Emission characteristics of planar field electron emitters containing carbon nanotubes operating in the high current density mode

Planar field electron emitters containing carbon nanotubes that demonstrate stable emission currents with densities about 1 A/cm2 have been fabricated using the chemical vapor deposition method. The analysis of field emission characteristics based on Fowler-Nordheim theory allowed one to calculate not only the field amplification coefficient β, but also the total emission area A of all the emitting nanotubes. Using the value of A and an estimate of the emission area of an individual nanotube fulfilled in this work, the approximate number of emitting nanotubes N before and after the flow of the high density emission current, has been calculated. It has been found that the concentration of the emitting nanotubes N in such field emitters after the high density emission current flow was about 105 cm−2. Besides this, the location of light radiating nanotubes heated by high density emission currents has been investigated. This has revealed the regions of the emitter surface that gave the main contribution to the electron emission.