JPS60243192A - Electrochromic element - Google Patents

Abstract

PURPOSE:An electrochromic element especially of totally solid type having improved responce speed and life, consisting of a transparent electrode, an electrochromic layer and an insulating layer composed of lanthanum oxide film. CONSTITUTION:For example, the first electrode 2 made of an ITO film provided with a proper drawer electrode part and a leading part is formed on the substrate 1 such as glass, etc. On the electrode, the first electrochromic layer, a coloring layer at the anode side, with 1,000Angstrom thickness, is formed by the use of nickel oxide as a deposition material by reactive high-frequency plating method. Then, on the layer, a lanthanum oxide layer as the electrical insulating material layer 4 with 2,000Angstrom thickness is formed, and, further on the insulating material layer, a transparent electrically-conductive AU film as the second electrode 5 with 300Angstrom thickness is formed, to give the desired electrochromic element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrochromic element that utilizes an electrochemical coloring/decoloring phenomenon, that is, an electrochromic phenomenon.

Electrochemically quenched dye elements, or electrochromic devices, utilize such electrochromic phenomena.
For example, it can be applied to numeric display elements, x-y matrix displays, optical shutters, aperture mechanisms, etc., and can be classified into liquid types and solid types based on their materials. , is related to the element.

[Background of the invention]

Two structural examples of all-solid-state electrochromic devices utilizing electrochromic phenomena are shown in FIGS. 1 and 2. These figures show the general structure of an all-solid-state electrochromic device to which the present invention is applied.

The electrochromic device shown in FIG. 1 consists of a transparent substrate 1, a first electrode 2 made of a transparent conductor film, an electrochromic layer 3 which is a coloring layer on the anode side, an insulating layer 4, and a conductor. It is formed by sequentially stacking second electrodes 5 each consisting of a film. Furthermore, the electrochromic element shown in FIG.
A second electrochromic layer 6, which is a coloring layer on the cathode side, is further laminated between the insulating layer 4 and the second electrode 5 in the structure shown in FIG.

In the above structure, the substrate 1 is generally formed of a glass plate, but it is not limited to a glass plate, and may be any colorless and transparent plate such as a plastic plate or an acrylic plate. It may be provided not under the first electrode 2 but above the second electrode 5, or may be provided on both sides depending on the purpose (for example, for the purpose of serving as a protective cover). 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, a transparent dust element can be created.

The transparent conductive film is an ITO film (indium oxide In2
A film in which tin oxide (SnO□) is doped into O3), a NESA' film, etc. are used. The electrochromic layer 3, which is the coloring layer on the anode side, has conventionally been made of chromium trioxide (Cr205), iridium hydroxide (Ir(0■)2), nickel hydroxide (
N1(OH)2), etc. Conventionally, the insulating layer 4 made of a dielectric material is made of zircon dioxide (Zr02
), tantalum pentoxide (Ta205), silicon oxide (s
5to2), or lithium fluoride (LiF), magnesium fluoride (LiF), etc.
In addition, the electrochromic layer, which is the coloring layer on the cathode side, is made of fluoride such as MgF2), which is made of tungsten oxide (WO, , WO, ).
, molybdenum oxide (MoO□+MoO3), nonadium pentoxide (V2O5), and the like.

In an all-solid-state electrochromic element having such a structure, a p-electrochemical reaction occurs when a voltage is applied between the first electrode 2 and the second electrode 5, and the element is colored or decolored. It is generally said that this coloring mechanism is due to, for example, electrochromic formation of bronze due to double innoequinone of cations and electrons to the layer 6. For example, in the case of using cypress as an electrochromic substance, an oxidation ring reaction represented by the following formula (1) occurs, resulting in coloration.

wo +xH"+xe'""HxWO(1)5 ← 3 According to formula (1), tungsten bronze HxV105
is formed and colored, but if the applied voltage is reversed at this point, the color disappears. In an all-solid-state electrochromic device, such a reaction of formula (1) causes coloration by supplying groton H+ by an insulating layer inside the device.

In the above-mentioned electrochromic element, conventionally, the electrochromic layer 3, which is the coloring layer on the anode side, is formed using a hydroxide such as iridium hydroxide (Ir(OH)z) using a reactive sector or an anodic oxidation film method. It is formed by

[Purpose of the invention]

An object of the present invention is to improve the response speed and life of such electrochromic devices.

[Summary of the invention]

As mentioned above, the insulating layer in the electrochromic element described above has conventionally been formed of oxides such as zirconium dioxide, mental pentoxide, and silicon oxide, or fluorides such as lithium fluoride and magnesium fluoride. As a result of numerous studies, the present inventor has found that by using a lanthanum oxide film as an insulating layer in an electrochromic device, the response speed and life of the device can be improved. Through comparison, they found that the response speed could be doubled and the lifespan could be improved by one order of magnitude, leading to the invention of the present invention.

That is, the electrochromic device according to the present invention is
An electrochromic element comprising a transparent electrode, an electrochromic layer, and an insulating layer, characterized in that the insulating layer is a lanthanum oxide film.

[Embodiments of the invention]

To explain the structure shown in FIGS. 1 and 2, the electrochromic device according to the present invention uses a lanthanum oxide film as the insulating layer 4.

The lanthanum oxide film is formed by a commonly used vacuum evaporation method, using lanthanum oxide (La203) as the evaporation material and storing it in N2 until immediately before evaporation. A reactive high frequency ion blating device is used to manufacture the electrochromic device according to the present invention. An example of a reactive high frequency ion grating device is shown in FIG. 11 in the figure is the main body of the reactive ion derating device;
12 is an electron gun (EB gun), 13 is an umbrella (board holder)
, 14 is a DC bias source that applies DC bias, 1
5 is a high frequency coil (RF coil), 16 is an H20 vapor supply source that supplies H20 vapor, and 17 is a gas that supplies 02 gas? Reference numerals 18 and 19 indicate Neil Palzo, and 20 indicates a substrate (deposited object).

Hereinafter, an embodiment of a method for manufacturing an electrochromic device according to the present invention using the apparatus shown in FIG. 3 will be described.

Example 1 Glass 0.8 m thick (Cornlng 7059
) A first electrode 2 made of an ITO film having suitable extraction electrode portions and lead portions was formed on the substrate 1 of 1.) and placed as shown at 20 in the apparatus shown in FIG. A first electrochromic layer 3, which is a coloring layer on the anode side, was formed on the first electrode 2 by a reactive high frequency ion grating method using NiO as a vapor deposition material. The conditions are that H20 steam is supplied from the H20 steam supply source 16 to 4
Introduce up to X10 Torr and set the deposition rate to 0.6X/s
It was set as ee. The film thickness was 1000X. This electrochromic layer consisted of a hydroxide, Kel (Nx(oH)2).

Next, a lanthanum oxide (La2O3) layer of 2000X was deposited on this film as an insulator layer 4 by vacuum deposition. The degree of vacuum at this time is 2. OX 10”” Torr%
The deposition rate was 2Vsea. Further, on these films, a Wos layer was formed as a second electrochromic layer 6, which is a coloring layer on the cathode side, by a vacuum evaporation method. At this time, the substrate was heated to 110° C. to obtain a film thickness of 4000×.

Further, a 300X semi-transparent conductive AU film was attached thereon as the second electrode 5.

When the all-solid-state electrochromic device manufactured in this way was driven by applying 2.2V between the first and second electrodes, the coloring density reached 0.4 in ΔOD by 2.5V.
It was 0m5ec. Also, the cycle life is 2X10'
This is 92 times compared to the one using Ta205 film as the insulating layer.
0 times better.

Example 2 Glass with thickness 0.8 w+ (Corning 7059
) A first electrode 2 made of an ITO film having appropriate extraction electrode portions and lead portions was formed on the substrate 1, and placed as shown at 20 in the apparatus shown in FIG. A first electrochromic layer 3, which is a coloring layer on the anode side, was formed on the first electrode 2 by a reactive high frequency ion grating method using metal iridium (Ir) as a vapor deposition material.

The conditions are: 4 x 10 0□ from 02 supply source 17
”” Torr, and the deposition rate was set to 0.1 Vse.
It was set as e. The film thickness was 600X.

This electrochromic layer consists of iridium hydroxide (Ir).
(OH)z).

Next, on this film, a layer of lanthanum oxide (La2O5) of 2500X was applied as an insulating layer 4 by a vacuum evaporation method. The degree of vacuum at this time is 2. OX10 Torr.

The deposition rate was 21/see. Further, on these films, a WO layer was formed as a second electrochromic layer 6, which is a coloring layer on the cathode side, by a vacuum evaporation method. At this time, the substrate was heated to 110° C. to obtain a film thickness of 4000×.

Further, a 300X semi-transparent conductive AU film was attached thereon as the second electrode 5.

When the all-solid-state electrochromic device manufactured in this way was driven by applying 1.7V between the first and second electrodes, the coloring density reached 0.3 in ΔOD by 25
It was 0m5ec. Also, the recombination life is 2 x 1
At 0' times, this was 915 times better than the one using Ta205 film as the insulating layer.

Example 3 0.8 m thick glass (Corning 7059
), a first electrode 2 made of an ITO film with appropriate extraction electrode parts and lead parts is formed, and then an oxidized insulating layer 4 is formed on this film by a vacuum evaporation method. 15001 layers of lanthanum (t, a2O,) were applied. The degree of vacuum at this time is 2. OX 10-5 Torr and deposition rate were 2V8ec. Further, on these films, a WO2 layer was formed as a second electrochromic layer 6, which is a coloring layer on the cathode side, by a vacuum evaporation method. At this time, the substrate was heated to 110° C. to obtain a film thickness of 4000×. Furthermore, a semi-transparent conductive AU film with a thickness of 30 mm is applied as the second electrode 5 on top of this.
I gave it 01.

When the all-solid-state electrochromic element manufactured in this way was driven by applying 2.2V between the first and second electrodes, the coloring density reached 0.3 at ΔOD of 40
It was 0m5ec. In addition, the recombination life is 8×lO5
In this case, a Ta205 film is used as the insulating layer and the friend 91
0 times better.

[Brief explanation of drawings]

1 and 2 are cross-sectional views showing two examples of electrochromic devices according to the present invention, and FIG. 3 is a schematic diagram showing a reactive ion grating device used to manufacture the device of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Substrate 2... First electrode 3... Electrochromic layer 4... Insulating layer 5... Second electrode 6... Electrochromic layer 11... Main body of the reactive ion grating device 12
...Electron gun (EB gun) 13...Umbrella (substrate holder) 14...DC bias source 15...High frequency coil (Rt coil) 16...H2
0 Steam supply source 17...0□IS? Npe18.19・
...Needle pulp 20...Substrate (deposited object).

Claims (1)

[Claims] An electrochromic device comprising a transparent electrode, an electrochromic layer, and an insulating layer, characterized in that the insulating layer is a lanthanum oxide film.