JP5434432B2 - Nanocarbon material composite substrate and electron-emitting device - Google Patents

Description

  The present invention relates to a nanocarbon material composite substrate, a nanocarbon material composite substrate manufacturing method suitable for manufacturing the nanocarbon material composite substrate, an electron-emitting device using the nanocarbon material composite substrate, and the nanocarbon material composite substrate The present invention relates to a field electron emission lamp using the above.

Nano-carbon materials have nanometer (nm) -sized fine shapes composed of sp ² hybrid orbitals of carbon atoms, and therefore have characteristics that surpass conventional materials or that do not exist in conventional materials. Therefore, application as next-generation functional materials such as strength reinforcing materials, electron-emitting device materials, battery electrode materials, electromagnetic wave absorbing materials, catalyst materials, and optical materials is expected.

  Various methods have been proposed as a method for producing the above-described nanocarbon material.

  For example, a method has been proposed in which carbon nanotubes are oriented and grown on catalytic metal particles formed on a substrate using chemical vapor deposition (CVD) (see Patent Document 1).

  For example, it is based on a unique interfacial decomposition reaction resulting from contact between a solid substrate and an organic liquid with a rapid temperature difference, and can synthesize high-purity carbon nanotubes that do not require purification, resulting in a very high yield A solid-liquid interface catalytic decomposition method, which is a synthesis method, has been proposed (see Patent Document 2).

  Field electron emission (field emission) refers to a phenomenon in which when a strong electric field is applied to a material having a large aspect ratio, electron emission occurs from the surface of the material due to the tunnel effect. A field electron emission lamp is an apparatus that uses electrons emitted by field emission to enter a phosphor to excite and emit the phosphor, and is used as a lighting fixture. Field electron emission lamps have excellent features such as low power consumption and low pollution compared to conventional incandescent bulbs and fluorescent lamps, and are attracting attention as next-generation lighting fixtures.

  Examples of materials for emitting electrons by field emission include nanocarbon materials such as carbon nanotubes, carbon nanofibers, carbon nanowalls, carbon nanofilaments, carbon nanocoils, and carbon nanohorns. These nanocarbon materials have physical properties suitable as an electron-emitting material, such as a low work function, a high electric field concentration factor, and high electrical conductivity and thermal conductivity.

  Taking advantage of the physical properties as described above, research has been conducted in which a nanocarbon material is grown on a substrate surface and used as an electron emission material, and applied to a field electron emission lamp or the like. At this time, it is known that electric field concentration occurs more efficiently on the nanocarbon material by patterning and growing the nanocarbon material on the substrate surface.

  For example, a method has been proposed in which a catalyst for carbon nanotube growth is deposited on the surface of the substrate and then annealed to form a pattern by atomizing the catalyst to grow a nanocarbon material only on the patterned catalyst support site. (See Patent Document 3).

  For example, in order to protect carbon nanotubes by patterning and growing carbon nanotubes on the surface of the substrate, a method of covering with a patterned insulating thin film has been proposed (see Patent Document 4).

JP 2001-167721 A JP 2008-214141 A JP 2005-259600 A JP 2007-299697 A

When the nanocarbon material is patterned on the substrate surface, the nanocarbon material is relatively less than when the nanocarbon material is formed on the entire surface of the substrate. Run short. For this reason, it has the fault that the stability with respect to the spark etc. which occur when an impact or an electric field is applied is impaired.
In addition, when a nanocarbon material is patterned on the surface of the substrate and the periphery thereof is coated, the high aspect ratio of the nanocarbon material cannot be utilized, resulting in a lower electric field concentration effect. .

  Accordingly, an object of the present invention is to provide a method for producing a nanocarbon material composite substrate, which can be grown by suitably patterning a nanocarbon material on a substrate.

One embodiment of the present invention includes a substrate having a surface layer, a catalyst layer, and a back layer, an opening formed to expose the catalyst layer on the substrate, and the catalyst layer exposed in the opening. includes a nanocarbon material formed on a surface, the side surface of the opening portion is formed in a tapered shape, nanocarbon said back layer is electrically conductive, and wherein the possible conduction with the cathode electrode It is a material composite substrate.

Further, the nanocarbon material composite substrate is characterized in that it does not include a cathode electrode, a gate electrode, and an anode electrode.

Moreover, it is preferable that the nanocarbon material deposited on the surface of the catalyst layer does not protrude from the surface of the surface layer of the substrate.

  One embodiment of the present invention is an electron-emitting device using the above-described nanocarbon material composite substrate.

  According to another embodiment of the present invention, there is provided a field electron emission lamp using the above-described electron-emitting device, wherein the electron-emitting device and a gate having a gate opening disposed opposite to the electron-emitting device. A field electron emission lamp comprising: an electrode; an anode electrode disposed opposite to the electron-emitting device with the gate electrode interposed therebetween; and a phosphor provided on the anode electrode. is there.

  By using the method of the present invention, a nanocarbon material composite substrate in which a catalyst layer is exposed in a cross-sectional portion of an opening formed on a substrate and a nanocarbon material is grown only in the portion where the catalyst layer is exposed. Can be made. For this reason, in the nanocarbon material composite substrate of the present invention, the nanocarbon material is generated only in the catalyst layer exposed by the opening, and the nanocarbon material is arranged by patterning, so that the electric field tends to concentrate. It can be expected that excellent electron emission characteristics are exhibited. In addition, since each nanocarbon material is protected by the surface layer of the substrate, it can protect the nanocarbon material from impacts and sparks, and the nanocarbon material composite substrate exhibits excellent durability Is possible.

It is the schematic process drawing which showed an example of embodiment of the nanocarbon material composite substrate manufacturing method of this invention. It is the schematic process drawing which showed an example of embodiment of the nanocarbon material composite substrate manufacturing method of this invention. It is the schematic process drawing which showed an example of embodiment of the nanocarbon material composite substrate manufacturing method of this invention. It is the schematic which showed an example of the field electron emission type | mold lamp of this invention.

  Hereinafter, a nanocarbon material composite substrate manufacturing method according to an embodiment of the present invention will be described.

<Board preparation process>
First, the substrate 11 is prepared. The substrate 11 used in the present invention has a multilayer structure including a surface layer 12, a catalyst layer 13, and a back layer 14. The substrate 11 may be a substrate 11 in which the catalyst layer 13 is laminated on both sides with a material different from the material used for the catalyst layer 13, and a multilayer substrate having three or more layers may be used.

  The catalyst layer 13 is made of a material having catalytic ability for forming a nanocarbon material. Specifically, iron, nickel, cobalt, and an alloy material containing at least one of these metals can be used.

  The surface layer 12 and the back layer 14 are made of a material that does not have catalytic ability to form a nanocarbon material. Specifically, metal materials such as copper, aluminum, zinc, chromium, magnesium, silicon, ceramic materials such as alumina, aluminum nitride, silicon carbide, silicon nitride, zirconium oxide, polyimide, polyimide amide, polyacetal, polyether imide, etc. Resin materials can be used.

  The substrate 11 having such a multilayer structure is bonded to the surface layer 12, after the surface layer 12, the catalyst layer 13, and the back layer 14 are bonded together, and after the catalyst layer 13 is formed on the surface of the back layer 14, the substrate 11 is bonded. The catalyst layer 12 and the back surface layer 13 are bonded to each other, and then the surface layer 12 is formed on the surface thereof.

  For example, a method of bonding copper, iron-nickel alloy and copper substrates, a method of bonding a nickel plate on a copper plate and then bonding a nickel surface to another copper plate, a method of bonding a copper plate and a nickel plate, and then nickel The substrate 11 can be manufactured by utilizing a method of forming a resin layer on the surface of the plate.

<Catalyst layer exposure process>
Next, an opening 16 having a depth reaching the surface layer 12, at least the catalyst layer 13, is formed on the substrate 11, and the catalyst layer 13 is exposed at the bottom of the opening 16. The opening 16 is formed by appropriately using a known process such as etching or machining. The depth and shape of the opening 16 should be processed in a desired shape and size according to (1) adjustment of reaction conditions such as etching method and etching species, and (2) processing accuracy range of the micromachining apparatus. I can do it.

In addition, a large number of openings may be formed in the substrate 11, and the plurality of openings may be arranged in patterns.
Here, the pattern arrangement is defined as indicating a state in which the openings are regularly arranged. For this reason, for example, those arranged in an array such as a grid pattern or a honeycomb structure (honeycomb structure) are included, and the present invention is not limited to these arrays.

Further, in the catalyst layer exposing step, the opening formed on the substrate may have a depth reaching the surface layer and the catalyst layer of the substrate.
When the deepest part of the opening is the catalyst layer, the nanocarbon material can be continuously arranged on the entire bottom surface of the opening (see, for example, FIG. 1 (e)).

Further, in the catalyst layer exposing step, the opening formed on the substrate may have a depth reaching the surface layer, the catalyst layer, and the back layer of the substrate.
When the deepest part of the opening is the back layer, the nanocarbon material can be disposed on the side surface divided by the back layer that is the bottom of the opening (see, for example, FIG. 2E).
At this time, since the nanocarbon material 17a is formed not on the bottom surface portion of the opening 16a but only on a part of its cross section, an electric field is applied to the nanocarbon material 17a when the nanocarbon material composite substrate 18a is used as an electron-emitting device. Concentration is likely to occur, and as a result, improvement in electron emission characteristics can be expected.

In the catalyst layer forming step, the opening formed on the substrate may penetrate the substrate.
When the opening is a through hole, a nanocarbon material can be disposed on the side surface of the opening (see, for example, FIG. 3E).
At this time, since the opening 16b is formed so as to penetrate the substrate 11, when the nanocarbon material composite substrate 18b is used as an electron-emitting device, electric field concentration is likely to occur due to the nanocarbon material 17a inside the opening 16b. As a result, further improvement in electron emission characteristics can be expected.

Moreover, it is preferable that the side surface of the said opening part is formed in the taper shape.
By forming the opening in a tapered shape, it becomes possible to form the nanocarbon material 17 in the direction of the opening of the opening 16 in the <nanocarbon material growth step> described later, and the nanocarbon material composite substrate 18 is formed into an electron. When used as an emission element, an improvement in electron emission characteristics can be expected.

<Nanocarbon material growth process>
Next, the nanocarbon material composite substrate 18 is produced by forming the nanocarbon material 17 on the surface of the catalyst layer 13 exposed at the bottom of the opening 16. At this time, it is desirable to employ a synthesis method in which the nanocarbon material 17 is vertically aligned on the exposed surface of the catalyst layer 13.
Specifically, (1) a method of aligning and growing carbon nanotubes on catalytic metal particles formed on a substrate using chemical vapor deposition (CVD), and (2) transition in an organic liquid And a solid-liquid interfacial catalytic cracking method in which a substrate carrying a catalyst made of a metal or transition metal oxide is heated to synthesize carbon nanotubes on the substrate.

At this time, the nanocarbon material grown on the surface of the catalyst layer 13 is preferably such that the tip of the nanocarbon material does not protrude from the surface of the surface layer 12 of the substrate 11.
Since the tip of the nanocarbon material does not protrude from the surface of the surface layer 12 of the substrate 11, the structure is protected by the surface layer 12 located on the catalyst layer 13. For this reason, when the nanocarbon material composite substrate 18 is used as an electron-emitting device, the nanocarbon material 17 can be protected from impacts, sparks, and the like. Furthermore, the nanocarbon material 17 is more reliably protected by taking a form in which the nanocarbon material 17 does not protrude from the surface of the substrate 11 (the height of the tip of the nanocarbon material 17 does not exceed the surface of the surface layer 12). It becomes possible to do.

  The method for producing a nanocarbon material composite substrate of the present invention comprises forming an opening with respect to a substrate having a multilayer structure of a surface layer, a catalyst layer, and a back layer, and exposing the catalyst layer to form nanocarbon in an arbitrary pattern. The material can be deposited. By patterning the nanocarbon material to form a film, it can be expected that when the nanocarbon material composite substrate is used as an electron-emitting device, the electric field is easily concentrated on each nanocarbon material. In addition, since the nanocarbon material deposited on the surface of the catalyst layer has a structure protected by the surface layer, when the nanocarbon material composite substrate is used as an electron-emitting device, the nanocarbon material is affected by impact or spark. It can be protected and durability can be expected to improve.

Hereinafter, a specific first embodiment of the method for producing a nanocarbon material composite substrate of the present invention will be described with reference to FIG.
First, a multilayer substrate in which the surface layer 12, the catalyst layer 13, and the back layer 14 are laminated in this order is prepared (FIG. 1A).
Next, a resist 15 is applied in a desired pattern on the surface of the surface layer 12 (FIG. 1B).
Next, etching is performed using the patterned resist 15 as a mask to form openings 16 on the surface of the substrate 11. At this time, the opening 16 reaches the surface layer 12 and the catalyst layer 13, so that the catalyst layer 13 is exposed at the bottom of the opening 16 (FIG. 1 (c)).
Next, after the opening 16 is formed, the resist 15 is removed (FIG. 1D). Next, a nanocarbon material composite substrate 18 is fabricated by depositing a nanocarbon material 17 on the surface of the catalyst layer 13 exposed at the bottom of the opening 16 (FIG. 1E).

  In the embodiment shown in FIG. 1, the deepest part of the opening is the catalyst layer, and the nanocarbon material can be continuously arranged on the entire bottom surface of the opening (see, for example, FIG. 1 (e)).

Hereinafter, the second embodiment of the method for producing a nanocarbon material composite substrate of the present invention will be described with reference to FIG.
First, a multilayer substrate in which the surface layer 12, the catalyst layer 13, and the back layer 14 are laminated in this order is prepared (FIG. 2A).
Next, a resist 15 is applied in a desired pattern on the surface of the surface layer 12 (FIG. 2B).
Next, etching is performed using the patterned resist 15 as a mask to form openings 16 on the surface of the substrate 11. At this time, the opening 16a reaches the back layer 1413, and therefore, the back layer 14 is exposed at the bottom of the opening 16a (FIG. 2C).
Next, after the opening 16a is formed, the resist 15 is removed (FIG. 2D).
Next, a nanocarbon material composite substrate 18 is fabricated by depositing a nanocarbon material 17 on the surface of the catalyst layer 13 exposed through the opening 16a (FIG. 2E).

In the embodiment shown in FIG. 2, the deepest part of the opening is the back layer, and the nanocarbon material can be disposed on the side surface divided into the back layer that is the bottom of the opening (for example, FIG. )reference).
At this time, since the nanocarbon material 17a is formed not on the bottom surface portion of the opening 16a but only on a part of its cross section, an electric field is applied to the nanocarbon material 17a when the nanocarbon material composite substrate 18a is used as an electron-emitting device. Concentration is likely to occur, and as a result, improvement in electron emission characteristics can be expected.

Hereinafter, the third embodiment of the method for producing a nanocarbon material composite substrate of the present invention will be described with reference to FIG.
First, a multilayer substrate in which the surface layer 12, the catalyst layer 13, and the back layer 14 are laminated in this order is prepared (FIG. 3A).
Next, a resist 15 is applied in a desired pattern on the surface of the surface layer 12 (FIG. 3B).
Next, etching is performed using the patterned resist 15 as a mask to form openings 16b on the surface of the substrate 11. At this time, the opening 16a is a through-hole penetrating from the surface layer 12 to the back layer 14, and the catalyst layer 13 is exposed on the side surface of the opening 16b (FIG. 3C).
Next, after the opening 16b is formed, the resist 15 is removed (FIG. 3D).
Next, a nanocarbon material composite substrate 18 is fabricated by depositing a nanocarbon material 17 on the surface of the catalyst layer 13 exposed through the opening 16b (FIG. 3E).

In the embodiment shown in FIG. 3, the opening is a through hole, and a nanocarbon material can be disposed on the side surface of the opening (see, for example, FIG. 3E).
At this time, since the opening 16b is formed so as to penetrate the substrate 11, when the nanocarbon material composite substrate 18b is used as an electron-emitting device, electric field concentration is likely to occur due to the nanocarbon material 17a inside the opening 16b. As a result, further improvement in electron emission characteristics can be expected.

  Hereinafter, a field electron emission lamp using the nanocarbon material composite substrate of the present invention as an electron emission source will be described in detail with reference to FIG. However, the present invention is not limited to the preferred embodiments described below.

  As shown in FIG. 4, a field electron emission lamp using the nanocarbon material composite substrate of the present invention as an electron emission source is a triode structure type field electron device including a cathode electrode 19, a gate electrode 31, and an anode electrode. This is a discharge lamp.

  The cathode electrode 19 is made of a conductive material made of a metal material or a semimetal material, for example, copper, aluminum, nickel, or an alloy such as steel, stainless steel, invar, kovar, or silicon. The nano carbon material composite substrate 18 is disposed on the surface of the cathode electrode 16 facing the gate electrode 31. When the back layer 14 of the nanocarbon material composite substrate 18 is made of a conductive material, the nanocarbon material composite substrate 18 may be used as a cathode electrode by using this. In this case, the cathode electrode 19 is omitted, and the nanocarbon material composite substrate 18 is directly connected to an external circuit (not shown).

  The gate electrode 31 is made of a metal material such as copper, aluminum, nickel, steel, stainless steel, invar, and kovar. The gate electrode 31 is a flat electrode made of a metal material that emits electrons from the nanocarbon material composite substrate 18 on the cathode electrode 19 and guides the electrons toward the anode electrode 42.

  The gate electrode 31 is manufactured by forming the opening 32 in a metal material by a technique such as machining, etching, or screen printing. At this time, the region where the opening 32 is formed and the form thereof are not necessarily limited to the form shown in FIG. 4 and may be formed in any form such as a circle, a rectangle, or a line. Alternatively, it may be formed in the same pattern as the opening 16 formed in the nanocarbon material composite substrate 18.

  Further, instead of forming the gate electrode 31 by forming the opening 32 in the metal material as described above, a mesh made of a metal material may be used as the gate electrode 31.

  The anode electrode 42 is a transparent conductive film such as indium tin oxide, zinc oxide, tin oxide, etc., and is formed on the anode substrate 41 by sputtering, vacuum deposition, laser ablation, ion plating, CVD, spraying, dipping, or the like. A film is formed. The anode substrate 41 is made of a highly transparent material such as glass, acrylic resin, or polycarbonate.

  A surface of the anode electrode 42 facing the gate electrode 31 is coated with a dispersion solution of fine particles of zinc oxide, titanium oxide, aluminum oxide, yttrium oxide, etc. by inkjet, screen printing, etc., and then dried and fired for fluorescence. A body layer 43 is formed.

  The region where the phosphor layer 43 is formed and the region are not necessarily limited to the form shown in FIG. It is sufficient that the phosphor layer 43 is formed on the anode electrode 42 immediately above the opening 32 on the gate electrode 31 when viewed from a direction perpendicular to the anode electrode 42 and the gate electrode 31. .

  The cathode electrode 19, the gate electrode 31, and the anode electrode 42 are installed in a light-emitting container (not shown) that is evacuated. An external power source 51 is connected between the cathode electrode 19 and the gate electrode 31, and an external power source 52 is connected between the cathode electrode 19 and the anode electrode 42 from the outside of the light emitting container. It is possible to arbitrarily set the voltage.

  By applying a DC voltage between the cathode electrode 19 and the gate electrode 31 by the external power source 51 and between the cathode electrode 19 and the anode electrode 42 by the external power source 52, the opening of the nanocarbon material composite substrate 18 is applied. Electrons are emitted from the nanocarbon material 17 formed inside 16 by field emission. The electrons pass through the opening 32 provided in the gate electrode 31 and enter the phosphor layer 43 on the anode electrode 42. At this time, visible light is emitted from the phosphor layer 43, and this visible light is transmitted through the anode substrate 41 and emitted outside the lamp.

  In the field electron emission lamp using the nanocarbon material composite substrate of the present invention as an electron emission source, the electric field tends to concentrate on each nanocarbon material, and the nanocarbon material has a structure protected by a surface layer. Therefore, it can be expected that the emission characteristics and durability of the field electron emission lamp are improved.

The nanocarbon material composite substrate of the present invention is expected to be used as a substrate for strength reinforcing materials, battery electrode materials, electromagnetic wave absorbing materials, catalyst materials, optical materials, electron-emitting device materials, and the like.
In particular, it is expected to be used as a field emission type electron-emitting device that emits electrons by a strong electric field. Specifically, for example, an electron generation source such as an optical printer, an electron microscope, an electron beam exposure apparatus, an electron gun, a plane The present invention is useful as an electron-emitting device for applications such as a surface electron source of an array-shaped field emitter array constituting a display, an illumination lamp, and the like.
In particular, when used as an electron-emitting device of an illumination lamp, (1) Display application: liquid crystal backlight, projector light source, LED display light source, (2) Signal application: traffic signal lamp, industrial / commercial rotary lamp / signal lamp, emergency lamp, Guide light, (3) Sensing application: infrared sensor light source, industrial optical sensor light source, optical communication light source, (4) Medical / image processing application: medical light source (fundus camera / slit lamp), medical light source (internal view) Mirror), image processing light source, (5) photochemical reaction application: curing / drying / adhesion light source, cleaning / surface modification light source, water sterilization / air sterilization light source, (6) automotive light source: headlamp, rear Combination lamps, interior lamps, (7) general lighting: office lighting, store lighting, facility lighting, stage lighting / stage lighting, outdoor lighting, residential lighting, display lighting (pachi) Co machines, vending machines, refrigerated showcases), equipment and fixtures embedded lighting, is applied to lighting applications, such as is expected.
In addition, the use of the nanocarbon material composite substrate of the present invention is not limited to the above use.

DESCRIPTION OF SYMBOLS 11 ... Substrate 12 ... Surface layer 13 ... Catalyst layer 14 ... Back layer 15 ... Resist 16, 16a, 16b ... Openings 17, 17a, 17b ... Nano carbon material 18, 18a, 18b ... Nano Carbon material composite substrate 19 ... cathode electrode 31 ... gate electrode 32 ... opening 41 ... anode substrate 42 ... anode electrode 43 ... phosphor layer 51 ... external power source 52 ... external power source

Claims (4)

A substrate having a surface layer, a catalyst layer, a back layer, and
An opening formed to expose the catalyst layer on the substrate;
Comprising a nanocarbon material deposited on the surface of the catalyst layer exposed in the opening,
The side surface of the opening is formed in a tapered shape,
A nanocarbon material composite substrate, wherein the back layer has conductivity and can be electrically connected to a cathode electrode.   The nanocarbon material composite substrate according to claim 1, wherein the nanocarbon material composite substrate does not include a cathode electrode, a gate electrode, and an anode electrode. Nanocarbon material formed on a surface of the catalyst layer, nanocarbon according to claim 1, 2 or, characterized in that the tip of the nano-carbon material does not protrude on the surface of the surface layer of the substrate Material composite substrate.   An electron-emitting device using the nanocarbon material composite substrate according to claim 1.