Robust CNT field emitters: Growth and in situ welding on metal surfaces

Abstract

Methods to grow carbon nanotubes (CNTs) on titanium (Ti) dies using Chem. Vapor Deposition were developed. Post-growth treatment of the dies at elevated temps. (1050 °cC) under inert atm. allows for the metal surface to deform and subsequently aid in anchoring the surface-grown CNTs to the surface. Addn. of a layer of copper to the grown CNTs prior to heat treatment further enhances the CNT surface adhesion. Mech. tests demonstrated that the welded CNTs were attached to the substrate stronger than the compared to unwelded samples. The field emission properties of these anchored CNTs were tested and compared to analogous unwelded titanium samples. The anchored samples demonstrated an improvement in the field emission properties over samples that did not undergo the post-growth heat treatment. This process can be extrapolated to the fabrication of various other CNT devices that require patterned, vertically aligned CNTs but generally suffer from poor adhesion to the substrate.