USA As Represented by Secretary of the Navy

Other

David S Y Hsu

Henry F Gray

Jonathan L Shaw

Yongchi Tian

Syed B Qadri

Jianping P Yang

Banhalli R Ratna

Jonathan L Show

A method of making an integrally gated carbon nanotube field ionization device comprising forming a first insulator layer on a first side of a substrate, depositing a conductive gate layer on the first insulator layer, forming a cavity in the substrate by etching a second side of the substrate to near the first insulator layer, wherein the second side is opposite the first side and wherein a portion of the first insulator is over the cavity, etching an aperture in the portion of the first insulator layer and the conductive gate layer to form an aperture sidewall, depositing a second insulator layer removing the second insulator layer from the top surface, depositing a metallization layer over the second insulator layer, depositing a catalyst layer on the metallization layer and growing a carbon nanotube from the catalyst layer.

Method of making an integrally gated carbon nanotube field ionizer device

Described herein is a field ionization and electron impact ionization device consisting of carbon nanotubes with microfabricated integral gates that is capable of producing short pulses of ions.

Integrally gated carbon nanotube ionizer device

A field ionization device can include a first insulator layer on a first side of a substrate, a conductive gate layer on the first insulator layer, a cavity in the substrate, a portion of first insulator over the cavity, an aperture in the portion of the first insulator layer and the conductive gate layer thereby forming an aperture and aperture sidewall. The device can include a second insulator layer on the aperture sidewall and surface of the cavity, a metallization layer over the second insulator layer, a catalyst layer on the metallization layer, and a carbon nanotube. The cavity can be made by etching a second side of the substrate to near the insulator layer, wherein the second side is opposite the first side. The carbon nanotube can be grown from the catalyst layer. The device can further include a collector located near the carbon nanotube. The conductive gate layer can be biased negative with respect to the carbon nanotube. An electric field can exist between the carbon nanotube and the conductive gate layer. Another embodiment can include an array of multiple devices as described herein wherein the multiple devices are in close proximity to each other. Also provided is a method of making the device.

Integrally gated carbon nanotube field ionizer device and method of manufacture therefor

The present invention relates to a method of preparing a multilayer phosphor (film) product on a substrate. The method comprises adding solid particulate precursor to a solution of an alkoxide precursor and a dopant precursor before hydrolysis is allowed to occur. The mixture is then allowed to hydrolyze, resulting in a sol-gel condensation reaction. The solid particulate precursor can be fumed silica, and acts as a nucleation site for the sol-gel reaction product. After the sol-gel reaction, the mixture is dried and fired to form a multilayer phosphor (film). The phosphor film is especially suitable for applications in which there is low voltage operation.

Method for preparing efficient low voltage multilayer phosphor films

A field emitter cell includes a thin-film-edge emitter normal to the gate layer. The field emitter cell may include a conductive substrate layer, an insulator layer having a perforation, a gate layer having a perforation, an emitter layer, and other optional layers. The perforation in the gate layer is larger and concentrically offset with respect to the perforation in the insulating layer and may be of a tapered construction. Alternatively, the perforation in the gate layer may be coincident with, or larger or smaller than, the perforation in the insulating layer, provided that the gate layer is shielded from the emitter from a direct line-of-sight by a nonconducting standoff layer. Optionally, the thin-film-edge emitter may include incorporated nanofilaments. The field emitter cell has low gate current making it useful for various applications such as field emitter displays, high voltage power switching, microwave, RF amplification and other application that require high emission currents.

Method of making low gate current multilayer emitter with vertical thin-film-edge multilayer emitter

An apparatus and method for regulating the emission current from a single (macroscopic) field emitter, from groups of emitters within a large (microscopic) array, or from each cell within an array is described. The apparatus includes an additional aperture, fabricated at each field emitter array cell, to create and electron energy filter. The filter aperture of the electron energy filter is similar to the gate aperture but located above or in front of the gate aperture, and is held at a positive potential lower than the gate. The filter allows only those electrons with energy greater than some minimum (the cutoff energy) to pass through. A current-limiting circuit is placed in series with the gate aperture, limiting the total current of electrons that do not pass through the filter. Thus, emission from low energy states is limited without limiting emission from states near the Fermi level.

Method and apparatus for regulating electron emission in field emitter devices

A field emitter cell includes a thin film edge emitter normal to a gate layer. The field emitter is a multilayer structure including a low work function material sandwiched between two protective layers. The field emitter may be fabricated from a composite starting structure including a conductive substrate layer, an insulation layer, a standoff layer and a gate layer, with a perforation extending from the gate layer into the substrate layer. The emitter material is conformally deposited by chemical beam deposition along the sidewalls of the perforation. Alternatively, the starting material may be a conductive substrate having a protrusion thereon. The emitter layer, standoff layer, insulation layer, and gate layer are sequentially deposited, and the unwanted portions of each are preferentially removed to provide the desired structure.

Field emitter cell and array with vertical thin-film-edge emitter

A field emitter cell includes a thin-film-edge emitter normal to the gate layer. The field emitter cell may include a conductive substrate layer, an insulator layer having a perforation, a gate layer having a perforation, an emitter layer, and other optional layers. The perforation in the gate layer is larger and concentrically offset with respect to the perforation in the insulating layer and may be of a tapered construction. Alternatively, the perforation in the gate layer may be coincident with, or larger or smaller than, the perforation in the insulating layer, provided that the gate layer is shielded from the emitter from a direct line-of-sight by a nonconducting standoff layer. Optionally, the thin-film-edge emitter may include incorporated nanofilaments. The field emitter cell has low gate current, making it useful for various applications such as field emitter displays, high voltage power switching, microwave, RF amplification and other applications that require high emission currents.

Low gate current field emitter cell and array with vertical thin-film-edge emitter

Method of manufacturing a low gate current field emitter cell and array with vertical thin-film-edge emitter

The present invention discloses a new field emitter cell and array consisting of groups of nanofilaments forming emitter cathodes. Control gates are microprocessed to be integrally formed with groups of nanofilament emitter cathodes on a substrate. Groups of nanofilaments are grown directly on the substrate material. As a result, the control gates and groups of nanofilaments are self-aligned with one another.

Self-aligned integrally gated nanofilament field emitter cell and array

Methods for manufacture of self-aligned integrally gated nanofilament field emitter cell and array

Doped phosphors (e.g., metal orthosilicates) are made by adding solid particulate precursor to a solution of an alkoxide precursor and a dopant precursor before hydrolysis is allowed to occur. The mixture is then allowed to hydrolyze, resulting in a sol-gel condensation reaction. The solid particulate precursor can be fumed silica, and acts as a nucleation site for the sol-gel reaction product. After the sol-gel reaction, the mixture is dried and fired to form phosphors. The phosphors are especially suitable for applications in which there is low voltage operation.

Method for preparing efficient low voltage phosphors and products produced thereby

Nanocrystalline phosphors are formed within a bicontinuous cubic phase.

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Alexandria, VA, United States of America

David S Y Hsu