An emitter is configured to emit charged particles. The emitter comprises a body, a metal layer and a charged particle source layer. The body has a point. The metal layer is of a first metal on at least the point. The charged particle source layer is on the metal layer. The point comprises a second metal other than the first metal.

A method for making field emission devices so that they have emitter tips in the form of a needle-like point with a width and length configured such that ratio of the width to the length ranges from about 0.001 to about 0.05, and associated methods for making the tips by 3-D printing.

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.

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.

A method for making field emission devices so that they have emitter tips in the form of a needle-like point with a width and length configured such that ratio of the width to the length ranges from about 0.001 to about 0.05, and associated methods for making the tips by 3-D printing.

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.

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.

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.

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.

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.