Long-term Stable Field Electron Transfer from Carbon Nanotube Arrays at High Emission Current Densities

Abstract

The stability behaviors of multiwalled carbon nanotube arrays during field electron emission are studied. The results indicate that the stability, even at a high emission current density, has been greatly improved by an aging process, and a degradation of about 0.66% in the emission current density at 21.86 mA/cm 2 during a 10-hour stability test has been obtained. A detailed analysis of the deterioration of the field electron emission characteristics is given, and the generation of Joule heat during field emission is found to be able to burn o the extruded carbon nanotubes, which will directly reduce the number of emission sites. On the other hand, the Joule heating eect may induce an annealing of the defects existing in the carbon nanotubes and may influence the distribution of electron energy states, both having a bad influence on the field emission characteristics. An aging process, especially aging at high emission current densities, can greatly reduce the influence of Jouleheating induced current degradation. Hence, an aging process at high emission current densities provides an eective way to realize long-term stable field electron emission from carbon nanotube arrays.