Search

The Coulomb blockade effect is commonly used in solid state electronics for the control of electron flow at the single-particle level. Potentially, it allows the creation of single-electron point sources demanded for prospective electron microscopy instruments and other vacuum electronics devices. Here we realize this potential via creation of a stable point electron source composed of a carbon nanowire electrically coupled to a diamond nanotip by a tunnel junction. Using energy spectroscopy analysis, we characterize the electrons liberated from the nanometer scale carbon heterostructures in time and energy domains. Our experimental results demonstrate perfect agreement with theory prediction of Coulomb oscillations of the Fermi level in the nanowire and allow to determine the mechanisms of their suppression. Persistence of the oscillations at room temperature, high intensity field emission with currents up to 1 μA, and other characteristics of our emitters are very promising for practical realization of coherent single-electron guns. Image 1 [ABSTRACT FROM AUTHOR]

In this article, we present a comparative study of field emission (FE) properties of the films of pristine, annealed and CuCl-filled single-walled carbon nanotubes (SWCNTs). The current-voltage dependencies and emission site distributions were measured in the diode configuration with a flat phosphor-coated anode. A significant increase of the threshold field was observed after annealing and doping of the films. It was explained by the selective oxidation of the small-diameter nanotubes confirmed by the Raman spectroscopy. The FE properties of annealed and filled SWCNTs were found to coincide with each other. At the same time, their Raman spectra differ significantly indicating the strong p-type doping induced by encapsulated CuCl. The obtained result reveals that the CuCl filling leads to significant changes in macroscopically averaged electronic properties but do not change the local work function at the apexes of emitting nanotubes, which is important for the further development of SWCNTs-based FE cathodes. [ABSTRACT FROM AUTHOR]