JPS61103982A - Electrochromic element - Google Patents

Abstract

PURPOSE:In an electrochromic element having a specific structure, an electrochromic structure useful as a figure display element, etc., having improved response speed and life, using a laminate of a ZrO2 thin film and a La2O5 thin film as an electrical insulating layer. CONSTITUTION:An electrical insulating layer consists of a dielectric material film obtained by laminating the first electrode 2 comprising an electrically- conductive film (e.g., ITO film, etc.), the electrochromic layer [e.g., Ir(OH)2 film, etc.] 3 as a coloring layer at the anode side by reactive high-frequency sputtering method, the ZrO2 thin film (preferably 1,000-4,000Angstrom ) 4a by vacuum deposition method, and the La2O3 thin film (preferably 10-1,000Angstrom thickness) 4b to the transparent substrate 1. The electrical insulating layer, and the second electrochromic layer (e.g., WO3 film, etc.) 6 as a coloring layer at the cathode side are laminated successively to the second electrode (e.g., semitransparent Au electrode) 5 comprising an electrically-conductive membrane, to give the aimed electrochromic element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrochromic device that utilizes electrochemical color development/decolorization phenomenon, that is, electrochromic phenomenon.

Electrochemically quenched dye elements, or electrochromic devices, utilize such electrochromic phenomena.
For example, numeric display elements, x-y matrix displays, optical shutters, apertures, etc. 74f+! It can be applied to structures, etc., and can be classified into liquid type and solid type, depending on the material, but the present invention particularly relates to an all-solid type electrochromic element.

[Background of the invention]

Two structural examples of an electrochromic element utilizing the electrochromic phenomenon are shown in Fig. 2 and Fig. 3. These figures are electrochromic.

This figure shows the general structure of the element.

The electrochromic element shown in FIG. 2 consists of an upper surface of a transparent substrate 1, a first electrode 2 made of a transparent conductive film, an electrochromic layer 3 which is a coloring layer on the anode side, an electric conductor 714 made of a dielectric film, and a first electrode 2 made of a transparent conductive film. The second electrode 5 made of a film is sequentially laminated.

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 cathode side,
The second layer 6 is laminated.

In the above structure, the substrate 1 is generally formed of a glass plate, but it is not limited to a glass plate, but can also be made of plastic,
Any colorless and transparent plate such as a mirror plate or an acrylic plate may be used, and its position may be above the second electrode 5 instead of under the first electrode 2, depending on the purpose (e.g. , for the purpose of serving as a protective cover, etc.) may be provided on both sides. However, depending on these cases, it is necessary to make the second electrode 5 a transparent conductive film or to make both the electrodes on both sides transparent conductive films. If both electrodes are transparent electrodes, a transparent element can be created. The insulating layer 4 may be made of not only a dielectric but also a solid electrolyte or the like.

The transparent conductive film is an ITO film (indium oxide In2
A film containing 8nO□ of tin oxide) is used. The electrochromic layer 3, which is the coloring layer on the anode side, has conventionally been made of chromium dioxide (CrzOρ, iridium hydroxide (Ir(OH)2), dihydroxide, Kel (
It is formed from Nl(OH)2) and the like. The insulating layer 4 made of dielectric material is made of zirco dioxide (ZrO□), tantalum pentoxide (T12O3), silicon oxide (sto,
sto□), or 7. It is formed using a 7 compound represented by lithium oxide (LIF), magnesium heptadide (MgF2), etc. Furthermore, the electrochromic layer 6, which is the coloring layer on the cathode side, is made of tungsten oxide x ten (WO2J WO5), moly oxide: "f/
(MeO2lMo0= ), panadicum pentoxide (v
2O3), etc., and has a structure such as
By applying a voltage between the first electrode 2 and the second electrode 5, a vapor chemical reaction occurs in the stain, causing coloring and decoloring. It is generally said that this coloring mechanism is based on the formation of bronze due to the injection of cations and electrons into the electrochromic layer 6, for example. For example, when using wOs as an electrochromic substance, the following (
1) An oxidation-reduction reaction expressed by the formula occurs and coloration occurs.

5 + xH" + x・-=H darkness, (1) According to (1) 2, tungsten bronze Hx is formed and colored, but if the applied voltage is reversed here, it will be in a decolorized state. (1 ) In the elm chromi element, protons H+ are supplied by the insulating layer inside the element and the element is colored.

[Problem that the invention seeks to solve]

Such electrochromic devices still have problems in terms of response speed and lifespan.

The insulating layer used in conventional electronic devices has poor insulation properties, which causes charge to escape, resulting in poor response speed and memory performance.

In addition, even if the insulating layer had good insulation properties, it had poor ionic conductivity and the response speed was not good (electrochromic does not change color by giving or receiving electrons, but rather ions (mainly KH)
+) for color development/discoloration).

[Purpose of the invention]

The present invention aims to provide such an electrochromic element that has better response speed and longer life than conventional electrochromic elements.

[Summary of the invention]

The 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 anode side, an insulating layer made of a dielectric, and a coloring layer on the cathode side. In an electrochromic device in which a second electrochromic layer and a second electrode made of a conductive film are sequentially laminated, the insulating layer is a two-layer laminated dust layer, and the two layers are a ZrO2 layer and a LjL20.2 layer. The reason lies in the fact that it is made up of layers.

〔Effect of the invention〕

ZrO□ film has a strong odor when used as the so-called insulating layer (which can also be considered as a solid electrolyte) of an electric cylindrical ROMI element, but its electron blocking performance is lower than that of La2O3 film, and furthermore, when used as a single film alone, Stability (life) is also poor. On the other hand, the La2O3 film is manufactured by Electronic Professional.

King's performance is good, but its ionic conductivity is poor, and when used as a single film, it deteriorates the characteristics of electrolumic devices.

The electrochromic device according to the present invention has the above-mentioned Zr
02M and I, a20. By constructing the insulating layer, which is a laminate of films, the above-mentioned drawbacks of these films can be compensated for, and the performance that could not be achieved with each single film alone can be demonstrated by stacking them, making it possible to improve performance compared to conventional films. This also provides a far superior electrochromic device.

[Embodiments of the invention]

An embodiment of the electrochromic device according to the present invention is shown in I
It is shown in Figure Jc1. Since the basic structure of this electrochromic device is the same as that shown in FIG. 3, the same parts as shown in FIG. 3 are designated by the same reference numerals.

In the illustrated embodiment, l is a transparent substrate, 2 is a tIcl electrode made of a transparent conductor, 3 is a first electrochromic layer which is a coloring layer on the anode side, and 6 is a second electrochromic layer which is a coloring layer on the cathode side. The second electrode is composed of an electrochromic layer and 5 is a conductive film.

The insulating layer disposed between the first and second electronic layers 3 and 6 is constituted by a laminate of a ZR02 film 4a and a 2O3 film 4b.

Note that the first electrochromic layer 3 and the second electrochromic layer 6 may be reversed.

In addition, the insulating layer made by laminating Zr0z film and La2O3 film is
Preferably, the ZrO2 film side is in contact with the coloring layer on the cathode side. Also, the thickness of each film is 10
00~4000! SLa2o3M is 100-1000
Preferably between i.

Example 1 On a transparent substrate 1, an electrode 2 made of tTogI was formed, having appropriate extraction electrode parts and lead parts. H2
, gas with a ratio of 1=2 to 0□ gas is introduced, and under a pressure of 4 Torr, the metal! Ir(
OH)25I 500 layers are formed, and then an insulating layer 41,
As 4b, 3 g of Lazo5 was added by vacuum evaporation method.
001 and Zr0z films to 25001 (t,
&2o, j ZrO2 was used as the vapor deposition material).

The second electrochromic Ffl is a color forming layer on the cathode side.
6, a film was formed at 4000×, and a semi-transparent BAAu electrode was attached as a second electrode 5 on top of these films.

The electrochromic device formed in this way has two
．． When driven at a constant voltage of 0V, the response speed until ΔO, D0.3 is 160 m5ec, and the lifespan is up to 10' times K.
Significant improvements were seen in response speed and lifespan.

[Brief explanation of the drawing]

Figure gX1 is a black-and-white diagram showing an embodiment of the electrochromic element according to the present invention, and Figures 2 and 3 are cross-sectional views showing the general structure of the electrochromic element. l...Substrate 2-aE 1 electrode 3...
Electrochromic layer 4...Insulating layer 4at4b...Insulating layer 5.
-・tlc2 electrode

Claims (1)

[Claims] A first electrode made of a conductive film, an electrochromic layer which is an anode side coloring layer, an insulating layer made of a dielectric film, a second electrochromic layer which is a cathode side coloring layer, and a second electrochromic layer made of a conductive film. An electrochromic device comprising two electrodes laminated in sequence, characterized in that the insulating layer is a lamination of a ZrO_2 thin film and a La_2O_3 thin film.