Theory of field emission from dielectric coated surfaces

Abstract

This paper presents an exact analytical theory for field emission from dielectric coated cathode surfaces, by solving the one-dimensional (1D) Schrödinger equation with a double-triangular potential barrier introduced by the coating. The effects of the cathode material (work function and Fermi energy), dielectric properties (dielectric constant, electron affinity, and thickness), applied dc field strength, and cathode temperature are analyzed in detail. For 1D flat cathode surfaces with coating, it is found that the emission current density can be larger than the uncoated case when the dielectric constant is smaller than a certain value edielth and the dielectric thickness is larger than the threshold value dth[nm]≈edielW/eF with the dielectric constant ediel