Multilayer carbon-based field emission electron device for high current density applications

摘要

An electron field emission device is provided by placing a substrate in a reactor, heating the substrate and supplying a mixture of hydrogen and a carbon-containing gas at a concentration of about 8 to 13 per cent to the reactor while supplying energy to the mixture of gases near the substrate for a time to grow a first layer of carbon-based material to a thickness greater than about 0.5 micrometers, subsequently reducing the concentration of the carbon-containing gas and continuing to grow a second layer of carbon-based material, the second layer being much thicker than the first layer. The substrate is subsequently removed from the first layer and an electrode is applied to the second layer. The device is free-standing and can be used as a cold cathode in a variety of electronic devices such as cathode ray tubes, amplifiers and traveling wave tubes. The surface of the substrate may be patterned before growth of the first layer to produce a patterned surface on the field emission device.