Field emission current noise analysis of carbon based materials

Field emission current noise analysis of carbon based materials such as multiwalled carbon nanotubes, undoped graphene, nitrogen doped graphene, boron doped graphene, and polyaniline nanotubes is carried out at base pressure of ~1× 10
^-8
mbar. All the field emitters exhibited `step' and `spike' like fluctuations in the field emission current. The power spectra revealed that the noise is 1/f
^α
type, with α ~ 0.8 for all emitters. The origin of `step' and `spike' like fluctuations is explained on the basis of various processes such as adsorption/desorption, migration of residual gas atoms/molecules and ion bombardment induced effects on the emitter surface.