A vertical vacuum transistor with a sharp tip structure, and associated fabrication process, is provided that is compatible with current vertical CMOS fabrication processing. The resulting vertical vacuum channel transistor advantageously provides improved operational characteristics including a higher operating frequency, a higher power output, and a higher operating temperature while at the same time providing a higher density of vertical transistor devices during the manufacturing process.

A photocathode can include a body fabricated of a wide bandgap semiconductor material, a metal layer, and an alkali halide photocathode emitter. The body may have a thickness of less than 100 nm and the alkali halide photocathode may have a thickness less than 10 nm. The photocathode can be illuminated with a dual wavelength scheme.

A photocathode can include a body fabricated of a wide bandgap semiconductor material, a metal layer, and an alkali halide photocathode emitter. The body may have a thickness of less than 100 nm and the alkali halide photocathode may have a thickness less than 10 nm. The photocathode can be illuminated with a dual wavelength scheme.

A flat top laser beam is used to generate an electron beam with a photocathode that can include an alkali halide. The flat top profile can be generated using an optical array. The laser beam can be split into multiple laser beams or beamlets, each of which can have the flat top profile. A phosphor screen can be imaged to determine space charge effects or electron energy of the electron beam.

A flat top laser beam is used to generate an electron beam with a photocathode that can include an alkali halide. The flat top profile can be generated using an optical array. The laser beam can be split into multiple laser beams or beamlets, each of which can have the flat top profile. A phosphor screen can be imaged to determine space charge effects or electron energy of the electron beam.

A field emission neutralizer is provided. The field emission neutralizer comprises a bottom plate and at least one field emission cathode unit located on the bottom plate. The field emission cathode unit comprises a substrate, a shell located on the substrate, a mesh grid, a shielding layer insulated and spaced from the mesh grid, and at least one cathode emitter located inside the shell, and insulated and spaced from the mesh grid. The cathode emitter comprises two cathode electrode sheets and a graphitized carbon nanotube structure, the graphitized carbon nanotube structure comprises a first portion and a second portion, the first portion is clamped between the two cathode electrode sheets, and the second portion is exposed outside of the two cathode electrode sheets.

A field emission neutralizer is provided. The field emission neutralizer comprises a bottom plate and at least one field emission cathode unit located on the bottom plate. The field emission cathode unit comprises a substrate, a shell located on the substrate, a mesh grid, a shielding layer insulated and spaced from the mesh grid, and at least one cathode emitter located inside the shell, and insulated and spaced from the mesh grid. The cathode emitter comprises two cathode electrode sheets and a graphitized carbon nanotube structure, the graphitized carbon nanotube structure comprises a first portion and a second portion, the first portion is clamped between the two cathode electrode sheets, and the second portion is exposed outside of the two cathode electrode sheets.

The present invention generally relates to a field emission light source and specifically to a field emission light source adapted to emit ultraviolet (UV) light. The light source has a UV emission member provided with an electron-excitable UV emitting material. The material is at least one of LuPO.sub.3:Pr.sup.3+, Lu.sub.2Si.sub.2O.sub.2:Pr.sup.3+, LaPO.sub.4:Pr.sup.3+, YBO.sub.3:Pr.sup.3+ and YPO.sub.4:Bi.sup.3+.

The present invention generally relates to a field emission light source and specifically to a field emission light source adapted to emit ultraviolet (UV) light. The light source has a UV emission member provided with an electron-excitable UV emitting material. The material is at least one of LuPO.sub.3:Pr.sup.3+, Lu.sub.2Si.sub.2O.sub.2:Pr.sup.3+, LaPO.sub.4:Pr.sup.3+, YBO.sub.3:Pr.sup.3+ and YPO.sub.4:Bi.sup.3+.

Nanoscale field-emission devices are presented, wherein the devices include at least a pair of electrodes separated by a gap through which field emission of electrons from one electrode to the other occurs. The gap is dimensioned such that only a low voltage is required to induce field emission. As a result, the emitted electrons energy that is below the ionization potential of the gas or gasses that reside within the gap. In some embodiments, the gap is small enough that the distance between the electrodes is shorter than the mean-free path of electrons in air at atmospheric pressure. As a result, the field-emission devices do not require a vacuum environment for operation.