JPS62177529A - Electrochromic display element - Google Patents

Abstract

PURPOSE:To suppress driving deterioration and self deterioration phenomena by airtightly sealing the constitution of a substrate, an fully solid electrochromic element, an air space and a board. CONSTITUTION:The electrochromic element having the airtightly sealed structure of the substrate the fully solid electrochromic element, the air space, and the substrate is constituted of a glass substrate 1, transparent electrodes 2, 6, an anode color developing layer 3, an insulating layer 4, and a cathode color developing layer 5. In addition, sealing agents 7 consisting of spacers and adhesives, the air space 8 and a glass substrate 9 are also arranged. Non-oxidizing gas such as nitrogen, argon and helium is used as the gas to be charged and sealed in the gas space 8 in addition to air. Although it is rigidly proper to use a semiconductor package airtight sealing material such as melted glass as the sealing agents 7, epoxy resin or the like can be also used. Consequently, driving deterioration or self deterioration can be sharply suppressed and high reliability can be obtained.

Description

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

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 as liquids. The present invention particularly relates to an all-solid-state electrochromic device.

[Prior Art] Figure 1 shows an example of a general structure of an all-solid-state electrochromic device that utilizes electrochromic phenomena. 2. Electrochromic layer which is the anode side coloring layer 3. An insulating layer 4 made of a dielectric film, a second electrochromic layer 5 which is a coloring layer on the cathode side. A second layer made of a conductive film
It is formed by sequentially stacking electrodes 6.

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, and its position is limited to below the first electrode 2. It may be provided first on the second electrode 4, or may be provided on both sides depending on the purpose (for example, for the purpose of serving as a protective cover).

First? Li electrode 2 is made of TTO film (4:5n in In2o3
02) and NESA M (S
It is composed of a transparent conductive film such as n02). If the second electrode 6 is also a transparent electrode, a transparent element can be obtained.

Substances forming the first electrochromic layer 3 with color-forming properties include V2O3, WO2, Cu2O, Nip, and S.
nO.

PbO, Ce2O3, Tie, Ca2O, Ag;+
0. Hg20. Ding b203゜Sin, Tag
, Fed, OsO, Au203. MnO4, Cr
y, CdO.

Examples include Ir2O3, MnO, VO2, GoO, and the like.

Materials forming the insulating layer 4 include titanium oxide, zirconium oxide, hafnium oxide, tantalum pentoxide, silicon dioxide, germanium oxide, chalcogenide glass, sodium chloride, potassium chloride, magnesium fluoride, calcium fluoride, polyvinyl chloride, and polystyrene. , polyvinyl alcohol, polyester, cellulose, and many other materials can be used.

Examples of substances forming the second electrochromic layer 5 having reduction coloring properties include WO3, V2O5, Gap, and MnO3.

5n02. rr02. Nb2O5, VO3, TeO
2, CdO, Cr2CL+.

MnO2, Ta205. CO2O3, Red), Au2
03. Fe2o3゜5b20s, TiO2, CeO2
, 5b203. Examples include AgOtt.

The electrochromic device having such a configuration has electrodes 2.
By applying a voltage between 6 and 6, an electrochemical reaction is induced, resulting in coloring and decoloring.

For example, the oxidation coloring layer 3 is IrOx, and the reduction coloring layer 5 is WO.
IrOx
and WO3 are respectively IrOx+ y)12oad →Ir0x(OH)y+
714”+ ye-WO3+ yH medium+ ye-+
Through the reaction HyW (h (where H20a d indicates adsorbed water contained in the element)), one colored species 1rOx(0)1)y, Hy
It is thought that WO3 is generated and colored, and by reversing the electric field, a reaction opposite to the above equation occurs and the color disappears.

In this coloring/decoloring reaction, the insulating layer 4 acts as a supply source of H20a d and at the same time prevents the reverse reaction due to recombination of colored species, in other words, conducts ions and blocks electrons. .

[Problems to be Solved by the Invention] Conventionally, this type of element has a structure in which it is in direct contact with the outside air, so that the content of the reaction contributing substance (H2O) changes depending on the desorption equilibrium. The reliability of an electrochromic element is determined by changes in the amount of colored species, interface deterioration, and reaction-contributing substances with respect to durability deterioration (pulse drive deterioration) and aging deterioration phenomena. Therefore, the conventional electrochromic device has a problem in that its reliability deteriorates over time. Another problem is that the cathode coloring layer is oxidized by oxygen in the outside air.

The present invention suppresses drive deterioration and neglect phenomena caused by factors such as (1) deterioration of colored species, (2) deterioration of interface, and (3) change in amount of reaction contributing substances, which are the problems of the prior art described above. By doing so, the aim is to significantly improve the reliability of electrochromic devices.

[Means and effects for solving the problems] According to the present invention, an all-solid-state electrochromic device is characterized in that it has a hermetically sealed configuration (substrate-all-solid-state electrochromic element-gas space-substrate). An element is provided.

FIG. 2 shows the configuration of the electrochromic device of the present invention. 1 is a glass substrate, 2 and 6 are transparent electrodes, 3 is an anode coloring layer, 4 is an insulating layer, and 5 is a cathode coloring layer, and the above constitutes a conventional all-solid-state electrochromic device. Furthermore, 7 is a sealant made of a spacer and an adhesive, 8 is a gas space, and 9 is a glass substrate.

As the type of gas to be filled and sealed in the gas space 8, in addition to air, non-oxidizing gases such as nitrogen, argon, and helium are preferably used.

Strictly speaking, a semiconductor package hermetic sealing material such as molten glass is suitable as the sealant 7, but epoxy resin or the like may also be used.

In the present invention, the electrocomic element surrounded by the two glass substrates 1 and 9 and the sealant 7 may be of a conventional type, and any of the materials mentioned above can be used as its material.

[Example] Example 1 In FIG. 2, an ITO film is used as the transparent electrode 2 on the top of the glass substrate 1, an IrO2 film is used as the anode coloring layer 3, a Ta205 film is used as the insulating layer 4, a WCh film is used as the cathode coloring layer 5,
ITO films are sequentially laminated as transparent electrodes 6.

The thickness of both ITO films is 1.000 A, I
Roxna power is 200 A, TazOs film is 3.0
0OA, and the WO2 film was set to 4,000A. This was isolated from the outside air using a spacer, a sealant 7 made of an adhesive, and a glass substrate 9 to produce an electrochromic display element. Note that the gas space 8 was made of air.

Example 2 An electrochromic display element was manufactured in the same manner as in Example 1 except that nitrogen was filled in the gas space 8 as a non-oxidizing gas.

Comparative Example An electrochromic display element as shown in FIG. 1 was manufactured in the same manner as in Example 1, using a glass substrate and a sealing agent for airtight sealing.

The electrochromic device manufactured according to Example 1 has a concentration change ΔOD of 107 cycles.
was 90% or more of the initial value, and neither driving deterioration nor neglecting deterioration was observed. The electrochromic device manufactured according to Example 2 also showed a concentration change Δ after 107 cycles.
The OD was 90% or more of the initial value, and neither driving deterioration nor deterioration due to neglect was observed.

On the other hand, in the comparative electrochromic device which is not hermetically sealed, the concentration changes ΔOD after 105 cycles.
has fallen to 25% of its initial value.

[Effects of the Invention] As described above, the electrochromic display element of the present invention can significantly suppress drive deterioration and storage deterioration and achieve high reliability compared to conventional electrochromic display elements that are not hermetically sealed. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a conventional all-solid-state electrochromic device, and FIG. 2 is a sectional view showing the structure of an all-solid-state electrochromic device according to the present invention. 1 is a glass substrate, 2 is a transparent electrode, 3 is an anode coloring layer, and 4 is an insulating layer. 5 is a cathode coloring layer, 6 is a transparent electrode, 7 is a sealant, 8 is a gas space, 9 is a glass substrate

Claims (2)

[Claims] (1) An all-solid-state electrochromic device characterized by having a hermetically sealed configuration (substrate-all-solid-state electrochromic device-gas space-substrate). (2) The all-solid-state electrochromic device according to claim 1, wherein the gas space is a non-oxidizing gas space.