JPH055535Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a novel electrochromic device. Hereinafter, "electrochromic" will be abbreviated as EC, and EC element will be abbreviated as ECD. [Prior Art] ECDs generally consist of a pair of electrode layers, at least one of which is transparent, and a sandwich sandwich between them.
Consists of EC layer. This ECD becomes colored when a voltage equivalent to that obtained from a dry battery is applied between a pair of electrodes, and disappears when the opposite voltage is applied, returning to its original colorless and transparent state. Therefore, ECD is a display device, especially a numeric display device using seven segments in the shape of a Japanese character.
It is being actively researched for use in devices that control the amount of transmitted or reflected light, and other applications. To color EC materials e.g. WO ₃ , electron ( ^e- )
The reaction formula for coloring and ^decoloring is believed to be as follows. Uncolored state: WO ₃ +ne ^- +nX ⁺ ↑↓ Colored state: XnWO ₃ And as the cation (X ⁺ ), H ⁺ and Li ⁺ , which have a small ionic radius and are easily mobile, are mainly used. The cation (X ⁺ ) does not need to be a cation all the time; it is sufficient that the cation is generated when a voltage is applied and an electric field is formed, so especially in the case of H ⁺ , water is used as a cation source. It appears that a very small amount of water is sufficient, and when the ECD is exposed to the atmosphere, it is often sufficient to require only the amount of water that naturally enters the layer from the atmosphere. However, even if the WO ₃ layer is simply sandwiched between a pair of electrodes and colored by applying a voltage, the color cannot be easily erased. This is because even if a reverse voltage is applied to erase the color, electrons (e ^- ) will flow in from the electrode side in contact with the cathode, so if H ⁺ is present, WO ₃ +ne ^- +nH ⁺ →HnWO ₃ This is because the reaction takes place and the color develops. Therefore, SKDeb et al. developed an ECD with an insulating layer such as SiO ₂ or MgF ₂ between the WO ₃ layer and one electrode.
(Special Publication No. 52-46098). This insulating layer is
Although electrons cannot move, ions such as H ⁺ and OH ^- can move freely, and these H ⁺ and OH ^- ions carry electricity. It is thought that the OH ^- ion reacts at the interface with the anode according to the reaction formula OH ^- → 1/2H ₂ O + 1/4O ₂ ↑+e ^- and releases electrons to the anode side. It can be done. In other words, when coloring, the reaction is estimated to be as follows: cathode side: WO ₃ +ne ^- +nH ⁺ →HnWO ₃ anode side: nOH ^- →n/2H ₂ O+n/4O ₂ ↑+ne ^- , and when decolorizing, anode side: HnWO ₃ →WO It is estimated that the following reaction occurs: ₃ +ne ^- +nH ⁺ cathode side: nH ₂ O+ne ^- →nOH ^- +n/2H ₂ ↑. As is clear from these equations, S.
K. Deb et al.'s ECD consumes water during the coloring and decoloring process, so if water is not quickly supplied from the atmosphere, the ECD will no longer be colored.
The disadvantage is that delamination occurs because O ₂ and H ₂ gases are released. Therefore, Y. Takahashi et al. proposed an ECD with an oxidation-colored EC layer between the ion conductive layer and the electrode layer.
(Japanese Patent Application Laid-Open No. 1983-4679). This ECD uses, for example, iridium hydroxide as an oxidative coloring EC layer, and when WO ₃ is colored, the anode side is mainly colorless and transparent: Ir(OH)m+n(OH ^- ) ↓ Coloring: Ir(OH)p・qH ₂ O+rH ₂ O+S
(e ^- ), and when decolorizing WO ₃ , Ir(OH)p・qH ₂ O+rH ₂ O+S mainly on the cathode side.
(e ^- ) ↓ It is estimated that it reacts with Ir(OH)m+n(OH ^- ). Therefore, since the water is regenerated, it will not be consumed and run out, and O ₂ and H ₂ gas will not be released during driving. In addition, there are also combinations of an EC layer and a lithium solid electrolyte layer, and combinations of an EC layer and a proton-containing or proton-releasing solid or semi-solid resin layer. [Problems that the invention aims to solve] By the way, when the display area of conventional ECDs is large, when coloring or decoloring occurs, it takes time for the entire display to be colored or decolorized, resulting in unevenness. It was hot. Therefore, an object of the present invention is to alleviate this problem of unevenness. [Means for solving the problem] Therefore, in an ECD with a large display area formed on a substantially quadrangular substrate, the present invention is designed to solve the problem by The lead-out portion is made of low-resistance electrode material along three adjacent sides of the substrate in an approximately square shape, and the lead-out portion of the low-electrical-resistance electrode is made of low-resistance electrode material in a band shape along the remaining side of the board. The device is characterized in that external wiring is connected to each extraction portion. [Operation] In ECD, there is a pair of electrode layers sandwiching the EC layer, one of which must be transparent in order to visually recognize the color change of the EC layer. However, transparent electrode materials currently have high electrical resistance, so even if external wiring is directly connected to them, a charge is supplied at a point, so especially when the electrode area is large, the entire electrode is charged. It takes time to get around. Therefore, it takes time for coloring and decoloring to occur, causing unevenness. Therefore, in the present invention, by providing a take-out part made of a low-resistance electrode material with as large an area as possible on the high-resistance electrode side and connecting external wiring to this, charge is supplied to the high-resistance electrode layer by a line instead of a point. Or a surface - a line or surface as large as possible.
In order to do this, a take-out portion having a shape and size approximately corresponding to three adjacent sides of the substrate is provided. Electrode materials used for ECD include Al,
Metals such as Ag, Ni, Pt, Au, Pd, Cr, Ir, Ru, Rh, and carbon, SnO ₂ , In ₂ O ₃ , ITO (SnO ₂ and In ₂
O ₃ mixture), transparent conductive oxides such as ZnO, etc. are selectively used. The former is opaque but has low electrical resistance, and the latter is colorless and transparent but has high electrical resistance. As a method for forming or laminating electrodes, thin film forming methods such as vacuum evaporation, reactive evaporation, ion plating, reactive ion plating, sputtering, reactive sputtering, and CVD are generally used. Depending on the case, it may be formed by a thick film method (coating a solution of an organometallic compound such as a metal alcoholate or its oligomer and baking to form a film). In the case of transparent conductive oxides, the appropriate thickness of the electrode is generally 0.01 to 0.5 μm, although it depends on the resistance value, and in the case of metals, 8 × 10 ^-5 to 10 ^-1 mm is appropriate. It is. As the EC layer sandwiched between a pair of electrodes, a reduction colored type or an oxidized colored type EC material is mainly used. As a reduction colored EC material,
Besides inorganic oxides, for example WO ₃ or MoO ₃ it is also possible to use organic materials. Oxidation colored EC
Materials include iridium hydroxide or oxide, nickel, chromium, vanadium,
In addition to inorganic materials such as ruthenium and rhodium, organic materials are also used. The EC layer may be used alone, or may be a double layer of a reduced colored EC layer and an oxidized colored EC layer, or may be combined with an ion conductive layer. The most preferable structure is a three-layer structure consisting of a reduced colored EC layer/ion conductive layer/oxidized colored EC layer (or one that is reversibly electrolytically oxidized although no clear coloring is observed). These EC layers are generally 0.01 to several μm each
formed to a thickness of As a forming method, the above-mentioned thin film forming method is mainly used. Depending on the case, the ion conductive layer that may be provided is
Although it is an insulator for electrons, protons (H ⁺ )
It is a good conductor for hydroxyl ions (OH ^- ). This is provided as necessary in order to give the ECD of the present invention a memory property, that is, the property that the colored state is maintained even after the voltage application is stopped after being colored.The specific material is as follows. Examples include: Inorganic dielectric thin film such as tantalum oxide (Ta ₂
O ₅ ), niobium oxide (Nb ₂ O ₅ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), hafnium oxide (HfO ₂ ), yttrium oxide (Y ₂ O ₃ ), lanthanum oxide (La ₂ O ₃ ) Silicon oxide (SiO ₂ ), magnesium fluoride, zirconium phosphate, or mixtures thereof (these substances are insulators for electrons, but are insulators for protons (H ⁺ ) and hydroxy ions (OH ^- ). is a good conductor.) All solid-state type ECDs, especially thin-film types.
ECD has the advantage that it can be made extremely thin and there is no need to worry about liquid leakage. In that case, it is desirable to choose this inorganic dielectric material as the ion conductive layer; sodium chloride, potassium chloride, bromide. Sodium, potassium bromide, Na ₃ Zr ₂ Si ₂ PO ₁₂ , Na _1+x
Solid electrolyte such as ZrSi _x P _3-x O ₁₂ , Na ₅ YSi ₄ O ₁₂ , RbAg ₄ I ₅ ; water or a synthetic resin containing a proton source, such as β-hydroxyethyl methacrylate and 2-acrylamide-2-methylpropane. Copolymers with sulfonic acid, hydrated vinyl polymers such as hydrated methyl methacrylate copolymers, hydrated polyesters, etc.; Electrolytes such as sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid,
acids such as butyric acid, oxalic acid or their aqueous solutions;
Aqueous solutions of alkalis such as sodium hydroxide, potassium hydroxide, aqueous solutions of solid strong electrolytes such as sodium chloride, lithium chloride, potassium chloride, lithium sulfate; semi-solid gel electrolytes, such as electrolyte aqueous solutions with gelling agents such as polyvinyl alcohol, CMC,
Examples include gelatinized with agar, gelatin, etc. Therefore, the ion conductive layer can be formed using vacuum thin film formation technology,
It is formed by a thick film method, encapsulation, injection, coating, or other means, and the thickness varies from about 0.01 μm to 1 mm depending on the material. Furthermore, depending on the case, an oxidatively colored EC layer, a reversible electrolytically oxidizable layer, or a catalyst layer may be used,
Examples include iridium oxide or hydroxide, nickel, chromium, vanadium,
Examples include ruthenium and rhodium. These substances may be dispersed in other transparent ion conductor layers or transparent electrodes. Hereinafter, the present invention will be explained in detail with reference to Examples. [Example 1] Figure 1A is a schematic plan view of the ECD of this example, Figure 1B is a cross-sectional end view taken in the direction of arrows in Figure 1A, and Figure 2A (plan view) shows the manufacturing process of this ECD. )
and FIG. 2B (an end view taken in the direction of arrows in FIG. 2A). (1) A high-resistance ITO film is formed on a rectangular glass substrate S measuring 10 cm long x 20 cm wide, and then patterned by photoetching to form a preliminary extraction part A for the lower electrode B and the upper electrode extraction part. ₁ (see FIG. 2A 1 and FIG. 2B 1). Instead of patterning by photoetching, mask deposition or other means may be used to obtain the desired pattern from the beginning. Further, after forming an electrode on one surface, patterning may be performed by laser cutting instead of photoetching. (2) Next, an iridium oxide-tin oxide mixed layer D, a tantalum oxide layer E, and a tungsten oxide layer F were laminated in this order (see FIG. 2A 2 and FIG. 2B 2). (3) On top of that, a low resistance Al electrode A is used as the upper electrode.
was formed by mask vapor deposition (see FIG. 2A, FIG. 3, and FIG. 2B, FIG. 3). In this case, a part of the upper electrode A is brought into contact with the already formed pre-extraction part _A1 . The manufacturing method and manufacturing conditions for each layer or film are shown in Table 1 below. (4) In this state, the band-shaped outer edge of the preliminary extraction portion _A1 of the upper electrode and the "〓"-shaped outer edge of the lower electrode B are exposed to a sufficient extent. Next, for the preliminary lead-out part _A1 of the low resistance upper electrode A, the cross section has a "U" shape and the part 1 of the substrate S is
A gutter-shaped conductive clip C _A having a length approximately equivalent to the sides is prepared, and for the high-resistance lower electrode B, the cross section is "U" shaped and each side is connected to each of the remaining parts of the substrate. Prepare a square-shaped conductive clip C _B with a length approximately equivalent to the side, and as shown in Figure 2C,
The clip C _A was attached to the strip-shaped outer edge of the preliminary extraction portion A ₁ , and the clip C _B was attached to the “〓”-shaped outer edge of the lower electrode B, thereby forming the respective extraction portions. This clip has a springy thickness, for example.
A metal with a cross section of 0.05 to 2 mm, such as phosphor bronze, has a “C” shape.
It is made by bending it into a square shape, but it has a much lower electrical resistance than the high-resistance lower electrode. Finally, external wiring L _A and L _B were connected to these clips C _A and C _B , respectively, by soldering or conductive adhesive. The appearance and structure of the ECD obtained in this way are
This is shown in Figure A and Figure 1B. The external wiring connections do not have to be on opposite sides as shown in Figure 1A, but may be placed closest to each other.

[Example 2]

In Example 1, when depositing the Al electrode A as the upper electrode with a mask, the shape of the mask was changed,
The upper Al electrode A, the continuous strip-shaped lead-out part C _A , and the square-shaped lead-out part C _B separated from the upper electrode A - the lead-out part of the lower electrode B made of ITO were formed all at once. . Therefore, the clip used in Example 1 is not used here. The plan view of the ECD obtained in this way is shown in Figure 3A.
A cross-sectional end view is shown in FIG. 3B. [Example 3] In Example 2, when mask-evaporating the Al electrode A as the upper electrode without providing the preliminary extraction part A ₁ -made of ITO for the upper Al electrode A on the substrate in advance, By changing the mask shape, the upper Al electrode A and
A continuous strip-shaped lead-out part C _A and a square-shaped lead-out part C _B separated from the upper electrode A - the lead-out part of the lower electrode B made of ITO were formed at once. Therefore, the clip used in Example 1 is not used here either. A cross-sectional end view of the ECD thus obtained is shown in FIG. The ECDs of these examples are useful as anti-glare mirrors for automobiles because the amount of reflected light can be electrically controlled. [Effects of the invention] As described above, according to the invention, among the pair of electrodes of the ECD, the high resistance electrode is
Since a low-resistance lead-out part is formed in the shape of 〓 along the side, by connecting the external wiring to this lead-out part, charge can be supplied from the external wiring to the high-resistance electrode through the low-resistance lead-out part with a large contact area. carried out,
Therefore, even if the area of the display section is large, the response speed for coloring/decoloring is fast, and uneven coloring/decoloring is less likely to occur.

[Brief explanation of drawings]

FIG. 1A shows an ECD according to Embodiment 1 of the present invention.
FIG. FIG. 1B is a schematic cross-sectional end view of FIG. 1A. FIG. 2A and FIG. 2C are plan views of each step of manufacturing the ECD of Example 1. FIG. 2B is a schematic cross-sectional end view of FIG. 2A. FIG. 3A is a schematic plan view of an ECD according to Example 2 of the present invention. FIG. 3B is a schematic cross-sectional end view of FIG. 3A. Fourth
The figure is a schematic cross-sectional end view of the ECD according to Example 3. All drawings are partially deformed and do not represent accurate dimensional ratios. Explanation of symbols of main parts, A... Upper electrode, A ₁
...Preliminary extraction part of the upper electrode, B...Lower electrode,
C _A ...The lead-out part of the upper electrode or a conductive clip as an example thereof, C _B ...The lead-out part of the lower electrode or a conductive clip as an example thereof, F...The reduction colored EC layer or WO as an example thereof ₃ layers, L _A
...External wiring, L _B ...External wiring.

Claims (1)

[Claims for Utility Model Registration] In an electrochromic device with a large display area formed on a substantially quadrilateral substrate, the lead-out portion of the electrode with high electrical resistance of a pair of electrodes of the device is connected to the substrate. A low resistance electrode material is formed along the three adjacent sides in an approximately square shape, and a low resistance electrode material is formed in a band shape along the remaining side of the substrate to take out the electrode with low electrical resistance. An electrochromic device characterized by having external wiring connected to each part.