Low-voltage field desorption in carbon nanotubes

Abstract

Influence of gas sorption and desorption on field emission current evolution from carbon nanotube cathodes was investigated. Two types of nanotube cathodes were made: nanotubes grown from gas phase on stainless steel and nanotubes deposited from solution on Si substrate. Exposure of cathode to air at atmospheric pressure leads to increase of starting current with rapid decrease. We associate this effect of reversible degradation with some kind of field desorption. Sorbed gases reduce the work function and thus increase emission current. Different gases demonstrate different effect on the current behavior. We observed desorption process in low field values ~10⁴−10⁵ V/cm.