Field emission characteristics of self-assembled carbon nanotubes on the gold surface

Abstract

A method was studied to fabricate carbon nanotube (CNT) field emitters through self-assembly of thiol-modified CNTs onto a gold-coated substrate. By adsorption through simple immersion of the gold-coated substrate into thiol-modified CNT solution overnight, deposition of CNTs was accomplished. It was found that CNTs were deposited on the substrate as random aggregates of CNT bundles. The population density of CNTs on the gold-coated substrate was varied by controlled CNT concentration in ethanol. The I–V measurement of the self-assembled CNTs shows relatively good field emission characteristics with a low turn-on field (2.5 V/μm) and a high current density (40 μA/cm2 at 3 V/μm). In addition, more-populated CNTs on the substrate produce a higher current density. Therefore, the technique of self-assembly of CNTs on a selected area is expected to be a reliable way to prepare large-size panels with easy process and low cost. These advantages recommend further investigation of the self-assembly of CNTs.