Field emission properties of carbon nanotubes and their applicationto display devices

Abstract

Field emission microscopy (FEM) of carbon nanotubes (CNTs) revealed that the adsorption and desorption of gas molecules on the tip were responsible for stepwise increases and decreases in the emission current, respectively. Long-term emission experiments under various ambient gases (such as H 2 , He, N 2 , O 2 , H 2 O, CH 4 , CO 2 , Ar) have shown that the degradation of emission current occurred most sensitively in O 2 , H 2 O and CH 4 atmosphere. Electron emission from CNT films prepared by spray-deposition of preformed CNTs was also measured as a function of the distance (d) between the nanotube cathode and an anode plate, and the macroscopic field strength E av (voltage divided by distance between the cathode and the anode) that sustain a certain constant current was found to rise steeply with the decrease of d, for a small gap region (d<ca. 40 w m) while the E av slowly decreases with increasing d for a large gap. Finally, we report our recent fabrication of nanotube-based ultra-high luminance light sources that provide intense light of 10 6 cd/m 2 for green at 30 kV dc-driving voltage.