Field emission cathode array coated with electron work function reducing material, and method

摘要

A field emission cathode device is disclosed herein and includes an array of electron emitting cathode tips supported by a base electrode or electrodes, a gate electrode spaced from and associated with each tip, and dielectric material located between each gate electrode and the base electrode of its associated cathode tip for insulating the two from one another. The device also includes means for establishing an electric field between the gate electrodes and tips sufficient to cause the tips to emit current. In addition, each electron emitting cathode tip is coated with an electrically conductive material that reduces its electron work function. At the same time, the dielectric material which insulates the base electrodes and gate electrodes from one another is maintained sufficiently free of the electron work function reducing material so as not to result in any appreciable current leakage between the base and gate electrodes. The specific method of coating the cathode tips is also disclosed herein.