Large current density from carbon nanotube field emitters

We observe that field emitters made from carbon nanotubes exhibit excellent macroscopic emission properties; they can operate at a very large current density, as high as 4 A/cm². At electric fields as low as 4-7 V/μm, they emit technologically useful current densities of 10 mA/cm². We show that the emission originates from nanotube ends with a characteristic structured ring pattern. The emission characteristics and durability of the carbon nanotube cold cathodes offer promising applications for vacuum microelectronic devices