Field Emission from the Perspective Cathodes on the Nanostructured SiC base: a New Approach for the Field Enhancement Coefficient Consideration

A new comprehensive theory for the field emission from the nanostructured semiconducting SiC was built with allowance for specially worked out analytical model of the field enhancement coefficient for the case of comparatively “smooth” protrusions, described by the curve of Lorenzian type. For the purpose of this analytical model a verification of the direct numerical computation of the field enhancement coefficient for the mentioned protrusions was carried through solving of the Poisson-Boltzmann equation using the finite elements method. The obtained numerical estimations confirm the perspectives of these cathodes. For the “sharp” protrusions with the height greater than the half-width, the emission current of 1 mA order can be harvested from one square cm for the fields ~3×108 V/m. The advantage of the proposed nanostructured cathodes based on SiC is the simplicity of their fabrication.