Study on Field Emission Characteristics of Normal-Gated and Under-Gated Carbon Nanotube Cold Cathode

Abstract

Based on the classical electrostatic theory, the distributions of potential and electrical field at the apex of the carbon nanotubes (CNTs), both in normal-gate type triode structure and under-gate type triode structure, were simulated and calculated respectively. The gate electrode's position and gate aperture's effect on CNTs' field emission characteristics were analyzed. The results indicate that under-gate structure, compared with normal-gate structure, has better field emission performance and lower threshold voltage. Both the gate aperture and the distance between gate electrode and CNTs' apex have crucial effect on field enhancement factors of normal-gate structure and under-gate structure.