JPS6326635A - Semiconductor containing element - Google Patents

Abstract

PURPOSE:To obtain a new solid thin film element usable to the element using the semiconductor having a photoresponsible property as a base electrode, or the like, by incorporating an electron doner, an electron acceptor and the semiconductor to a base material and by constituting at least one of the electron donor and the electron acceptor from a high molecular metal complex. CONSTITUTION:The titled element comprises the electron donor, the electron acceptor and the semiconductor in the base material. At least one of the electron donor and the electron acceptor is composed of the high molecular metal complex. The electron donor is exemplified by an insoluble mixed valence polynuclear metal complex representative to prussian blue, and a soluble high molecular metal complex which coordinates a transition metal ion having a low valence state such as iron (II) and cobalt (II), etc., with a high mol.wt. substance having a functional group capable of binding with a metal, such as polyvinyl pyridine, etc. While, the electron acceptor is exemplified by an insoluble mixed valence polynuclear metal complex representative to prussian blue and a soluble high molecular metal complex, etc., which coordinates a transition metal ion having a high valence state such as iron (III) and cobalt (III) etc., with a metal coordinatable high molecule.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a semiconductor-containing element containing an electron donor, an electron acceptor, and a semiconductor in a base material, and the present invention relates to a semiconductor-containing element that contains an electron donor, an electron acceptor, and a semiconductor in a base material, and which is used as a light-driven display element or a recording element, for example. It is related to the technical field used as a

[Prior art]

Electrochromic display elements (hereinafter referred to as ECDs) are being actively developed as non-emissive display elements along with liquid crystal display elements (hereinafter referred to as LCDs).LCDs are being put to practical use in wall-mounted TVs, etc. However, while ECDs have better display characteristics than LCDs, such as being easy to see, not dependent on viewing angle, and have good memory, their short lifespans have delayed their practical application. Under these current circumstances, in order to proceed with product development of ECDs as practical devices in the future, it is important to design devices that take advantage of functional characteristics different from those of LCDs. That is, E.C.
Focusing on the display memory properties of D, it can be used as a display element with recording properties rather than a mere display element, for example, for use in bulletin boards for education and conferences, and public displays such as at stations. Furthermore, commercialization as a new type of electrolytic recording element is also considered.

By the way, note! When considering use as an element, recording density or recording freedom becomes an issue, but as long as conventional ECD principles are used, a base electrode is required, so these problems cannot be fundamentally solved. , i.e., ECD
In this case, it was necessary to install a base electrode in a shape corresponding to the character or design to be expressed, and this required extremely complicated wiring for high-density recording and display, which was a major practical obstacle. Therefore, in order to fundamentally solve this problem, the inventors of the present invention considered producing a light-driven ECD.

That is, a device (Ph
otoelectrochromic Device
;hereinafter referred to as PRCD).

The principle of PECD is, for example, J, E Electro
chem.

Sac,, 127.1582-1588. (1980)
has already been reported. According to this report, n-type Zn
P was deposited on the ZnO electrode by photoredox reaction using
bO! Attempts have been made to optical recording methods to form a coating.

Furthermore, J. Electrochea, Soc.
, 127 +333-338, (1980) discloses a method of optical recording by using p-type GaAs and precipitating viologen cation radicals on a GaAs electrode by photoredox reaction.

However, in these conventional methods, the reaction system handled is a reaction in an aqueous solution, and they merely propose the operating principle of PF, CI).

(Problems to be Solved by the Invention) An object of the present invention is to provide a novel solid state thin film element that can be used, for example, in PECD.

[Means for solving problems]

The present invention relates to a semiconductor-containing element containing an electron donor, an electron acceptor, and a semiconductor in a base material, and at least one of the electron donor and the electron acceptor is a polymer metal complex. As a result of repeated efforts to solidify the device into a thin film, the constituent components of the device,
We have now developed a technology to efficiently incorporate this. Hereinafter, each component will be specifically explained, and a technique for incorporating these components into the base material will be described.

Examples of electron donors used in the present invention include insoluble mixed-valent polynuclear metal complexes represented by Prussian blue (hereinafter abbreviated as PB), and metal bonds such as polyvinylpyridine, polyvinylimidazole, polyacrylic acid, and polyvinyl alcohol. High molecular weight substances with possible functional groups (hereinafter referred to as metal coordination polymers) include iron (■), cobal)
(II), nickel (n), lii (1), etc., including soluble polymer metal complexes coordinately bonded with transition metal ions in a low valence state, tris(basophenandroline) iron(n) complexes, Low-molecular metal complexes such as tris(2,2'-bipyridine)iron (TI) Pa form, )lis(phenanthroline)cobalt(II) complex, ferrocene, polycyclic aromatics such as anthracene, acenaphthylene, carbazole, and tetrathiafulvalene compound, polypyrrole,
Conductive polymers obtained by oxidative polymerization such as polythiophene and polyaniline, hydroquinone, pyrogallol,
Reduced quinones such as catechol, organic acids such as tartaric acid, ethylenediaminetetraacetic acid, formic acid, methyl alcohol,
Examples include alcohols such as ethyl alcohol, polyvinyl alcohol, and cellulose, amines such as triphenylamine, butylamine, and triethanolamine, thiol compounds, and tetrahydrofuran.

On the other hand, as electron acceptors, insoluble mixed-valent polynuclear metal complexes represented by PB, iron (■) in metal coordination polymers, etc.
, cobalt (■), nickel (III), in (n)
Including soluble polymer metal complexes that coordinately bond transition metal ions in high valence states, such as methyl viologen,
4 such as heptyl viologen, benzyl viologen, etc.
．． Oxidized quinones such as 4′-bipyridinium salt, 9.10-anthraquinone-2,6-disulfonic acid disodium, 9.10-anthraquinone-1-sodium sulfonate, L3”butyl alloxazine, 1,3-disulfonate, etc. Examples include dodecyl alloxazine, vitamins, benzylnicotinamide, flavin mononucleotide, and tetracyanoquinodimethane.

The semiconductor used in the present invention may be amorphous fine particles or single crystal, and its types range from single semiconductors such as Ge5S1 to m-v group compound semiconductors such as Gaps and InP, and II semiconductors such as CdS and ZnO. - Basically, all semiconductors can be mentioned, such as Group VI compound semiconductors.

When the device of the present invention is used, for example, in a PRCD, it is preferable to solidify the device as a thin film.
It is necessary to efficiently incorporate each component of an electron donor, an electron acceptor, and a semiconductor into a thin film-like substrate. Examples of such a base material include materials such as high molecular weight substances and ceramics, but polymer base materials are preferred because they can easily be made into a large area, are flexible, and are inexpensive. Specific examples of such polymeric base materials include polystyrene,
Examples include polyethylene, polypropylene, polymethyl methacrylate, polytetrafluoroethylene, nylon, polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polyacrylonitrile, polyvinylpyridine, polyvinyl alcohol, poly-p-aminostyrene, Nafion (trademark), etc. can do. In addition, for device manufacturing, it is preferable that the above-mentioned polymer base material is insoluble in solvents such as water, and for this reason, it is desirable that the polymer base material has a crosslinked structure. are copolymers of metal-coordinating polymers such as styrene sulfonic acid, acrylic acid, acrylonitrile, 4-vinylpyridine, and p-7 minostyrene and crosslinkable monomers such as divinylbenzene and methylenebisacrylamide; polyvinyl alcohol; Examples include high molecular weight substances such as polyallylamine and other high molecular weight substances having reactive groups in their side chains, which are crosslinked with crosslinked networks such as geltaraldehyde, cyanuric chloride, and toluene diisocyanate.

A common method for incorporating a semiconductor into a polymer base material is the so-called "casting method", in which a semiconductor is dispersed in a solution of a polymer dissolved in a solvent, then cast, and the solvent is evaporated to dryness. As another method, metal ions are adsorbed in advance into a polymer base material, and the base material is treated with Has, NazsSNa.
Cal such as @5zOa, NazSe, Na@S@Ox,
There is also a method of generating and dispersing a semiconductor in a base material by bringing it into contact with a reducing agent containing a cogen element. This method is particularly useful for chalcogenide compound semiconductors.

When the electron donor or electron acceptor is a low molecular weight substance, it can be dissolved in a solvent, or if it is liquid, it can be left as it is. So, should it be impregnated into the semiconductor-containing base material? ! In the electron donor, the electron acceptor has an ionic group such as a carboxyl group or a quaternary ammonium group, or a reactive group such as an amino group or a water group, and the semiconductor-containing substrate has such an ionic group or If it has a functional group that can be bonded directly or indirectly to a reactive group via some kind of reagent, it can be incorporated by immobilizing the electron donor and/or electron acceptor to the base material with a chemical bond. . When the electron donor and/or electron acceptor is a high molecular weight substance and is soluble in a solvent, it can be immobilized by dissolving it in a solvent and applying it to the surface of the semiconductor-containing substrate and drying it.

When the electron donor and/or electron acceptor is a polymeric metal complex, such as a solvent-insoluble and infusible polynuclear metal complex represented by PH, the semiconductor-containing substrate is coated by a physical method such as a vacuum evaporation method. It is possible to fix it on a surface. Alternatively, a new thin film technology developed by the present inventors (hereinafter referred to as surface complexation method) can be used to stably and efficiently immobilize a polymer metal complex on the surface of a substrate. Can be done.

That is, -catalytic MN(LH)l (wherein, M represents a transition metal ion in an X-valent state, L: is a neutral or a-valent positive 1i-charged ligand, and a and l represents a positive integer including 0) and the general formula M: (L:)s(Lc)m (wherein, M represents a transition metal ion in a heptavalent state). In the expression, L is a ligand with a pentavalent negative charge, itself is a neutral or a ligand with a zero-valent negative charge, b is a negative integer, and C includes O. represents a negative integer, and
m is a positive integer, and n is a positive integer including 0), and an insoluble polynuclear metal complex is formed on the base material by mixing the complex anion in an amount equivalent to neutralizing the charge. be able to. That is, the above-mentioned cations or anions are adsorbed on the base material in advance, and then the base material is adsorbed with a 1σ material having an opposite charge to the ions contained in the base material.
A desired polymeric metal complex can be deposited on the surface of the substrate by immersing it in a solution containing ions. To specifically illustrate the transition metal ions and ligands constituting the various ions used here, M and M are FeR
-1Fe3+, Co'', Co''s N! ”,Ni
As a feed material of 0M, metal ions mainly in the low and high valence states of Group 11 of the periodic table such as ", Ru x +, Ru2-, Os"°, Os" are suitable.
lg, p a CI 3 , Ru Cl 3 , Co
Cl! , Fe50. ,Co(CH,Coo)z,
Examples include metal salts such as F@(N Hi) hCl x. Ll is usually ammonia,
Uncharged neutral ligands such as ethylenedi7mine, diethylenetriamine, bipyridine, phenanthroline, pyridine, and triethanolamine can be used. For example, a positively charged substituent such as a quaternary ammonium group may be bonded to these ligands.
Examples of L include CN-, as well as negatively charged crosslinked ligands such as dimercaptomaleic acid, pyromellitic acid, dithiogizamide (Rubeane #), naphthazarin, and 1,6-cyhydroxyphenazine. be able to. In addition, as Lc, including CN-, 5O
1-1A, 0;, citric acid, iminodiacetic acid, nitrilotriacetic acid, and other negatively charged ligands, or ammonia, water, -carbon oxide, and other ligands that do not have T15iz can be exemplified. .

At this time, Ks (Fe(CN-)i),
T4 (Fa(CN-) &), Kg (Fe(CN-)
)s(H,O), Ka (Ru(CN-)&), Km
(Os(CN-)h], Css (F e (CN-)
), (NH,)t (Fe(CN-)s (Co)), etc. can be used.

Further, as a method for incorporating a conductive polymer such as polypyrrole into a semiconductor-containing base material, the following method can be applied, for example. That is, a semiconductor-containing substrate is sandwiched between two-chamber separate cells, and one cell chamber is filled with a solution of dissolved 7-mer, which is used to synthesize a desired polymer, and the opposite cell chamber is filled with a solution containing the desired polymer. Add a solution containing a monomer polymerization initiator. By doing this, it is possible to form a thin film of the desired sit polymer on the semiconductor-containing film. In order to Gffl the receptor,
A necessary condition is that either the monomer or the polymerization initiator does not penetrate into the base film, or that it is extremely difficult for it to penetrate into the base film.

Therefore, to give a specific example where such a method is applicable, monomers include oxidatively polymerizable compounds such as pyrrole, thiophene, aniline, and thiophenol. Polymerization initiators for such monomers include Na g S 10 @, K t S x O
*, KRuO,, Ks (F@(CN)&), HtP
Compounds such as 2P t Cl 4 and KxlrCli which are ionically dissociated when dissolved in t C1 and have a polymerization active group having a negative charge can be exemplified.

When carrying out a reaction with such a combination, for example, if the semiconductor-containing membrane used as the base material is composed of a cation exchange membrane, the negative charge of the acid membrane and the dissociative group having a negative charge of the polymerization initiator will be combined. Due to the electrostatic anti-t8 force, the rate at which the polymerization initiator permeates into the base film is extremely slow. On the other hand, since the 7-mer molecule is electrically neutral, it permeates into the base film relatively quickly. As a result, polymerization of the monomer occurs only on the side of the cell chamber containing the polymerization initiator, so that the desired conductive polymer can be deposited only on one side of the semiconductor-containing film. The conditions for depositing a conductive polymer in the form of a thin film vary depending on the combination of monomers and polymerization initiator, and also vary depending on the desired film thickness of the conductive polymer, but generally speaking, the monomer concentration is 0. .1
~5 mol/l, polymerization initiator concentration 0.01-1 mol
/l, the reaction time is 1 to 30 minutes, and the temperature is about 4 to 50°C. In the present invention, it is preferred that at least one of the electron donor and the electron acceptor is a polymeric metal complex.

Considering that the semiconductor-containing device of the present invention is used, for example, in PECD, an electron donor, which is a constituent component of the device,
The arrangement of electron acceptors and semiconductors in the substrate becomes important. In other words, in order to efficiently receive and transfer electrons and holes generated when a semiconductor absorbs light to an electron acceptor and an electron donor, the electron donor and electron acceptor must be separated through the semiconductor. need to be. Specifically, it is desirable to immobilize an electron donor and an electron acceptor on opposite faces of a semiconductor-containing substrate, and for this purpose, at least one of the electron donor and electron acceptor must be a high molecular weight substance. In addition, considering the durability, functionality, etc. of the semiconductor-containing element, it is preferable that the high molecular weight substance is a polymer metal complex. The operating principle of the element in this case will be briefly explained. A semiconductor (hereinafter abbreviated as S) contained in the base material and an electron donor (hereinafter abbreviated as D)
and an electron acceptor (hereinafter abbreviated as A) have an energy relationship as shown in Figure 1 (i.e., the redox potential ill of D is more negative than the valence band position (2) of S). Therefore, the redox potential of A (4) is the position of the conduction band of S (3)
(and the redox potential of D is more positive than the redox potential (4)), S is excited by light irradiation, holes are generated in the valence band, and electrons are added to the conduction band. As a result, electrons are injected from D into the valence band of S, and at the same time, electrons excited in the conduction band of S are transferred to A. As a result, electrons move from D to A due to the photoexcitation effect of S, so that D is photo-oxidized and A is photo-reduced. At this time, as D and/or A, a substance M (electrochromic material: hereinafter referred to as EC) that changes color due to oxidation or reduction is used.
PEC material), the semiconductor-containing element is a PEC material.
It can be used as D. By the way, when both D and A are redox agents that undergo reversible oxidation-reduction, the chemical species (D゛) produced when D is oxidized and the chemical species (A-) produced when A is reduced come into contact. If the element structure is such that, according to the teachings of thermodynamics, an influx of electrons from A- to Do (hereinafter referred to as reverse electron transfer) will automatically occur. In the unlikely event that such reverse electron transfer occurs,
As a result, it is as if no chemical reaction occurred, and of course, in such a case, no photoelectrochromism is observed.Therefore, the obtained semiconductor-containing device is
In order to use it for CD, it is important to prevent this reverse electron transfer.

An effective way to prevent reverse electron transfer is to spatially completely separate A and D via S.

Specifically, A and D may be immobilized on opposing surfaces of the base material, for example, by laminating A and D in thin films on the base material, or by laminating A and D' on the base material. It is possible to chemically immobilize the 411S material on the surface of the base material by utilizing bonding forces such as covalent bonds, ionic bonds, and hydrogen bonds between the 411S materials. An effective example of the former method is the surface complexation method described above. That is, according to the above procedure, a polymeric metal complex such as PB can be laminated in a thin film form on both surfaces or one surface of the base film. P.B.
is a polymeric metal complex in a mixed valence state in which Fe'' and Fe'' are three-dimensionally bridged with a CN-bridging ligand.
According to the formula il+ and formula (2), it is reversibly reduced and oxidized: therefore, PB also acts as an electron donor,
With 9, which also acts as an electron acceptor, an element can be manufactured in which PB is laminated on both surfaces of a base material.

For example, if the element is used as a PEC, P
B is reduced and oxidized under light irradiation according to formulas +11 and (2) above, changing color from blue to colorless and from blue to green, respectively. In this case, for example, if CdS is used as the semiconductor and Nafion is used as the base film, the semiconductor-containing base material will act as a bright yellow background, and the contrast will change from dark green to yellow on the reduction side of PB. On the other hand, the oxidized side of PB is visible to the naked eye as a change from dark green to yellowish green, and the contrast is not very good. Therefore, when using PB, it is desirable to use the reduced side as the display surface. It is also possible to precipitate PB only on one side of the substrate, use this as the display surface on the reduction side, and use a different substance It (as a child donor) on the oxidation side.

For example, according to the method described above, polypyrrole (P P y
) is laminated on the surface opposite to PB, and if CdS is used as the semiconductor contained in the base material, by irradiating the 221 surface with light, it is possible to increase the Even better results can be obtained. In this way, device performance can be controlled by the combination of semiconductor, electron donor, and electron acceptor.

Another method for preventing reverse electron transfer is to use an electron donor that is irreversibly oxidized (hereinafter referred to as sacrificial electron donor and abbreviated as D3). In such a case, even if D9 and A-, which are photooxidation and reduction products, come into contact, D cannot return to its original state, so no reverse electron transfer occurs. does not necessarily have to be separated and immobilized on the surface of the base material, but only needs to be contained in the base film. Examples of such sacrificial electron donors include organic acids such as the above-mentioned tartaric acid, ethyl alcohol, etc. Examples include alcohols such as alcohol, amine\thiol compounds, and tetrahydrofuran.

However, in such cases, replenishment of the sacrificial electron donor is required when the device is operated repeatedly.

Furthermore, the reduced or oxidized species A- or D' is
and/or when D becomes insoluble in the water or other solvent used to incorporate it into the base material, A- and/or D'' may precipitate on the surface of the semiconductor particles in the base material under irradiation with light. As a result of preventing contact between D9 and A-, D
Even if and A are not isolated and immobilized in the substrate and are not irreversible reagents, reverse electron transfer may be prevented.

Examples of this include the case where A is a viologen (particularly a derivative in which the alkyl group is highly hydrophobic), and the case where D is a quinone type or a compound.

In order to erase the display, the semiconductor-containing base material is sandwiched between supporting electrodes, the voltage polarity is set so as to cause the reactions D"-D and A--A, and a predetermined potential is applied. good.

〔Effect of the invention〕

PRCD, which is an example of the use of the semiconductor-containing element of the present invention, is
Since it is a light-driven ECD, the degree of freedom in display is significantly increased compared to a normal ECD.

In PRCD, only the light irradiated part can change color, so any pattern can be displayed anywhere on the electrode, which eliminates the need for a base electrode, which is required in a normal ECD, and therefore improves the display. Freedom has been greatly improved. Furthermore, since it is a solid type, it is easy to handle. In addition, since the display can be rewritten, it can also be used as a rewritable optical recording element by using a laser as a display light source and narrowing down the light irradiation area to the order of microns or submicrons.

[Example 1] 50% of Nafion membrane (Nafion 117 manufactured by DuPont)
After being immersed in an mM cadmium acetate aqueous solution for 3 hours, it was washed with water and then immersed in hydrogen sulfide saturated water for 10 hours.

During this time, the transparent Nafion membrane turned yellow, and the precipitation of cadmium sulfide fine particles inside the membrane was observed with the naked eye.
The acid film was placed in a 10mM ferrous chloride aqueous solution under an argon atmosphere.
After being immersed for a period of time, the sample was thoroughly rinsed with water and then immersed again in a 10 mM potassium ferricyanide aqueous solution for 1 minute under an argon stream. At this time, the yellow cadmium sulfide dispersed film turned yellow-green due to the precipitation of Prussian blue on the film surface. The film thus obtained was sandwiched between two glass plates and irradiated with light. A 300 W tungsten lamp was used as a light source, and the light intensity on the sample surface was about 90 rnW/cj. still,
A water tank with a thickness of 5 cs was placed between the light source and the glass plate sandwiching the film to prevent the temperature of the film from increasing due to light irradiation.The film gradually changed from yellow-green to light yellow as it was irradiated with light, and after about 5 minutes, the film disappeared. Almost the entire surface turned pale yellow. By removing the film from the two glass plates and applying a voltage of +1.3 V to the film, the original yellow-green color could be restored, and such color changes were observed repeatedly.

[Example 2] A Nafion membrane containing fine particles of cadmium sulfide prepared in the same manner as in Example 1 was immersed in a 50 mM ferrous chloride aqueous solution for 2 hours under an argon stream.Then, the acid film was thoroughly washed with water, and then soaked again. The membrane was immersed in a 50 mM potassium ferricyanide aqueous solution for 1 minute under an argon stream to precipitate Prussian blue on the membrane surface. At this time, the film changed from yellow to yellow-green. In order to incorporate the sacrificial electron donor into the membrane thus obtained, after immersing the membrane in methyl alcohol for 10 minutes,
It was placed between two glass plates and irradiated with light. 30 as a light source
Using a 0W tungsten lamp, the light intensity on the film surface is approximately 7
It was set to 5 mW/-. As in Example 1, a water tank with a thickness of 5 cm was placed between the light source and the film to prevent the temperature from rising. As the film was irradiated with light, the film gradually changed from yellow-green to yellow.
After a few minutes, almost the entire surface of the membrane turned yellow. By removing this film from the two glass plates and exposing it to air, it was possible to return it to its original yellow-green color. Such color tone changes were repeatedly observed.

[Example 3] A Prussian blue thin film prepared in the same manner as in Example 1 was
In order to contain triethanolamine as an 11-valent electron donor in the layered cadmium sulfide dispersed film, the acid film was adjusted to pH
On 2,8! Triethanolamine/water (1/
After being immersed for 10 minutes in a mixed solution of 9 F (volume ratio), it was sandwiched between two glass plates and irradiated with light.

As in Example 2, a 300W tungsten lamp was used as the light source, and the light intensity was approximately 75mW/-. A water tank with a five-layer thickness was provided between the light source and the membrane to prevent the temperature of the membrane from rising due to light irradiation.

As the film was irradiated with light, the color gradually changed from yellow-green to yellow, and after about 3 minutes, almost the entire surface of the film turned yellow.

By removing this film from the two glass plates and exposing it to air, it was possible to return it to its original yellow-green color.

Such color tone changes were repeatedly observed.

[Example 4] In order to contain tartaric acid as a sacrificial electron donor in a cadmium sulfide-dispersed film laminated with a Prussian blue thin film produced in the same manner as in Example 1, the film was adjusted to pH 2.1 at 50°C.
After being immersed in an mM tartaric acid aqueous solution for 30 minutes, it was sandwiched between two glass plates and irradiated with light.

As in Example 2, a 300W tungsten lamp was used as the light source, and the light intensity was approximately 75mW/-. A water tank with a thickness of 5c11 was placed between the light source and the film to prevent the temperature of the film from increasing due to light irradiation.About 3 minutes after the light irradiation, almost the entire surface of the film changed from yellow-green to yellow. By removing this film from the two glass plates and exposing it to air, it can return to its original yellow-green color, resulting in this color! Eleven changes were repeatedly observed.

[Example 5] Polyacrylonitrile (manufactured by Altrifuchi Co., Ltd., number average molecule M33.000) was dissolved in dimethylformamide at 50°C to prepare a uniform casting solution with a polymer concentration of 13 wt%. This solution was cast onto a glass plate and immediately heated to 10°C.
It was immersed in water to solidify it to a thickness of 150mm. Next, the acid film was sandwiched in the center of a two-chamber separate cell, and about 10 m of a 15mM cadmium acetate aqueous solution was placed on one side of the cell.
1, and the same amount of ion-exchanged distilled water was added to the other side, and hydrogen sulfide was bubbled through it. After about 30 minutes, the porous membrane was colored yellow, and the precipitation of cadmium sulfide fine particles in the membrane was observed with the naked eye. 30 μl of Nafion (trademark: DuPont, 5 wt% water-alcohol solution) was applied and dried by heating at 40°C for 1 hour. After being immersed in a ferrous aqueous solution for 2 hours and then washed with water, it was again immersed in a 10mM potassium ferricyanide aqueous solution for 1 minute under an argon stream.The film changed from yellow to yellow-green as Prussian blue precipitated. After immersing the film in methyl alcohol for 10 minutes, it was sandwiched between two glass plates and irradiated with light in the same manner as in Example 2. As the film was irradiated with light, it gradually changed from yellow-green to yellow, and the color changed to about 1
After o minutes, almost the entire surface of the film turned yellow. This film is 2
By removing it from the glass plate and exposing it to air, we were able to restore it to its original yellow-green color. Such color tone changes were repeatedly observed.

[Example 6] In order to incorporate a reversible electron donor into the cadmium sulfide-dispersed film prepared in Example 1, in which Prussian blue was laminated, it was immersed in a 50 mM hydroquinone aqueous solution (pH 6.3) for 30 minutes under an argon stream. Turned off. After dipping, the layer was sandwiched between two glass plates and irradiated with light in the same manner as in Example 2.

As the film was irradiated with light, the color gradually changed from yellow-green to light yellow, and after about 5 minutes, almost the entire surface of the film changed to 1 yellow. By applying a voltage of +1.3 V to this film, it was possible to return it to its original yellow-green color, and such a color tone change was repeatedly observed.

(Example 7) A Nafion membrane containing cadmium sulfide was produced in the same manner as in Example 1. The layer was sandwiched between two separate cells, and one cell chamber was filled with a purified aqueous pyrrole solution (approximately 0.3M).
was added, and then the atmosphere was replaced with argon. A 0.1 M potassium persulfate aqueous solution was placed in the other cell chamber, and the cell was left for about 4 minutes under an argon stream. Since the base Nafion membrane has an anionic dissociative group (-3O3-), persulfate ions (SzOs"-) used as a polymerization initiator for toro are difficult to penetrate into the base membrane. On the other hand, pyrrole has an anionic dissociative group (-3O3-). Since it is a neutral low molecular weight compound, it diffuses relatively easily within the base membrane.As a result, the pyrrole polymer (polypyrrole) is only present on one surface of the base membrane (potassium persulfate solution side). After thoroughly washing the membrane obtained here, it was sandwiched between two-chamber separate cells again, and a 10mM ferrous chloride aqueous solution was poured into the cell chamber on the opposite side from the polypyrrole deposition surface (black), and the polypyrrole side was separated. In order to balance the pressure, the same amount of distilled water was put into the cell chamber, and both solutions were replaced with argon.After soaking in this way for about 60 minutes, the ferrous chloride aqueous solution was taken out, and a 10mM potassium ferricyanide aqueous solution was added thereto. In this way, it was possible to produce a film in which polypyrrole was layered on one surface of the cadmium sulfide-containing film and Prussian blue was layered on the other surface. After immersing it in a 1M potassium perchlorate aqueous solution for several minutes, it was crimped between two transparent glass electrodes (temporary indium-tin oxide coated glass; surface resistance 10Ω/hole) so that the potential difference between the two terminals became zero. The temperature was adjusted using a potentiometer stand connected to an external circuit.When the surface of the polypyrrole side of the membrane thus installed was irradiated with a 500W xenon lamp, the color of the Prussian blue surface changed from green to yellow after about 40 seconds. In addition, during light irradiation, an ultraviolet and infrared cut filter (Toshiba IRA-25S and Y-43) is placed between the light source and the sample.
A water layer (5 cm thick) was also provided, and the light intensity on the sample surface was adjusted to 100 mW/cd. At this time, changes in the reflection spectrum of the film surface were tracked over time, and 650 nm
Figure 2 is a plot of the change in reflectance of m over time. After light irradiation, when a voltage of approximately 1.0 V was applied to the acid film in the dark, the color of the Prussian blue surface returned from yellow to its original green. By repeating such light irradiation and voltage application alternately, it was possible to perform optical recording and erasing reversibly.

[Brief explanation of the drawing]

FIG. 1 shows a PECD using the semiconductor-containing element of the present invention.
It is a diagram showing the relative relationship of the redonox potentiometers of each component in the system, and shows the operating principle of optical display and recording. A represents an electron acceptor, D represents an electron donor, and S represents a semiconductor, (1) is the redox potential of D, (2) is the valence band of S, (3) is the conduction band of S, and (4) represent the respective energy levels of the redox potential of A. FIG. 2 shows the change over time in the reflectance at 650 nm when a cadmium sulfide-containing Nafion film in which PB and polypyrrole were laminated on different sides was irradiated with light.

Claims (3)

[Claims] (1) A semiconductor-containing element containing (a) an electron donor, (b) an electron acceptor, and (c) a semiconductor in a base material, and at least one of (a) and (b) is a polymer metal complex. (2) The polymeric metal complex has the general formula M_A^X(L_A^
a) Complex cation represented by _l and general formula M_B^Y(
The semiconductor-containing element according to claim (1), which is a polynuclear metal complex formed from a complex anion represented by L_B^b)_m(L_C^c)_n (provided that M_A
^X and M_B^Y represent transition metal ions in X and Y valence states, respectively, and L_A^a is neutral or a
A ligand having a positive valence charge, L_B^b is a ligand having a negative charge of a valence B, and L_C^c represents a ligand having a neutral or negative charge of a valence C. Here, X and Y represent positive integers. a is a positive integer including 0, b is a negative integer, and c is a negative integer including 0. Furthermore, l is a positive integer including 0, m is a positive integer, and n is a positive integer including 0). (3) The complex anion is M_B^Y(CN^-)_b(L_
c^C) (However, M_B^Y and L_c represent the same meanings as above).