USA As Represented by Secretary of the Navy

Pehr E Pehrsson

Christopher Field

James E Butler

Junghoon Yeom

Paul M Natishan

Kevin J Johnson

Michael J Marchywka

Braden C Giordano

Hyun Jin In

Daniel Ratchford

Alan Shane Edelstein

Jeffrey M Calvert

Martin C Peckerar

Richard F Greene

Christie R Marrian

Benji Maruyama

Richard K Everett

Arthur A Morrish

Arthur M Morrish

Joseph Zahavi

Michael L Marchywka

Chistopher Field

Disclosed herein is a method of providing a structure having two electrodes connected by nanowires, exposing the structure to an analyte that can adsorb onto the nanowires, and passing an electrical current through the nanowires to heat the nanowires to desorb the analyte. Also disclosed herein is an apparatus having the above structure; a current source electrically connected to the electrodes, and a detector to detect the analyte.

Nanowire arrays for trace vapor preconcentration

Disclosed herein is a structure having: a support, a plurality of nanowires perpendicular to the support, and an electrode in contact with a first end of each nanowire. Each nanowire has a second end in contact with the support. The electrode contains a plurality of perforations. The electrode contains a plurality of perforations. Also disclosed herein is a method of: providing the above support and nanowires; depositing a layer of a filler material that covers a portion of each nanowire and leaves a first end of each nanowire exposed; depositing a plurality of nanoparticles onto the filler material; depositing an electrode material on the nanoparticles, the ends of the nanowires, and any exposed filler material; and removing the nanoparticles and filler material to form an electrode in contact with the first end of each nanowire; wherein the electrode contains a plurality of perforations.

Perforated contact electrode on vertical nanowire array

An apparatus for emitting electrons is provided. The apparatus includes a subsurface emitter having a sharp tip, a substrate including a base, and electrical continuity between the tip, the base, and an external circuit. This emitter structure may be used to form individual emitters or arrays of emitters. Also provided is a method of making electron emitters which is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ion into the diamond. The tips may then also be additionally coated with a layer of a wide band-gap semiconductor. An electrically conducting material may also be placed in proximity to the tips to generate an electric field sufficient to extract electrons from the conducting tips into either the region above the surface, or into the wide band-gap semiconductor layer in contact with the tips. Electrical contact is made to the electrically conducting damage tracks and the electrical circuit may be completed with an electrically conducting material on the surface of the wide band-gap semiconductor or diamond, or in the ambient above the surface of the emitter. The surface of the wideband gap semiconductor or diamond may be chemically modified to enhance the emission of electrons from the surface.

Apparatus for emitting electrons comprising a subsurface emitter structure

A method for fabricating an electron emitter. This emitter structure may be used to form individual emitters or arrays of emitters. The method is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ion into the diamond. The tips may then also be additionally coated with a layer of a wide band-gap semiconductor. An electrically conducting material may also be placed in proximity to the tips to generate an electric field sufficient to extract electrons from the conducting tips into either the region above the surface, or into the wide band-gap semiconductor layer in contact with the tips. Electrical contact is made to the electrically conducting damage tracks and the electrical circuit may be completed with an electrically conducting material on the surface of the wide band-gap semiconductor or diamond, or in the ambient above the surface of the emitter. The surface of the wideband gap semiconductor or diamond may be chemically modified to enhance the emission of electrons from the surface.

Method of making electron emitters

Methods for and products of modification and metallization of oxidizable surfaces, including diamond surfaces, by plasma oxidation

Filamentous substrates are coated with diamond by a chemical vapor deposition process. The substrate may then be etched away to form a diamond filament, such as a diamond tube or a diamond fiber. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrate-less diamond fiber is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, is filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.

Process for making diamond and diamond-coated filaments

A process for making diamond and diamond products includes the steps of implanting ions in a diamond substrate to form a damaged layer of non-diamond carbon below the top surface of the substrate, heating the substrate to about 600-1200.degree. C., growing diamond on the top surface of the heated substrate by chemical vapor deposition, and electrochemically etching the damaged layer to separate the grown diamond from the substrate along the damage layer. The diamond product consists of a first diamond layer and a second diamond layer attached to the first layer. The second layer contains damage caused by ions traversing the second layer.

Growing and releasing diamonds

Process of smoothing or polishing a diamond surface to reduce asperities reon to a level as low as about 20 nm from the horizontal by implanting the diamond surface with ions to form a non-diamond carbon damage layer on or below the diamond surface below the disparity depth and dissolving the non-diamond carbon by submerging the non-diamond carbon in a liquid having sufficient electric field to dissolve the non-diamond carbon.

Polishing diamond surface

A process for making diamond and diamond products includes the steps of ianting ions in a diamond substrate to form a damaged layer of non-diamond carbon below the top surface of the substrate, heating the substrate to about 600-1200.degree. C. growing diamond on the top surface of the heated substrate by chemical vapor deposition, and electrochemically etching the damaged layer to separate the grown diamond from the substrate along the damage layer. The diamond product consists of a first diamond layer and a second diamond layer attached to the first layer. The second layer contains damage caused by ions traversing the second layer.

Filamentous substrates are coated with diamond by a chemical vapor deposin process. The substrate may then be etched away to form a diamond filament. In a preferred embodiment, the substrate is copper-coated graphite. The copper initially passivates the graphite, permitting diamond nucleation thereon. As deposition continues, the copper-coated graphite is etched away by the active hydrogen used in the deposition process. As a result a substrateless diamond tubule is formed. Diamond-coated and diamond filaments are useful as reinforcement materials for composites, as filtration media in chemical and purification processes, in biomedical applications as probes and medicinal dispensers, and in such esoteric areas as chaff media for jamming RF frequencies.

Self-supporting diamond filaments

Method for improved photolithography using a laser induced metallization cess to produce a metal mask wherein a work piece surface is treated to have a predetermined pattern of at least two materials each having different electron band gaps, the treated work piece is positioned in a metallizing solution, and the workpiece is exposed to a laser beam having a wavelength corresponding to the electron gap of a selected one of the materials. The method can advantageously be used to produce ohmic contacts for microcircuit devices.

Growing community of inventors

Fairfax Station, VA, United States of America

Pehr E Pehrsson