An electron source (2) for generating an electron beam (8) having a cathode (1) and an anode (4) in the form of a graphene layer (6, 12) epitaxially grown on a silicon carbide substrate (5). The invention is suitable for monolithic preparation of a miniaturized source of a high-energy focused electron beam, including its use as an on-chip X-ray source. All components can be prepared from or on a single silicon carbide chip.

Systems, methods and apparatus related to a method for constructing a field emission device. The method includes providing a metal cathode substrate; shaping a carbon fiber fabric into a pattern, creating a patterned carbon fiber fabric; and brazing at least a portion of the patterned carbon fiber fabric to the metal cathode substrate.

Systems, methods and apparatus related to a method for constructing a field emission device. The method includes providing a metal cathode substrate; shaping a carbon fiber fabric into a pattern, creating a patterned carbon fiber fabric; and brazing at least a portion of the patterned carbon fiber fabric to the metal cathode substrate.

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 field emission cathode device and formation method involves a rotating field emission cathode including a field emission material deposited on a surface thereof, the field emission cathode rotating about an axis and being electrically connected to ground, and a planar gate electrode extending parallel to the surface of the rotating field emission cathode and defining a gap therebetween. A gate voltage source is electrically connected to the gate electrode and is arranged to interact therewith to generate an electric field, with the electric field inducing a portion of the surface of the rotating field emission cathode adjacent to the gate electrode to emit electrons from the field emission material toward and through the gate electrode.

A field emission cathode device comprises a field emission cathode including a cylindrical substrate and a field emission material deposited on a cylindrical surface thereof. The field emission cathode defines a longitudinal axis. A solenoid extends concentrically about the cylindrical surface, and defines a gap therebetween. The solenoid defines opposed open ends perpendicular to the longitudinal axis. A current source directs a constant polarity (DC) current to the solenoid, that forms a magnetic field along the solenoid. A gate voltage source electrically connected to the solenoid or the field emission cathode interacts therewith to generate an electric field inducing the field emission cathode to emit electrons from the field emission material into the gap. The emitted electrons are responsive to the magnetic field to spiral within the gap and about the longitudinal axis, in correspondence with the current flow in the solenoid, through the first open end of the solenoid.

An electron emission source is provided. The electron emission source includes a first electrode, an insulating layer, and a second electrode. The first electrode, the insulating layer, and the second electrode are successively stacked with each other. the second electrode is a graphene layer, and the graphene layer is an electron emission end to emit electron. A thickness of the graphene layer ranges from about 0.1 nanometers to about 50 nanometers.

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 emission source is provided. The electron emission source comprises a first electrode, an insulating layer, and a second electrode, The first electrode, the insulating layer, and the second electrode are successively stacked with each other. the second electrode is a graphene layer, and the graphene layer is an electron emission end to emit electron. A thickness of the graphene layer ranges from about 0.1 nanometers to about 50 nanometers.

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.