Abstract:
This invention provides compositions of matter that contain an electron emitting substance and an expansion material. The expansion material may, for example, be an intercalation compound. When a film is formed from the composition, expansion of the expansion material typically causes rupturing or fracturing of the film. No further treatment of the surface of the film is typically required after expansion of the expansion material to obtain good emission properties. A surface formed from such a fractured film acts as an efficient electron field emitter and thus is useful in vacuum microelectronic devices.
Abstract:
The invention relates to a field emission device comprising a cathode having an emission region (1) for electrons (2). The field emission device is embodied for generating technically useful electron currents at a voltage which is as low as possible, in such a way that the emission region (1) has an arrangement of a plurality of individually positioned or positionable atoms (4) or molecules.
Abstract:
Provided are carbide derived carbon prepared by thermochemically reacting carbide compounds and a halogen element containing gas and extracting all atoms of the carbide compounds except carbon atoms, wherein the intensity ratios of the graphite G band at 1590 cm−1 to the disordered-induced D band at 1350 cm−1 are in the range of 0.3 through 5 when the carbide derived carbon is analyzed using Raman peak analysis, wherein the BET surface area of the carbide derived carbon is 1000 m2/g or more, wherein a weak peak or wide single peak of the graphite (002) surface is seen at 2θ=25° when the carbide derived carbon is analyzed using X-ray diffractometry, and wherein the electron diffraction pattern of the carbide derived carbon is the halo pattern typical of amorphous carbon when the carbide derived carbon is analyzed using electron microscopy. The emitter has good uniformity and a long lifetime. An emitter can be prepared using a more inexpensive method than that used to manufacture conventional carbon nanotubes.
Abstract:
A carbon-based composite particle for an electron emission source comprises a particle of a material selected from the group consisting of metals, oxides, and ceramic materials; and a carbon-based material such as a carbon nanotube which is partially embedded inside the particle and which partially protrudes from the surface of the particle.
Abstract:
Disclosed is a carbon-based composite particle for an electron emission source comprising: a particle of a material selected from the group consisting of metals, oxides, and ceramic materials; and a carbon-based material such as a carbon nanotube which is partially buried inside of the particle and which partially protrudes from the surface of the particle.
Abstract:
Based on designs concerning boron nitride thin-films each including boron nitride crystals in acute-ended shapes excellent in field electron emission properties, and designs of emitters adopting such thin-films, it is aimed at appropriately controlling a distribution state of such crystals to thereby provide an emitter having an excellent efficiency and thus requiring only a lower threshold electric field for electron emission. In a design of a boron nitride thin-film emitter comprising crystals that are each represented by a general formula BN, that each include sp3 bonded boron nitride, sp2 bonded boron nitride, or a mixture thereof, and that each exhibit an acute-ended shape excellent in field electron emission property; there is controlled an angle of a substrate relative to a reaction gas flow upon deposition of the emitter from a vapor phase, thereby controlling a distribution state of the crystals over a surface of the thin-film.
Abstract:
This invention provides compositions of matter that contain an electron emitting substance and an expansion material. The expansion material may, for example, be an intercalation compound. When a film is formed from the composition, expansion of the expansion material typically causes rupturing or fracturing of the film. No further treatment of the surface of the film is typically required after expansion of the expansion material to obtain good emission properties. A surface formed from such a fractured film acts as an efficient electron field emitter and thus is useful in vacuum microelectronic devices.
Abstract:
This invention provides compositions of matter that contain an electron emitting substance and an expansion material. The expansion material may, for example, be an intercalation compound. When a film is formed from the composition, expansion of the expansion material typically causes rupturing or fracturing of the film. No further treatment of the surface of the film is typically required after expansion of the expansion material to obtain good emission properties. A surface formed from such a fractured film acts as an efficient electron field emitter and thus is useful in vacuum microelectronic devices.
Abstract:
In the present invention, there are provided self-assembled ZnO nanotips grown on relatively low temperatures on various substrates by metalorganic chemical vapor deposition (MOCVD). The ZnO nanotips are made at relatively low temperatures, giving ZnO a unique advantage over other wide bandgap semiconductors such as GaN and SiC. The nanotips have controlled uniform size, distribution and orientation. These ZnO nanotips are of single crystal quality, show n-type conductivity and have good optical properties. Selective growth of ZnO nanotips also has been realized on patterned (100) silicon on r-sapphire (SOS), and amorphous SiO2 on r-sapphire substrates. Self-assembled ZnO nanotips can also be selectively grown on patterned layers or islands made of a semiconductor, an insulator or a metal deposited on R-plane (01 12) Al2O3 substrates as long as the ZnO grows in a columnar structure along the c-axis [0001] of ZnO on these materials. Such self-assembled ZnO nanotips and nanotip arrays are promising for applications in field emission displays and electron emission sources, photonic bandgap devices, near-field microscopy, UV optoelectronics, and bio-chemical sensors.