveal that the film deposited at 300 °C show comparatively higher activation energy and appreciable response to ammonia at room temperature. The use of aqueous cupric nitrate as precursor results in the deposition of single phase copper oxide films.