Carbon nanotubes over metallic wires and its possible applications

Multi-walled carbon nanotubes were grown on a catalyst-coated Kanthal wire by the Cold Plasma Chemical Vapor Deposition (CP-CVD) technique. The simplicity and versatility of the growth technique allows one to tune the density and size of the nanotube. Growth time, growth temperature, and catalysts have been identified as influential growth control parameters. Adding an inert metal, such as aluminum (Al) into active catalyst results in a thinner nanotube. The field emission performance of these nanotube-coated wires was measured in a cylindrical geometry. Emission site density is found to, be one of the important parameters for controlling the field emission performance of the nanotube-coated wires. The role of the amount of the inert metal (Al) with respect to the amount of the catalyst was also investigated. A possible application of the nanotube-coated wires, i.e., luminescent device, and the potential of the proposed growth technique (CP-CVD) for other applications are discussed briefly.