EP0989579A2
Expired / Lapsed
EP
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Device comprising a carbon nanotube field emitter structure and process for forming device
Assignee: University of North Carolina at Chapel Hill
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Filing: 1999-09-14
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Granted: —
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Expires: 2019-09-14
Abstract
Abstract The invention provides improved devices containing adherent carbon nanotube films, in particular electron field emitter structures containing such films. Previously, attaining even moderate adherence of powdery or mat-like nanotubes to a substrate was difficult, because of the perfect fullerene structure of nanotubes, which tend to exhibit no dangling bonds or defect sites where chemical bonding to the substrate is able to occur. The invention overcomes these problems, and provides a strongly adherent nanotube film, by a variety of fabrication processes.
Inventors
- 👤 Christopher Andrew Bower
- 👤 Otto Zhou
- 👤 Wei Zhu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 14:36
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/304; B; B82; B82B; B82B3/00; C; C01; C01B; C01B32/00; C01B32/05; H01J9/00; H01J9/02; H01J9/022; H01J9/025; B82Y; B82Y10/00; H01J2201/00; H01J2201/30; H01J2201/304; H01J2201/30446; H01J2201/30453; H01J2201/30469; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/842
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
14 words
A device comprising: a substrate, and an adherent carbon nanotube film on the substrate.
Claim 2
Dependent Claim
23 words
A process for fabricating a device, comprising the steps of: providing a substrate, and disposing an adherent carbon nanotube film on the substrate.
Claim 3
Dependent Claim
93 words
A process for fabricating a device, comprising the steps of: providing a substrate that comprises at least one material selected from
the group consisting of carbon-dissolving elements, carbide-forming elements, and low
melting point materials; disposing carbon nanotubes on the substrate; and heating the substrate to a temperature sufficient to induce at least one of:
reaction of at least a portion of the nanotubes with the carbon-dissolving elements,
reaction of at least a portion of the nanotubes with the carbide-forming elements, and
melting of at least a portion of the low melting point materials.
Claim 4
Dependent Claim
37 words
A process for fabricating a device, comprising the steps of: providing a substrate; forming a dispersion of carbon nanotubes in a solvent; and spraying the dispersion at a substrate to coat the substrate surface with
the nanotubes.
Claim 5
Dependent Claim
23 words
The device of claim 1, wherein the device comprises a field emitter
structure that comprises the substrate and the adherent carbon nanotube film.
Claim 6
Dependent Claim
53 words
The device of claim 5, wherein the emitter structure exhibits a
threshold emission field of less than 20 V/µm at a current density of 10 mA/cm 2 , the
threshold field for example remaining at less than 20 V/µm for at least 50 hours at a
current density of 10 mA/cm 2 .
Claim 7
Dependent Claim
60 words
The device of claim 1, or the process of claim 2, 3 or 4 wherein the
substrate comprises at least one material selected from carbon-dissolving elements,
carbide-forming elements. and low melting point materials, and/or at least one element
selected from the group consisting of Ni, Fe, Co, Cr, Si, Mo, Ti, Ta, Mn, W, Nb, Zr, V,
Hf, and Al.
Claim 8
Dependent Claim
44 words
The device of claim 1, or the process of claim 2, 3 or 4, wherein the
nanotube film comprises at least 50 vol. % nanotubes, and/or comprises amorphous
carbon intermixed with the nanotubes, and/or has a thickness of about 0.1 to about
100 µm.
Claim 9
Dependent Claim
33 words
The device of claim 5, or the process of claim 2,3 or 4, wherein at
least 50 vol. % of the carbon nanotubes in the film are aligned in substantially the same
direction.
Claim 10
Dependent Claim
30 words
The device of claim 8, or the process of claim 2,3,4, or 8, wherein
the film is adhered to the surface of the substrate in the absence of polymeric material.
Claim 11
Dependent Claim
48 words
The device of claim 1, or the process of claims 2,3 or 4, wherein the
film comprises metal solder comprising at least one element selected from the group
consisting of Sn, In, Bi, and Pb, or the film comprises at least one polymer, such as a
conductive polymer.
Claim 12
Dependent Claim
21 words
The device of claim 2, wherein the device is a vacuum
microelectronic device, or comprises a microwave amplifier or a display.
Claim 13
Dependent Claim
42 words
The process of claim 2, or 7, wherein the step of disposing the
adherent carbon nanotube film or nanotubes comprises either disposing nanotubes
directly onto the substrate, and heating the substrate, or spraying a dispersion of
nanotubes and solvent at the substrate.
Claim 14
Dependent Claim
51 words
The process of claim 2, wherein the step of disposing the adherent
carbon nanotube film comprises either disposing amorphous carbon and carbon nanotubes directly onto the
substrate in a reaction chamber, or mixing carbon nanotubes with a solvent and a
binder; disposing the mixture onto the substrate; and heating the mixture.
Claim 15
Dependent Claim
80 words
The process of claim 9 or 14, wherein the step of aligning the
nanotubes comprises applying at least one of an electric field and a magnetic field while
disposing the film on the substrate, or the step of aligning the nanotubes comprises
mixing nanotubes with a polymer to form a composite material, subjecting the
composite material to a uniaxial load above the softening temperature of the composite
material, and releasing the load below the softening temperature of the composite
material.
Claim 16
Dependent Claim
19 words
The process of claim 15, wherein the film is disposed on the
substrate in the absence of polymeric material.
Claim 17
Dependent Claim
15 words
The process of claim 4, further comprising the steps of purifying and
ultrasonicating the nanotubes.
Claim 18
Dependent Claim
67 words
The process of claim 4, further comprising the step of heating the
substrate subsequent to the spraying step to a temperature sufficient to induce at least
one of: reaction of at least a portion of the nanotubes with the carbon-dissolving
elements, reaction of at least a portion of the nanotubes with the carbide-forming
elements, and melting of at least a portion of the low melting point materials.
Claim 19
Dependent Claim
55 words
A process for fabricating a device, comprising the steps of: providing a substrate; and disposing a carbon nanotube film on the substrate while applying at least
one of an electric field and a magnetic field, such that at least 50 vol. % of the
nanotubes of the film are aligned in substantially the same direction.
Claim 20
Dependent Claim
80 words
A process for fabricating a device, comprising the steps of: providing a substrate; mixing carbon nanotubes with a polymer to form a composite material, subjecting the composite material to a uniaxial load above the softening temperature of
the composite material, and releasing the load below the softening temperature of the
composite material, such that at least 50 vol. % of the nanotubes of the film are aligned
in substantially the same direction; and disposing the composite material on the substrate.
Claim 21
Dependent Claim
26 words
The process of claim 19 or 20, wherein at least 75 Vol. % of the
nanotubes in the film are aligned in substantially the same direction.
References Cited (Backward Citations)
No citation records indexed.
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