Large Current Emission from CNTs Cold Cathode

Abstract

Carbon nanotubes (CNTs) have attracted great interest in the scientific field because of their unique structure, remarkable properties and potential applications. CNTs have been synthesized by methods such as arc discharge, chemical vapor deposition, laser ablation, etc. Such sustained, high-current field emission is necessary for many technological applications: for example, flat-panel field-emission displays require 10 mA/cm2, while microwave power amplifier tubes require at least 400 mA/cm2. These high-current density levels were previously obtainable only by thermionic emission above 1000 K, or lithographically fabricated tips. Field emission has been reported from other forms of carbon, however, at lower current densities (0.3 mA/cm2 for graphite, 30 mA/cm 2 for diamond)