Low threshold field emission from nanoclustered carbon grown by cathodic arc

Abstract

Nanocluster carbon films grown using a cathodic arc process at room temperature in the presence of background gases such as He are found to be good electron emitters. The variation in the surface morphology and the corresponding emission characteristics of the films with change in helium partial pressure (5×10−4–50 Torr) during the film growth are reported. The effect of helium partial pressure on clustering was studied for films grown at nitrogen partial pressures of 10−4 and 10−3 Torr. The surface morphology of the films grown, varied from smooth through clusters (with sizes 50–200 nm), to fibrous films. The threshold field varied from 1 to 10 V/μm for an emission current density of 1 μA/cm2. These films exhibit an emission site density of ∼104–105/cm2 at an applied field of 5 V/μm.