CNTs and CNT/ZnO nanostructures for use as electron sources

The aim of this paper is to describe the growth and optimization of carbon nanotube (CNT) and CNT/Zinc Oxide nanostructures to produce novel electron sources. The emitters studied in this project are based on regular array of vertically aligned 5 µm height and 50 nm diameter CNTs with a pitch of 10 µm as described previously (1). Such a cathode design allows us to minimize electric field shielding effects and thus to help in optimizing the emitted current density. We have previously obtained a current density of 1 A/cm
²
from such arrays in DC mode, and over 12 A/cm
²
in pulsed mode at RF frequencies.