JP2008102273A - Electrochromic element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively manufacture an electrochromic element by a high speed film-deposition technique using inexpensive equipment. <P>SOLUTION: In the electrochromic element wherein a transparent conductive film, an oxidation coloring layer, an electrolyte layer, a reduction coloring layer and a transparent conductive layer are layered on a substrate, any one or two or more layers of the oxidation coloring layer, the electrolyte layer and the reduction coloring layer are film-deposited by a gas flow sputtering method in an atmosphere containing hydrogen. The gas flow sputtering method can be performed with inexpensive equipment since high vacuum evacuation is not needed and enables high speed film-deposition. Thereby, the electrochromic element can be inexpensively manufactured by reduction of an equipment cost by adopting the gas flow sputtering method and reduction of film-deposition time. Protons caused by hydrogen are introduced into any of the three layers and thus responsiveness of an electrochromic phenomenon is enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrochromic device and a method for manufacturing the same, and in particular, an electrochromic device for efficiently forming an oxidation coloring layer, an electrolytic layer, a reduction coloring layer, and a transparent conductive film on a substrate by gas flow sputtering. It relates to the manufacturing method.

An electrochromic element is an element that induces an electrochemical oxidation-reduction reaction by application of a voltage to cause coloring and decoloring, and is expected to be used for a display, a dimming window, and the like. As shown in FIG. 2, the electrochromic device includes a transparent conductive film (first electrode film) 2, an oxidation coloring layer 3, an electrolytic layer (ion conducting layer) 4, a reducing coloring layer 5, and a transparent conductive film on a substrate 1. (Second electrode film) 6 is sequentially laminated. Reference numeral 7 denotes a transparent substrate or a protective cover provided as necessary. A glass substrate is used as the transparent substrates 1 and 7, and an ITO film or the like is formed as the transparent conductive films 2 and 6. Further, as the oxidation coloring layer 3, nickel oxide (NiO), iridium oxide (IrO _x ) or the like is used, and as the reduction coloring layer 5, tungsten oxide (WO ₃ ), molybdenum oxide (MoO ₃ ), vanadium oxide (VO) or the like. Is formed. As the electrolytic layer 4, tantalum pentoxide (Ta ₂ O ₅ ), silicon oxide (SiO ₂ ), chromium oxide (Cr ₂ O ₃ ) or the like is formed as a solid electrolytic layer.

  There is also an electrochromic element provided with a liquid electrolytic layer as an electrolytic layer. Such an electrochromic element is formed by sealing an electrolytic solution with a sealing material (liquid sealing sealant) 8 as shown in FIG. An electrolytic layer 4A is formed. In FIG. 3, members having the same functions as those shown in FIG.

  Conventionally, the transparent conductive films 2, 6, the reduction color layer 3, the oxidation color layer 6, and the solid electrolyte layer 4 of the electrochromic elements 10, 10 </ b> A are formed by sputtering (planar magnetron sputtering. It may be referred to as “method”.) Or it is formed by vapor deposition.

Note that the gas flow sputtering method to be described later employed in the present invention is a known film formation method, and the applicant of the present invention first performed the gas flow sputtering method on the catalyst layer of the polymer electrolyte fuel cell electrode or the dye. The technique applied to formation of the semiconductor electrode layer for sensitized solar cells is proposed (patent documents 1-3).
Japanese Patent Application No. 2004-319592 Japanese Patent Application No. 2004-319548 Japanese Patent Application No. 2004-319598

  Conventional sputtering methods used to deposit oxidation coloring layers and reduction coloring layers of electrochromic devices can be formed uniformly, but the deposition rate is slow and the vacuum chamber is in a high vacuum state. However, since a large exhaust device is indispensable for exhausting the air, there is a disadvantage that expensive equipment is required.

  In particular, when forming a solid electrolytic layer, it is necessary to use a water-containing layer in order to impart ionic conductivity, but it is not easy to form an appropriate gap during sputtering formation of the electrolytic layer. There was also.

  Further, in the normal sputtering method, since a magnet is provided below the target, when a ferromagnetic material such as Ni is used as a target, only a thin target can be used, and there is a problem that the target is restricted.

  On the other hand, the vapor deposition method makes it difficult to form a uniform film, which limits the size of the element, limits the materials that can be formed, and requires an expensive exhaust device to exhaust the vacuum chamber to a high vacuum state. There is a disadvantage that it is necessary.

  The present invention solves the above-mentioned conventional problems, does not require expensive equipment such as the conventional sputtering method and vapor deposition method, and enables high-speed film formation, and film formation for void formation. It is an object to provide an electrochromic element with high coloring efficiency at low cost by a film forming technique that is easy to control conditions and is not restricted by a target.

  The electrochromic device of the present invention (Claim 1) is formed by laminating a first conductive film, an oxidation coloring layer, an electrolytic layer, a reducing coloring layer, and a second conductive film in this order or reverse order on a substrate. In an electrochromic device having a laminated film, any one or more of the oxidation coloring layer, the electrolytic layer, and the reduction coloring layer are formed by a gas flow sputtering method in a gas atmosphere containing hydrogen. It is characterized by becoming.

  The electrochromic element according to claim 2 is characterized in that, in claim 1, the oxidation coloring layer is formed by a gas flow sputtering method using Ni and / or Ir as a target.

  An electrochromic device according to a third aspect is formed by a gas flow sputtering method according to the first or second aspect, wherein the reduction coloring layer is a target selected from one or more selected from the group consisting of W, Mo, and V. It is characterized by.

  The electrochromic element according to claim 4 is the electrochromic element according to any one of claims 1 to 3, wherein the electrolytic layer is selected from the group consisting of Ta, Nb, Cr, Si, V, Zr, Hf, and Mg. The film is formed by gas flow sputtering using two or more kinds as targets.

  The electrochromic element according to claim 5 is the electrochromic element according to any one of claims 1 to 4, wherein at least one of the first conductive film and the second conductive film is a transparent conductive film, It is formed by gas flow sputtering using one or more selected from the group consisting of ITO, IZO, AZO, GZO, InSn alloy, InZn alloy, ZnAl alloy, and ZnGa alloy. To do.

  An electrochromic element according to a sixth aspect is the electrochromic device according to any one of the first to fifth aspects, wherein the substrate is made of glass or a polymer film.

  In the method of manufacturing an electrochromic device according to the present invention (invention 7), the first conductive film, the oxidation coloring layer, the electrolytic layer, the reduction coloring layer, and the second conductive film are arranged in this order or in reverse order on the substrate. In the method of manufacturing an electrochromic device by forming a laminated film formed by laminating, any one layer or two or more layers of the oxidation coloring layer, the electrolytic layer, and the reduction coloring layer in a gas atmosphere containing hydrogen The film is formed by gas flow sputtering.

  According to an eighth aspect of the present invention, there is provided a method for producing an electrochromic device according to the seventh aspect, wherein the oxidation coloring layer is formed by a gas flow sputtering method using Ni and / or Ir as a target.

  A method for producing an electrochromic device according to claim 9 is the method according to claim 7 or 8, wherein the reduction coloring layer is formed by gas flow sputtering using one or more selected from the group consisting of W, Mo and V as a target. It is characterized by forming a film.

  The method for producing an electrochromic element according to claim 10 is the method according to any one of claims 7 to 9, wherein the electrolytic layer is selected from the group consisting of Ta, Nb, Cr, Si, V, Zr, Hf, and Mg. It forms by the gas flow sputtering method which makes 1 type or 2 types or more a target.

  The method for producing an electrochromic element according to claim 11 is the method according to any one of claims 7 to 10, wherein at least one of the first conductive film and the second conductive film is a transparent conductive film. The conductive film is formed by gas flow sputtering using one or more selected from the group consisting of ITO, IZO, AZO, GZO, InSn alloy, InZn alloy, ZnAl alloy, and ZnGa alloy as a target. And

  A method for producing an electrochromic element according to a twelfth aspect is characterized in that the substrate is made of glass or a polymer film in any one of the seventh to eleventh aspects.

  The gas flow sputtering method is a method in which sputtering is performed under a relatively high pressure, and sputtered particles are transported to a deposition target substrate by a forced flow of gas and deposited. Since this gas flow sputtering method does not require high vacuum evacuation, it is possible to form a film by mechanical pump evacuation without using a large evacuation device like the conventional normal sputtering method. It can be implemented with inexpensive equipment. Moreover, the gas flow sputtering method can form a film 10 to 1000 times faster than the usual sputtering method. Therefore, according to the present invention, the electrochromic device can be manufactured at low cost by reducing the equipment cost and the film formation time by adopting the gas flow sputtering method.

  In particular, when the solid electrolytic layer is formed, the film forming speed is very high, so that voids can be easily formed during film forming, and an electrolytic layer excellent in ionic conductivity can be formed. Further, since a magnet is not provided under the target, even when a ferromagnetic material such as Ni is used as a target, there is no restriction on the thickness thereof.

  In addition, if the gas flow sputtering method is used, a film having good adhesion to the substrate can be formed, and a high-quality electrochromic element can be manufactured.

  Furthermore, in the present invention, any one layer or two or more layers of the oxidation coloring layer, the electrolytic layer, and the reduction coloring layer are formed by gas flow sputtering in a gas atmosphere containing hydrogen. In this layer, protons resulting from this hydrogen are introduced. Thereby, proton conductivity is imparted to the electrochromic element, and the responsiveness of the electrochromic phenomenon is improved.

  Embodiments of an electrochromic device and a method for manufacturing the same according to the present invention will be described in detail below.

  First, with reference to FIG. 1, the film-forming method by the gas flow sputtering method employ | adopted by this invention is demonstrated.

  FIG. 1A is a schematic diagram showing a schematic configuration of a gas flow sputtering apparatus suitable for carrying out the present invention, and FIG. 1B shows a target and back plate configuration of FIG. 1A. It is a perspective view.

  In the gas flow sputtering apparatus, a rare gas such as argon is introduced into the chamber 20 from the sputtering gas inlet 11 and is generated by discharge between the target 15 serving as a cathode connected to a power source 12 such as a DC power source and the anode 13. The target 15 is sputtered by the plasma, and the sputtered particles that have been blown off are transported to the substrate 16 and deposited by a forced flow of a rare gas such as argon. In the illustrated example, the substrate 16 is supported by a holder 17, and a reactive gas inlet 18 is disposed in the vicinity of the substrate 16 so that reactive sputtering can be performed. Reference numeral 14 denotes a water-cooled backing plate.

  In the present invention, by using such a gas flow sputtering apparatus, one or more of the oxidation coloring layer, the electrolytic layer, and the reduction coloring layer constituting the electrochromic element is used as a gas containing hydrogen. In an atmosphere, the film is formed by a gas flow sputtering method.

  Of these three layers, the electrolytic layer is particularly preferably formed by gas flow sputtering in a gas atmosphere containing hydrogen.

  Of these three layers, a layer that is not formed by a gas flow sputtering method in a gas atmosphere containing hydrogen may be formed by a gas flow sputtering method without containing hydrogen in the gas atmosphere. The conductive film may also be formed by gas flow sputtering.

  The film forming method and film forming conditions for each layer will be described below.

<Transparent conductive film>
When the transparent conductive film is formed by gas flow sputtering, as targets, ITO (Sn-doped In ₂ O ₃ ), IZO (In-doped ZnO), AZO (Al-doped ZnO), GZO (Ga-doped ZnO), InSn Using one or more selected from the group consisting of alloys, InZn alloys, ZnAl alloys, and ZnGa alloys, film formation can be performed under the following conditions.
Sputtering pressure: 10-100 Pa
Sputter power density: 1 to 25 W / cm ²
Argon: 0.5-30 SLM
Reactive gas: Oxygen 0-120sccm
Substrate temperature: room temperature

  Usually, the transparent conductive film is formed of ITO, IZO, AZO, GZO or the like to a thickness of about 10 to 500 nm, depending on the required resistance value. At that time, according to the present invention, by employing the gas flow sputtering method, high-speed film formation with a dynamic film formation rate of 30 to 150 nm · m / min can be performed.

<Oxidation coloring layer>
When forming the oxidation coloring layer by gas flow sputtering, Ni and / or Ir can be used as a target under the following conditions.
Sputtering pressure: 10-100 Pa
Sputter power density: 1 to 25 W / cm ²
Argon: 0.5-30 SLM
Reactive gas: Oxygen 0-120 sccm, hydrogen 0-120 sccm
Substrate temperature: room temperature

Usually, the oxidation coloring layer is formed of NiO, IrO _x or the like to a thickness of about 50 to 750 nm. At that time, according to the present invention, by employing the gas flow sputtering method, high-speed film formation with a dynamic film formation rate of 30 to 150 nm · m / min can be performed.

<Reduced coloring layer>
When forming the reduced coloring layer by the gas flow sputtering method, the target may be one or more selected from the group consisting of W, Mo, and V, and may be formed under the following conditions. it can.
Sputtering pressure: 10-100 Pa
Sputter power density: 1 to 25 W / cm ²
Argon: 0.5-30 SLM
Reactive gas: Oxygen 0-120 sccm, hydrogen 0-120 sccm
Substrate temperature: room temperature

Usually, the reduction coloring layer is formed with a thickness of about 100 to 1000 nm by WO ₃ , MoO ₃ , VO or the like. At that time, according to the present invention, by employing the gas flow sputtering method, high-speed film formation with a dynamic film formation rate of 30 to 150 nm · m / min can be performed.

<Electrolytic layer>
When the solid electrolytic layer is formed by gas flow sputtering, the target is one or more selected from the group consisting of Ta, Nb, Cr, Si, V, Zr, Hf, and Mg. The film can be formed under the following conditions.
Sputtering pressure: 10-100 Pa
Sputter power density: 1-35 W / cm ²
Argon: 0.5-30 SLM
Reactive gas: Oxygen 0-150 sccm, Hydrogen 0-150 sccm
Substrate temperature: room temperature

Usually, the electrolytic layer is formed to a thickness of about 200 to 3000 nm by Ta ₂ O ₅ , Cr ₂ O ₅ , Mb ₂ O ₅ , SiO ₂ or the like. At that time, according to the present invention, by employing the gas flow sputtering method, high-speed film formation with a dynamic film formation speed of 30 to 300 nm · m / min can be performed.

  Note that when forming each of the above layers by the gas flow sputtering method, it is also possible to form a composite oxide layer using two or more types of targets. Each layer can be a multilayer film of two or more materials.

  In order to manufacture an electrochromic device having a solid electrolytic layer according to the present invention, for example, a transparent conductive film, an oxidation coloring layer, an electrolytic layer, a reducing coloring layer, and a transparent conductive film on a transparent substrate such as a glass substrate or a polymer film. May be formed by gas flow sputtering. Alternatively, an oxidation coloring layer, an electrolytic layer, a reduction coloring layer, and a transparent conductive film may be sequentially formed on a transparent substrate on which a transparent conductive film is formed in advance.

  In the above description, as shown in FIG. 2, an electrochromic element having a transparent conductive film, an oxidation coloring layer, an electrolytic layer, a reduction coloring layer, and a transparent conductive film on a transparent substrate, and these layers on the transparent substrate in order. Although a method of manufacturing by laminating a film has been shown, the electrochromic device of the present invention is not limited to this, and has a transparent conductive film, a reduction coloring layer, an electrolytic layer, an oxidation coloring layer and a transparent conductive film on a transparent substrate. An electrochromic element may be used, and in this case, each layer may be laminated on the transparent substrate in this order. Further, one of the conductive films may not be transparent but may be an opaque conductive film such as a metal film.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the following, the ITO glass used as a substrate is a glass substrate having a thickness of 1 mm and an ITO film having a thickness of 250 nm formed on one surface of the glass substrate.

Example 1
Using the gas flow sputtering apparatus shown in FIG. 1, ITO glass is set as a substrate in the chamber, exhausted to 1 × 10 ⁻¹ Pa with a roughing pump (rotary pump + mechanical booster pump), and then a three-layer multilayer film Was formed into an electrochromic device shown in FIG. Note that when the multilayer film was formed, the substrate moving speed was adjusted in order to obtain the desired film thickness. Thereafter, a transparent conductive film (ITO thin film) having a thickness of 200 nm was formed by a normal DC sputtering method to obtain an electrochromic device.

  Specific film forming conditions are as shown in Table 1 below, and other conditions are as follows.

<Gas flow sputtering equipment>
・ Target dimensions: 80mm x 160mm x 6mmt
・ Cathode shape: Parallel plate facing type (disposed with the above two targets facing each other in parallel, distance 30 mm)
-Substrate temperature: Room temperature (no substrate heating)
-Substrate position: 105 mm distance between cathode end and substrate
<Oxidation coloring layer>
-Target material: Ni
<Electrolyte layer>
・ Target material: Ta
<Reduced coloring layer>
・ Target material: W
<DC sputtering equipment>
・ Target dimensions: 100mm x 400mm x 5mmt
・ Cathode shape: Planar magnetron, installed facing the substrate in parallel ・ Substrate temperature: Room temperature (no substrate heating)
・ Substrate position: Distance between cathode and substrate 80mm

Comparative Example 1
An electrochromic element having the same layer structure as in Example 1 was manufactured using a normal magnetron sputtering apparatus.

ITO glass is set in the vacuum chamber as a substrate, exhausted to 1 × 10 ⁻¹ Pa with a roughing pump (rotary pump + mechanical booster pump), then exhausted to 6 × 10 ⁻⁴ Pa with a turbo molecular pump, A four-layer multilayer film was formed. In addition, in order to obtain the target film thickness, the substrate moving speed was adjusted.

  Specific film forming conditions are as shown in Table 2 below, and other conditions are as follows.

<DC sputtering equipment>
・ Target dimensions: 100mm x 400mm x 5mmt
・ Cathode shape: Planar magnetron, installed facing the substrate in parallel ・ Substrate temperature: Room temperature (no substrate heating)
-Substrate position: 80mm distance between target and substrate

<Evaluation>
When a voltage was applied between both electrodes of the electrochromic element of Example 1 (a reduction color layer side was minus and an oxidation color layer side was plus and 1.5 V was applied between both electrodes), both color layers were colored and the transmittance Changed from 75% to 10%. On the other hand, when a voltage was applied in the reverse direction, the transmittance changed from 10% to 75%, and it was confirmed that reversible dimming performance was obtained.

  At this time, in Example 1, it was confirmed that the detachable color could be formed in about 4 seconds for coloring and about 2 seconds for decoloring. In contrast, Comparative Example 1 required 40 seconds for coloring and 20 seconds for decoloring.

  As a result, the following was confirmed. That is, the film formation speed is low in the normal sputtering method, and even if the film is formed with the same input power density as in the gas flow sputtering method, the substrate moving speed is low and a film with a large film thickness is formed. The film cannot be thickened without passing through the cathode several times. On the other hand, according to the present invention, high-speed film formation is possible by employing the gas flow sputtering method.

  In Example 1, electrochromic responsiveness can be improved by introducing hydrogen.

  Furthermore, in the case of a normal sputtering method, a magnet is provided below the target. Therefore, when a ferromagnetic material such as Ni is used as a target, only a thin target can be used. Even thick targets can be used.

FIG. 1A is a schematic diagram showing a schematic configuration of a gas flow sputtering apparatus suitable for carrying out the present invention, and FIG. 1B shows a target and back plate configuration of FIG. 1A. It is a perspective view. It is typical sectional drawing which shows the structural example of an electrochromic element. It is typical sectional drawing which shows the other structural example of an electrochromic element. It is typical sectional drawing which shows the other structural example of an electrochromic element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,7 Transparent substrate 2,6 Transparent conductive film 3 Oxidation coloring layer 4, 4A Electrolytic layer 5 Reduction coloring layer 8 Sealing material 10, 10A Electrochromic element 12 DC power supply 13 Anode 14 Backing plate 15 Target 16 Substrate 20 Chamber

Claims (12)

In an electrochromic device having a laminated film in which a first conductive film, an oxidation coloring layer, an electrolytic layer, a reducing coloring layer, and a second conductive film are laminated in this order or in reverse order on a substrate,
Any one or more of the oxidation coloring layer, the electrolysis layer, and the reduction coloring layer are formed by gas flow sputtering in a gas atmosphere containing hydrogen. .   2. The electrochromic device according to claim 1, wherein the oxidation coloring layer is formed by a gas flow sputtering method using Ni and / or Ir as a target.   3. The electrochromic according to claim 1, wherein the reduced coloring layer is formed by a gas flow sputtering method using one or more selected from the group consisting of W, Mo and V as a target. element.   The gas flow according to any one of claims 1 to 3, wherein the electrolytic layer targets one or more selected from the group consisting of Ta, Nb, Cr, Si, V, Zr, Hf, and Mg. An electrochromic element formed by sputtering.   5. The method according to claim 1, wherein at least one of the first conductive film and the second conductive film is a transparent conductive film, and the transparent conductive film is made of ITO, IZO, AZO, GZO, InSn. An electrochromic element formed by a gas flow sputtering method using one or more selected from the group consisting of an alloy, an InZn alloy, a ZnAl alloy, and a ZnGa alloy.   6. The electrochromic device according to claim 1, wherein the substrate is made of glass or a polymer film. An electrochromic device is manufactured by forming a laminated film in which a first conductive film, an oxidation coloring layer, an electrolytic layer, a reducing coloring layer, and a second conductive film are laminated in this order or in reverse order on a substrate. In the method
Production of an electrochromic device characterized in that any one or more of the oxidation coloring layer, the electrolytic layer, and the reduction coloring layer are formed by gas flow sputtering in a gas atmosphere containing hydrogen. Method.   8. The method of manufacturing an electrochromic device according to claim 7, wherein the oxidation coloring layer is formed by a gas flow sputtering method using Ni and / or Ir as a target.   9. The electrochromic device according to claim 7, wherein the reduction coloring layer is formed by gas flow sputtering using one or more selected from the group consisting of W, Mo and V as a target. Production method.   10. The gas flow according to claim 7, wherein the electrolytic layer targets one or more selected from the group consisting of Ta, Nb, Cr, Si, V, Zr, Hf, and Mg. A method for producing an electrochromic element, wherein the film is formed by a sputtering method.   11. The method according to claim 7, wherein at least one of the first conductive film and the second conductive film is a transparent conductive film, and the transparent conductive film is made of ITO, IZO, AZO, GZO, InSn. A method for producing an electrochromic device, comprising forming a film by a gas flow sputtering method using one or more selected from the group consisting of an alloy, an InZn alloy, a ZnAl alloy, and a ZnGa alloy.   12. The method of manufacturing an electrochromic device according to claim 7, wherein the substrate is made of glass or a polymer film.

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