JP2021027078A - Photoelectric conversion element, electronic apparatus, and power supply module - Google Patents

Abstract

To provide a photoelectric conversion element that can prevent a reduction in output in low-intensity light after high-temperature storage.SOLUTION: A photoelectric conversion element 101 has a first electrode 2 on a first substrate 1, has an electron transport layer 4 on the first electrode 2, has a photosensitization compound 5 on a surface of an electron transport material that form the electron transport layer 4, and has a hole transport layer 6 in an upper part and inside of the electron transport layer 4. The hole transport layer 6 contains a specific cyclic alkali metal salt compound having a large molecular size and a specific basic compound having a low fluidity even under a high temperature environment.SELECTED DRAWING: Figure 1

Description

The present invention relates to photoelectric conversion elements, electronic devices, and power supply modules.

In recent years, much attention has been paid to solar cells as photoelectric conversion elements that can efficiently generate electricity even with low-illuminance light. Such solar cells are expected to be widely applied as a self-supporting power source that does not require battery replacement or power supply wiring, as well as regardless of the installation location.

Amorphous silicon and organic solar cells are known as photoelectric conversion elements for indoor use, for example. Among the organic solar cells, the dye-sensitized solar cell can be easily manufactured because it is composed of layers in which the charge generation function and the charge transport function are separated. In general, dye-sensitized solar cells may have problems such as volatilization and leakage of the liquid because they contain an electrolytic solution, but in recent years, solid-type dye-sensitized solar cells using a P-type semiconductor material have been used. Has been proposed (see, for example, Patent Document 1).

Further, a photoelectric conversion element capable of suppressing a voltage drop and obtaining a high output even in a high temperature environment or a weak room light environment has been proposed (see, for example, Patent Document 2).

An object of the present invention is to provide a photoelectric conversion element capable of suppressing a decrease in output with low illuminance light after storage at a high temperature.

The photoelectric conversion element of the present invention as a means for solving the above-mentioned problems has a cyclic alkali metal salt compound represented by at least one of the following general formulas (1a) and (1b) and the following general formula (2). It has a hole transport layer containing the basic compound represented.
... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent.

According to the present invention, it is possible to provide a photoelectric conversion element capable of suppressing a decrease in output with low illuminance light after storage at a high temperature.

FIG. 1 is a schematic view showing an example of a photoelectric conversion element of the present invention. FIG. 2 is a schematic view showing another example of the photoelectric conversion element of the present invention. FIG. 3 is a schematic view showing another example of the photoelectric conversion element of the present invention. FIG. 4 is a schematic view showing another example of the photoelectric conversion element of the present invention. FIG. 5 is a schematic view showing an example of the photoelectric conversion element module of the present invention. FIG. 6 is a schematic view showing another example of the photoelectric conversion element module of the present invention. FIG. 7 is a schematic view showing an example in which a mouse is used as an electronic device. FIG. 8 is a schematic view showing an example in which a photoelectric conversion element is mounted on a mouse. FIG. 9 is a schematic view showing an example of using a keyboard used in a personal computer as an electronic device. FIG. 10 is a schematic view showing an example in which a photoelectric conversion element is mounted on a keyboard. FIG. 11 is a schematic view showing an example in which a small photoelectric conversion element is mounted on a part of the keys of the keyboard. FIG. 12 is a schematic view showing an example of using a sensor as an electronic device. FIG. 13 is a schematic view showing an example of using a turntable as an electronic device. FIG. 14 shows an example of an electronic device in which the photoelectric conversion element and / or the photoelectric conversion element module of the present invention is combined with a device that operates by the electric power generated by the photoelectric conversion element and / or the photoelectric conversion element module. It is a schematic diagram which shows. FIG. 15 is a schematic view showing an example in which a power supply IC for a photoelectric conversion element is incorporated between a photoelectric conversion element and a circuit of an apparatus in FIG. FIG. 16 is a schematic view showing an example in which the power storage device is incorporated between the power supply IC and the circuit of the device in FIG. FIG. 17 is a schematic view showing an example of a power supply module having a photoelectric conversion element and / or a photoelectric conversion element module of the present invention and a power supply IC. FIG. 18 is a schematic view showing an example of a power supply module in which a power storage device is added to the power supply IC in FIG.

As a result of diligent studies, the present inventors have found the following.
When a solid dye-sensitized solar cell is exposed to a high temperature environment, the morphology (structure) of the hole transport layer may change. Therefore, in order to suppress the voltage drop, it is necessary that the mixed state of the hole transport layer material, the basic material, the alkali metal salt, and the oxidizing agent in the hole transport layer is stabilized.
In particular, it is considered that the morphology of a basic material having a relatively low melting point is likely to change due to fluidization or the like. Further, the conventional lithium bis (trifluoromethanesulfonyl) imide has a small molecular size and is easily localized in the hole transport layer. However, the alkali metal salt in the present invention has a cyclic structure and has a large molecular size. Therefore, it was found that stable morphology can be obtained even in a high temperature environment and that it has higher heat resistance.

(Photoelectric conversion element)
The photoelectric conversion element of the present invention contains a cyclic alkali metal salt compound represented by at least one of the following general formulas (1a) and (1b) and a basic compound represented by the following general formula (2). It has a hole transport layer, a first substrate, a second substrate, a first electrode, a second electrode, a hole blocking layer, and an electron transport layer, and if necessary, a sealing member, It has other members.
... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent.

<Hall transport layer>
The hole transport layer contains a cyclic alkali metal salt compound and a basic compound, contains a hole transport material, and further contains other components as needed.

<< Cyclic alkali metal salt compound >>
The cyclic alkali metal salt compound is represented by any of the following general formulas (1a) and (1b).

... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.

... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.

Further, the cyclic alkali metal salt compound represented by the general formula (1a) is represented by the following general formula (3a), and the cyclic alkali metal salt compound represented by the general formula (1b) is represented by the following general formula (3b). ) Is preferable.
... General formula (3a)
However, in the general formula (3a), M represents lithium, sodium, potassium, or cesium, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent. ..
... General formula (3b)
However, in the general formula (3b), M represents an organic cation, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent.

When the hole transport layer contains the alkali metal salt, the output can be improved, and the light irradiation resistance and the high temperature storage resistance can be further improved.

Specific examples of the cyclic alkali metal salt compound represented by the general formula (1a) include, but are limited to, the following exemplified compounds (C-1) to (C-72). It's not a thing. These may be used alone or in combination of two or more.

Specific examples of the cyclic alkali metal salt compound represented by the general formula (1b) include, but are limited to, the following exemplified compounds (C-73) to (C-86). It's not a thing. These may be used alone or in combination of two or more.

The content of the alkali metal salt is preferably 5 mol% or more and 50 mol% or less, more preferably 20 mol% or more and 35 mol% or less, based on the hole transport material.

<< Basic compound >>
The basic compound is represented by the following general formula (2).

・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent.

Examples of the aryl group which may have the substituent include a phenyl group, a naphthyl group, a biphenyl group and the like. Examples of the substituent contained in the aryl group include an alkyl group and an alkoxy group.

When the hole transport layer contains the basic compound represented by the general formula (2), it is advantageous in that the output stability of the photoelectric conversion element is enhanced. In particular, it is also advantageous in that it is possible to reduce variations in output characteristics with respect to low-illuminance light and generate stable power.

Specific examples of the basic compound represented by the general formula (2) include, but are limited to, the following exemplified compounds (H-1) to (H-8). is not it. These may be used alone or in combination of two or more.

The content of the basic compound represented by the general formula (2) in the hole transport layer is preferably 20 mol% or more and 65 mol% or less, and 35 mol% or more and 50 mol, based on the hole transport material. More preferably, it is less than%. When the content of the basic compound is in a preferable range, a high open circuit voltage can be maintained, a high output can be obtained, and high stability and durability can be obtained even when used for a long period of time in various environments.

The hole transport layer has a hole transport material in order to obtain a function of transporting holes.

<< Hall transportation materials >>
The hole transporting material is not particularly limited as long as it can exhibit the function of transporting holes, and can be appropriately selected depending on the intended purpose. For example, an electrolytic solution in which a redox pair is dissolved in an organic solvent, redox Examples thereof include a gel electrolyte in which a liquid obtained by dissolving a pair in an organic solvent is impregnated in a polymer matrix, a molten salt containing a redox pair, a solid electrolyte, an inorganic hole transport material, an organic hole transport material, and a P-type semiconductor material. Among these, an electrolytic solution or a gel electrolyte can be used, but a solid electrolyte is preferable, and an organic hole transport material is more preferable.

Examples of the organic hole transport material include an oxadiazole compound, a triphenylmethane compound, a pyrazoline compound, a hydrazone compound, an oxadiazole compound, a tetraarylbenzidine compound, a stillben compound, and a spiro-type compound. Of these, spiro-type compounds are preferable.

Examples of the spiro-type compound include compounds containing the following general formula (7).

・ ・ ・ General formula (7)
However, in the general formula (7), R _{31 to} R ₃₄ may be the same or different from each other, and represent a substituted amino group such as a dimethylamino group, a diphenylamino group, or a naphthyl-4-tolylamino group. ..

Specific examples of the spiro-type compound represented by the general formula (7) include, but are limited to, the following exemplified compounds (D-1) to (D-20). is not it. These may be used alone or in combination of two or more.

In addition to having high hole mobility, the spiro-type compound forms an electron cloud that is close to a sphere because two benzidine skeleton molecules are twisted and bonded, and the hopping conductivity between the molecules is high. Good photoelectric conversion characteristics are exhibited. In addition, since it has high solubility, it dissolves in various organic solvents and is amorphous (amorphous substance having no crystal structure), so that it is easily filled in a porous electron transport layer. Further, since it does not have a light absorption characteristic of 450 nm or more, the photosensitizing compound can efficiently absorb light, which is particularly preferable for a solid dye-sensitized solar cell.

It is preferable to further add an oxidizing agent to the hole transport layer.
When the hole transport layer contains the oxidizing agent, the conductivity is improved, and the durability and stability of the output characteristics can be improved.

<< Oxidizing agent >>
The oxidizing agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tris (4-bromophenyl) hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluovorate, silver nitrate. , Metal complexes, hypervalent iodine compounds and the like. Among these, a metal complex is preferable, and a hypervalent iodine compound is more preferable.
When the oxidizing agent is the metal complex or the hypervalent iodine compound, the solubility in an organic solvent is high, so that the content can be increased with respect to the hole transport layer.

<<< Metal Complex >>
The metal complex is composed of a metal cation, a ligand, and an anion.
Examples of the metal cation include cations such as chromium, manganese, iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, renium, osmium, iridium, gold and platinum. Of these, cobalt, iron, nickel, and copper cations are preferable, and cobalt complexes are more preferable.
The ligand preferably contains a 5-and / or 6-membered heterocycle containing at least one nitrogen, and may have a substituent.

Specific examples of the ligand include, but are not limited to, the following exemplified compounds (E-1) to (E-33). These may be used alone or in combination of two or more.

Examples of the anion include hydride ion (H − ), fluoride ion (F − ), chloride ion (Cl − ), bromide ion (Br − ), iodide ion (I − ), and hydroxide ion. (OH − ), cyanide ion (CN − ), nitrate ion (NO 3 − ), nitrite ion (NO 2 − ), hypochlorite ion (ClO − ), chlorite ion (ClO 2 − ), chlorate ion (ClO 3 -), perchlorate ion (ClO 4 -), permanganate ion (MnO 4 -), acetate ion (CH 3 COO -), bicarbonate ions (HCO 3 -), phosphate dibasic hydrogen ions (H 2 PO 4 -), hydrogen sulfate ion (HSO 4 -), hydrogen sulphide ions (HS -), thiocyanate ion (SCN -), tetra fluoroalkyl boronic acid ion (BF 4 -), hexafluorophosphate acid ion (PF 6 -), tetracyanoquinodimethane boronic acid ions (B (CN) 4 -) , dicyano amine ion (N (CN) 2 -) , p- toluenesulfonate ion (TsO -), trifluoromethyl sulfonic acid ion (CF 3 SO 2 -), bis (trifluoromethylsulfonyl) amine ions (N (SO 2 CF 3) 2 -) tetra hydroxo aluminate ions ([Al (OH) 4] -, or [Al (OH) 4 (H 2 O) 2 ] − ), dicyanosilver (I) acid ion ([Ag (CN) 2 ] − ), tetrahydroxochrome (III) acid ion ([Cr (OH) 4 ] − ), tetrachloro gold (III) ion ([AuCl 4] -), oxide ions (O 2-), sulfide (S 2-), peroxide ions (O 2 2-), sulfate ion (SO 4 2- ), sulfite ion (SO 3 2-), thiosulfate (S 2 O 3 2-), carbonate ions (CO 3 2-), chromate ion (CrO 4 2-), dichromate ion (Cr 2 O 7 2), hydrogen phosphate ions (HPO 4 2-), tetra hydroxo zinc (II) ion ([Zn (OH) 4] 2-), tetracyano zinc (II) ion ([Zn (CN) 4] 2-), tetrachloro copper (II) ion ([CuCl 4] 2-), phosphate ion (PO 4 3-), hexyl Sacyo iron (III) acid ion ([Fe (CN) 6 ] 3- ), bis (thiosulfato) silver (I) acid ion ([Ag (S 2 O 3 ) 2 ] 3- ), hexacyanoferrate (II) acid Ions ([Fe (CN) 6 ] 4- ) and the like can be mentioned. Among these, tetraflooloborate ion, hexafluorophosphate ion, tetracyanoborate ion, bis (trifluoromethylsulfonyl) amine ion, and perchlorate ion are preferable.

As the metal complex, a trivalent cobalt complex represented by the following general formula (4) is particularly preferable. When the metal complex is a trivalent cobalt complex, it is advantageous in that it has an excellent function as an oxidizing agent.

・ ・ ・ General formula (4)
However, in the above general formula (4), R _{8 to} R ₁₀ may be the same or different from each other, and at least one of a hydrogen atom, a methyl group, an ethyl group, a t-butyl group, and a trifluoromethyl group. Any of them is represented, and X represents any of the following structural formulas (1) to (4).

BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)

... Structural formula (3)

... Structural formula (4)

Specific examples of the metal complex include, but are not limited to, the following exemplified compounds (F-1) to (F-20). These may be used alone or in combination of two or more.

Among these, the trivalent cobalt complex of the above (F-18) represented by the following structural formula (5) is preferable.

... Structural formula (5)

Further, as the metal complex, a trivalent cobalt complex represented by the following general formula (8) is also effectively used.

However, in the above general formula (8), R _{11 to} R ₁₂ may be the same or different from each other, and represent a hydrogen atom, a methyl group, an ethyl group, a tershal butyl group, or a trifluoromethyl group. .. X indicates any one selected from the above anions.

Specific examples of the cobalt complex represented by the general formula (8) will be described below. However, it is not limited to these. These may be used alone or in combination of two or more.

Among these, the trivalent cobalt complex of the above (F-22) represented by the following structural formula (6) is preferable.

... Structural formula (6)

<<< Hypervalent Iodine Compound >>>
The hypervalent iodine compound is a compound containing an iodine atom having a hypervalent molecule, and has more than eight electrons required by the octet rule.
As the hypervalent iodine compound, for example, the peryodinane compound represented by the following general formula (5) and the diaryliodonium salt represented by the following general formula (6) have high solubility, low crystallinity and low acidity. Depending on the degree, a high output can be obtained when used as an oxidizing agent in the hole transport layer. The higher the acidity of the hole transport layer, the lower the open circuit voltage. It is possible to increase the open circuit voltage by increasing the amount of the basic material added, but as the concentration of the hole transport material decreases, the series resistance increases and the output in high-intensity light decreases.

・ ・ ・ General formula (5)
However, in the above general formula (5), R _{1 to} R ₅ may be the same or different from each other and represent a hydrogen atom or a methyl group, and R ₆ and R ₇ are a methyl group or trifluoromethyl. Represents a group.

・ ・ ・ General formula (6)
However, in the general formula (6), X represents any of the following structural formulas.

BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)

... Structural formula (3)

... Structural formula (4)

Specific examples of the peryodinane compound represented by the general formula (5) include, but are not limited to, the following exemplified compounds (G-1) to (G-6). .. These may be used alone or in combination of two or more.

Specific examples of the diallyl iodonium salt represented by the general formula (6) include, but are not limited to, the following exemplified compounds (G-7) to (G-10). Absent. These may be used alone or in combination of two or more.

Examples of the hypervalent iodine compound include, but are not limited to, the following exemplified compounds (G-11) to (G-14). These may be used alone or in combination of two or more.

The content of the oxidizing agent is preferably 1 mol% or more and 30 mol% or less, more preferably 5 mol% or more and 20 mol% or less, based on the whole transport material. It is not necessary that all the hole transport materials are oxidized by the addition of the oxidizing agent, and it is effective if only a part of them is oxidized.
The oxidizing agent may be used alone or in combination of two or more. By using two or more of them together, the hole transport layer is less likely to crystallize, and high heat resistance can be obtained.

Further, it is preferable that the hole transport layer further contains an alkali metal salt. When the hole transport layer contains the alkali metal salt, the output can be improved, and the light irradiation resistance and the high temperature storage resistance can be further improved.

Examples of the alkali metal salt include lithium salt, sodium salt, potassium salt and the like.
Examples of the lithium salt include lithium chloride, lithium bromide, lithium iodide, lithium perchlorate, lithium bis (trifluoromethanesulfonyl) diimide, lithium diisopropylimide, lithium acetate, lithium tetrafluoroborate, and pentafluorophosphate. Examples thereof include lithium and lithium tetracyanoborate.
Examples of the sodium salt include sodium chloride, sodium bromide, sodium iodide, sodium perchlorate, sodium bis (trifluoromethanesulfonyl) diimide, sodium acetate, sodium tetrafluoroborate, sodium pentafluorophosphate, and tetracyano. Examples include sodium boronate.
Examples of the potassium salt include potassium chloride, potassium bromide, potassium iodide, potassium perchlorate and the like.
Among these, lithium salts are preferable, and lithium bis (trifluoromethanesulfonyl) diimide and lithium diisopropylimide are more preferable, because the durability and stability of the output characteristics can be improved by improving the conductivity.

The content of the alkali metal salt is preferably 1 part by mass or more and 50 parts by mass or less, and more preferably 15 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the hole transport material.

In the presence of an anion in the alkali metal salt, the hypervalent iodine compound and the whole transport material are mixed to form an electron-accepting compound. In particular, it was found that more electron-accepting compounds were formed by mixing under a halogen-based organic solvent. The monocation radicalized whole transport material is anion-doped to become a stable electron-accepting compound.
Further, by mixing the trivalent cobalt complex and the hole transport material, an electron accepting compound is similarly formed. It is conceivable that the reduced divalent cobalt complex is oxidized by a hypervalent iodine compound, oxygen inside the seal, or the like to return to a trivalent cobalt complex.
Therefore, it is considered that by permanently obtaining the electron-accepting compound, a high hole transport function can be exhibited, high output under high-intensity light, and high durability can be obtained. A hypervalent iodine compound having a smaller molecular size than a conventional trivalent cobalt complex material tends to form an electron-accepting compound in the pores of the porous electron transport layer. Therefore, higher light durability can be obtained.

In order to obtain high output under low illuminance, it is necessary to suppress the leakage current. It is important to impart high charge transport capacity with a hypervalent iodine compound with relatively low acidity, a trivalent cobalt complex, or an alkali metal salt, mainly using a basic material that is highly compatible with the hole transport material. I found that.

The hole transport layer may have a single layer structure made of a single material, or may have a laminated structure containing a plurality of compounds.
When the hole transport layer has a laminated structure, it is preferable to use a polymer material for the hole transport layer near the second electrode. The use of a polymer material having excellent film-forming properties is advantageous in that the surface of the porous electron transport layer can be further smoothed and the photoelectric conversion characteristics can be improved. Further, since the polymer material does not easily penetrate into the porous electron transport layer, it has excellent coating properties on the surface of the porous electron transport layer, and is effective in preventing a short circuit when an electrode is provided. In some cases.

The polymer material used for the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include known hole transport polymer materials.
Examples of the hole-transporting polymer material include polythiophene compounds, polyphenylene vinylene compounds, polyfluorene compounds, polyphenylene compounds, polyarylamine compounds, and polythiasizole compounds.
Examples of the polythiophene compound include poly (3-n-hexylthiophene), poly (3-n-octyloxythiophene), poly (9,9'-dioctyl-fluorene-co-bithiophene), and poly (3,3). '''-Gidodecyl-quarterthiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene), poly (2,5-bis (3-decylthiophen-2-yl) thieno [3,2] -B] thiophene), poly (3,4-didecylthiophene-cothieno [3,2-b] thiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene-cothieno [3,2-b] 3,2-b] thiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene-co-thiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene-co- Bithiophene) and the like.
Examples of the polyphenylene vinylene compound include poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene] and poly [2-methoxy-5- (3,7-dimethyloctyloxy)-. 1,4-phenylene vinylene], poly [(2-methoxy-5- (2-ethylphenyloxy) -1,4-phenylene vinylene) -co- (4,4'-biphenylene-vinylene)], etc. Be done.
Examples of the polyfluorene compound include poly (9,9'-zidodecylfluorenyl-2,7-diyl) and poly [(9,9-dioctyl-2,7-dibiphenylene fluorene) -alt-co. -(9,10-anthracene)], poly [(9,9-dioctyl-2,7-divinylene fluorene) -alt-co- (4,4'-biphenylene)], poly [(9,9-dioctyl) -2,7-Divinylene fluorene) -alt-co- (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene)], poly [(9,9-dioctyl-2,7-diyl) ) -Co- (1,4- (2,5-dihexyloxy) benzene)] and the like.
Examples of the polyphenylene compound include poly [2,5-dioctyloxy-1,4-phenylene] and poly [2,5-di (2-ethylhexyloxy-1,4-phenylene]].
Examples of the polyarylamine compound include poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (N, N'-diphenyl) -N, N'-di (p). -Hexylphenyl) -1,4-diaminobenzene], poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (N, N'-bis (4-octyloxyphenyl)) Benzene-N, N'-(1,4-diphenylene)], poly [(N, N'-bis (4-octyloxyphenyl) benzidine-N, N'-(1,4-diphenylene)], poly [ (N, N'-bis (4- (2-ethylhexyloxy) phenyl) benzidine-N, N'-(1,4-diphenylene)], poly [phenylimino-1,4-phenylene vinylene-2,5- Dioctyloxy-1,4-phenylene vinylene-1,4-phenylene], poly [p-triluimino-1,4-phenylene vinylene-2,5-di (2-ethylhexyloxy) -1,4-phenylene vinylene-1 , 4-Phenylene], poly [4- (2-ethylhexyloxy) phenylimino-1,4-biphenylene] and the like.
Examples of the polythiadiazole compound include poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (1,4-benzo (2,1', 3) thiadiazole]] and poly. (3,4-didecylthiophene-co- (1,4-benzo (2,1', 3) thiadiazole)) and the like can be mentioned.
Among these, polythiophene compounds and polyarylamine compounds are preferable from the viewpoint of carrier mobility and ionization potential.

The average thickness of the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable that the hole transport layer has a structure in which the pores of the electron transport layer are porous. It is preferably 0.01 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less, and further preferably 0.2 μm or more and 2 μm or less on the transport layer.

The hole transport layer can be formed directly on the electron transport layer on which the photosensitizing compound is adsorbed. The method for producing the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include a method of forming a thin film in vacuum such as vacuum vapor deposition and a wet film forming method. Among these, the wet film forming method is particularly preferable in terms of manufacturing cost and the like, and the method of coating on the electron transport layer is preferable.
When the wet film forming method is used, the coating method is not particularly limited and can be carried out according to a known method. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, etc. As a blade coating method, a gravure coating method, and a wet printing method, various methods such as letterpress, offset, gravure, concave plate, rubber plate, and screen printing can be used.

Further, the film may be formed in a supercritical fluid or a subcritical fluid having a temperature and pressure lower than the critical point. The supercritical fluid exists as a non-aggregating high-density fluid in a temperature and pressure region exceeding the limit (critical point) at which a gas and a liquid can coexist, does not aggregate even when compressed, is above the critical temperature, and has a critical pressure. The fluid in the above state is not particularly limited and may be appropriately selected depending on the intended purpose, but a fluid having a low critical temperature is preferable.

Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvent, hydrocarbon solvent, halogen solvent, ether solvent and the like.
Examples of the alcohol solvent include methanol, ethanol, n-butanol and the like.
Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene and the like. Examples of the halogen solvent include methylene chloride, chlorotrifluoromethane and the like.
Examples of the ether solvent include dimethyl ether and the like.
These may be used alone or in combination of two or more.
Among these, carbon dioxide is preferable because it has a critical pressure of 7.3 MPa and a critical temperature of 31 ° C., so that a supercritical state can be easily created, and it is nonflammable and easy to handle.

The sub-critical fluid is not particularly limited as long as it exists as a high-pressure liquid in the temperature and pressure regions near the critical point, and can be appropriately selected depending on the intended purpose. The compounds listed as supercritical fluids can also be suitably used as subcritical fluids.

The critical temperature and critical pressure of the supercritical fluid are not particularly limited and may be appropriately selected depending on the intended purpose. However, the critical temperature is preferably -273 ° C. or higher and 300 ° C. or lower, and 0 ° C. or higher and 200 ° C. or lower. Is more preferable.

Further, in addition to the supercritical fluid and the subcritical fluid, an organic solvent or an entrainer can be used in combination. By adding an organic solvent and an entrainer, the solubility in a supercritical fluid can be adjusted more easily.
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a ketone solvent, an ester solvent, an ether solvent, an amide solvent, a halogenated hydrocarbon solvent and a hydrocarbon solvent.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like.
Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate and the like.
Examples of the ether solvent include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane and the like.
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.
Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichlorethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene and the like. Be done.
Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, and p-xylene. , Ethylbenzene, xylene and the like.
These may be used alone or in combination of two or more.

Further, the hole transport material may be laminated on the electron transport layer on which the photosensitizing compound is adsorbed, and then a press treatment step may be performed. By performing the press treatment, the hole transport material is brought into close contact with the electron transport layer which is a more porous electrode, so that the efficiency may be improved.
The press processing method is not particularly limited and may be appropriately selected depending on the intended purpose. A press molding method using a flat plate as represented by an IR tablet molding machine, a roll pressing method using a roller or the like. And so on.
The pressure is preferably 10 kgf / cm ² or more, and more preferably 30 kgf / cm ² or more.
The press processing time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 hour or less.

In addition, heat may be applied during the pressing process. During the pressing process, a mold release agent may be sandwiched between the press machine and the electrodes.

Examples of the release agent include polytetrafluoride ethylene, polychlorotrifluoroethylene, tetrafluoride ethylene hexafluoride propylene copolymer, perfluoroalkoxyfluorine resin, polyvinylidene fluoride, and ethylene tetrafluoride ethylene copolymer. Examples thereof include a coalescence, an ethylene chlorotrifluorinated ethylene copolymer, and a fluororesin such as polyvinyl fluoride. These may be used alone or in combination of two or more.

After performing the press treatment step and before providing the second electrode, a metal oxide may be provided between the hole transport material and the second electrode.
Examples of the metal oxide include molybdenum oxide, tungsten oxide, vanadium oxide, nickel oxide and the like. These may be used alone or in combination of two or more. Of these, molybdenum oxide is preferable.
The method of providing the metal oxide on the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. A method of forming a thin film in vacuum such as sputtering or vacuum deposition or a wet film forming method And so on.
As the wet film forming method, a method of preparing a paste in which a metal oxide powder or a sol is dispersed and applying it on a hole transport layer is preferable. When the wet film forming method is used, the coating method is not particularly limited and can be performed according to a known method. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade As a coating method, a gravure coating method, and a wet printing method, various methods such as letterpress, offset, gravure, concave plate, rubber plate, and screen printing can be used.

The average thickness of the applied metal oxide is preferably 0.1 nm or more and 50 nm or less, and more preferably 1 nm or more and 10 nm or less.

The photoelectric conversion element of the present invention has a substrate. The substrate may be provided on either or both of the outermost surface of the photoelectric conversion element of the present invention on the first electrode side and the outermost surface on the second electrode side.
Hereinafter, the substrate provided on the outermost side of the first electrode side is referred to as a first substrate, and the substrate provided on the outermost side on the second electrode side is referred to as a second substrate.

<First substrate>
The shape, structure, and size of the first substrate are not particularly limited and may be appropriately selected depending on the intended purpose.
The material of the first substrate is not particularly limited as long as it has translucency and insulating properties, and can be appropriately selected depending on the intended purpose. For example, a substrate such as glass, plastic film, or ceramic can be used. Can be mentioned. Among these, when a step of firing is included when forming the electron transport layer as described later, a substrate having heat resistance to the firing temperature is preferable. Further, as the first substrate, one having flexibility is preferable.

<First electrode>
The shape and size of the first electrode are not particularly limited and may be appropriately selected depending on the intended purpose.
The structure of the first electrode is not particularly limited and may be appropriately selected depending on the intended purpose, and may be a single-layer structure or a structure in which a plurality of materials are laminated.
The material of the first electrode is not particularly limited as long as it has transparency and conductivity with respect to visible light, and can be appropriately selected depending on the intended purpose. For example, transparent conductive metal oxide and carbon. , Metal, etc.
Examples of the transparent conductive metal oxide include indium tin oxide (hereinafter referred to as “ITO”), fluorine-doped tin oxide (hereinafter referred to as “FTO”), and antimony-doped tin oxide (hereinafter referred to as “ATO”). , Niobdope tin oxide (hereinafter referred to as “NTO”), aluminum-doped zinc oxide, indium-zinc oxide, niobium-titanium oxide and the like.
Examples of the carbon include carbon black, carbon nanotubes, graphene, fullerenes and the like.
Examples of the metal include gold, silver, aluminum, nickel, indium, tantalum, titanium and the like.
These may be used alone or in combination of two or more. Among these, a transparent conductive metal oxide having high transparency is preferable, and ITO, FTO, ATO, and NTO are more preferable.

The average thickness of the first electrode is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 nm or more and 100 μm or less, and more preferably 50 nm or more and 10 μm or less. When the material of the first electrode is carbon or metal, the average thickness of the first electrode is preferably such that the translucency can be obtained.

The first electrode can be formed by a known method such as a sputtering method, a vapor deposition method, or a spray method.

Further, the first electrode is preferably formed on the first substrate, and an integrated commercially available product in which the first electrode is previously formed on the first substrate is used. Can be done.
Examples of the integrated commercial product include FTO-coated glass, ITO-coated glass, zinc oxide: aluminum-coated glass, FTO-coated transparent plastic film, ITO-coated transparent plastic film, and the like. Other integrated commercial products include, for example, a transparent electrode in which tin oxide or indium oxide is doped with cations or anions having different valences, or a metal having a structure capable of transmitting light such as a mesh or stripe. Examples thereof include a glass substrate provided with electrodes.
These may be used individually by 1 type, or may be mixed or laminated in combination of 2 or more types. Further, a metal lead wire or the like may be used in combination for the purpose of lowering the electrical resistance value.
Examples of the material of the metal lead wire include aluminum, copper, silver, gold, platinum, nickel and the like.
The metal lead wire can be used in combination by forming the metal lead wire on a substrate by, for example, vapor deposition, sputtering, crimping or the like, and providing an ITO or FTO layer on the substrate.

<Hole blocking layer>
The hole blocking layer is formed between the first electrode and an electron transport layer described later.
The hole blocking layer is generated by a photosensitizing compound and transports electrons transported to the electron transport layer to the first electrode, and prevents contact with the hole transport layer described later. As a result, the hole blocking layer makes it difficult for holes to flow into the first electrode, and it is possible to suppress a decrease in output due to the recombination of electrons and holes. The solid type photoelectric conversion element provided with the hole transport layer has a faster recombination rate of electrons in the hole and the electrode surface in the hole transport material than the wet type using an electrolytic solution, and therefore the hole blocking layer. The effect of the formation of is very large.

The material of the hole blocking layer is not particularly limited as long as it is transparent to visible light and has electron transporting property, and can be appropriately selected depending on the intended purpose. For example, silicon, germanium and the like. Examples thereof include elemental semiconductors, compound semiconductors typified by metallic chalcogenides, and compounds having a perovskite structure.
Examples of the metal chalcogenide include oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, ittrium, lanthanum, vanadium, niobium, and tantalum; cadmium, zinc, lead, silver, and so on. Antimony, bismuth sulfide; cadmium, lead selenium; cadmium telluride. Examples of other compound semiconductors include phosphodies such as zinc, gallium, indium, and cadmium; gallium arsenic, copper-indium-selene, copper-indium-sulfide, and the like.
Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate and the like.
Among these, oxide semiconductors are preferable, titanium oxide, niobium oxide, magnesium oxide, aluminum oxide, zinc oxide, tungsten oxide, tin oxide and the like are more preferable, and titanium oxide is further preferable.
These may be used alone or in combination of two or more. Further, it may be laminated as a single layer. The crystal type of these semiconductors is not particularly limited and may be appropriately selected depending on the intended purpose, and may be single crystal, polycrystalline, or amorphous.

The method for producing the hole blocking layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of forming a thin film in vacuum (vacuum film forming method) and a wet film forming method. Be done.
Examples of the vacuum film forming method include a sputtering method, a pulse laser deposition method (PLD method), an ion beam sputtering method, an ion assist method, an ion plating method, a vacuum deposition method, and an atomic layer deposition method (ALD method). , Chemical vapor deposition method (CVD method) and the like.
Examples of the wet film forming method include a sol-gel method. The sol-gel method is a method in which a gel is prepared from a solution through a chemical reaction such as hydrolysis, polymerization, or condensation, and then heat treatment is performed to promote densification. When the sol-gel method is used, the method for applying the sol solution is not particularly limited and can be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, or a roller coating method can be used. The method, the blade coating method, the gravure coating method, and the wet printing method include a letterpress, offset, gravure, concave plate, rubber plate, screen printing, and the like. The temperature during the heat treatment after applying the sol solution is preferably 80 ° C. or higher, more preferably 100 ° C. or higher.

The film thickness of the hole blocking layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 nm or more and 1 μm or less, more preferably 500 nm or more and 700 nm or less for wet film formation, and 5 nm for dry film formation. More preferably 30 nm or less.

<Electron transport layer>
The electron transport layer is formed for the purpose of transporting electrons generated by the photosensitizing compound to the first electrode or the hole blocking layer. Therefore, the electron transport layer is preferably arranged adjacent to the first electrode or the hole blocking layer.

The structure of the electron transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, in at least two photoelectric conversion elements adjacent to each other, the electron transport layers are not extended to each other. preferable. If the electron transport layers are not extended to each other, electron diffusion is suppressed and the leakage current is reduced, which is advantageous in that the light durability is improved. Further, the structure of the electron transport layer may be a continuous layer single layer or a multilayer in which a plurality of layers are laminated.

The electron transporting layer contains an electron transporting material and, if necessary, other materials.

<< Electron transportable material >>
The electron transporting material is not particularly limited and may be appropriately selected depending on the intended purpose, but a semiconductor material is preferable.
The semiconductor material has a fine particle shape, and it is preferable that the semiconductor material is formed into a porous film by joining them. The photosensitizing compound is chemically or physically adsorbed on the surface of the semiconductor fine particles constituting the porous electron transport layer.
The semiconductor material is not particularly limited, and known materials can be used. Examples thereof include elemental semiconductors, compound semiconductors, and compounds having a perovskite structure.
Examples of the elemental semiconductor include silicon and germanium.
Examples of the compound semiconductor include metal cadmium, specifically oxides such as titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum. Cadmium, zinc, lead, silver, sulfides such as antimony and bismuth; selenium products such as cadmium and lead; tellurides such as cadmium and the like. Examples of other compound semiconductors include phosphates such as zinc, gallium, indium and cadmium, gallium arsenic, copper-indium-selenium and copper-indium-sulfide.
Examples of the compound having a perovskite structure include strontium titanate, calcium titanate, sodium titanate, barium titanate, potassium niobate and the like.
Among these, oxide semiconductors are preferable, and titanium oxide, zinc oxide, tin oxide and niobium oxide are particularly preferable. When the electron transporting material of the electron transporting layer is titanium oxide, the conduction band is high and a high open circuit voltage can be obtained. In addition, the refractive index is high, and a high short-circuit current can be obtained due to the light confinement effect. Further, the high dielectric constant and high mobility are advantageous in that a high curve factor can be obtained.
These may be used alone or in combination of two or more. The crystal type of the semiconductor material is not particularly limited and may be appropriately selected depending on the intended purpose, and may be single crystal, polycrystalline, or amorphous.

The number average particle diameter of the primary particles of the semiconductor material is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 nm or more and 100 nm or less, and more preferably 5 nm or more and 50 nm or less. Further, semiconductor materials larger than the number average particle size may be mixed or laminated, and the conversion efficiency may be improved by the effect of scattering the incident light. In this case, the number average particle size is preferably 50 nm or more and 500 nm or less.

The average thickness of the electron transport layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 nm or more and 100 μm or less, more preferably 100 nm or more and 50 μm or less, and further preferably 120 nm or more and 10 μm or less. When the average thickness of the electron transport layer is within a preferable range, a sufficient amount of the photosensitizing compound per unit projected area can be secured, the light capture rate can be maintained high, and the diffusion distance of the injected electrons can be increased. It is advantageous in that it is difficult to increase and the loss due to charge recombination can be reduced.

The method for producing the electron transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of forming a thin film in a vacuum such as sputtering and a wet film forming method. Among these, the wet film forming method is preferable from the viewpoint of manufacturing cost, and a paste (dispersion liquid) in which powder or sol of a semiconductor material is dispersed is prepared and placed on a first electrode as an electron collecting electrode substrate, or A method of applying on the hole blocking layer is more preferable.
The wet film forming method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, and a gravure coating method can be selected. The law etc. can be mentioned.
As the wet printing method, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used.

Examples of the method for producing the dispersion liquid of the semiconductor material include a method of mechanically pulverizing using a known milling device or the like. By this method, a dispersion liquid of a semiconductor material can be prepared by dispersing the particulate semiconductor material alone or by dispersing a mixture of the semiconductor material and a resin in water or a solvent.

Examples of the resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic acid ester, and methacrylate ester, silicone resins, phenoxy resins, polysulfone resins, polyvinyl butyral resins, polyvinyl formal resins, and polyester resins. , Cellulose ester resin, cellulose ether resin, urethane resin, phenol resin, epoxy resin, polycarbonate resin, polyarylate resin, polyamide resin, polyimide resin and the like. These may be used alone or in combination of two or more.

Examples of the solvent include water, alcohol solvent, ketone solvent, ester solvent, ether solvent, amide solvent, halogenated hydrocarbon solvent, hydrocarbon solvent and the like.
Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, α-terpineol and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like.
Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate and the like.
Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane and the like.
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.
Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichlorethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene and the like. Be done.
Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, and p-xylene. , Ethylbenzene, xylene and the like.
These may be used alone or in combination of two or more.

An acid, a surfactant, a chelating agent, or the like may be added to the dispersion liquid containing the semiconductor material or the paste containing the semiconductor material obtained by the sol-gel method or the like in order to prevent reaggregation of particles. Good.
Examples of the acid include hydrochloric acid, nitric acid, acetic acid and the like.
Examples of the surfactant include polyoxyethylene octylphenyl ether and the like.
Examples of the chelating agent include acetylacetone, 2-aminoethanol, ethylenediamine and the like.

Further, it is also an effective means to add a thickener for the purpose of improving the film forming property.
Examples of the thickener include polyethylene glycol, polyvinyl alcohol, ethyl cellulose and the like.

Further, after the semiconductor material is applied, the particles of the semiconductor material are electronically brought into contact with each other and fired in order to improve the film strength and the adhesion to the substrate, or irradiated with microwaves or electron beams. Alternatively, a laser beam can be irradiated. These treatments may be performed individually by 1 type or in combination of 2 or more types.
When the electron transport layer formed from the semiconductor material is fired, the firing temperature is not particularly limited and can be appropriately selected depending on the intended purpose. However, if the temperature is too high, the resistance of the substrate increases. It is preferably 30 ° C. or higher and 700 ° C. or lower, and more preferably 100 ° C. or higher and 600 ° C. or lower, because it may melt or melt. The firing time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 minutes or more and 10 hours or less.
When the electron transport layer formed from the semiconductor material is irradiated with microwaves, the irradiation time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 hour or less. In this case, irradiation may be performed from the surface side on which the electron transport layer is formed, or from the surface side on which the electron transport layer is not formed.

After the electron transport layer made of the semiconductor material is fired, for the purpose of increasing the surface area of the electron transport layer and increasing the electron injection efficiency from the photosensitizing compound described later into the semiconductor material, for example, an aqueous solution of titanium tetrachloride or the like. Chemical plating using a mixed solution with an organic solvent or electrochemical plating treatment using an aqueous solution of titanium trichloride may be performed.
A film obtained by sintering a semiconductor material having a diameter of several tens of nm can form a porous state. Such a nanoporous structure has a very high surface area, which can be expressed using a roughness factor. The roughness factor is a numerical value representing the actual area inside the porous medium with respect to the area of the semiconductor particles coated on the first substrate. Therefore, the roughness factor is preferably larger, but is preferably 20 or more in relation to the average thickness of the electron transport layer.

Further, the particles of the electron transporting material may be doped with a lithium compound. Specifically, it is a method in which a solution of a lithium bis (trifluoromethanesulfonimide) compound is deposited on particles of an electron-transporting material using spin coating or the like, and then fired.
The lithium compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include lithium bis (trifluoromethanesulfonimide), lithium perchlorate and lithium iodide.

<< Other ingredients >>
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include photosensitizing compounds.

<<< Photosensitizer >>>
The photosensitizer compound is adsorbed on the surface of the semiconductor material constituting the electron transport layer in order to further improve the output and photoelectric conversion efficiency.
The photosensitizing compound is not particularly limited as long as it is a compound photoexcited by light irradiated to the photoelectric conversion element, and can be appropriately selected depending on the intended purpose. Examples thereof include the following known compounds. Be done.
Specifically, J. Phys. Chem. C, 7224, Vol. 111 (2007) and the like, the coumarin compound, Chem. Commun. , 4887 (2007), etc., J. Mol. Am. Chem. Soc. , 12218, Vol. 126 (2004), Chem. Commun. , 3036 (2003), Angew. Chem. Int. Ed. , 1923, Vol. 47 (2008) and the like. Am. Chem. Soc. , 16701, Vol. 128 (2006), J. Mol. Am. Chem. Soc. , 14256, Vol. 128 (2006) and the like, thiophene compound, cyanine dye, merocyanine dye, 9-arylxanthene compound, triarylmethane compound, J. Mol. Phys. Chem. , 2342, Vol. 91 (1987), J. Mol. Phys. Chem. B, 6272, Vol. 97 (1993), Electrical. Chem. , 31, Vol. 537 (2002), J. Mol. Porphyrins Phthalocyanines, 230, Vol. 3 (1999), Angew. Chem. Int. Ed. , 373, Vol. 46 (2007), Langmuir, 5436, Vol. Examples thereof include the phthalocyanine compound and the porphyrin compound described in 24 (2008) and the like.
Among these, metal complex compounds, coumarin compounds, polyene compounds, indolin compounds, and thiophene compounds are preferable, and are represented by the following structural formulas (7), the following structural formulas (8), and the following structural formulas (9) manufactured by Mitsubishi Paper Co., Ltd. The compound to be used, and the compound containing the following general formula (7) are more preferable. In addition, these photosensitizer compounds may be used alone or may be used in mixture of 2 or more types.

... Structural formula (7)

... Structural formula (8)

... Structural formula (9)

・ ・ ・ General formula (7)
However, in the general formula (7), X ₁ and X ₂ represent an oxygen atom, a sulfur atom, and a selenium atom. R ₁₁ represents a methine group which may _{have a substituent, R 12} represents an alkyl group, an aryl group and a heterocyclic group which may have a substituent, and R ₁₃ represents a carboxylic acid, a sulfonic acid, and the like. It represents an acidic group such as a phosphonic acid, a boronic acid, or a phenol, Z ₁ and Z ₂ represent a substituent forming a cyclic structure, and m represents an integer from 0 to 2.

Examples of the substituent in R ₁₁ include an aryl group such as a phenyl group and a naphthyl group, and a heterocycle such as a thienyl group and a frill group.
Examples of the alkyl group as the substituent in R ₁₂ include a methyl group, an ethyl group, a 2-propyl group and a 2-ethylhexyl group, and examples of the aryl group and the heterocyclic group include the above-mentioned ones.
Examples of the Z ₁ include condensed hydrocarbon compounds such as a benzene ring and a naphthalene ring, and a heterocycle such as a thiophene ring and a furan ring, each of which may have a substituent. Examples of the condensed hydrocarbon compound in Z _{1 and} the substituent in the heterocycle include alkoxy groups such as the above-mentioned alkyl group, methoxy group, ethoxy group and 2-isopropoxy group.
Examples of the Z ₂ include (A-1) to (A-22) shown below.

Specific examples of the photosensitizing compound represented by the general formula (7) include, but are limited to, the following exemplified compounds (B-1) to (B-36). is not it. These may be used alone or in combination of two or more.

As a method of adsorbing the photosensitizer compound on the surface of the semiconductor material of the electron transport layer, for example, an electron containing the semiconductor material in a solution of the photosensitizer compound or a dispersion liquid of the photosensitizer compound. A method of immersing the transport layer, a method of applying a solution of a photosensitizing compound, or a method of applying a dispersion of a photosensitizing compound to an electron transport layer and adsorbing it can be used. In the case of a method of immersing the electron transport layer having the semiconductor material formed in the solution of the photosensitizer compound or the dispersion liquid of the photosensitizer compound, a dipping method, a dip method, a roller method, or an air knife method. Etc. can be used. In the case of a method in which the solution of the photosensitizer compound or the dispersion liquid of the photosensitizer compound is applied to the electron transport layer and adsorbed, the wire bar method, the slide hopper method, the extrusion method, the curtain method, or the spin method is used. A method, a spray method, or the like can be used. It can also be adsorbed in a supercritical fluid using carbon dioxide or the like.

When adsorbing the photosensitizer compound on the semiconductor material, a condensing agent may be used in combination.
The condensing agent physically or chemically acts on the surface of the semiconductor material to have a catalytic action such as binding a photosensitizer compound, or acts stoichiometrically to move the chemical equilibrium advantageously. It may be any of them. Further, a thiol, a hydroxy compound or the like may be added as a condensation aid.

Examples of the solvent that dissolves or disperses the photosensitizing compound include water, an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, an amide solvent, a halogenated hydrocarbon solvent, and a hydrocarbon solvent.
Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like.
Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate and the like.
Examples of the ether solvent include diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane and the like.
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.
Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichlorethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene and the like. Be done.
Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, and p-xylene. , Ethylbenzene, xylene and the like.
These may be used alone or in combination of two or more.

Depending on the type of the photosensitizer, there are some that work more effectively if the aggregation between the compounds is suppressed. Therefore, an aggregation dissociator may be used in combination.
The coagulation / dissociating agent is not particularly limited and may be appropriately selected depending on the dye to be used, but steroid compounds such as cholic acid and chenodeoxycholic acid, long-chain alkylcarboxylic acids and long-chain alkylphosphonic acids are preferable.
The content of the coagulation dissociator is preferably 0.01 parts by mass or more and 500 parts by mass or less, and more preferably 0.1 parts by mass or more and 100 parts by mass or less with respect to 1 part by mass of the photosensitizer compound.

The temperature at which the photosensitizer compound, or the photosensitizer compound and the coagulation dissociator are adsorbed on the surface of the semiconductor material constituting the electron transport layer, is preferably −50 ° C. or higher and 200 ° C. or lower. .. The adsorption time is preferably 5 seconds or more and 1,000 hours or less, more preferably 10 seconds or more and 500 hours or less, and further preferably 1 minute or more and 150 hours or less. The step of adsorbing is preferably performed in a dark place. Further, the step of adsorbing may be carried out by standing still or while stirring.
The method of stirring is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method using a stirrer, a ball mill, a paint conditioner, a sand mill, an attritor, a disperser, an ultrasonic dispersion, and the like. Be done.

<Second electrode>
The second electrode can be formed on the hole transport layer or on the metal oxide in the hole transport layer. Further, as the second electrode, the same one as that of the first electrode can be used, and a support is not always necessary when the strength is sufficiently maintained.
Examples of the material of the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers.
Examples of the metal include platinum, gold, silver, copper, and aluminum.
Examples of the carbon compound include graphite, fullerene, carbon nanotube, graphene and the like.
Examples of the conductive metal oxide include ITO, FTO, ATO and the like.
Examples of the conductive polymer include polythiophene and polyaniline.
These may be used alone or in combination of two or more.

The second electrode can be formed by a method such as coating, laminating, vapor deposition, CVD, or laminating on the hole transport layer as appropriate, depending on the type of material used and the type of hole transport layer.
In the photoelectric conversion element of the present invention, it is preferable that at least one of the first electrode and the second electrode is substantially transparent. A method in which the first electrode side is transparent and the incident light is incident from the first electrode side is preferable. In this case, it is preferable to use a material that reflects light on the second electrode side, and a metal, glass, plastic, or a metal thin film on which a conductive oxide is vapor-deposited is preferably used. It is also an effective means to provide an antireflection layer on the incident light side.

<Second board>
The second substrate is not particularly limited, and known ones can be used, and examples thereof include substrates such as glass, plastic film, and ceramics. The joint portion between the second substrate and the sealing member may form an uneven portion in order to improve the adhesion.
The method for forming the uneven portion is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a sandblasting method, a waterblasting method, abrasive paper, a chemical etching method, and a laser processing method.
As a means for improving the adhesion between the second substrate and the sealing member described later, for example, organic substances on the surface may be removed or hydrophilicity may be improved. The means for removing the organic matter on the surface of the second substrate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include UV ozone cleaning and oxygen plasma treatment.

<Sealing member>
The sealing member shields at least the electron transport layer, the hole transport layer, and the second electrode from the external environment of the photoelectric conversion element.

Examples of the sealing member include acrylic resin, epoxy resin, and low melting point glass resin.
As the cured product of the acrylic resin, any known material can be used as long as the monomer or oligomer having an acrylic group in the molecule is cured.
As the cured product of the epoxy resin, any known material can be used as long as the monomer or oligomer having an epoxy group in the molecule is cured.

The epoxy resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-dispersed type, solvent-free type, solid type, thermosetting type, hardener mixed type and ultraviolet curable type. Be done. Among these, the thermosetting type and the ultraviolet curable type are preferable, and the ultraviolet curable type is more preferable. It is possible to heat it, and it is preferable to heat it even after it has been cured by ultraviolet rays.
Examples of the epoxy resin include bisphenol A type, bisphenol F type, novolak type, cyclic aliphatic type, long-chain aliphatic type, glycidylamine type, glycidyl ether type, and glycidyl ester type. These may be used alone or in combination of two or more.

The epoxy resin may contain a curing agent and various additives, if necessary.
Examples of the curing agent include amine-based, acid anhydride-based, polyamide-based, and other curing agents.
Examples of the amine-based curing agent include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.
Examples of the acid anhydride-based curing agent include phthalic anhydride, tetra and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, hetic anhydride, dodecenyl succinic anhydride and the like. Be done.
Examples of the other curing agent include imidazoles and polyethercaptans. These may be used alone or in combination of two or more.

Examples of the additive include a filler, a gap agent, a polymerization initiator, a desiccant (moisture absorbent), a curing accelerator, a coupling agent, a flexible agent, a colorant, a flame retardant aid, and oxidation. Examples include inhibitors and organic solvents. These may be used alone or in combination of two or more. Among these, fillers, gap agents, curing accelerators, polymerization initiators and desiccants (moisture absorbents) are preferable, and fillers and polymerization initiators are particularly preferable.

The filler is effective in suppressing the infiltration of water and oxygen in the external environment, reduces volume shrinkage during curing, reduces the amount of gas generated during curing or heating, and has mechanical strength. It is possible to obtain effects such as improvement, control of thermal conductivity and fluidity, and it is very effective in the present invention as well in maintaining a stable output in various environments.
The output characteristics and durability of the photoelectric conversion element can ignore not only the influence of moisture and oxygen that enter the inside of the photoelectric conversion element from the external environment, but also the influence of gas generated during curing and heating of the sealing member. Can not. In particular, the influence of the gas generated during heating has a great influence on the output characteristics when stored in a high temperature environment.
In this case, by incorporating the filler, the gap agent, and the desiccant in the sealing member, these themselves can suppress the infiltration of water and oxygen, and the amount of the sealing member used can be reduced. The effect of reducing the generation of gas can be obtained. This is effective not only at the time of curing but also when the photoelectric conversion element is stored in a high temperature environment.

The filler is not particularly limited, and known materials can be used. For example, crystalline or amorphous silica, talc, alumina, aluminum nitride, silicon nitride, calcium silicate, calcium carbonate and the like can be used. Inorganic fillers are preferably used. These may be used alone or in combination of two or more.

The average primary particle size of the filler is preferably 0.1 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. When the average primary particle size of the filler is 0.1 μm or more and 10 μm or less, the effect of suppressing the invasion of water and oxygen can be sufficiently obtained, the viscosity becomes appropriate, and the adhesion and desorption with the substrate are achieved. It is also effective for improving foamability, controlling the width of the sealing portion, and workingability.

The content of the filler is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less with respect to the total amount of the sealing member. When the content of the filler is 10 parts by mass or more and 90 parts by mass or less, the effect of suppressing the infiltration of water and oxygen is sufficiently obtained, the viscosity is appropriate, and the adhesion and workability are also good.

The gap agent is also referred to as a gap control agent or a spacer agent, and can control the gap in the sealing portion. For example, when the sealing member is applied on the first substrate or the first electrode and the second substrate is placed on the sealing member for sealing, the gap agent is applied to the epoxy resin. By mixing the above, the gap of the sealing portion is aligned with the size of the gap agent, so that the gap of the sealing portion can be easily controlled.

As the gap agent, a known material can be used as long as it is granular, has a uniform particle size, and has high solvent resistance and heat resistance. Those having a high affinity with the epoxy resin and having a spherical particle shape are preferable. Specific examples thereof include glass beads, silica fine particles, and organic resin fine particles. These may be used alone or in combination of two or more.

The particle size of the gap agent can be selected according to the gap of the sealing portion to be set, but is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

The polymerization initiator is a material added for the purpose of initiating polymerization using heat or light. Those that initiate polymerization using heat may be referred to as thermal polymerization initiators, and those that initiate polymerization using light may be referred to as photopolymerization initiators.
The thermal polymerization initiator is a compound that generates active species such as radicals and cations by heating, and specifically, an azo compound such as 2,2'-azobisisobutyronitrile (AIBN) or benzoyl peroxide (AIBN). Peroxides such as BPO) are used. Such an initiator may be referred to as a thermal cationic polymerization initiator.
As the thermal cationic polymerization initiator, a benzenesulfonic acid ester, an alkylsulfonium salt, or the like is used.

On the other hand, in the case of an epoxy resin, a photocationic polymerization initiator is preferably used as the photopolymerization initiator. When the photocationic polymerization initiator is mixed with the epoxy resin and irradiated with light, the photocationic polymerization initiator is decomposed to generate a strong acid, and the acid causes the epoxy resin to polymerize, and the curing reaction proceeds. .. The photocationic polymerization initiator has the effects of less volume shrinkage during curing, no oxygen inhibition, and high storage stability.

Examples of the photocationic polymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metatheron compounds, silanol-aluminum complexes and the like.
Further, a photoacid generator having a function of generating an acid by irradiating with light can also be used.
The photoacid generator acts as an acid for initiating cationic polymerization, and examples thereof include onium salts such as an ionic sulfonium salt type and an iodonium salt type composed of a cation part and an anion part. These may be used alone or in combination of two or more.

The content of the polymerization initiator is preferably 0.5 parts by mass or more and 10 parts by mass or less, and more preferably 1 part by mass or more and 5 parts by mass or less, based on the total amount of the sealing member. When the content of the polymerization initiator is 0.5 parts by mass or more and 10 parts by mass or less, curing proceeds appropriately, the residual uncured material can be reduced, and the amount of gas generated is prevented from becoming excessive. It is possible and effective.

The desiccant is also called a hygroscopic agent, and is a material having a function of physically or chemically adsorbing and absorbing moisture. By containing the desiccant in the sealing member, the moisture resistance can be further enhanced or the outgas can be contained. It is effective because the effect can be reduced in some cases.
The desiccant is preferably in the form of particles, and examples thereof include inorganic water-absorbing materials such as calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, silica gel, molecular sieve, and zeolite. Among these, zeolite having a large amount of moisture absorption is preferable. These may be used alone or in combination of two or more.

The curing accelerator, also called a curing catalyst, is used for the purpose of increasing the curing rate, and is mainly used for thermosetting epoxy resins.
Examples of the curing accelerator include DBU (1,8-diazabicyclo (5,4,0) -undesen-7) and DBN (1,5-diazabicyclo (4,3,0) -nonen-5). Tertiary amines or tertiary amine salts, imidazole systems such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, triphenylphosphine, tetraphenylphosphonium, tetraphenylborate, etc. Examples thereof include phosphine or phosphonium salt. These may be used alone or in combination of two or more.

The coupling agent has an effect of enhancing the molecular binding force, and examples thereof include a silane coupling agent, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycid. Xipropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N -(2-Aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3 Examples thereof include silane coupling agents such as −aminopropyltrimethoxysilane hydrochloride and 3-methacryloxypropyltrimethoxysilane. These may be used alone or in combination of two or more.

The low melting point glass resin is brought into close contact with the glass substrate while being melted by an infrared laser or the like after the resin component is decomposed by a firing step of about 550 ° C. after the resin is applied. At this time, the low melting point glass component diffuses inside the metal oxide layer and is physically bonded, so that high sealing performance can be obtained. Further, since the resin component has disappeared, outgas such as acrylic resin and epoxy resin is not generated, so that the photoelectric conversion element is not deteriorated.

As the sealing member, an epoxy resin composition commercially available as a sealing material, a sealing material or an adhesive is known, and it can be effectively used in the present invention as well. Among them, there are epoxy resin compositions developed and commercially available for applications such as solar cells and organic EL devices, which can be used particularly effectively in the present invention.
Examples of the commercially available products include trade names: TB3118, TB3114, TB3124, TB3125F (manufactured by ThreeBond Co., Ltd.), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyoritsu Kagaku Sangyo Co., Ltd.), WB90US (P) (above, (Made by Moresco), etc.
Further, the epoxy resin composition is disclosed in, for example, Japanese Patent No. 4918975, Japanese Patent No. 5812275, Japanese Patent No. 5835664, Japanese Patent No. 5930248, Japanese Patent Application Laid-Open No. 2012-136614, and these are also used. can do.

Further, in the present invention, a sheet-shaped encapsulant can also be effectively used.
The sheet-shaped encapsulant has an epoxy resin layer formed on the sheet in advance, and glass, a film having a high gas barrier property, or the like is used for the sheet, which corresponds to the substrate in the present invention. The sealing member and the substrate can be formed at once by attaching the sheet-shaped sealing material on the photoelectric conversion element or the second electrode of the photoelectric conversion element module and then curing the sheet-shaped sealing material. Depending on the formation pattern of the epoxy resin layer formed on the sheet, it is possible to form a structure in which a gap is provided inside the photoelectric conversion element, which is effective.

The position of the sealing member is not particularly limited as long as it is arranged at least at a position where the electron transport layer, the hole transport layer, and the second electrode are shielded from the external environment of the photoelectric conversion element, depending on the purpose. It can be appropriately selected. For example, it may be provided on the entire surface so as to cover the electron transport layer, the hole transport layer, and the second electrode, or a substrate may be arranged above the second electrode and sealed. The member may be provided on the outer edge of the substrate and adhered to at least one of the first substrate, the first electrode and the hole blocking layer.
In the latter configuration in which the substrate is arranged and the sealing member is provided on the outer edge thereof, a gap portion can be provided inside the photoelectric conversion element or the photoelectric conversion element module. Oxygen and humidity can be controlled in the voids, which is effective in improving output and durability.

In the present invention, it is particularly preferable to contain oxygen in the void portion. By containing oxygen, the hole transport function of the hole transport layer can be stably maintained for a long period of time, and the durability of the photoelectric conversion element or the photoelectric conversion element module can be improved. In the present invention, the oxygen concentration in the voids inside the photoelectric conversion element provided by sealing is effective if it contains oxygen, but is 1.0% by volume or more and 21.0% by volume or less. It is preferably 3.0% by volume or more and 15.0% by volume or less.

The oxygen concentration in the void can be controlled by sealing in a glove box in which the oxygen concentration is set. The oxygen concentration can be set by a method using a gas cylinder having a specific oxygen concentration or a method using a nitrogen gas generator. The oxygen concentration in the glove box is measured using a commercially available oxygen concentration meter or oxygen monitor.

The oxygen concentration in the void formed by the sealing can be measured by, for example, an atmospheric pressure ionization mass spectrometer (API-MS). Specifically, the photoelectric conversion element or the photoelectric conversion element module is installed in a chamber filled with an inert gas, the seal is opened in the chamber, and the gas in the chamber is quantitatively analyzed by API-MS. The oxygen concentration can be obtained by quantifying all the components in the gas contained in the voids and calculating the ratio of oxygen to the total.
As the gas other than oxygen, an inert gas is preferable, and nitrogen, argon and the like can be mentioned.

When sealing, it is preferable to control the dew point as well as the oxygen concentration in the glove box, which is effective in improving the output and its durability.
The dew point is defined as the temperature at which condensation begins when a gas containing water vapor is cooled. The dew point is preferably 0 ° C. or lower, more preferably −20 ° C. or lower. The lower limit is preferably −50 ° C. or higher.

Further, a passivation layer may be provided between the second electrode and the sealing member. The passivation layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, aluminum oxide, silicon nitride, silicon oxide and the like are preferable.

The method for forming the sealing member is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dispensing method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method, etc. Examples include letterpress, offset, intaglio, rubber plate, and screen printing.

<Other parts>
The other members are not particularly limited and may be appropriately selected depending on the intended purpose.

[Embodiment]
Hereinafter, an example of the photoelectric conversion element of the present invention will be described with reference to the drawings. However, the present invention is not limited to these, and for example, the number, position, shape, and the like of the following constituent members that are not described in the present embodiment are also included in the category of the present invention.

FIG. 1 is a schematic view showing an example of a photoelectric conversion element of the present invention.
As shown in FIG. 1, the photoelectric conversion element 101 has a first electrode 2 on the first substrate 1. The electron transport layer 4 is provided on the first electrode 2, and the photosensitizer compound 5 is provided on the surface of the electron transport material constituting the electron transport layer 4. A hole transport layer 6 is provided above and inside the electron transport layer 4, and a second electrode 7 is provided on the hole transport layer 6. A second substrate 9 is arranged above the second electrode 7, and the second substrate 9 is fixed to and from the first electrode 2 by a sealing member 8. The photoelectric conversion element 101 shown in FIG. 1 has a hollow portion between the second electrode 7 and the second substrate 9. By having the hollow portion, it is possible to control the amount of water and the oxygen concentration in the hollow portion, and there is an advantage that the power generation performance and its durability can be improved. Further, since the second electrode 7 and the second substrate 9 are not in contact with each other, it is possible to prevent the second electrode 7 from being peeled off or broken.
The oxygen concentration in the hollow portion is not particularly limited and can be freely selected, but is preferably 0% or more and 21% or less, more preferably 0.05% or more and 10% or less, and further preferably 0.1% or more and 5% or less. preferable.
Although not shown, the first electrode 2 and the second electrode 7 each have a path conducting to the electrode take-out terminal.

FIG. 2 is a schematic view showing another example of the photoelectric conversion element of the present invention, and has a hole blocking layer 3 between the first substrate 1 and the electron transport layer 4. By having the hole blocking layer 3, it is possible to prevent the recombination of electrons and holes, which is effective in improving the power generation performance. The photoelectric conversion element shown in FIG. 2 has a hollow portion between the second electrode 7 and the second substrate 9 as in FIG. 1.

FIG. 3 is a schematic view showing another example of the photoelectric conversion element of the present invention, and is an example in which the hollow portion of FIG. 2 is covered with the sealing member 8 without providing the hollow portion of the sealing portion. .. For example, the sealing member 8 can be formed by applying the sealing member 8 to the entire surface on the second electrode 7 and providing the second substrate 9 on the entire surface, or by using the above-mentioned sheet-shaped sealing material. In this case, the hollow portion inside the seal may be completely eliminated, or a part of the hollow portion may be left. By covering almost the entire surface with the sealing member in this way, it is possible to reduce peeling or breakage of the second substrate 9, and it is possible to increase the mechanical strength of the photoelectric conversion element.

FIG. 4 is a schematic view showing another example of the photoelectric conversion element of the present invention, in which the sealing member 8 is adhered to the first substrate 1 and the second substrate 9. With such a configuration, the adhesiveness of the sealing member 8 to the substrate is increased, and the effect of increasing the mechanical strength of the photoelectric conversion element can be obtained. Further, by increasing the adhesion, it is possible to obtain an effect of further enhancing the sealing effect of preventing the infiltration of water and oxygen.

(Photoelectric conversion element module)
The photoelectric conversion element of the present invention can be a photoelectric conversion element module having the following configuration.
The photoelectric conversion element module using the photoelectric conversion element of the present invention has a photoelectric conversion element arrangement region in which a plurality of photoelectric conversion elements are arranged adjacent to each other and connected in series or in parallel, and the plurality of photoelectric conversion elements are described. Has a hole transport layer containing a cyclic alkali metal salt compound represented by at least one of the following general formulas (1a) and (1b) and a basic compound represented by the following general formula (2). It has a first substrate, a second substrate, a first electrode, a second electrode, a hole blocking layer, and an electron transporting layer, and further has a sealing member and other members, if necessary.
... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent.

The configuration of each layer of the photoelectric conversion element module can be the same as that of the photoelectric conversion element.

The photoelectric conversion element module may be in the form of a continuous layer in which at least the hole transport layers are extended from each other in at least two photoelectric conversion elements adjacent to each other.
Further, when the hole blocking layer is provided, the photoelectric conversion element module has, in at least two photoelectric conversion elements adjacent to each other, the first electrode in one of the photoelectric conversion elements and the other photoelectric conversion element. The second electrode may be electrically connected by a conductive portion penetrating at least from the hole transport layer to the hole blocking layer.

The photoelectric conversion element module has a pair of substrates and has a photoelectric conversion element arrangement region connected in series or in parallel between the pair of substrates, and the sealing member is sandwiched between the pair of substrates. Can be configured.

[Embodiment]
Hereinafter, an example of the photoelectric conversion element module of the present invention will be described with reference to the drawings. However, the present invention is not limited to these, and for example, the number, position, shape, and the like of the following constituent members that are not described in the present embodiment are also included in the category of the present invention.

FIG. 5 is a schematic view showing an example of a photoelectric conversion element module of the present invention, and is an example showing a cross section of a part of a photoelectric conversion element module including a plurality of photoelectric conversion elements and connected in series. ..
In FIG. 5, the hole transport layer 6 is formed, the penetrating portion 11 is formed, and then the second electrode 7 is formed, whereby the second electrode material is introduced into the penetrating portion 11 and adjacent to the second electrode material. It can be made conductive with the first electrode 2b of the cell. Although not shown in FIG. 5, the first electrode 2a and the second electrode 7b have a path conducting to the electrode of the adjacent cell or the output take-out terminal.

The penetrating portion 11 may penetrate the first electrode 2 and reach the first substrate 1, or may stop processing inside the first electrode 2 and may not reach the first substrate 1. May be good.
When the shape of the penetrating portion 11 is a micropore that penetrates the first electrode 2 and reaches the first substrate 1, if the total opening area of the micropores becomes too large with respect to the area of the penetrating portion 11, the first As the film cross-sectional area of the electrode 2 of 1 decreases, the resistance value increases, which may cause a decrease in photoelectric conversion efficiency. Therefore, the ratio of the total opening area of the micropores to the area of the penetrating portion 11 is preferably 5/100 or more and 60/100 or less.

The method for forming the penetrating portion 11 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a sandblasting method, a waterblasting method, abrasive paper, a chemical etching method, and a laser processing method. Among these, the laser processing method is preferable. As a result, fine holes can be formed without using sand, etching, resist, or the like, and can be processed cleanly and with good reproducibility. Further, when the penetration portion 11 is formed, at least one of the hole blocking layer 3, the electron transport layer 4, the hole transport layer 6, and the second electrode 7 can be removed by impact peeling by a laser processing method. Become. As a result, it is not necessary to provide a mask at the time of laminating, and removal and formation of the fine penetrating portion 11 can be easily performed at the same time.

FIG. 6 is a schematic view showing an example of the photoelectric conversion element module of the present invention, which includes a plurality of photoelectric conversion elements, which are connected in series, and a sealing member 12 is provided in a gap between cells like a beam. This is an example showing a cross section of a part of the provided photoelectric conversion element module.
When a gap is provided between the second electrode 7 and the second substrate 9 as shown in FIG. 2, the second electrode 7 can be prevented from peeling or breaking, but the mechanical strength of the sealing is lowered. May be done. On the other hand, when the space between the second electrode 7 and the second substrate 9 is filled with a sealing member as shown in FIG. 3, the mechanical strength of the sealing is increased, but the second electrode 7 is peeled off. There are concerns. Here, in order to increase the power generation, it is effective to increase the area of the photoelectric conversion element module, but when there is a gap, a decrease in mechanical strength is unavoidable.
Therefore, by providing the sealing member 12 like a beam as shown in FIG. 6, it is possible to prevent peeling or breakage of the second electrode 7 and increase the mechanical strength of the sealing, which is effective. is there.
The sealing member 12 may be made of the same material as the sealing member 8 or may be made of a different material.

(Electronics)
The electronic device of the present invention has the photoelectric conversion element and / or the photoelectric conversion element module of the present invention, and further has other devices as needed.

(Power supply module)
The power supply module of the present invention has the photoelectric conversion element and / or the photoelectric conversion element module of the present invention, and further has other devices as needed.

A specific embodiment of the photoelectric conversion element of the present invention, the photoelectric conversion element module, and an electronic device having a device operated by the electric power obtained by generating electric power thereof will be described.
FIG. 7 shows an example in which a mouse is used as the electronic device.
As shown in FIG. 7, a photoelectric conversion element, a photoelectric conversion element module, a power supply IC, and a power storage device (sometimes referred to as an electric double layer capacitor) are combined, and the supplied power is used as a power source for a mouse control circuit. Connecting. As a result, the power storage device can be charged when the mouse is not in use, and the mouse can be operated with the electric power, and a mouse that does not require wiring or battery replacement can be obtained. In addition, the weight can be reduced by eliminating the need for batteries, which is effective.
FIG. 8 shows a schematic view in which a photoelectric conversion element is mounted on a mouse. The photoelectric conversion element, the power supply IC, and the power storage device are mounted inside the mouse, and the upper part of the photoelectric conversion element is covered with a transparent housing so that the photoelectric conversion element is exposed to light. It is also possible to mold the entire mouse housing with a transparent resin. The arrangement of the photoelectric conversion element is not limited to this, and for example, even if the mouse is covered with a hand, it can be arranged at a position where light is irradiated, which may be preferable.

The photoelectric conversion element of the present invention, the photoelectric conversion element module, and other embodiments of an electronic device having a device operated by the electric power obtained by generating electricity thereof will be described.
FIG. 9 shows an example in which a keyboard used in a personal computer is used as the electronic device.
As shown in FIG. 9, the photoelectric conversion element, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the keyboard control circuit. As a result, the power storage device can be charged when the keyboard is not in use, and the keyboard can be operated with the electric power, and a keyboard that does not require wiring or battery replacement can be obtained. In addition, the weight can be reduced by eliminating the need for batteries, which is effective.
FIG. 10 shows a schematic view in which a photoelectric conversion element is mounted on a keyboard. The photoelectric conversion element, the power supply IC, and the power storage device are mounted inside the keyboard, and the upper part of the photoelectric conversion element is covered with a transparent housing so that the photoelectric conversion element is exposed to light. It is also possible to mold the entire keyboard housing with transparent resin. The arrangement of the photoelectric conversion element is not limited to this. In the case of a small keyboard in which the space for incorporating the photoelectric conversion element is small, as shown in FIG. 11, it is possible and effective to embed the small photoelectric conversion element in a part of the keys.

The photoelectric conversion element of the present invention, the photoelectric conversion element module, and other embodiments of an electronic device having a device operated by the electric power obtained by generating electricity thereof will be described. FIG. 12 shows an example of using a sensor as the electronic device.
As shown in FIG. 12, the photoelectric conversion element, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the sensor circuit. This makes it possible to configure the sensor module without the need to connect to an external power source and to replace the battery. As sensing targets, it can be applied to various sensors such as temperature / humidity, illuminance, human sensation, CO ₂ , acceleration, UV, noise, geomagnetism, and atmospheric pressure, and is effective. As shown in FIG. 12, the sensor module is configured to periodically sense the measurement target and transmit the read data to a PC, smartphone, or the like by wireless communication.
With the advent of the IoT society, the number of sensors is expected to increase rapidly. Replacing the batteries of these innumerable sensors one by one takes a lot of time and effort, which is not realistic. In addition, the sensor is located in a place where it is difficult to replace the battery, such as a ceiling or a wall, which also deteriorates workability. The ability to supply power with a photoelectric conversion element is also a great advantage. Further, the photoelectric conversion element of the present invention can obtain a high output even in low illuminance and has a small dependence on the light incident angle of the output, so that it has an advantage that the degree of freedom of installation is high.

The photoelectric conversion element of the present invention, the photoelectric conversion element module, and other embodiments of an electronic device having a device operated by the electric power obtained by generating electricity thereof will be described.
FIG. 13 shows an example of using a turntable as the electronic device.
As shown in FIG. 13, the photoelectric conversion element, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the turntable circuit. This makes it possible to configure the turntable without the need to connect to an external power source and to replace the battery.
Turntables are used, for example, in showcases for displaying products, but the wiring of the power supply does not look good, and the displayed items must be removed when replacing the batteries, which takes a lot of time and effort. By using the photoelectric conversion element of the present invention, such a problem can be solved and it is effective.

The photoelectric conversion element and the photoelectric conversion element module of the present invention, an electronic device having a device operated by the electric power obtained by generating electric power thereof, and a power supply module have been described above, but these are only a few. The photoelectric conversion element or the photoelectric conversion element module of the present invention is not limited to these applications. Further, as the above-mentioned power storage device, although the electric double layer capacitor has been described, a lithium ion capacitor may be used.

The photoelectric conversion element and the photoelectric conversion element module can be applied to, for example, a power supply device by combining with a circuit board or the like that controls the generated current.
Examples of devices that use the power supply device include electronic desk calculators, wristwatches, mobile phones, electronic organizers, and electronic papers.
Further, a power supply device having a photoelectric conversion element can be used as an auxiliary power source for prolonging the continuous use time of the rechargeable or dry battery type electric appliance.

<Use>
The photoelectric conversion element and the photoelectric conversion element module of the present invention can function as a self-supporting power source, and the device can be operated by using the electric power generated by the photoelectric conversion. Since the photoelectric conversion element and the photoelectric conversion element module of the present invention can generate electric power by being irradiated with light, it is not necessary to connect an electronic device to a power source or replace a battery. Therefore, it is possible to operate the electronic device even in a place where there is no power supply facility, to carry it around while wearing it, and to operate the electronic device even in a place where it is difficult to replace the battery without replacing the battery. In addition, when a dry battery is used, the electronic device becomes heavier and larger in size, which may hinder installation on a wall or ceiling, or portability. However, the photoelectric conversion of the present invention may occur. Since the element and the photoelectric conversion element module are lightweight and thin, the degree of freedom of installation is high, and there is a great advantage in wearing and carrying around.
As described above, the photoelectric conversion element and the photoelectric conversion element module of the present invention can be used as a self-supporting power source and can be combined with various electronic devices. For example, electronic desk calculators, watches, mobile phones, electronic organizers, electronic paper and other display devices, personal computer accessories such as mice and keyboards, various sensor devices such as temperature and humidity sensors and human sensor, and transmission of beacons and GPS. It can be used in combination with many electronic devices such as machines, auxiliary lights, and remote controls.

Since the photoelectric conversion element and the photoelectric conversion element module of the present invention can generate electricity even with low-illuminance light, they can generate electricity indoors or even in a dim shadow, and therefore have a wide range of application. In addition, unlike dry batteries, there is no liquid leakage, and unlike button batteries, there is no accidental ingestion, and safety is high. Further, it can be used as an auxiliary power source for prolonging the continuous use time of rechargeable or dry battery type electric appliances. In this way, by combining the photoelectric conversion element and the photoelectric conversion element module of the present invention and the device that operates by the electric power generated by the photoelectric conversion, the weight is reduced, the usability is good, and the degree of freedom of installation is high. It can be reborn as an electronic device that does not require replacement, has excellent safety, and is effective in reducing the environmental burden.

FIG. 14 shows a basic configuration diagram of an electronic device in which a photoelectric conversion element and / or a photoelectric conversion element module of the present invention is combined with a device operated by electric power generated by the photoelectric conversion. This can generate electric power when the photoelectric conversion element is irradiated with light, and can extract electric power. The circuit of the device can be operated by its electric power.

However, since the output of the photoelectric conversion element changes depending on the ambient illuminance, the electronic device shown in FIG. 14 may not be able to operate stably. In this case, as shown in FIG. 15, in order to supply a stable voltage to the circuit side, it is possible and effective to incorporate a power supply IC for the photoelectric conversion element between the photoelectric conversion element and the circuit of the device. ..
However, the photoelectric conversion element can generate electricity if it is irradiated with light having a sufficient illuminance, but if the illuminance sufficient to generate electricity is insufficient, the desired power cannot be obtained, which is also a drawback of the photoelectric conversion element. In this case, as shown in FIG. 16, by mounting a power storage device such as an electric double layer capacitor between the power supply IC and the device circuit, it is possible to charge the power storage device with surplus power from the photoelectric conversion element. Therefore, even when the illuminance is too low or the photoelectric conversion element is not exposed to light, the electric power stored in the power storage device can be supplied to the device circuit, and stable operation can be performed.
As described above, in an electronic device in which the photoelectric conversion element and / or the photoelectric conversion element module of the present invention is combined with a device circuit, by combining a power supply IC and a power storage device, it is possible to operate even in an environment without a power source. It is not necessary to replace the battery, it can be driven stably, and the advantages of the photoelectric conversion element can be fully utilized.

On the other hand, the photoelectric conversion element and / or the photoelectric conversion element module of the present invention can also be used as a power supply module and is useful. For example, as shown in FIG. 17, when the photoelectric conversion element and / or the photoelectric conversion element module of the present invention is connected to the power supply IC for the photoelectric conversion element, the power generated by the photoelectric conversion of the photoelectric conversion element is converted into the power supply IC. A DC power supply module that can be supplied at a constant voltage level can be configured.
Further, as shown in FIG. 18, by adding a power storage device to the power supply IC, it becomes possible to charge the power storage device with the electric power generated by the photoelectric conversion element, and when the illuminance is too low or the photoelectric conversion element is used. It is possible to configure a power supply module that can supply electric power even when the light does not hit the surface.
The power supply module of the present invention shown in FIGS. 17 and 18 can be used as a power supply module without battery replacement as in a conventional primary battery.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1)
(Manufacturing of photoelectric conversion element)
Indium-doped tin oxide (ITO) and niob-doped tin oxide (NTO) as the first electrode are sequentially sputtered onto a glass substrate as the first substrate, and then a dense layer made of titanium oxide as the hole blocking layer. (20 nm) was formed by reactive sputtering with oxygen gas.
Next, 3 g of titanium oxide (ST-21 manufactured by Ishihara Sangyo Co., Ltd.), 0.2 g of acetylacetone, 0.3 g of a surfactant (polyoxyethylene octylphenyl ether, manufactured by Wako Pure Chemical Industries, Ltd.), 5.5 g of water, A bead mill treatment was carried out with 1.0 g of ethanol for 12 hours, and 1.2 g of polyethylene glycol (# 20,000, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the obtained titanium oxide dispersion to prepare a paste. The obtained paste is applied onto the hole blocking layer so that the average thickness is about 1.5 μm, dried at 60 ° C., and then calcined in air at 550 ° C. for 30 minutes to form a porous electron transport layer. Formed.
A glass substrate on which an electron transport layer is formed is mixed with 120 mg of a photosensitizing compound represented by B-5 and 150 mg of kenodeoxycholic acid (manufactured by Tokyo Kasei Co., Ltd.) with acetonitrile / t-butanol (volume ratio 1: 1). In addition, it was immersed in a stirred solution and allowed to stand in a dark place for 1 hour to adsorb the photosensitizing compound on the surface of the electron transport layer.
Next, in 1 mL of the chlorobenzene solution, 150 mM of the organic hole transport material (SHT-263, manufactured by Merck Co., Ltd.) represented by D-7, and lithium hexafluoropropane-1 which is a cyclic alkali metal salt compound represented by C-58. , 3-Disulfonylimide (manufactured by Tokyo Kasei Co., Ltd.) 60 mM and 130 mM of the basic compound represented by H-1 were added and dissolved to prepare a hole transport layer coating solution.
Next, on the electron transport layer on which the photosensitizing compound was adsorbed, a hole transport layer coating liquid was used, and a hole transport layer having a diameter of about 500 nm was formed by spin coating. After that, the end portion of the glass substrate on which the sealing member is provided was etched by laser processing, and further, a through hole for connecting to the ITO layer serving as the terminal extraction portion was formed by laser processing. Further, silver was vacuum-deposited on the silver to form a second electrode having a diameter of about 100 nm.
The edge of the glass substrate was coated with an ultraviolet curable resin (TB3118, manufactured by ThreeBond Holdings Co., Ltd.) using a dispenser (2300N, manufactured by Sanei Tech Co., Ltd.) so as to surround the power generation region. After that, it is moved into a glove box having a dew point of -40 ° C and an oxygen concentration controlled to 2.5%, a cover glass as a second substrate is placed on an ultraviolet curable resin, and it is cured by ultraviolet irradiation to generate electricity. Sealing was performed to produce the photoelectric conversion element 1 of the present invention shown in FIG.

(Examples 2 to 7)
In Example 1, the photoelectric conversion elements 2 to 7 are the same as in Example 1 except that the dye, the cyclic alkali metal salt compound, the basic compound, and the organic hole transport material are changed to the materials shown in Table 1. Was produced.

(Example 8)
In Example 3, the photoelectric conversion element 1 was produced in the same manner as in Example 3 except that 10 mM of the trivalent cobalt complex compound represented by F-11 was added.

(Example 9)
In Example 8, the photoelectric conversion element 9 was produced in the same manner as in Example 8 except that 10 mM of the hypervalent iodine compound represented by G-4 was added.

(Comparative Example 1)
The photoelectric conversion element 10 was produced in the same manner as in Example 1 except that the alkali metal salt compound was changed to lithium bis (trifluoromethanesulfonyl) imide (manufactured by Kanto Chemical Co., Inc.).

(Comparative Example 2)
The photoelectric conversion element 11 was produced in the same manner as in Example 1 except that the alkali metal salt compound was changed to potassium bis (trifluoromethanesulfonyl) imide (manufactured by Kanto Chemical Co., Inc.).

(Comparative Example 3)
A photoelectric conversion element 12 was produced in the same manner as in Example 1 except that the basic compound was changed to dimethylaminopyridine (DMAP, manufactured by Tokyo Kasei Co., Ltd.) in Example 1.

Next, for each of the manufactured photoelectric conversion elements, the "open circuit voltage (Voc) maintenance rate and maximum output voltage (Pmax) maintenance rate" were measured as follows. The results are shown in Table 2.

[Open circuit voltage (Voc) maintenance rate and maximum output voltage (Pmax) maintenance rate]
The IV characteristics of the obtained photoelectric conversion element 1 are evaluated using a solar cell evaluation system (As-510-PV03, manufactured by NF Circuit Design Block Co., Ltd.) under white LED irradiation adjusted to a light intensity of 2000 lux or 200 lux. Then, the initial open circuit voltages Voc1 and Voc2 (V), and the maximum output powers Pmax1 and Pmax2 (μW / cm ² ) were measured.
After that, it was stored in an environment of 80 ° C. for 500 hours, then returned to a normal temperature environment, and the IV characteristics of the light source under the same conditions were evaluated again. (ΜW / cm ² ) was measured.
By dividing the obtained Voc3 by the initial value Voc1, the "open-circuit voltage (Voc) maintenance rate after high-temperature storage at 2000 lux" (Voc3 / Voc1) was determined.
Further, by dividing the obtained Pmax3 by the initial value Pmax1, the "maximum output voltage (Pmax) maintenance rate after high temperature storage at 2000 lux" (Pmax3 / Pmax1) was obtained.
By dividing the obtained Voc4 by the initial value of Voc2, the "open-circuit voltage (Voc) maintenance rate after high-temperature storage at 200 lux" (Voc4 / Voc2) was determined.
Further, by dividing the obtained Pmax4 by the initial value Pmax2, the "maximum output voltage (Pmax) maintenance rate after high temperature storage at 200 lux" (Pmax4 / Pmax2) was obtained. The results are shown in Table 2.

As shown in the results of Table 2, the photoelectric conversion element of the present invention has a maximum output voltage and an open circuit voltage even after being stored at a high temperature for a long period of time or when irradiated with low-illuminance light such as 200 lux to 2000 lux. It was shown that the maintenance rate is high and the power generation stability is high, that is, it is possible to suppress the decrease in output with low-illuminance light after storage at high temperature.
Further, from the results in Table 2, it was found that, as compared with Comparative Examples 1 to 9, the deterioration of the characteristics of Examples 1 to 9 can be suppressed by low illuminance light before and after exposure to a high temperature. As the results of Examples 6, 8 and 9 show, the maintenance rate of the high open circuit voltage and the maximum output voltage was shown even at the time of 2000 lux irradiation. This is because a hypervalent iodine compound is formed in the pores of the porous electron transport layer, and a cobalt complex compound is formed in the hole transport layer, respectively, to form an electron-accepting compound, thereby obtaining high durability. It is probable that it was possible. Although the initial properties were low, the potassium salt compound was able to obtain high durability.

Examples of aspects of the present invention are as follows.
<1> It has a hole transport layer containing a cyclic alkali metal salt compound represented by at least one of the following general formulas (1a) and (1b) and a basic compound represented by the following general formula (2). It is a photoelectric conversion element characterized by this.
... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent.
<2> The cyclic alkali metal salt compound represented by the general formula (1a) is represented by the following general formula (3a).
The cyclic alkali metal salt compound represented by the general formula (1b) is the photoelectric conversion element according to <1>, which is represented by the following general formula (3b).
... General formula (3a)
However, in the general formula (3a), M represents lithium, sodium, potassium, or cesium, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent. ..
... General formula (3b)
However, in the general formula (3b), M represents an organic cation, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent.
<3> The _{aryl group in Ar 1} and Ar ₂ is at least one of a phenyl group, a naphthyl group, and a biphenyl group.
The photoelectric conversion element according to any one of <1> to <2>, wherein the substituent of the aryl group in _{Ar 1} and Ar _{2 is at least one of an alkyl group and an alkoxy group.}
<4> The photoelectric conversion element according to any one of <1> to <3>, wherein the hole transport layer contains a compound represented by the following general formula (4).
・ ・ ・ General formula (4)
However, in the above general formula (4), R _{8 to} R ₁₀ may be the same or different from each other, and at least one of a hydrogen atom, a methyl group, an ethyl group, a t-butyl group, and a trifluoromethyl group. Any of them is represented, and X represents any of the following structural formulas (1) to (4).
BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)
... Structural formula (3)
... Structural formula (4)
<5> Either of the above <1> to <4>, wherein the hole transport layer contains a peryodinane compound represented by the following general formula (5) or a diaryliodonium salt represented by the following general formula (6). The photoelectric conversion element described in 1.
・ ・ ・ General formula (5)
However, in the general formula (5), R _{1 to} R ₅ may be the same or different from each other, represent a hydrogen atom or a methyl group, and R ₆ and R ₇ may be the same as each other. It may be different and represents a methyl group or a trifluoromethyl group.
・ ・ ・ General formula (6)
However, in the general formula (6), X represents any of the following structural formulas (1) to (4).
BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)
... Structural formula (3)
... Structural formula (4)
<6> Further, it has an electron transport layer.
The photoelectric conversion element according to any one of <1> to <5>, wherein the electron transport layer contains porous titanium oxide particles on which a photosensitizing compound is adsorbed.
<7> An electronic device having the photoelectric conversion element according to any one of <1> to <6>.
<8> A power supply module having the photoelectric conversion element according to any one of <1> to <6>.

According to the photoelectric conversion element according to any one of <1> to <6>, the electronic device according to <7>, and the power supply module according to <8>, the conventional problems can be solved. The object of the present invention can be achieved.

1 1st substrate 2, 2a, 2b 1st electrode 3 Hole blocking layer 4 Electron transport layer 5 Photosensitizer 6 Hole transport layer 7, 7a, 7b 2nd electrode 8 Sealing member 9 2nd substrate 10 Void part 11 Penetration part 12 Sealing member 101 Photoelectric conversion element 102 Photoelectric conversion element module

Japanese Unexamined Patent Publication No. 2014-14333 JP-A-2018-113305

Claims (7)

It is characterized by having a hole transport layer containing a cyclic alkali metal salt compound represented by at least one of the following general formulas (1a) and (1b) and a basic compound represented by the following general formula (2). Photoelectric conversion element.
... General formula (1a)
However, in the general formula (1a), M represents lithium, sodium, potassium, or cesium, and X ₁ and X ₂ may be the same or different from each other, and may be a carbonyl group, a sulfonyl group, or It represents a sulfone group, X ₃ may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
... General formula (1b)
However, in the general formula (1b), M represents an organic cation, and X ₁ and X ₂ may be the same or different from each other, and represent a carbonyl group, a sulfonyl group, or a sulfone group, and X. _3, may have a fluorine atom or a substituent, an alkenyl group, or an arylene group.
・ ・ ・ General formula (2)
However, in the general formula (2), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent. The cyclic alkali metal salt compound represented by the general formula (1a) is represented by the following general formula (3a).
The photoelectric conversion element according to claim 1, wherein the cyclic alkali metal salt compound represented by the general formula (1b) is represented by the following general formula (3b).
... General formula (3a)
However, in the general formula (3a), M represents lithium, sodium, potassium, or cesium, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent. ..
... General formula (3b)
However, in the general formula (3b), M represents an organic cation, and X ₃ represents an alkenyl group or an arylene group which may have a fluorine atom or a substituent. The photoelectric conversion element according to any one of claims 1 to 2, wherein the hole transport layer contains a compound represented by the following general formula (4).
・ ・ ・ General formula (4)
However, in the above general formula (4), R _{8 to} R ₁₀ may be the same or different from each other, and at least one of a hydrogen atom, a methyl group, an ethyl group, a t-butyl group, and a trifluoromethyl group. Any of them is represented, and X represents any of the following structural formulas (1) to (4).
BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)
... Structural formula (3)
... Structural formula (4) The photoelectric conversion element according to any one of claims 1 to 3, wherein the hole transport layer contains a periodinan compound represented by the following general formula (5) or a diaryliodonium salt represented by the following general formula (6). ..
・ ・ ・ General formula (5)
However, in the general formula (5), R _{1 to} R ₅ may be the same or different from each other, may be the same or different from each other, represent a hydrogen atom or a methyl group, and represent R. ₆ and R ₇ may be the same or different from each other and represent a methyl group or a trifluoromethyl group.
・ ・ ・ General formula (6)
However, in the general formula (6), X represents any of the following structural formulas (1) to (4).
BF ₄ ... Structural formula (1)
PF ₆ ... Structural formula (2)
... Structural formula (3)
... Structural formula (4) In addition, it has an electron transport layer
The photoelectric conversion element according to any one of claims 1 to 4, wherein the electron transport layer contains porous titanium oxide particles on which a photosensitizing compound is adsorbed. An electronic device comprising the photoelectric conversion element according to any one of claims 1 to 5. A power supply module comprising the photoelectric conversion element according to any one of claims 1 to 5.