A cathode structure for cold field electron emission and method of fabricating a single-tip cathode structure for cold field electron emission. The cathode structure comprises a pointed cathode wire; and a graphene-based coating on at least a tip of the pointed cathode wire. In a preferred embodiment, graphene is coated on nickel tips by chemical vapour deposition wherein nickel functions as a catalyst for growth of graphene. The cathode structure provides stable cold field emission for electron microscopy and lithography applications and exhibits an ultralow work function value of about 1.1 eV.

A field-emission type electron source includes (i) a single-crystal tungsten rod having a sharpened terminus and (ii) a mass of ZrO formed only on a portion of the surface, or the entire surface, of the sharpened terminus. In preferred design, the single-crystal tungsten rod is placed in a gaseous medium that consists of oxygen and a non-oxygen gas. The molar ratio between oxygen and the non-oxygen gas is greater than 1:1.

Electron emitters and method of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

A light modulated electron source utilizes a photon-beam source to modulate the emission current of an electron beam emitted from a silicon-based field emitter. The field emitter's cathode includes a protrusion fabricated on a silicon substrate and having an emission tip covered by a coating layer. An extractor generates an electric field that attracts free electrons toward the emission tip for emission as part of the electron beam. The photon-beam source generates a photon beam including photons having an energy greater than the bandgap of silicon, and includes optics that direct the photon beam onto the emission tip, whereby each absorbed photon creates a photo-electron that combines with the free electrons to enhance the electron beam's emission current. A controller modulates the emission current by controlling the intensity of the photon beam applied to the emission tip. A monitor measures the electron beam and provides feedback to the controller.

An electron source capable of suppressing consumption of an electron emission material is provide. The present invention provides an electron source including: an electron emission material; and, an electron emission-suppressing material covering a side surface of the electron emission material, wherein a work function of the electron emission-suppressing material is higher than that of the electron emission material, and a thermal emissivity of the electron emission-suppressing material is lower than that of the electron emission material.

The present disclosure provides a method of manufacturing an electron source. The method includes forming one or more fixed emission sites on at least one needle tip, the fixed emission sites including a reaction product formed by metal atoms on a surface of the needle tip and gas molecules.

The present disclosure provides an electron source, including one or more tips, wherein at least one of the tips comprises one or more fixed emission sites, wherein at least one of the tips includes one or more fixed emission sites, wherein the emission sites includes a reaction product of metal atoms on a surface of the tip with gas molecules.

The present disclosure provides a method of regenerating an electron source, the electron source including at least one emission site fixed on a needle tip, and the emission site including a reaction product formed by metal atoms and gas molecules. The method includes regenerating the electron source in situ if an emission capability of the electron source satisfies a regeneration condition.

A device for controlling electron flow is provided. The device comprises a cathode, an elongate electrical conductor embedded in a diamond substrate, an anode, and a control electrode provided on the substrate surface for modifying the electric field in the region of the end of the conductor. A method of manufacturing the device is also provided.

Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.