Field electron emission from individual carbon nanotubes of a vertically aligned array

Field electron emission behavior of individual multiwalled carbon nanotubes (MWNTs), that are elements of a vertically aligned array grown on a Si wafer, were analyzed with a scanning anode field emission microscope. The electron emission of each MWNT followed the conventional Fowler–Nordheim field emission mechanism after their apexes were freed from the erratic adsorption species using a conditioning process at room temperature. The conditioning process led to stable emission currents and reduced their variations $\mathrm{\Delta I/I}$ to less than 30% between different MWNTs of the array. This opens the possibility for using MWNTs in an array as independent electron sources for massively parallel microguns.