On-Chip Thermionic Electron Emitter Based on Single-Walled Carbon Nanotube

Carbon nanotube is regarded as a promising material for electron emission because of its excellent properties, such as high electrical and thermal conductivity, good chemical stability, high aspect ratio and high melting point. Here, we report the scaling down of thermionic emitter to the nanoscale by using microfabrication technologies and a single-walled carbon nanotube (SWCNT), the thinnest conducting filament we can use. The CNT nanoscale thermionic electron emitters (NTEEs) are found to exhibit a low working voltage of a few volts and controllable and repeatable emission performances in a low vacuum (~10
^-2
Pa). Importantly, the emission density of the CNT NTEE is measured to be ~10
⁴
A/cm
²
, which is superior to that of traditional thermionic emitters. With the excellent emission performance and capability to be integrated on silicon chip, the CNT NTEE demonstrate tremendous potential in on-chip electron source applications.