TWI343591B - Field emission componet and method for making same - Google Patents

Description

1343591 _•Operation on March 21st, 2001, the replacement of the page, the invention description: [Technical field of the invention] [0001] The present invention relates to a field emission element and a preparation method thereof, and more particularly to a carbon nanotube field Emitter element and method of preparing the same. [Prior Art] [0002] Carbon Nanotube (CNT) is a new type of carbon material discovered by Japanese researcher Iijima in 1991. Please refer to "He ical Microtubules of Graphitic Carbon", S.

Iijima, Nature, vol. 354, p56 (1 991). The carbon nanotubes have excellent electrical conductivity, good chemical stability and large aspect ratio, and they have a tip surface area close to the theoretical limit (tip table. The smaller the area, the more concentrated the local electric field), Therefore, carbon nanotubes have potential application prospects in the field of field emission. Current research shows that one of the best field emission materials known for the carbon nanotube system, its tip size is only a few nanometers to tens of nanometers, with very low field emission voltage (less than 100 volts). It transmits extremely large current density, and its current is extremely stable and has a long service life of Φ. Therefore, it is very suitable as an excellent field emission element for use in electronic ridge parts of devices such as field emission displays. A conventional carbon nanotube field emission element generally includes at least a conductive cathode electrode and a carbon nanotube as a transmitting end, and the carbon nanotube is formed on the conductive cathode electrode. At present, the preparation methods of the carbon nanotube field emission elements mainly include mechanical methods and in situ growth methods. Among them, mechanical methods include screen printing and gluing. Screen printing is generally performed by mixing a carbon nanotube powder into a slurry and printing it onto a conductive cathode by screen printing. This method usually requires a uniform distribution of carbon nanotube slurry 095123830 Form No. A0101 Page 3 / 18 pages 1003097669-0 1343591 On March 21, 100, the shuttle is replacing the crucible, which needs to be dried, rubbed after printing. In addition to the steps of dust 'sintering, the process is complicated, and the printing method is not suitable for making a large current or high-precision field emission element. The viscose method manipulates the synthesized carbon nanotubes by atomic force microscopy and fixes the carbon nanotubes to the conductive cathode with a conductive paste. This method is simple, but complicated and inefficient. The prepared emitter has a low current carrying capacity. In addition, during the operation of the viscose method, the chemical layer penetrates into the tiny carbon nanotube gap, and the surface tension easily changes the carbon nanotube emitter. shape. In addition, because chemical glue can not withstand the requirements of electronic vacuum components under normal conditions: sealing or exhaust temperature (generally 30 (TC ~ 50 (TC),: Therefore, application is limited ' * . -V.. . 5 - V . ' *1^- : · ί · [0004]

The in-situ growth method precedes the conductive cathode, and then directly grows a carbon nanotube on the conductive \:i: :··.': cathode by chemical vapor deposition, arc discharge, or laser burnt green method. Square; _ simple, the electrical contact H of the carbon nanotubes with the conductive cathode. The binding ability of the tube to the conductive cathode is weak, so that it is collapsed or is affected by the electric field.

The force is pulled out, causing the field emission element to work. Lie, because the method is not

Oitice is easy to control the amount and direction of growth of carbon nanotubes, so there are still problems of low efficiency and poor controllability. In addition, the in-situ growth method has a choice of cathode substrate materials, such as ruthenium, aluminum oxide, ruthenium oxide, high melting point metal, etc., which do not affect the chemical vapor phase conditions, or a layer of isolation on the surface of the substrate. Moreover, the base material also needs to be able to withstand the high temperature range in which the carbon nanotubes grow, so the method is costly and unfavorable for practical use. In view of this, it is easy to fix to a conductive cathode, has good electrical connection, high current carrying capacity, and is easy to manufacture and operate, and is easy to be practically applied. 095123830 Form No. A0101 Page 4 / 18 pages 1003097669-0 [0005] 1343591 100 years It is necessary to correct the field emission element of the replacement page and the preparation method thereof on March 21st. SUMMARY OF THE INVENTION [0006] Hereinafter, a field emission element and a method of fabricating the same will be described in several embodiments, which have the characteristics of being easily fixed to a conductive cathode, having good electrical connection, being easy to produce and operate, and being easy to practically apply. a field emission element comprising a support body wire and a carbon nanotube field emission layer, the nano carbon tube field emission layer being a single layer wound around an outer surface of the support body wire or A multilayer carbon nanotube film is constructed. [0008] The carbon nanotube film comprises a plurality of carbon nanotube bundles, and the ends of the plurality of carbon nanotube bundles are arranged end to end in the same direction. [0009] The carbon nanotube film is obtained by drawing from a carbon nanotube array. [0010] The carbon nanotube field emission layer may also be a single layer or a plurality of layers of carbon nanotube film, and the carbon nanotube film has a thickness of 5 nm to 10 μm. [0011] The carbon nanotube film comprises a plurality of carbon nanotubes. 5纳米〜100纳米。 [0012] The diameter of the carbon nanotubes is 0. 5 nanometers ~ 100 nanometers. [0013] The support wire material is copper, silver, gold, nickel, molybdenum, glass or ceramic [0014] A method for preparing a field emission element, comprising the steps of: providing a support wire; outside the support wire A carbon nanotube field emission layer is formed on the surface; the support wire of the carbon nanotube field emission layer is formed by cutting the outer surface according to a predetermined length, and is surface-treated after cutting to form a field emission element. [0015] The cutting method includes mechanical shearing or laser cutting. 095123830 Form No. A0101 Page 5 of 18 1003097669-0 fM3591 [0016] [0018] [0020] [0021] 095123830 On March 21, 100, the shuttle is replacing the surface treatment method including laser Irradiation, mechanical friction or large current field emission aging. The carbon nanotube field emission layer is a carbon nanotube film layer. The preparation method of the δHenne carbon nanotube film layer as the nano carbon tube field emission layer comprises the following steps: clamping a bundle of carbon nanotubes in a carbon nanotube array by a wrong one or by tape Applying external force to form a strip of carbon nanotube film; wrapping the strip of carbon nanotube film on the outer surface of the support wire; immersing the wound support wire in an organic solvent, #成奈米碳管Field emission layer The ribbon-shaped nanocarbon acoustic film can be wound in a single layer or multiple layers

::3⁄4 face: y.. mo Compared to the prior art, the field emission element comprising the support body edge #r nanocarbon field emission layer has the advantages of reading Wei', using carbon nanotubes The field emission layer acts as an emitter to generate an electron beam jI*li g ^, and the carbon tube itself has excellent electron emission performance; secondly, the 1i meter carbon tube field is Γ 〇 ΘρΘ?... the field emission component formed by the shot layer, The fixing and supporting effect of the support wire on the carbon nanotube field emission layer makes the field emission element have good mechanical properties, is easy to be fixed on the cathode electrode, is easy to operate, can be mass-produced and is conveniently applied to various vacuum field emission devices. [Embodiment] Hereinafter, the present invention will be further described in detail with reference to the accompanying drawings. Referring to FIG. 1 and FIG. 2, an embodiment of the present invention provides a field emission device 10, which includes a support body wire 12 and a cover sheet number Α0101, page 6 / 18 pages 1003097669- 0

[0022] Correction replacement page on March 21, 100. The outer surface of the support wire 12 is > the field emission layer is emitted from the emission field 14 of the rice field. The carbon nanotube field launching machine provides a mechanism for the support and protection of the nano carbon, and also provides a conductive effect. [〇〇23] The support wire 丨2 can be selected from copper, ^ -V- ^ ^ s J silver, gold, recorded, miscellaneous or other metal materials. The shape of the wire (four) is linear, and its diameter can be twisted according to actual needs. This embodiment is preferably several tens of micrometers to several millimeters. Just the Nai (4) tube if the emissive layer 14 can be _Nicheb polymer composite material or nano carbon camp glass composite material, the thickness of which is 丨 micron ~ 1 〇〇〇 micron 0 [0025] linear carbon nanotube-polymerization The composite material comprises a polymeric material and a carbon nanotube uniformly dispersed in the polymeric material. The polymer material of this embodiment may be selected from the group consisting of polyethylene terephthalate (卩〇1丫6-7 to 1611661X phthalate, PET), polycarbonate (p〇iyCarbonate, PC), acrylonitrile A polymer material such as Acrylonitrile-Butadiene Styrene Terpolymer (ABS), polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS). Wherein, the mass percentage of the carbon nanotubes in the composite material is 0.2% to 10%, and in this embodiment, it is preferably 2%. [0〇26] The carbon nanotube-glass composite material is a glass of carbon nanotubes and conductive metal particles containing carbon nanotubes and conductive metal particles uniformly dispersed in the glass. The conductive metal particles may be selected from silver or indium tin oxide. Preferably, the conductive metal particles are made of silver, and the weight of silver is about 15 times the weight of the glass. 095123830 Form No. A0101 Page 7 / Total 18 Page 1003097669-0 «43591 [0027] [0030] [0031] 095123830 On March 21, 100, the core was replaced by 寅 in order to obtain better dispersion performance, 2%〜10° The weight percentage of the glass and the conductive metal particles is 0.2%~10°, the weight percentage of the glass and the conductive metal particles is 0.2%~10°. /〇. In addition, the carbon nanotube field emission layer 14 of the present embodiment may also be coated with a strip of carbon nanotube film on the outer surface of the support wire 1 2 to form the field emission element 10 . The carbon nanotube film is a ribbon-shaped carbon nanotube film formed by pulling a continuous nano carbon line with a width of a super-sequential carbon nanotube array, which contains a large number of carbon nanotubes. The carbon nanotubes are tightly coupled to each other by Van der Waals. In the present embodiment, the nano-disc tube is rotated; the taste of the rice: the diameter of the carbon nanotubes is 〇·5 nm to 100 nm, and the thickness of the carbon nanotube film of the ginseng rice is 5 nm-1 J.

IEQ The field emission element of the present embodiment is required to fix a single or a plurality of field emission elements ίο via its support body wire 436 to the cathode electrode to form a single field emission electron source or a field array electron source of a planar array arrangement, and The carbon nanotubes are electrically connected to each other, and are directly applied through the cathode electrode: the carbon nanotube field emission layer 14 is obtained, or the carbon nanotube field emission layer 14 is applied through the support wire 12, and the excellent electrons of the carbon nanotube material itself can be utilized. Field emission performance emits electrons. Referring to FIG. 3, a method for fabricating a field emission device according to an embodiment of the present invention includes the following steps: (1) providing a support body wire. The support wire can be made of copper, silver, gold, nickel, molybdenum or other metal materials, or ceramic or glass. The shape of the support wire is linear, Form No. A0101 Page 8 of 18 1003097669-0

1343591 __ • 100 years D3, 21st, the shuttle replacement page The diameter can be selected according to actual needs, and the embodiment is preferably several tens of micrometers to several millimeters. [0032] (2) forming a carbon nanotube field emission layer on the outer surface of the support wire [0033] The carbon nanotube field emission layer material may be selected from a carbon nanotube-polymer composite material, a carbon nanotube A glass composite or carbon nanotube film. [0034] The preparation method of the carbon nanotube-polymer composite material as the nano carbon tube field emission layer in the embodiment includes the following steps: adding a carbon nanotube to the molten polymer material, stirring and stirring The method is uniformly dispersed; the mixture is applied to the outer surface of the support wire" to form a carbon nanotube field emission layer after cooling. [0035] The preparation method of the carbon nanotubes can adopt the chemical vapor deposition method, the arc discharge method, the laser ablation method and the like in the prior art, and the carbon nanotubes used in the present embodiment are used in the chemical vapor deposition method. The diameter range is 0. 5 nm ~ 100 nm

[0036] The polymer material of this embodiment may be selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (Polycarbonate, PC), acrylonitrile, butadiene propylene A polymer material such as a copolymer (Acrylonitrile-Butadiene Styrene Terpolymer, ABS) or a polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS). The carbon nanotube polymer composite material obtained in the present embodiment has a mass percentage of the carbon nanotubes in the composite material of 0.2% to 10%, preferably 2% in this embodiment. In this embodiment, the carbon nanotube-glass composite material is used as the carbon nanotube field 095123830. Form No. A0101 Page 9/18 pages 1003097669-0 [0037] 1343591 100 years 03 see 21 nuclear replacement • re-shooting layer The preparation method comprises the following steps: [0038] First, a certain amount of carbon nanotubes, conductive metal particles, organic carrier and glass powder are provided; wherein the organic carrier is preliminarily used as a solvent mass percentage of about 95%. Terpineol and a mixture formed as a stabilizer having a mass percentage of about 5% in an ethylcellulose water bath at 80 °C. 5纳米〜100纳米。 The carbon nanotubes can be prepared by a chemical vapor deposition method, an arc discharge method or a laser ablation method, the length of 0. 1 micron to 20 microns, a diameter of 0. 5 nanometers ~ 100 nanometers. [0041] Next, the nano-carbon powder is mixed to form a slurry; preferably, the formed slurry has an organic carrier and glass of about 20%.

The mass percentage of the conductive metal particles 154 is about 791# the mass of the sensitive glass powder. · :v'k. The percentage is about 5%. 2%〜1 The mass percentage of the carbon nanotubes relative to the conductive gold fr particles and the glass powder is about 0. 2%~1

Intel lech [0042]

Finally, the outer surface of the above mixed slurry is coated, and dried, rubbed, dust removed, and ruthenium to form a field emission element. [0043] This embodiment preferably performs drying and firing at 300 to 600 ° C to form a field emission element. The purpose of drying is to volatilize the organic vehicle. The purpose of the calcination is to melt the glass frit to bond the conductive metal particles and the carbon nanotubes. [0044] The preparation method of the carbon nanotube film as the carbon nanotube field emission layer 14 in the embodiment includes the following steps: 095123830 Form No. A0101 Page 10 / Total 18 Page 1003097669-0 1D0 Year D March 21 Replacement page [〇〇45] First, a strip of carbon nanotube film is provided. [0046] The method for preparing the carbon nanotube film of the embodiment comprises the steps of: providing an array of carbon nanotubes, clamping or smearing a super-aligned carbon nanotube array with a tape at a certain width; A bundle of carbon nanotubes is applied by external force. Due to the effect of van der Waals force, the ends of the carbon nanotube bundles are connected end to end, forming a strip of carbon nanotube film along the direction of the grapefruit. [0047] Next, the strip-shaped carbon nanotube film is wound around the outer surface of the support wire to form a field emission element. [0048] In this embodiment, a single-layer or multi-layered carbon nanotube film may be wound on the outer surface of the support wire to cover the outer surface of the entire support wire and immersed in an organic solvent to make the nanocarbon' The tube film is firmly adhered to the outer surface of the support wire. The organic solvent selected for this example is ethanol. [0049] The above-mentioned carbon nanotube array capable of drawing a carbon nanotube film needs to satisfy the following three conditions: the surface of the substrate is smooth and smooth; the growth rate is high; and the partial pressure of the reaction precursor is low. [0050] In addition, the width and thickness of the strip-shaped carbon nanotube film can be controlled by the tip of the drawing tool, .... - 'end size or tape size, and the length of the strip-shaped carbon nanotube film is made up of carbon nanotubes The area of the array is determined. The force of the carbon nanotubes is determined by the width and thickness of the carbon nanotubes. The greater the width and thickness, the greater the force required. The thickness of the strip-shaped carbon nanotube film of the embodiment is preferably in the range of 5 nm to 10 μm. [0051] The field emission element of the embodiment can be directly formed into the length of the required field emission element according to actual needs, or alternatively For the convenience of production, it can be made into a long line first, and then cut into the required length by mechanical shearing or laser cutting. The bat number A0101 Page 11 / 18 pages 1003097669-0 1343591 100 years old March 21 The K field emission element is being replaced. Further, the field emission element of the present embodiment may also be subjected to a surface treatment process such as laser irradiation or mechanical rubbing to process the field emission element such that the carbon nanotubes are dispersed in the polymer or glass material to improve field emission. performance. The field emission element can also be processed by means of large current field emission aging or the like to enable the field emission element to fully utilize the field emission performance of the carbon nanotube itself. [0052] The present invention includes a field emission element of a support wire and a carbon nanotube field emission layer, which has the advantage that, first, a nanocarbon carbon nanotube field emission layer is used as an emitter to emit electrons, and a nanocarbon preparation ginseng can be utilized. Liang #electron emission performance, followed by 'supporting body line# mining field into the field

The components are macroscopically too large, using layer fixing and support to make the field test field launch mechanical performance 'easy to operate, mass production and convenient) 1|_ with various vacuum field emission devices.综 [0053] In summary, the present invention has indeed been replaced by 丨f, and patent applications are filed according to law. However, the preferred embodiment of the above month can not limit the application of this case ([multi-f (5) is sufficient). Equivalent modifications or variations made by those skilled in the art to the spirit of the invention are intended to be included within the scope of the following claims. [0056] BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a field emission element according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view of Figure 1 taken along line 11-11. Fig. 3 is a flow chart showing a method of preparing a field emission element of an embodiment of the present invention. 095123830 Form nickname A0101 Page 2 of 18 Page 303097669-0 1343591 _ , · March 21, 2011 Correction replacement page [Key element symbol description] [0057] Field emission element 10, 20 [0058] Support body wire 12, 22 [0059] Nano Carbon Tube Emission Layer 14, 24 095123830 Form No. A0101 Page 13 of 18 Page 1003097669-0

Claims (1)

«43591 100 years ϋ March 21 revised replacement He Qi, patent application scope: 1. A field emission element, the improvement is that the field emission element comprises a support body wire and a carbon nanotube field emission layer, the nanometer The carbon tube field emission layer is a single-layer or multi-layered carbon nanotube film wound on the outer surface of the support wire, and the carbon nanotube film comprises a plurality of carbon nanotube bundles, and the ends of the plurality of carbon nanotube bundles are connected end to end. 2. The field emission element of claim 1, wherein the plurality of carbon nanotube bundles are arranged in the same direction. 3 . The field emission element according to claim 1 , wherein the nai The nano carbon tube carbon tube film of the nai is from the Naigang pepper column t #粞翻如如专利范. #3rd item of the carbon nanotube film is formed by a super-shunned nanowire The carbon nanotube thin is as in the field emission element described in claim 1, wherein the carbon nanotube film comprises a plurality of nano carbon, and the thickness of the film is 5 nm to 10 μm. . Rv as in the application of patent scope 5, the field of rape, wherein the diameter of the carbon nanotubes is 0.5 nm ~ 100 Nai: one by one 7. The field emission element of claim 1, wherein the support wire material is copper, silver, gold, nickel, molybdenum, glass or ceramic. 8. A method of preparing a field emission element, comprising the steps of: providing a support body wire; forming a carbon nanotube field emission layer on an outer surface of the support body wire; cutting the outer surface to form a nanometer according to a predetermined length The support wire of the carbon tube field emission layer is surface-treated after cutting to form a field emission element 095123830. Form No. A0101 Page 14/18 pages 1003097669-0 On March 21, 100, the shuttle is replacing the page. A method of producing a field emission element according to claim 8, wherein the cutting method comprises mechanical shearing or clock cutting. The method for preparing a field emission element according to claim 8, wherein the surface treatment method comprises laser irradiation, mechanical friction or large current field emission aging, such as the field emission element according to claim 8 of the patent application. The preparation method, wherein 'the carbon nanotube field emission layer is a carbon nanotube film layer. The method for preparing a field emission element according to claim 11, wherein the method for preparing the carbon nanotube film layer as a field emission layer of the carbon nanotube comprises the following step: clamping or tape with a tweezers Sticking a bundle of carbon nanotubes of a certain width in the carbon nanotube array, applying external force to form a strip of carbon nanotube film; wrapping the strip of carbon nanotube film on the outer surface of the support wire; The entangled branch body wire is immersed in an organic solvent to form a Neyle carbon tube field emission layer. A method of producing a field emission element according to claim 12, wherein the strip-shaped carbon nanotube film is wound around a single layer or a plurality of layers on the outer surface of the support wire. Form No. Α0101 Page 15 of 18 1003097669-0