Control over the number of local emitting nanodimensional protrusions on the surface of a field emitter

A procedure is described that allows the number of emitting nanodimensional protrusions on the surface of a tungsten carbide field emitter to be controlled. According to the proposed approach, a sufficiently large number of nanoprotrusions are grown initially on the emitter surface by means of a thermofield treatment, which usually encounters no difficulties. Then, the applied field strength is decreased in a controlled manner at a certain fixed temperature of the emitter, which allows the number of emitting nanoprotrusions on the surface to be gradually reduced, even to retain a single one.