Catastrophic destruction of carbon nanotubes during degradation of field emitters

Abstract

The catastrophic degradation of emission cathodes based on carbon nanotubes is simulated, which occurs due to the destruction of the nanotube in the defective region as a result of overheating. The model takes into account the heating of the nanotube by releasing Joule heat, as well as radiation and cooling due to the Notingham effect, which consists in reducing the temperature of the emitting end due to the energy carried away by the flow of emitted electrons. The proposed model is compared with an experiment on the degradation of a single nanotube. The experiment confirms the catastrophic destruction and shows that the destruction is facilitated by the occurrence of thermoelectronic emission, which causes a rapid increase in the current and, accordingly, the temperature of the defective region of the nanotube. Keywords: field emitters, degradation, nanotube heating, defects, catastrophic destruction.