JPS5955416A - All solid-state type electrochromic element - Google Patents

Abstract

PURPOSE:To realize coloring with desired coloring density, by composing an electrochromic layer as a cathode-side coloring layer of the mixture of >=2 electrochromic materials having different absorption bands. CONSTITUTION:The 1st electrode 2, electrochromic layer 3 as the cathode-side coloring layer, an insulating layer 4, and the 2nd electrode 5 are laminated successively on a transparent substrate 1. The electrochromic layer 3 is formed by mixing >=2 kinds of electrochromic materials having different absorption bands together. When a voltage is applied between the electrodes 2 and 5, material WO3 changes in color from colorless to blue, Bi2O3 colors in dark brown and TiO2 colors in gray green, so those materials are mixed to realize coloring approximate to black. Thus, the coloring with desired coloring density is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrochromic device that utilizes an electrochemical coloring/decoloring phenomenon, that is, an electrochromic phenomenon.

Electrochromic phenomenon refers to the phenomenon in which substances that are good for redox reactions change color when voltage is applied. Electrochemical quenching dye elements, that is, electrochromic elements that utilize such electrochromic phenomena, can be applied to, for example, numeric display elements, x-y matrix displays, optical shutters, aperture mechanisms, etc., and can be classified according to their materials. Although electrochromic devices can be divided into liquid type and solid type, the present invention particularly relates to all-solid type electrochromic devices.

Two conventional examples of all-solid-state electrochromic devices utilizing electrochromic phenomena are shown in FIGS. 1 and 2.

The electrochromic element shown in FIG. 1 consists of a transparent substrate l, a first electrode 2 made of a transparent conductive film, an electrochromic layer 3 which is a coloring layer on the cathode side, an insulating layer 4 made of a dielectric film, and a conductive layer 4. It is made by sequentially laminating second electrodes 5 made of body membranes.

Furthermore, the electrochromic element shown in FIG.
Between the insulating layer 4 and the second electrode 5 in the structure shown in the figure,
Furthermore, a second electrochromic layer, which is a coloring layer on the anode side,
The second layer 6 is laminated.

In the above structure, the substrate l is generally formed of a glass plate, but it is not limited to a glass plate, and may be any transparent plate such as a plus deck plate or an acrylic plate.
As for its position, it may be provided on the second electrode 5 instead of under the first electrode 2, or it may be provided on both sides depending on the purpose (for example, for the purpose of providing protection or warmth). Good too.

However, in these cases, it is necessary to make the second electrode 5 a transparent conductive film, or to make both electrodes transparent conductive films.

Representative examples of film materials commonly used in the above-mentioned all-solid-state electrochromic device are listed below. t'th
11? , 1k 2 k The transparent conductive film constituting the I
TO film (5n02' in In2'Oq,
c)) and Nesa membrane, etc. The elect J chromic layer 3, which is the coloring layer on the cathode side, is made of tungsten dioxide (
WO2), tungsten trioxide (WO3), molybdenum dioxide (MoO, ), molybdenum trioxide (MOO3)
, vanadium pentoxide (v205), etc. The insulating layer 4, which is a dielectric film, is made of zircon dioxide (Z
r02), silicon oxide (Sin), silicon dioxide (Si
Oxides such as Ta20s), quantal pentoxide (Ta20s), and fluorides such as lithium fluoride (LIF) and magnesium oxide (MgF*) are used. For the second electrode 5, a semitransparent conductive film made of, for example, Au is used. In the one shown in FIG. 2, the second electrochromic layer 6, which is the coloring layer on the anode side, is made of chromium oxide (Cr203), irizoum hydroxide (Ir(
OH)2), nickel hydroxide (Nj(OH)z)
Form using etc.

In the all-solid-state electrochromic device having such a structure, when a voltage is applied between the first electrode 2 and the second electrode 5, an electrochemical reaction occurs, and color is developed or discolored.

It is generally said that this color development mechanism is based on formation of bronze by double injection of cations and electrons into the electrochromic layer 3, for example. For example, when WO3 is used as the electrochromic substance, an oxidation-reduction reaction expressed by the following formula (1) occurs and color is generated.
) According to formula (1), tungsten bronze I (xW0
3 is formed and develops color, but if the applied voltage is reversed at this point, the color disappears. However, the all-solid-state electrochromic device having such a structure has drawbacks such as the inability to obtain a desired coloring density during color development.

An object of the present invention is to improve the drawbacks of conventional electrochromic devices as described above, and to obtain an all-solid-state electrochromic device that can obtain a desired coloring density during color development.

The all-solid-state electrochromic device according to the present invention is characterized by a first electrode made of a conductive film, an electrochromic layer which is a coloring layer on the cathode side, and an insulating film made of a dielectric film, as shown in FIG. An all-solid-state electrochromic device is constructed by sequentially laminating a layer and a second electrode made of a conductive film, or as shown in FIG. Further, in an all-solid-state electrochromic element configured by laminating a second electrochromic layer which is an anode coloring layer, two or more types of electrochromic layers which are a cathode til1 coloring layer each have different absorption and gund. It consists of a mixture of electrochromic substances.

That is, for example, if WO3 alone is used in the electrochromic layer, which is the coloring layer on the cathode side, it will only be colored blue, but if a substance that colors other colors is mixed, a color close to black can be obtained. , high color density can be obtained. In this way, the electrochromic layer is formed using a mixture of several substances with different absorption bands, or the different electrochromic substances are simultaneously deposited. By forming a mixed electrochromic layer, a desired color density of gold can be obtained.

Embodiments of the present invention will be described below. Figure 3 shows
DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in which it is applied to an electrochromic device having the structure shown in FIG. 1 above. This electrochromic device is similar to the one shown in FIG.
Electrode 2, electrochromic layer 3 which is a coloring layer on the cathode side
, an insulating layer 4 made of a dielectric film, and a second electrode 5 made of a conductive film are sequentially laminated, and the electrochromic layer 3, which is a coloring layer on the cathode side, has different absorption bands. It is composed of a mixture of two or more types of electrochromic substances.

For example, the first electrode 2 is ITO, the insulating layer 41d is Ta20
B. The second cable 5 is formed of a semi-transparent Au film.

In addition, the electrochromic layer 3 may be made of, for example, a mixture of WO3 and 20 g of Bi, a mixture of WO3 and TlO2, or a mixture of WO3 and 20 g of Bi.
It is formed by a mixture of 1, TlO2, and v205. The electrochromic substances constituting the electrochromic layer 3 have different absorption bands and are colored in different colors. To explain the examples given here, when voltage is applied, WO31'7j changes color from colorless to evening yellow, Bi2O3 changes color from colorless to blackish brown, and TiO
2 is colored from colorless to gray-green, and 205-C is colored from colorless to gray-green, and by mixing these electrochromic substances, a color close to black can be obtained.

FIG. 4 shows a second embodiment of the present invention applied to an electrochromic element having the structure shown in FIG. 2 above. This electrochromic element includes an insulating layer 4 and a second electrode 5 in the electrochromic element shown in FIG.
A second electrochromic layer 6, which is a coloring layer on the anode side, is further laminated between the two electrochromic layers 3 and 3, and a second electrochromic layer 6, which is a coloring layer on the cathode side, is further laminated. , similarly to the above, each is composed of a mixture of electrochromic substances with different absorption bands.

The mixed electrochromic material layer described above can be formed using a mixed material in which all of these substances are mixed together, or it can be formed by simultaneous vapor deposition of these substances.

Next, examples of the present invention will be described.

Example I A first electrode 2 made of an ITO film having appropriate extraction electrode parts and lead parts was formed on a substrate 1 made of borosilicate glass with a thickness of 0.7 mm, and a vacuum evaporation method was applied thereon. nijt
), WO3+Bi2O3f: mixed (mixing ratio 1:J) The electrochromic layer 3 was formed by full vacuum deposition. The film thickness was 3000X. Next, a Ta205.1 insulating layer 4 with a total thickness of 3000 mm was laminated thereon in the same manner, and a semi-transparent Au conductive film with a thickness of 300 mm was attached as the second electrode 5. An all-solid-state electrochromic device having the structure shown in FIG. 3 was formed. The vapor deposition conditions were a vacuum degree of 2. OX10
Torr, and the deposition rate was JOλ/sec.

When the thus obtained all-solid-state electrochromic element was driven by applying 2.2 V between the first and second electrodes, a coloring density of 0.56 at ΔOD was obtained. I was able to do that. This means that the electrochromic layer of the coloring layer on the tri-electrode side had a density approximately 19 times higher than that of only WO3.

Example 2 Jl? Is it 0.7 mm? 1lll, l silicate glass!
A first electrode 2 made of an ITO film having appropriate extraction electrode parts and lead parts is formed on the substrate 1,
An electrochromic layer 3 was formed thereon by vacuum evaporating a mixture of WO3 and TlO2 (mixing ratio 2:1) using a vacuum evaporation method. The film thickness was 3000X. Next, an insulating layer 4 made of Ta205 with a thickness of 3000X was laminated thereon in the same manner, and a semi-transparent Au conductive film with a thickness of 300X was completely applied as the second electrode 5, as shown in FIG. An all-solid-state electrochromic device with the structure shown below was fabricated. The evaporation conditions were a vacuum level of 2.0 x I O Torr and a evaporation rate of 15i/
It was seconds.

When the thus obtained all-solid-state electrochromic device was driven by applying 2.2μ between the first and second electrodes, a coloring density of ΔOD of 0.50 could be obtained. Ta. This means that the electrochromic layer of the coloring layer on the cathode side had a density approximately 1.7 times higher than that of only WO3.

Example 3 An ITO layer AJ:υ with suitable extraction electrode parts and lead parts on a substrate l made of borosilicate glass with a thickness of 0.7 mm.
A first electrode 2 is formed, and a mixture of WO3tTlO2rv205';C (mixing ratio, 3:1:1) is vacuum-deposited thereon using a vacuum evaporation method to form an electrochromic layer 3. was deposited.

The film was J'f3oooCA. Next, on top of that, an insulating layer 4 made of Ta205 is applied in the same manner.
The all-solid-state electrochromic element having the structure shown in FIG.
For 1° evaporation products, the degree of vacuum is 2. Q X 10'ro
rr, and the deposition rate was C↓15×7×.

In this way, the all-solid-state electrochromic device obtained in (-) was driven by applying 2.2 V between the first and second electrodes.
．． It was possible to obtain 58 colors. This is t, Yin Jt
fi l [ll1 The electrochromic layer of the coloring layer is W
This means that a concentration approximately 1.93 times higher than that obtained using only O3 was obtained.

As explained above, the desired coloring density w (
) An all-solid-state electrochromic device is provided.

[Brief explanation of the drawing]

1 and 2 are structural cross-sectional views showing two examples of conventional all-solid-state electrochromic devices, and FIGS. 3 and 4 are structural cross-sectional views showing two examples of conventional all-solid-state electrochromic devices.
It is a structural cross-sectional view showing the embodiment of the -1 mic element. 1... Substrate, 2... First electrode, 3...
・Electrochromic layer, 4... Insulating layer, 5... Second electrode, 6...
...$2 electrochromic layer. Fig. 1 j Fig. 2 4-/ Fig. 3- Z-/- Fig. 4 Otsu J 4-" 3-no

Claims (1)

[Claims] A first electrode made of a conductive film, an electrochromic layer which is a coloring layer on the cathode side, an insulating layer made of a dielectric film, and a second electrode made of a conductive film are sequentially laminated, or the above insulating layer and the second electrode are laminated in sequence. In an all-solid-state electrochromic device in which a second electrochromic layer, which is a coloring layer on the anode side, is laminated between two electrodes, the electrochromic layer, which is a coloring layer on the cathode side, has two layers each having a different absorption band.
An all-solid-state electrochromic device characterized in that it is made of a mixture of more than one type of electrochromic substance.