JP4984064B2 - Light reflection / transmission material, light reflection / transmission device, and light reflection / transmission window - Google Patents

Description

  The present invention relates to a light reflecting / transmitting material that is used in a light transmitting state by being hydrogenated and in a light reflecting state by being dehydrogenated, and that can be switched between a light transmitting state and a light reflecting state. The present invention also relates to a light reflection / transmission device and a light reflection / transmission window using the light reflection / transmission material.

  Conventionally, there is an alloy material containing Mg as a light reflection / transmission material, for example, an alloy composed of Mg and Ni (hereinafter referred to as MgNi alloy) is known (for example, Patent Document 1). The MgNi alloy exhibits a metallic luster, but when it is hydrogenated, it becomes a compound composed of Mg, Ni and H (hereinafter referred to as MgNiH compound), and exhibits light transmittance. Hydrogenation includes a gas chromic method and an electrochromic method. The gas chromic hydrogenation is also performed by blowing hydrogen gas to the MgNi alloy. Electrochromic hydrogenation is performed by applying a voltage to the MgNi alloy film through a proton-containing film containing protons (hydrogen nuclei). Examples of the light reflecting / transmitting material other than MgNi that can be used as the light reflecting / transmitting material include an MgPd alloy (for example, Patent Document 2).

The light reflecting / transmitting material described above can be used for, for example, a window glass of a building or a vehicle, and the light transmitting state in which sunlight incident from the window glass is taken in by hydrogenation and dehydrogenation, and the sunlight incident from the window glass. It is possible to switch between a light reflection state where the light is reflected and blocked.
Japanese Patent Application Laid-Open No. 2003-335553 “Light Control Mirror Glass Using Magnesium / Nickel Alloy Thin Film” JP2007-71547 "Hydrogen sensor using magnesium-palladium alloy thin film" K. Yoshimura et al, Appl.Phys.lett 81 4709 (2002) TJRichardson Appl.Phys.Lett 78 3047 (2001) Y.Song Phys. Rev B69 094205 (2004) (especially FIG. 5 (a), FIG. 5 (b), FIG. 6 (b))

However, the conventional alloy material containing Mg has a light transmittance in a visible light wavelength region of about 45% (in the case of Non-Patent Document 1) in a light transmission state in which hydrogenated hydrogen compounds are obtained, or It is said that it is about 15% (in the case of nonpatent literature 2).
Therefore, a light reflection / transmission material that exhibits higher light transmittance in the visible light wavelength region is desired.

  Therefore, an object of the present invention is to provide a light reflection / transmission material, a light reflection / transmission device, and a light reflection / transmission window that exhibit higher light transmittance in the visible light wavelength region in a light transmission state.

In order to achieve the above object, according to the present invention, a light reflecting / transmitting material that becomes a light transmitting state when hydrogenated and becomes a light reflecting state when dehydrogenated,
A substance having a valence band and a conduction band in a hydrogenated light transmission state, wherein the band gap between the valence band and the conduction band is larger than the photon energy of visible light belonging to a predetermined visible light wavelength region A light reflecting / transmitting material is provided.

  In the above configuration, the light reflection / transmission material has a valence band and a conduction band in a hydrogenated light transmission state, and a band gap between the valence band and the conduction band belongs to a predetermined visible light wavelength region. Since it is made of a material larger than the photon energy of visible light, visible light belonging to a predetermined visible light wavelength region cannot excite electrons from the valence band to the conduction band beyond the band gap. The light reflecting / transmitting material is transmitted without being absorbed. Therefore, visible light belonging to a predetermined visible light wavelength region becomes transmitted light and contributes to light transmittance. Therefore, high visible light transmittance can be realized by using a substance having a large band gap.

  Preferably, the substance is an alloy composed of Mg and Al (hereinafter referred to as MgAl alloy). In this case, the MgAl alloy has a band gap of 3.1 eV in a hydrogenated state, and the wavelength of a photon having an energy of 3.1 eV is about 400 nm. Therefore, a hydrogenated MgAl alloy has a band gap of about 400 nm or less. It is easy to absorb light having a wavelength of less than 400 nm and allows light having a wavelength greater than about 400 nm to pass through. Therefore, the visible light transmittance can be greatly improved. That is, as will be described later, the visible light transmittance of the MgAlH compound is improved by 1.22 times compared to the MgNiH compound having a band gap of 1.9 eV. The hydrogenated MgAl alloy is a compound composed of Mg, Al, and H, and hereinafter referred to as an MgAlH compound.

In the reference example, the substance is an alloy composed of Mg and Cu (hereinafter referred to as MgCu alloy) . In this case, the MgCu alloy has a band gap of 2.2 eV in a hydrogenated state, and the wavelength of a photon having an energy of 2.2 eV is about 563 nm. Therefore, the hydrogenated MgCu alloy has a band gap of about 563 nm or less. It is easy to absorb light having a wavelength of λ and transmits light having a wavelength greater than about 563 nm. Therefore, the visible light transmittance can be improved. That is, as will be described later, the transmittance of visible light is improved 1.05 times in the MgCuH compound as compared with the MgNiH compound having a band gap of 1.9 eV. The hydrogenated MgCu alloy is a compound composed of Mg, Cu, and H, and hereinafter referred to as an MgCuH compound.

In order to achieve the above object, according to the present invention,
A transparent material plate,
A light reflection / transmission material film formed to be supported by the transparent material plate and made of the above-mentioned light reflection / transmission material; and
And a gas supply device that hydrogenates the light-reflecting / transmitting material film to hydrogenate the light-reflecting / transmitting material film to bring the light-reflecting / transmitting material film into a light-transmitting state. A reflective transmission device is provided.

  Thus, by supplying the hydrogenation gas to the light-reflecting / transmitting material film by the gas supply device, the light-reflecting / transmitting material film can be brought into a light-transmitting state, and then the light-reflecting / transmitting material film is exposed to air. By supplying the dehydrogenation gas to the light reflection / transmission material film by the gas supply device, the light reflection / transmission material film can be returned to the light reflection state. Thereby, the light reflection / transmission material film can be switched between the light transmission state and the light reflection state.

In order to achieve the above object, according to the present invention,
A transparent material plate,
A light reflection / transmission material film formed to be supported by the transparent material plate and made of the above-mentioned light reflection / transmission material; and
A proton-containing film formed on the light-reflecting / transmitting material film and containing protons;
The light reflecting / transmitting material film is hydrogenated by applying a voltage to the light reflecting / transmitting material film through the proton containing film with the light reflecting / transmitting material film as the negative electrode side and the proton containing film as the positive electrode side. The light reflecting / transmitting material film is made to be in a light transmitting state by applying a voltage to the light reflecting / transmitting material film through the proton containing film with the light reflecting / transmitting material film as the positive electrode side and the proton containing film as the negative electrode side. There is provided a light reflection / transmission device comprising: a voltage application device that dehydrogenates the film into a light reflection state.

  In this way, by applying a voltage to the light-reflecting / transmitting material film through the proton-containing film with a voltage application device and switching the voltage application direction, the light-reflecting / transmitting material film is changed between the light transmitting state and the light reflecting state. Can be switched between.

  In order to achieve the above object, according to the present invention, there is provided a light reflection / transmission window in which the above-mentioned light reflection / transmission device is attached as a window of a building or a vehicle.

  Thereby, a light reflection / transmission window in which the light reflection / transmission material film can be switched between a light transmission state and a light reflection state can be realized, and in the light transmission state, a high visible light transmittance can be realized as described above.

According to the present invention described above, the visible light transmittance of the light reflecting / transmitting material in the light transmitting state can be improved. Since the light reflecting / transmitting material is an MgAl alloy , the visible light transmittance can be greatly improved .

  The best mode for carrying out the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

The light reflecting / transmitting material according to the embodiment of the present invention is in a light transmitting state by being hydrogenated, and is in a light reflecting state by being dehydrogenated.
For comparison with the prior art, in the case of the MgNi alloy conventionally used as a light reflecting and transmitting material, the band gap between the valence band and the conduction band of the MgNiH compound in which the MgNi alloy is hydrogenated is: 1.9 eV (for example, Non-Patent Document 3). When 1.9 eV is converted to a photon wavelength, it is about 650 nm. Accordingly, light having a wavelength of about 650 nm or less among the light incident on the MgNiH compound can excite valence band electrons to the conductor beyond the band gap, and thus is difficult to pass through the MgNiH compound.

  According to an embodiment of the present invention, a substance that becomes a light transmission state when hydrogenated and becomes a light reflection state when dehydrogenated, and has a band gap of MgNiH compound when hydrogenated. The larger material was used as the light reflecting / transmitting material.

  According to this embodiment, an MgAl alloy can be used as the light reflecting / transmitting material. The MgAl alloy has a band gap of 3.1 eV in the hydrogenated state (that is, in the state of the MgAlH compound) and is about 400 nm when 3.1 eV is converted into a photon wavelength. It easily absorbs light and transmits light having a wavelength greater than about 400 nm. Therefore, by using the MgAl alloy as the light reflecting / transmitting material, the visible light transmittance can be greatly improved as compared with the case of the MgNi alloy.

Instead, in the reference example, an MgCu alloy can be used as the light reflecting / transmitting material. The MgCu alloy has a band gap of 2.2 eV in the hydrogenated state (that is, in the state of the MgCuH compound), and is about 563 nm when 2.2 eV is converted into a photon wavelength. It easily absorbs light and transmits light having a wavelength greater than about 563 nm. Therefore, by using the MgCu alloy as the light reflecting / transmitting material, the visible light transmittance can be improved as compared with the case of the MgNi alloy.

  When MgAl alloy or MgCu alloy was used as the light reflection / transmission material, the light transmittance of the hydrogenated light reflection / transmission material with respect to the amount of light (energy) of sunlight was calculated as follows.

  The light transmittance of the MgNiH compound was used as a standard for calculating the light transmittance.

  FIG. 1 is a transcription of the light transmittance data of the MgNiH compound described in Non-Patent Document 1. That is, FIG. 1 shows the light transmittance of the MgNiH compound for a plurality of values of the light wavelength. In FIG. 1, the square mark indicates the light transmittance data of the Pd film formed on the glass plate, and the triangle mark indicates the Pd film and MgNi alloy film (ie, hydrogenated MgNiH compound) on the glass plate. The data of the light transmittance of what formed these are shown.

FIG. 2 shows the light transmittance data of the MgNiH compound of FIG. 1 in units.
The vertical axis in FIG. 2 is obtained by converting the unit “light transmittance” of the vertical axis in FIG. 1 into a light absorption coefficient α, and applying each light absorption coefficient α to the following indirect band gap equation (1). The obtained value is shown. In equation (1), h is the Planck constant and ν is the frequency.

(H ・ ν ・ α) ^0.5 ... (1)

The horizontal axis of FIG. 2 indicates a value (eV) obtained by converting the unit “light wavelength” of the horizontal axis of FIG. 1 into photon energy hν.

  As shown in FIG. 2, the band gap of the MgNiH compound is estimated to be 1.85 eV by drawing an oblique straight line with respect to the rhombus mark. This 1.85 eV is a value described in Non-Patent Document 3 and close to a band gap of 1.9 eV, and the calculated band gap of Non-Patent Document 3 is a reasonable value.

Based on the data of FIG. 2, the light transmittance of the MgAlH compound and the MgCuH compound is estimated.
Since the band gap of the MgAlH compound is 3.1 eV (for example, Non-Patent Document 3), when the data of the MgAlH compound is estimated based on the data of the MgNiH compound, the triangular mark in FIG. 2 is obtained.
Further, since the band gap of the MgCuH compound is 2.2 eV (for example, Non-Patent Document 3), when the data of the MgCuH compound is estimated based on the data of the MgNiH compound, the square mark in FIG. 2 is obtained.

When the data of FIG. 2 obtained in this way is converted into units of the vertical axis and the horizontal axis of FIG. 1, the data of FIG. 3 is obtained.
That is, in FIG. 3, the vertical axis indicates the light transmittance, and the horizontal axis indicates the light wavelength. In FIG. 3, triangular marks indicate data on MgNiH compounds, diamond marks indicate data on MgCuH compounds, and square marks indicate data on MgAlH compounds. Strictly speaking, a triangular mark indicates that a Pd film and an MgNiH compound film are formed on a glass plate, and a rhombus mark indicates that a Pd film and an MgCuH compound film are formed on a glass plate, and a square mark Shows a Pd film and a MgAlH compound film formed on a glass plate.

In FIG. 3, the data of the solar spectrum indicated by the circle mark is further superimposed.
In FIG. 3, for each wavelength, the transmission value represented by the rhombic curve indicating the MgNiH compound is multiplied by the intensity of the sunlight spectrum, and this multiplication value is expressed in wavelength over the visible light region (250 nm to 750 nm). Integrated. This integrated value is the total transmitted light amount of sunlight in the visible light region (250 nm to 750 nm).
Similarly, for the MgAlH compound and the MgCuH compound, the integrated value, that is, the total transmitted light amount was obtained.
As a result, when the total amount of sunlight transmitted through the MgNiH compound is 1, the total amount of sunlight transmitted through the MgAlH compound is 1.22 (22% increase), and the total amount of sunlight transmitted through the MgCuH compound is 1.05. (Up 5%).
Therefore, by using the MgAl alloy as the light reflecting / transmitting material, the light transmittance with respect to sunlight can be significantly improved (1.22 times) in comparison with the MgNiH compound in a hydrogenated state. Further, by using the MgCu alloy as the light reflecting / transmitting material, the light transmittance with respect to sunlight can be improved (1.05 times) compared with the MgNiH compound in a hydrogenated state.

  Next, a light reflection / transmission device using the above-described light reflection / transmission material will be described.

  A case where hydrogenation of the light reflecting / transmitting material is performed by a gas chromic method will be described.

As shown in FIG. 4, the light reflection / transmission device 10 includes a light reflection / transmission material film 3 and a gas supply device 5. The light reflecting / transmitting material film 3 is formed to be supported by the transparent material plate 9 and made of the above-described MgAl alloy or MgCu alloy. The gas supply device 5 supplies hydrogen-containing gas containing hydrogen to the light reflecting / transmitting material film 3 to hydrogenate the light reflecting / transmitting material film 3 to be in a light transmitting state. On the other hand, by supplying a dehydrogenation gas (for example, oxygen gas), the light reflecting / transmitting material film 3 is dehydrogenated to be in a light reflecting state. Instead of supplying the dehydrogenation gas to the light reflecting / transmitting material film 3, the light reflecting / transmitting material film 3 is exposed to the air directly or via the Pd film 7 described later, so that the light reflecting / transmitting material film 3 is irradiated with light. You may return to a reflective state.
The light reflection / transmission device 10 may include a Pd film 7. A light reflecting / transmitting material film 3 is formed on the transparent material plate 9, and a Pd film 7 made of Pd is formed on the light reflecting / transmitting material film 3. The thickness of the light reflecting / transmitting material film 3 may be 1 nm to 100 nm, and the thickness of the Pd film 7 may be 1 nm to 10 nm. The Pd film 7 has a function of separating hydrogen molecules in the hydrogenation gas into hydrogen atoms. Accordingly, the hydrogen molecules from the gas supply device 5 are decomposed into hydrogen atoms in the Pd film 7 and introduced into the light reflecting / transmitting material film 3, whereby the light reflecting / transmitting material film 3 can be hydrogenated. The transparent material plate 9 may be a transparent glass plate, a plastic plate, or other appropriate material.

The light reflection / transmission device 10 can be applied to a window of a building or a vehicle, for example. In this case, the configuration described in Patent Document 1 can be adopted, and the configuration shown in FIG. In FIG. 5, two transparent material plates 9 are arranged to face each other with a gap therebetween, and the peripheral portions of these transparent material plates 9 are sealed with a seal member 11. On one of the two transparent material plates 9, the light reflection / transmission material film 3 and the Pd film 7 are sequentially laminated as described above. Thereby, a sealed space 13 is formed between the two transparent material plates 9.
The gas supply device 5 supplies the aforementioned hydrogenated gas or dehydrogenated gas to the space 13. When the exhaust port 15 is opened to the outside, hydrogenated gas is supplied from the gas supply device 5 to the space 13, the light reflecting / transmitting material film 3 is in a light transmitting state, and the gas in the space 13 is replaced with hydrogenated gas. The exhaust port 15 is closed with a lid 17.
When the light reflecting / transmitting material film 3 is switched to the light reflecting state, the gas supply device 5 supplies the dehydrogenation gas (for example, oxygen gas) to the space 13 with the lid 17 opened. Thereby, the light reflecting / transmitting material film 3 can be dehydrogenated and switched to the light reflecting state.

  A case where hydrogenation of the light reflecting / transmitting material is performed by an electrochromic method will be described.

  As shown in FIG. 6, the light reflection / transmission device 20 includes a light reflection / transmission material film 3, a proton-containing film 21, and a voltage application device 23. The light reflecting / transmitting material 3 is a film made of the above-described MgAl alloy or MgCu alloy, which is formed so as to be supported by the transparent material plate 25, 26 or 27. The proton-containing film 21 contains protons. The voltage application device 23 applies a voltage to the light reflection / transmission material film 3 through the proton-containing film 21 with the light reflection / transmission material film 3 as the negative electrode side and the proton-containing film 21 as the positive electrode side. By applying a voltage to the light-reflecting / transmitting material film 3 through the proton-containing film 21 with the light-transmitting / transmitting material film 3 as the positive electrode side and the proton-containing film 21 as the negative electrode side, the film 3 is hydrogenated. The light reflecting / transmitting material film 3 is dehydrogenated to a light reflecting state. The transparent material plates 25 and 26 are transparent conductive films (for example, ITO) each having a film thickness of about 10 nm to 2000 nm in the example of FIG. The transparent material plate 27 may be a transparent glass plate, a plastic plate, or other appropriate material.

As shown in FIG. 6, the proton-containing membrane 21 includes a proton accumulation layer 21a, a solid electrolyte layer 21b, and a catalyst layer 21c.
The proton accumulation layer 21a is formed on the transparent conductive film 25 and stores hydrogen atoms used for hydrogenation of the light reflecting / transmitting material film 3 as protons. The proton storage layer 21a may be, for example, a transition metal compound thin film such as a tungsten oxide thin film or a niobium oxide thin film. The proton storage layer 21a may have a thickness of about 500 nm.
The solid electrolyte layer 21b is a layer that is formed on the proton storage layer 21a, is transparent, and has a property that protons can easily move inside. The solid electrolyte layer 21b may be, for example, a tantalum oxide thin film, a zirconium oxide thin film, or another material having the above characteristics. The thickness of the solid electrolyte layer 21b may be about 500 nm.
The catalyst layer 21c is transparent and is formed on the solid electrolyte layer 21b, and has a characteristic of accelerating protons in and out of the solid electrolyte layer 21b and the light reflecting / transmitting material film 3. The catalyst layer 21c may be, for example, palladium, platinum, or another material having the above characteristics. Moreover, the thickness of the catalyst layer 21c may be about 0.5 nm to 10 nm. The catalyst layer 21c also serves to prevent the light reflecting / transmitting material film 3 from coming into direct contact with the solid electrolyte layer 21b. Instead of the catalyst layer 21c, a protective film made of an appropriate transparent material that can transmit protons may be used.
A light reflection / transmission film 3 having a film thickness of about 1 nm to 100 nm is formed on the catalyst layer 21c, and a transparent conductive film 26 having a film thickness of about 10 nm to 2000 nm is formed on the light reflection / transmission film 3. In the example of FIG. 6, the voltage application device 23 applies a voltage to the light reflection / transmission film 3 and the proton-containing film 21 with the transparent conductive films 25 and 26 serving as positive electrodes or negative electrodes, respectively.

When the voltage application device 23 applies a voltage of several volts with the light reflection / transmission material film 3 as the negative electrode side and the proton-containing film 21 as the positive electrode side, positively charged protons pass from the proton accumulation layer 21a through the solid electrolyte layer 21b. It moves to the light reflecting / transmitting material film 3. As a result, the proton accumulation layer 21a becomes transparent, and the light reflecting / transmitting material film 3 is also hydrogenated and becomes transparent (light transmitting state).
Conversely, when the voltage application device 23 applies a voltage of several volts with the light reflection / transmission film 3 as the positive electrode side and the proton-containing film 21 as the negative electrode side, protons pass from the light reflection / transmission material film 3 through the solid electrolyte layer 21b. It moves to the proton accumulation layer 21a. As a result, the proton accumulation layer 21a is colored, and the light reflecting / transmitting material film 3 is also dehydrogenated to be in a light reflecting state.
6 can be applied to a window of a building or a vehicle.

  In the embodiment of the present invention described above, when the light reflecting / transmitting material is an MgAl alloy, the MgAl alloy has a band gap of 3.1 eV in a hydrogenated state, and the wavelength of a photon having an energy of 3.1 eV is Since the thickness is about 400 nm, the hydrogenated MgAl alloy easily absorbs light having a wavelength of about 400 nm or less and transmits light having a wavelength greater than about 400 nm. Therefore, the visible light transmittance can be greatly improved. That is, as described above, the visible light transmittance of the MgAlH compound is improved by 1.22 times compared to the MgNiH compound having a band gap of 1.9 eV.

  When the light reflecting / transmitting material is an MgCu alloy, the MgCu alloy has a band gap of 2.2 eV in a hydrogenated state, and the wavelength of a photon having an energy of 2.2 eV is about 563 nm. The converted MgCu alloy easily absorbs light having a wavelength of about 563 nm or less and transmits light having a wavelength greater than about 563 nm. Therefore, the visible light transmittance can be improved. That is, as described above, the visible light transmittance of the MgCuH compound is improved 1.05 times as compared with the MgNiH compound having a band gap of 1.9 eV.

  In addition, when using the MgAl alloy or the MgCu alloy as the light reflecting / transmitting material, the above-described light reflecting / transmitting device 10 or 20 or the light reflecting / transmitting window is manufactured to switch between the light transmitting state and the light reflecting state. High light transmission can be realized in a light transmission state.

  The light transmittance in the light transmission state can be adjusted by adjusting the supply amount of the hydrogenating gas or by adjusting the voltage value applied to the light reflecting / transmitting material 3 through the proton-containing film 21. You can do it.

The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.
For example, the light reflection / transmission devices 10 and 20 described above may be applied to a screen of a display device, for example, in addition to windows of buildings and vehicles.

The light transmittance data of the MgNiH compound described in the nonpatent literature 1 are shown. The light transmittance data of the MgNiH compound in FIG. 1 is shown together with the light transmittance data of the MgAlH compound and the MgCuH compound by converting the unit. The light transmittance data of the MgNiH compound, the MgAlH compound, and the MgCuH compound are shown superimposed on the data of the sunlight spectrum. The block diagram of the gas-chromic-type light reflective transmission apparatus is shown. The structure at the time of applying the gas-chromic light reflection transmission apparatus to a window is shown. The block diagram of the electrochromic light reflection transmission apparatus is shown.

Explanation of symbols

3 light reflection / transmission material (light reflection / transmission material film), 5 gas supply device, 7 Pd film,
9 transparent material plate, 10 light reflection / transmission device, 11 seal member,
13 space, 15 exhaust port, 17 lid, 20 light reflection / transmission device,
21 proton-containing membrane, 21a proton storage layer, 21b solid electrolyte layer 21c catalyst layer, 23 voltage application device, 25, 26 transparent conductive film (transparent material plate)
27 Glass plates (transparent material plates)

Claims (4)

A light-reflecting and transmitting material used as a material that is made light-transmissive by hydrogenation and light-reflective by dehydrogenation ,
A substance having a valence band and a conduction band in a hydrogenated light transmission state, wherein the band gap between the valence band and the conduction band is larger than the photon energy of visible light belonging to a predetermined visible light wavelength region Become
A light reflecting / transmitting material, wherein the substance is an alloy of Mg and Al . A transparent material plate,
It is formed so as to be supported in the transparent material plate, and a light reflecting transmitting material film made of a light reflecting transparent material according to claim 1,
And a gas supply device that hydrogenates the light-reflecting / transmitting material film to hydrogenate the light-reflecting / transmitting material film to bring the light-reflecting / transmitting material film into a light-transmitting state. Reflective transmission device. A transparent material plate,
It is formed so as to be supported in the transparent material plate, and a light reflecting transmitting material film made of a light reflecting transparent material according to claim 1,
A proton-containing film formed on the light-reflecting / transmitting material film and containing protons;
The light reflecting / transmitting material film is hydrogenated by applying a voltage to the light reflecting / transmitting material film through the proton containing film with the light reflecting / transmitting material film as the negative electrode side and the proton containing film as the positive electrode side. The light reflecting / transmitting material film is made to be in a light transmitting state by applying a voltage to the light reflecting / transmitting material film through the proton containing film with the light reflecting / transmitting material film as the positive electrode side and the proton containing film as the negative electrode side. And a voltage applying device for dehydrogenating the film to bring it into a light reflecting state. 4. A light reflection / transmission window to which the light reflection / transmission device according to claim 2 is attached as a window of a building or a vehicle.

Images