JPS6015482A - Preparation of optical color developing element - Google Patents

Abstract

PURPOSE:To prepare the titled optical color developing element which makes writing and erasing possible and produces fine patterns, by forming a color developing layer by sputtering using a target which contains components selected from among W, Mo, etc. and from Li, Na, etc. CONSTITUTION:The optical color developing element is prepd. by forming a color developing layer by sputtering using a target which contains at least one of tungsten, molybudenum, iridium, rhodium and nickel and at least one of lithium, sodium, hydrogen and OH. The film develops color when irradiated with ultraviolet light and the color can be erased by application of thermal energy such as infrared light. Thus an optical color developing element with a simple structure which makes it possible to effect writing and erasing without need of any electrode nor multilayer structure and forms fine patterns in high contrast is obtainable.

Description

[Detailed description of the invention] Industrial applications The present invention is an optical memory that can be written and erased.

The present invention relates to a method of manufacturing an optical coloring element that is effective for display and the like.

Structure of conventional examples and their problems Electrochromic materials are known as oxides of tungsten, molybdenum, 11dium, rhodium, and nickel, which contain light elements (Li+, Na+, etc.).

When ions and electrons (H+, OH) are supplied, acid: l! The valence of the metal changes due to the chemical reaction, and the color develops, and the reverse reaction causes the color to disappear. To explain tungsten oxide in detail as an example, when Li ions and electrons are double-injected I-, tungsten oxide becomes WO3+ xLi'-1-xe-+Li) (WO3
3! It undergoes a slow chemical change, forms tungsten bronze, changes from W6''- on the left side to a mixture of W5''- and W6+ on the right side, and changes from a transparent film to a blue bronze. This coloring is said to be due to absorption of light due to electron transition between W64- and W5+.

Conventionally, the above chemical changes were induced by moving Ham 1''- ions or H+ ions using an electric field and penetrating them into the WOs film. As shown in FIG. 1, the optical coloring element is WO
At least a multilayer structure in which the s membrane 1 and the ion source 2 are sandwiched between the electrodes 3 is required. The same applies to other metal oxide electrochromic elements. In addition, at least one of the electrodes must be transparent, and it is also necessary to take out the lead from the electrode 3, making it difficult to manufacture.
It is difficult to apply this method to an optical memory device or the like which requires a fine structure Φ by using only this as a simple display element. 4 is a substrate.

The present inventors have discovered that an oxide film sputter-deposited using a target metal containing two metals and a light element is well colored by irradiation with ultraviolet light, and irradiated with thermal energy, e.g. infrared light. Based on this discovery, we invented a method for manufacturing optical color elements that can realize fine color patterns and also allow writing and erasing.

OBJECTS OF THE INVENTION 1. The present invention provides a method for producing a one-dimensional or two-dimensional optical coloring element that has a simple structure, can be written and erased, and is capable of realizing a fine pattern that exhibits good contrast and luster in the visible to infrared region. The purpose is to provide.

Structure of the Invention The method for producing an optical coloring element according to the present invention uses tungsten, molybdenum, iridium, and rhodium.

The coloring layer is formed by sputter deposition using target gold containing at least one of nickel and at least one of lithium, sodium, hydrogen, and OH. Oxides containing the above metals and light elements obtained in this way +1! ::4 is irradiated with ultraviolet light (11), and the area develops a good color, and by applying thermal energy (e.g., infrared light) to the coloring area, the color can be effectively erased. , does not require electrodes or multilayer structures,
We were able to realize a fine colored pattern, a good contrast, and an optical color element that can be written and erased.

Description of Examples First, the mechanism of color development and decolorization will be described next. The above metal oxides are ions of light elements.

The valence of the metal atom changes depending on how it bonds with OH-, H'', Li+, Na+, etc., or in other words, whether it shares electrons: a valence with WI+ energy and a valence with low energy. When electronic states with different energy valences exist, absorption of fumeton occurs due to the energy transition between them, which causes color development.

The oxide film containing metal and light element ions in a colorless state is stable in the low energy state. When ultraviolet light is irradiated here, the electronic state of the di-metal atom is excited, and the above-mentioned high-energy state is induced, resulting in color development. In other words, the film develops color upon irradiation with ultraviolet light.

When thermal energy is applied to this color-forming film, ions of the light elements mentioned above become more likely to move within the film and combine with metal atoms in a high-energy state that contribute to color development. In other words, it becomes easier to change to a more energetically stable state, so the high energy state disappears.5. For this reason, the color disappears. That is, the coloring film can be decolored by thermal energy. Regarding this decoloring process, the movement of light elements in the film is important, and if the film is in an amorphous state, the movement of light elements in the film becomes easier.

Sputter deposition is the most suitable method for forming an amorphous film, and it is possible to obtain a uniform, stable film of any width. 4) will be done.

Further, even with a substance having a high subside of 1 point, a film having a composition of 0:0 can be formed depending on the mixture thereof, and an oxide film can be obtained by performing sputtering in an oxygen atmosphere.

2. Mixing of metal regions and light elements 11. By mixing the powders of each element or compound and using it as a target, it is possible to easily obtain a uniform amorphous oxide film with a uniform composition by sputter deposition. I can do it.

The present inventors have discovered that when an oxide (powder or ceramic plate may be used) that is a mixture of the above-mentioned metals and light elements is used as a target, the amorphous sputtered film becomes a uniform amorphous oxide film that is very microscopically uniform. confirmed. In addition, oxides are relatively stable and easy to handle for any metal or light element, making it easier to form a film. The present inventors also confirmed that a sputter-deposited film using a mixed oxide of tungsten and lithium as a target is particularly effective as an optical element.

In other words, the oxide film containing tungsten and lithium is the tungsten bronze LizWO3 (W5 +
+W6+) When q is formed, it is colored blue.

On the other hand, there is also a colorless substance that has the chemical composition of Li2WO4 (W''), and it is thought that once this substance is formed, it will not be colored.The oxide film sputter-deposited using the target layer containing tungsten and lithium is colorless. When this film is irradiated with photo-sound in the ultraviolet region, the electronic state of W is excited, tungsten bronze is formed, and W5+
It is thought that a transition between and W6+ occurs, resulting in coloration.

On the other hand, when irradiated with thermal energy, for example light in the infrared region,
It is thought that the movement of lithium ions causes the arrangement of atoms to change to a more stable one in terms of energy, Li2WO4 is formed, and tungsten becomes stable W6+, decolorizing it. In this decoloring, the presence of lithium is particularly important. When coloring, tungsten oxide without lithium becomes blue when irradiated with ultraviolet light, although the sensitivity is weak; however, when decoloring, tungsten oxide without lithium is exposed to thermal energy, such as heating or red light. It shows no change due to external light irradiation.

The optimum mixing ratio of tungsten and lithium for the sputter target in manufacturing this optical element is 0.1≦L
The discoverers have confirmed that ″/W≦10.L
When i/w<0.1, color development by ultraviolet light is poor, and 1o
<LL/W is popular and difficult to obtain a stable film.

In this case, sputter deposition is performed in an oxygen atmosphere, but by changing the mixing ratio of argon and oxygen in the sputtering gas, it is possible to obtain a film with uniform color development and a film with no color development at all using the same target. be able to. The mixing ratio of argon and oxygen in Rimasys locust gas is set to 0.
2/, r) o, o When the film is 1, a film with no color is obtained, and when sputter-deposited with only Ar, a film with a deep and evenly colored film is obtained. The membrane that has not developed color is
A colored pattern can be formed using ultraviolet light, and this color can be decolored and erased again using thermal energy. In addition, in a film that is colored all the time, a decoloring pattern can be formed using infrared light, and this pattern can be colored again and erased using ultraviolet light. In this manner, sputter deposition can easily produce both positive and negative type optical coloring elements using the same target, and is a very effective manufacturing method.

FIG. 2 shows an optical coloring element according to an embodiment of the present invention. An oxide containing lithium and tungsten at a ratio of 1:1 is placed on a fused silica substrate 4, and an oxygen atmosphere (Ar:0
2′==1:1), and an optical element was obtained as a sputtered oxide film 5 in a colorless amorphous state. In this case, the substrate 4Fi is not limited to fused silica, but may be any material that is stable against sputter deposition. Further, the substrate 4 is not necessarily required as long as the coloring layer can be stably maintained.

When this film 6 is partially irradiated with ultraviolet light 6 (excimer laser) at a wavelength of 249 nmr and a density of about 16 omJ/aj, the film becomes colored and absorbs more than 10 dB of He-Ne laser light at a wavelength of 6328 nm. A colored portion 7 having a large contrast in the visible region was formed. By condensing the above ultraviolet light with a lens and irradiating it, a colored part with a size of 1μ21 or less can be formed,
Writing was possible as a dot-shaped optical memory.

A third
As shown in the figure, infrared light 8 (
By irradiating the area several times with C02 laser) wavelength 106 μm 11 at a density of about tsW/cm, it was possible to erase the surrounding area 9 to the same colorless state ('p) where no writing was performed.

The above has only described an optical element using a sputtered film using all oxide targets, including tungsten and lithium, but lithium may be a light element such as hydrogen or OH; ,
Rhodium or nickel may also be used. In addition, the metals tungsten, molybdenum, iridium, rhodium, and nickel are
They may be used in combination with each other.

FIG. 4 shows an optical coloring element according to a second embodiment of the present invention. When the oxide film 5 is formed in an oxygen-free Ar 2 atmosphere during the sputter deposition, an optical element having a colored amorphous coloring layer 10i as shown in FIG. 4 is obtained. When this was irradiated with infrared light 8 (CO2 laser) similar to that in the first embodiment, the color could be partially erased, and a negative type pattern 11 opposite to the above pattern could be formed.

As described above, the present invention provides tungsten, molybdenum,
At least one of iridium, rhodium, and nickel, and lithium, thorium, and hydrogen.

This is a method of manufacturing an optical element in which a film is formed by sputter deposition using a target containing at least one OH.

The optical element obtained by the manufacturing method according to the present invention can be colored and written with ultraviolet light and completely erased with thermal energy, e.g. infrared light, and is easy to write and erase. It is possible to realize an excellent saw optical element that can realize fine patterns with good contrast in the visible and infrared regions. As described above, the industrial value of the present invention is human.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional electrochromic device, FIG. 2 is a schematic diagram of an optical device according to a first embodiment of the present invention, and FIG.
The figure is an explanatory diagram of erasing in the first embodiment, and FIG. 4 is a schematic explanatory diagram of a negative type optical element according to the second embodiment of the present invention. 4...Substrate, 6...Color forming layer of oxide film containing at least lithium and tungsten, 6...
・Ultraviolet light, 7...Coloring pattern, 8...
・Infrared light.

Claims (3)

[Claims] (1) The coloring layer is formed by sputter deposition using a target containing at least one of tungsten, molybdenum, iridium, rhodium, and nickel, and at least one of lithium, thorium, hydrogen, and OH. A method for producing an optical coloring element. (2) A method for producing an optical coloring element according to claim 1, characterized in that an oxide is used as the target. (3) The method according to claim 2, characterized in that the target is an oxide of tungsten (W) and lithium A (Li) mixed at a mixing ratio Q in the range of 1≦Lvw×1o. A method for producing an optical coloring element.