Collective emission degradation behavior of carbon nanotube thin-film electron emitters

The current-induced emission degradation of a carbon nanotube (CNT) thin-film electron emitter is studied under constant emission current for different current levels, using a scanning anode field emission microscope. A permanent emission degradation is observed for emission currents higher than 300 nA per CNT and is associated with resistive heating at the CNT–substrate interface for the sample under investigation. A second field-induced emission degradation mechanism, associated with the removal of CNTs from the substrate, is also reported.