Very large current density from carbon nanotube field emitters

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. The emission originates from nanotube ends with a characteristic structured ring pattern