SYNTHESIS, CHARACTERIZATION AND FIELD EMISSION BEHAVIOR OF CuO NANOSTRUCTURES

Abstract

CuO is a narrow band-gap semiconductor demonstrating applications in/as catalysts, gas sensors, adsorbents, superconductors and as electrodes of photocells, super-capacitors and lithium-ion batteries. One-dimensional CuO nanostructures are of particular interest in most of these device applications owing to their huge surface area. Strong bonding between nanomaterials and substrate is essential for extended device life. Hence, knowledge about strength of nanomaterial-substrate bond is highly desired. In this research work, CuO nanotubes were synthesized directly on Cu substrate and its adhesion strength was quantified using nano-scratch based technique. The adhesion energy of CuO nanotubes (for 711 of reaction period) on Cu substrate was measured to be 82 Jm* The bonding strength can be correlated with the structure of the material. Results of this research will be valuable in analysing and improving life time of CuO nanotube based devices and the technique could be further extended to other 1 -D transition metal oxide nanostructures. After quantifying the adhesion strength, field emission (FE) response of CuO nanotubes along with other CuO nanostructures like nanorods and nanoflakes have been characterized. The results indicated that the FE properties are significantly dependent on the shape and morphologies of CuO nanostructures. Typical turn-on voltage for CuO nanotubes, nanorods and nanoflakes are found to be 5.69, 6.37 and 8.5 V/jim respectively.