Field emission current fluctuations from isolated carbon nanotubes


Field emission current fluctuations from single carbon nanotubes created by a chemical vapor deposition (CVD) process were studied using a field emission microscope equipped with a moveable Faraday cup. The aperture at the entrance to the cup defined the solid angle subtended and allowed conversion of current into angular intensity. A time record of current was constructed by sampling, from which the average current and standard deviation were calculated. Simultaneously, a power spectrum from 1 Hz to 1 kHz was acquired. Normalized comparisons of power spectral densities for nanotube, Schottky and thermal field emitters are presented. The effect of heating the nanotube emitter substrate on the current fluctuation is shown. A limit of ∼0.1 mA sr−1 was observed for angular intensity from carbon nanotubes.

Document Type




carbon nanotube, field emission, current fluctuation, noise power, angular intensity

Publication Date


Journal Title

Surface and Interface Analysis