Abstract:
A method of reducing electronic work function, reducing threshold field emission values, converting semiconducting behavior to metallic behavior, increasing the electron density state at the Fermi level, and increasing electron emission site density, of nanostructure or nanotube-containing material, the method including: forming openings in the nanotube-containing material; introducing a foreign species such as an alkali metal into at least some of the openings; and closing the openings, thereby forming capsules filled with the foreign species, and forming field emission cathode and flat panel displays using these capsules.
Abstract:
A carbon nanotube (CNT) field emission display has a cathode substrate having a cathode layer patterned on a glass substrate. The surface of the cathode layer is defined as a plurality of electron-emitting areas apart from each other, and a plurality of CNT structures is grown on the plurality of electron-emitting areas respectively.
Abstract:
An electron-emitting device including a protective layer that is formed on a catalyst layer to protect the catalyst layer from the deleterious environmental conditions before or during a cathode process. The present invention further includes a half etching process that is adapted to partially remove portions of the protective layer from the catalyst layer to etch the catalyst layer except carbon nano-tube growing portions. Portions of the protective layer still remain on the catalyst layer to protect the catalyst layer from the deleterious conditions from next cathode formation process.
Abstract:
A field emission cathode device consisting of an electrically conducting material and with a narrow, rod-shaped geometry or a knife edge, to achieve a high amplification of the electric field strength is characterized in that the electron-emitting part of the field emission cathode at least partly has preferred cylindrical host molecules and/or compounds with host compounds and/or cylindrical atomic networks, possibly with end caps with diameters measuring in the nanometer range.
Abstract:
The present invention relates to a field emitter array used in various devices including a nanotube-based display and a microwave-amplifying device. In prior art, an electron accelerated by an electric field collides, for example, with a phosphor on the screen. Light is emitted as a positive ion drops out of the phosphor. Destruction or deformation of the emitter's structure can occur if the positive ion becomes accelerated and collides with the emitter, which results in instability or interruption of the emitter's operation. According to the present invention, coating a carbon nanotube with a very thin semiconductor or insulating material with a high degree of hardness can protect the carbon nanotube from the external particles (particularly, positive ions). The thin layer also provides for easy electron emission under low voltage, thereby greatly improving the uniformity and stability of electron emission.
Abstract:
A flat panel display device includes a first substrate, an electron emission assembly formed on the first substrate, a second substrate provided at a predetermined distance from the first substrate and forming a vacuum assembly with the first substrate, and an illumination assembly formed on the second substrate, the illumination assembly being illuminated by electrons emitted from the electron emission assembly. The illumination assembly includes at least one anode electrode formed on a surface of the second substrate facing the first substrate, phosphor layers formed in a predetermined pattern on the at least one anode electrode, and conductive layers formed of a carbon-based material on the phosphor layers.
Abstract:
This invention relates generally to a method for growing single-wall carbon nanotube (SWNT) from seed molecules. The supported or unsupported SWNT seed materials can be combined with a suitable growth catalyst by opening SWNT molecule ends and depositing a metal atom cluster. In one embodiment, a suspension of seed particles containing attached catalysts is injected into an evaporation zone to provide an entrained reactive nanoparticle. A carbonaceous feedstock gas is then introduced into the nanoparticle stream under conditions to grow single-wall carbon nanotubes. Recovery of the product produced can be done by filtration, centrifugation and the like.
Abstract:
A fabrication method for an emitter includes the steps of forming on a glass substrate (10) a CNT film (12) which contains a plurality of carbon nanotubes (CNTs) (12a) and constitutes an emitter electrode (12b), forming a gate electrode (16) via an insulating film (13) on the CNT film (12), forming a plurality of gate openings (17) in the gate electrode (16) and the insulating film (13), and aligning upright the CNTs (12a) in the gate opening (17). The upright alignment generates a stable uniform emission current and provides excellent emission characteristics.
Abstract:
An isotope-doped carbon nanotube (40) includes a plurality of first carbon nanotube segments (402) having carbon-12 isotopes and a plurality of second carbon nanotube segments (404) having carbon-13 isotopes. The first and second carbon nanotube segments are alternately arranged along a longitudinal direction of the carbon nanotube. Three preferred methods employ different isotope sources to form isotope-doped carbon nanotubes. In a chemical vapor deposition method, different isotope source gases are alternately introduced. In an arc discharge method, a power source is alternately switched between different isotope anodes. In a laser ablation method, a laser is alternately focused on different isotope targets. In addition, an apparatus for implementing the preferred methods is provided.
Abstract:
This invention provides novel methods of fabricating novel gated field emission structures that include aligned nanowire electron emitters (individually or in small groups) localized in central regions within gate apertures. It also provides novel devices using nanoscale emitters for microwave amplifiers, electron-beam lithography, field emission displays and x-ray sources. The new emission structures are particularly useful in the new devices