JPH0255342A - electrochromic element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electrochromic element that utilizes an electrochemical coloring/decoloring phenomenon, that is, an electrochromic phenomenon. Regarding chromic elements.

(Prior Art) Electrochromic phenomenon refers to a phenomenon in which a substance is colored or decolored due to an oxidation-reduction reaction when a voltage is applied.

Electrochemical quenching dye elements that utilize such electrochromic phenomena, that is, electrochromic elements, are used, for example, in dimming (anti-glare) mirror variable ND filters, numeric display elements, x-y matrix displays, optical shutters, It is expected to be applied to aperture mechanisms, etc.

As shown in FIG. 1, a conventional electrochromic element generally has a first electrode 2 made of a conductive film on a substrate 1, a first electrochromic layer 3 which is a colored layer on the anode side, and an insulating layer 4 made of a dielectric film. , a second electrochromic layer 5, which is a colored layer on the cathode side, and a second electrode 6 are sequentially laminated.

In order to apply such an electrochromic element to a light control mirror, a reflective layer is required, and this reflective layer has conventionally been used also as the first electrode 2.

In the structure of the conventional electrochromic device described above, the substrate 1 is generally formed of a glass plate;
As long as it is an insulator, it is not limited to a glass plate, and may be a plastic plate such as polystyrene, polycarbonate, or acrylic.

If the first electrode 2 also serves as a reflective layer, a metal such as A1, 8g, or ○ is used for the first electrode 2, and ITO (In203 5n0 inside
2), SnO2, In2
O3 etc. are used.

The first electrochromic layer 3, which is the colored layer on the anode side,
For example, iridium oxide (Ire), nickel oxide (
Nip, ), chromium trioxide (Cr20+), etc., and the dielectric insulating layer 4 is made of tantalum pentoxide (Ta20s), zirconium dioxide (7, r02), etc.
, oxides represented by silicon dioxide (SiO□), lithium fluoride (LiF), magnesium fluoride (Mg
It is formed using a fluoride such as F 2 ).

Further, a second electrochromic layer 5 which is a colored layer on the cathode side
are tungsten trioxide (WO3), tungsten dioxide (WO2), molybdenum dioxide (02), molybdenum trioxide (MOO3), vanadium pentoxide (V2O5).
) etc.

The all-solid-state electrochromic device having the structure described above is one in which an electrochemical reaction occurs in the electrochromic layer and colors or disappears when a voltage is applied between the first electrode 2 and the second electrode 6. It is generally said that the coloring mechanism is, for example, formation of bronze by double injection of cations and electrons into the electrochromic layer 5.

For example, when WOl is used as an electrochromic substance, an oxidation-reduction reaction expressed by the following formula (1) occurs, resulting in coloration.

V403+xll” +xe-z 1lJO3 (1) Tungsten bronze + I, Wo
, is formed and colored, but if the applied voltage is reversed at this point, the color disappears.

In such a reaction expressed by formula (1), in an all-solid-state electrochromic device, protons are supplied by an insulating layer inside the device to cause coloring.

(Problems to be Solved by the Invention) In the conventional method for producing an electrochromic dimming mirror as described above, the electrode 2, which also serves as a reflective layer, is formed in advance on the substrate 1 by a vacuum evaporation method, and then the electrode A metal oxide, which is a colored layer on the anode side, was formed as a first electrochromic layer 3 on top of the electrochromic layer 2 . When this first electrochromic layer 3 is formed by an anodizing method, a metal film to be further anodized is formed on the electrode 2 that also serves as a reflective layer formed in advance,
All of this metal film was anodized to obtain a first electrochromic layer 3 made of metal oxide.

As described above, the conventional technology has the disadvantage that the production process is complicated.

Therefore, it is an object of the present invention to eliminate the drawbacks of the above-mentioned conventional examples and to efficiently produce an electrochromic element suitable as a light control mirror.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention includes a first electrode made of one conductor, a first electrochromic layer which is a colored layer on the anode side, an insulating layer made of a dielectric film, a second electrochromic layer which is a colored layer on the cathode side, and a conductor. In an electrochromic element formed by sequentially laminating a second electrode made of a film, the first electrode is a metal layer, and the first electrochromic layer is an oxide obtained by anodizing the upper part of the metal layer of the first electrode. This is an electrochromic element characterized by the following.

(Function) In the case of the anodic oxidation method, since oxidation gradually progresses from the surface of the metal film to the inside, a metal layer is formed on the substrate as the first electrode, and the upper part of this metal layer is By oxidizing to obtain the first electrochromic layer, the production process can be simplified and an electrochromic element suitable as a light control mirror can be efficiently produced.

(Preferred Embodiments) Next, the present invention will be explained in more detail with reference to preferred embodiments shown in the drawings.

FIG. 1 is a sectional view of a conventional electrochromic device, and FIG. 2 is a sectional view of an electrochromic device of the present invention.

In the present invention, as shown in the second diagram, a metal layer 7 is formed on the surface of the substrate l, having a thickness (7a) for the second electrode and a thickness (7b) for forming the first electrochromic layer 3 by oxidation. The metal layer 7b of the metal layer 7 is oxidized to form the first electrochromic layer 3, and the metal layer 7b is anodized to form the first electrochromic layer 3, and the remaining metal layer 7a is left as the metal. By making one electrode 2 serve as both the electrode 2 and the reflective layer, the first electrochromic layer 3 and the first electrode 2 (reflective layer) can be manufactured by a simple process.

Note that the metal layer 7 formed in the present invention preferably uses a transition metal, so the first electrode 2 is made of a transition metal, and the first electrochromic layer 3 is made of an oxide of the same transition metal as the above-mentioned second electrode 2.

The above is a preferred embodiment of the first electrode and the base metal (metal layer 7) of the first electrochromic layer, which mainly characterizes the present invention. The structures of the second electrochromic layer 5 and the second electrode 6 may be the same as those of the prior art as described above, and are not particularly limited.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Example 1 As shown in Fig. 2, metallic iridium (lr) l was deposited on a glass substrate l to a thickness of 1,300 mm by the subadhering method.
l! 27 was formed into a film. This metal IIS! 7 has a thickness of 1,000 people as the first electrode 7a which also serves as a reflective layer, and 300 people as the part 7b which is later oxidized to form the first electrochromic layer 3, which has a total thickness of 1,300 people. . Only this 300-layer metal iridium film 7b was oxidized by an anodic oxidation method to obtain a second electrochromic layer 3 consisting of an 800-layer iridium oxide (Ire) film.

Furthermore, a Ta205 film 4 was added as an insulating layer to 3,000 J7 layers.
Then, a WO3 film 5 is formed as a second electrochromic layer on top of the WO3 film 5 to a thickness of 4,000 yen by electron beam method, and then an ITO film 6 is formed as a second electrode on top of the WO3 film 5 as a second electrochromic layer.
A film was formed to a thickness of 1,200 mm using the reactive ion blating method, and an electrochromic light control mirror shown in FIG. 2 was created.

When a DC voltage is applied between the first electrode 2 and the second electrode 6 of this element, the first electrochromic layer 3 and the second electrochromic layer 5 are simultaneously colored according to the voltage, and the reflectance decreases, and vice versa. When voltage is applied, it becomes a dimming mirror that disappears and returns to its original state.

According to this embodiment, it is possible to completely omit the process of forming metal films such as AI and heg for forming the electrode 2, which was conventionally necessary, and it is possible to efficiently create a light control mirror.

Example 2 As shown in FIG. 2, a metal nickel (Ni) film 7 with a thickness of 1,000 in total, 800 in 7a and 200 in 7b, was formed on a glass substrate 1 by resistance heating. It was filmed. Only this 7b portion is oxidized by anodic oxidation method to 30%
A first electrochromic layer 3 consisting of nickel oxide (Nip, l) was obtained. Furthermore, as in Example 1, Ta
205 Membrane 4, WO.

1i5 and an ITO film 6 were formed to produce an electrochromic light control mirror shown in FIG.

According to this embodiment, electrodes 2 such as ^l and heg, which were conventionally necessary, are removed.
The process of forming the light control mirror could be completely omitted, and the light control mirror could be manufactured efficiently.

(Effects of the Invention) As explained above, according to the present invention, the first electrochromic layer is obtained by anodizing the upper part of the first electrode that also serves as a reflective layer, so that an electrochromic dimming mirror can be used more efficiently than before. was able to create.

[Brief explanation of the drawing]

Figure 1 shows a conventional all-solid-state electrochromic device.
FIG. 2 is a sectional view showing an example of an all-solid-state electrochromic device according to the present invention. Patent applicant: Canon Co., Ltd. - Figure 1 Figure 2

Claims (2)

[Claims] (1) A first electrode made of a conductive film, a first electrochromic layer that is a colored layer on the anode side, an insulating layer made of a dielectric film, a second electrochromic layer that is a colored layer on the cathode side, and a second electrochromic layer that is a colored layer on the cathode side. In an electrochromic element formed by sequentially laminating two electrodes, the first electrode is a metal layer,
An electrochromic device characterized in that the first electrochromic layer is an oxide obtained by anodizing the upper part of the metal layer of the first electrode. (2) The electrochromic device according to claim 1, wherein the metal of the first electrode is a transition metal, and the first electrochromic layer is an oxide of the same transition metal as the first electrode.