High density electron emission source based on carbon nanotubes for industrial applications

Vertically aligned multi-walled carbon nanotubes (MWCNTs) have been grown by Catalyzed-Chemical Vapour Deposition (C-CVD) both on bare doped silicon and thin TiN film on silicon, aiming at the development of high density and stable cold emission sources for industrial applications. Iron and nickel have been used as catalysts on the afore-mentioned substrates, respectively. Field emission characteristics of MWCNTs have been evaluated using a sphere-to-plane electrodes geometry. Current densities up to 150 mA/cm2 have been obtained at applied electrical field of 6 V/µm. Emission stability measurements have been performed which prove a medium-term stability. Structural and morphological characterization of MWCNTs has been carried out by SEM and Raman spectroscopy. The dependence of the emission characteristics on the emitter structure and morphology and on the working conditions will be presented.