JPS63104029A - Electrochromic device - Google Patents

Abstract

PURPOSE:To obtain a low-cost EC device of a large area by vapor-depositing a cobalt phthalocyanine layer on a transparent electrode to form an EC electrode and by holding an electrolyte between the EC electrode and a counter electrode. CONSTITUTION:A prescribed amt. of cobalt phthalocyanine is charged into a boat as a vapor deposition source and a cobalt phthalocyanine layer 3 is vapor-deposited on a glass substrate 1 having an ITO (indium tin oxide) film 2 by a resistance heating method to form an EC electrode. After a resist layer 4 is formed on the layer 3, the EC electrode is combined with a counter electrode 6 of platinum such as a platinum wire and a satd. aq. soln. 5 of potassium chloride as an electrolyte to obtain an EC device. Since the cobalt phthalocyanine layer 3 of a proper thickness is formed on the transparent electrode, the EC device has a polychromatic EC function. The polychromatic EC device can be easily produced at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to electrochromism, which is a phenomenon in which light absorption characteristics change by appropriately controlled voltage application.

[Prior art and its problems]

In recent years, with the remarkable progress of electronics, the role played by display elements has become increasingly important. These display elements are broadly classified into spontaneous light-emitting types such as electroluminescence and non-light-emitting types such as liquid crystal.

Electronics A
sm (hereinafter abbreviated as EC) utilizes an electrochemical reversible coloring/decoloring reaction and belongs to the latter non-luminous type mentioned above.

Many EC materials have been developed to date, and the most representative one is gold pA oxide such as tungsten. It is believed that tungsten oxide is colored by electrochemical reduction and decolored by electrochemical oxidation, and the coloring/decoloring mechanism is generally WO3+ xM + Xe −+ MxWO3 (colorless).
(Blue) It is said to be +. However, here, N1 is a counter ion of the electrolyte, such as H, L+, Na, etc.

In this way, the mechanism of coloring and fading has been elucidated, and while there are metal oxides that are actively being developed for use in display elements, organic EC materials are also being widely studied. organic matter EC
It has been recognized that EC materials are lagging behind the aforementioned metal oxide EC materials in terms of elucidation of the coloring/decoloring mechanism and application to display elements.
], but compared to metal oxides, it is cheaper and easier to make and mold into large-area sheets.

It has the advantage of being easy to process, such as cutting, and can be coated in some cases.

Typical organic EC materials include viologen and phthalocyanine compounds. It is known that viologen changes monochromatically from colorless to blue or violet when the electrolyte is a solution type device.

Furthermore, polypyrrole and polythiophene are examples of electrolytically polymerized films exhibiting the EC phenomenon. These are LiBF4 and LiC
When oxidized in an electrolytic solution such as acetonitrile containing lO4, the film is doped with BF' or C10''4, and the film exhibits conductivity and a color change.

On the other hand, it is known that the electrolyte of phthalocyanine compounds such as rare earth lutetium siphthalodianine (Lu(Pc)z) and erbium ice cream siphthalodianine (ErH(Pc)2) changes color from red to blue. ing.

Usually, EC elements are made of tin oxide (Sn02), which is a transparent electrode.
An EC thin film layer is formed on a transparent conductive film substrate such as indium oxide (In2O3) or indium oxide (In2O3) by a vapor deposition method.
An EC element is composed of an electrode, a counter electrode, and an electrolyte placed between them.

The present inventors focused on alcobalt phthalocyanine, which is a type of phthalocyanine compound, and found that when a thin film layer of cobalt phthalocyanine was formed by controlling the film thickness appropriately using a vapor deposition method, this thin film layer had an EC function. be.

[Purpose of the invention]

An object of the present invention is to provide a large-area, inexpensive EC element using cobalt phthalocyanine.

[Key points of the invention]

This object is achieved according to the invention by providing a cobalt phthalocyanine vapor-deposited layer on a transparent electrode to form an EC@ electrode and placing an electrolyte between this electrode and the counter electrode.

The electrolyte here may be a liquid electrolyte consisting of saturated potassium chloride, for example.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on examples.

A predetermined amount of cobalt phthalocyanine is charged into the evaporation source hoard, and the evaporation source heater is heated to a temperature of 480°C using the resistance heating method!
I TO (Indium
Cobalt phthalocyanine 3 was deposited on a glass substrate 1 to form an EC electrode, and a resist layer 4 was formed thereon. Its configuration is shown in FIG.

The effective area of the electrode is 1 d.

The thickness of the deposited layer 3 of iron phthalocyanine was evaluated by determining the absorption spectrum of visible light and using the peak value of absorbance at a wavelength of 610 nm as a substitute value. FIG. 4 shows the visible absorption spectrum of the deposited film. As is clear from the figure, the absorbance of cobalt phthalocyanine charged in the evaporation source boat is
Although the shape of the absorption spectrum remains the same, both have absorption peaks at a wavelength of 610 nm and a wavelength of 680 nm.

Next, as shown in FIG. 1, an EC element was formed using the ECK electrode obtained above, a platinum counter electrode 6, and a saturated potassium chloride aqueous solution 5 as an electrolyte, and a voltage was applied between the EC electrode and the platinum counter electrode. In addition to measuring the voltage-current characteristics, the coloring/decoloring phenomenon at each predetermined voltage was observed using visible light spectroscopy.

The results are shown in Figure 2. In the same figure, curves d, e, and f are
The applied voltages are -2, 5V, OV, +2, respectively.
．． 5 V O) Show the case.

In FIG. 4, in all the deposited layers having a film thickness of 1.64 and an absorbance of 1.64 at the wavelength f)lQnm, a coloring/decoloring phenomenon was observed when the voltage '1 applied to the electrode was from -2.5V to +2.5V. That is, when the applied voltage is -2.5V, the red color is, and when the applied voltage is QV, the blue color is +2.5.
V showed a yellow polychromatic change.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a cobalt phthalocyanine evaporated N layer with an appropriate thickness on a transparent electrode, an EC composed of this evaporated layer, a counter electrode, and an electrolyte can be used.
This has the effect that the element exhibits a multicolor-changing EC function.

Furthermore, according to the present invention, by using cobalt phthalocyanine, it is possible to use cobalt phthalocyanine rather than rare earth phthalocyanine compounds, which are difficult to obtain or synthesize, and tend to be expensive.
This method has the advantage that an ECX element that changes in multiple colors can be easily produced at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the structure of an EC device according to an embodiment of the present invention, FIG. 2 is a graph showing the visible absorption spectrum of the EC device according to an embodiment of the present invention, and FIG.
1 and fbl are a side view and a plan view, respectively, showing the electrode configuration used in the EC device according to the example of the present invention, and FIG. 4 is a graph showing the visible absorption spectrum of the deposited film of FIG. 3. l...Glass substrate, 2...I'l''0,3...Cobalt phthalocyanine vapor deposited film, 4...Resist, 5...
...Saturated potassium chloride aqueous solution. Lao 1 ward Chestnut 2 ward

Claims (1)

[Claims] 1) An electrochromic electrode obtained by forming a cobalt phthalocyanine vapor-deposited layer on a transparent electrode substrate, a counter electrode of this electrode, and an electrolyte disposed between the electrode and the counter electrode. Characteristic electrochromism element. 2) An electrochromism device according to claim 1, characterized in that it is composed of a liquid electrolyte made of a saturated potassium chloride aqueous solution and a platinum counter electrode inserted into the liquid electrolyte.