WO2019082844A1

WO2019082844A1 - Ink, solidified film of ink, and photoelectric conversion element

Info

Publication number: WO2019082844A1
Application number: PCT/JP2018/039195
Authority: WO
Inventors: 大輔猪口
Original assignee: 住友化学株式会社
Priority date: 2017-10-23
Filing date: 2018-10-22
Publication date: 2019-05-02
Also published as: CN111263982A; JP7129995B2; JPWO2019082844A1

Abstract

There is a demand for improvement in the external quantum efficiency of a photoelectric conversion element. This ink contains a p-type semiconductor material, an n-type semiconductor material, a first solvent that is a nitrogen-containing heterocyclic compound, and a second solvent that is an aromatic hydrocarbon. An active layer in this photoelectric conversion element is a solidified film of the ink.

Description

Ink, solidified film of ink, and photoelectric conversion element

The present invention relates to an ink, a solidified film of the ink, and a photoelectric conversion element.

Conventionally, a solar cell having an active layer containing a p-type semiconductor material and an n-type semiconductor material is known, and a technology for forming an active layer by an ink composition containing a combination of these semiconductor materials and a specific solvent is known. (Patent Document 1).

International Publication No. 2016/076213

A photoelectric conversion element can function as a light detection element when light is irradiated in a state where a reverse bias voltage is applied, and a photocurrent flows. In order to improve the detection sensitivity of the light detection element, it is required to improve the external quantum efficiency of the photoelectric conversion element.
In addition, the photoelectric conversion element can function as a solar cell. Solar cells that use natural energy do not consume resources such as fossil fuels during power generation and do not emit greenhouse gases. Therefore, a solar cell is expected as a power supply source using green energy, and its performance improvement is required. Therefore, also when making a photoelectric conversion element function as a solar cell, higher external quantum efficiency is calculated | required by the photoelectric conversion element similarly.

In order to solve the above problems, as a result of intensive investigations, the present inventor has found that the external quantum efficiency of a photoelectric conversion element in which an active layer is formed using an ink containing a specific solvent can be improved, and completes the present invention I did. That is, the present invention provides the following.

[1] An ink comprising a p-type semiconductor material, an n-type semiconductor material, a first solvent which is a nitrogen-containing heterocyclic compound, and a second solvent which is an aromatic hydrocarbon.
[2] The ink according to [1], wherein the n-type semiconductor material is a fullerene derivative.
[3] The nitrogen-containing heterocyclic compound contains a six-membered ring structure, and the six-membered ring structure contains one or two hetero atoms, and the one or two hetero atoms are each a nitrogen atom, The ink according to [1] or [2].
[4] The ink according to [3], wherein the 6-membered ring structure is a pyridine ring structure, a tetrahydropyridine ring structure, a piperidine ring structure, or a pyrazine ring structure.
[5] The first solvent may have quinoline which may have a substituent, 1,2,3,4-tetrahydroquinoline which may have a substituent, and may have a substituent The ink according to any one of [1] to [4], which is one or more selected from the group consisting of quinoxalines.
[6] Any one of [1] to [5], wherein the weight ratio of the first solvent to the second solvent (first solvent / second solvent) is 1/99 or more and 20/80 or less Ink described in
[7] The ink according to any one of [1] to [6], wherein the weight percentage of the total of the first solvent and the second solvent in the ink is 95% by weight or more and 99% by weight or less.
[8] The ink according to any one of [1] to [7], which is for forming an active layer of a photoelectric conversion element.
[9] A solidified film of the ink according to any one of [1] to [8].
[10] A solidified film according to [9], comprising a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode in this order, Photoelectric conversion element.
[11] The photoelectric conversion device according to [10], which is a light detection device.
[12] An image sensor comprising the photoelectric conversion element according to [10] or [11].
[13] A fingerprint authentication apparatus comprising the photoelectric conversion device according to [10] or [11].
[14] A step (i) of applying the ink according to any one of [1] to [8] to a coating target to obtain a coated film, and a step of removing a solvent from the obtained coated film (ii) A method of producing a solidified film, comprising:
[15] A method of manufacturing a photoelectric conversion element, comprising a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode in this order,
The process of forming the said active layer including the process of forming the said active layer, apply | coating the ink as described in any one of [1]-[8] to application object, and obtaining a coating film (i) And the process (ii) of removing a solvent from the obtained coating film, The manufacturing method of a photoelectric conversion element.

The present invention can improve the external quantum efficiency of the photoelectric conversion element.

FIG. 1 is a schematic view showing an embodiment of the photoelectric conversion element of the present invention. FIG. 2 is a view schematically showing a configuration example of an image detection unit for a solid-state imaging device. FIG. 3 is a view schematically showing a configuration example of a fingerprint detection unit configured integrally with the display device.

Hereinafter, the present invention will be described in detail by way of embodiments and exemplifications. However, the present invention is not limited to the embodiments and exemplifications described below, and may be arbitrarily changed and implemented without departing from the scope of the claims and the equivalents thereof.

[1. Explanation of common terms]
In the present specification, the “polymer compound” means a polymer having a molecular weight distribution and having a polystyrene-equivalent number average molecular weight of 1 × 10 ³ or more and 1 × 10 ⁸ or less. The structural units contained in the polymer compound are 100 mol% in total.

In the present specification, the "constituent unit" means a unit which is present in one or more in the polymer compound.

In the present specification, the "hydrogen atom" may be a light hydrogen atom or a deuterium atom.

As used herein, "halogen atom" includes fluorine atom, chlorine atom, bromine atom and iodine atom.

In the present specification, unless otherwise specified, the "alkyl group" may be linear, branched or cyclic. The number of carbon atoms of the linear alkyl group is usually 1 to 50, preferably 1 to 30, and more preferably 1 to 20, not including the number of carbon atoms of the substituent. The carbon atom number of the branched or cyclic alkyl group is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20, not including the carbon atom number of the substituent.

The alkyl group may have a substituent. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isoamyl group, 2-ethylbutyl group, n- Hexyl, cyclohexyl, n-heptyl, cyclohexylmethyl, cyclohexylethyl, n-octyl, 2-ethylhexyl, 3-n-propylheptyl, adamantyl, n-decyl, 3,7-dimethyl Non-substituted alkyl group such as octyl group, 2-ethyloctyl group, 2-n-hexyl-decyl group, n-dodecyl group, tetradecyl group, hexadecyl tomb, octadecyl group, eicosyl group; trifluoromethyl group, pentafluoroethyl group , Perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, 3 Phenylpropyl, 3- (4-methylphenyl) propyl group, 3- (3,5-di -n- hexyl phenyl) propyl group, and substituted alkyl groups such as 6-ethyloxy-hexyl group.

The “aryl group” means an atomic group remaining after removing one hydrogen atom directly bonded to a carbon atom constituting a ring from an aromatic hydrocarbon which may have a substituent.

The aryl group may have a substituent. Specific examples of the aryl group include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 2-phenylphenyl group, 3-phenylphenyl group, 4-phenylphenyl group, and a hydrogen atom in these groups is an alkyl group, an alkoxy group, An aryl group, a group substituted with a fluorine atom and the like can be mentioned.

The "alkoxy group" may be linear, branched or cyclic. The carbon atom number of the linear alkoxy group is usually 1 to 40, preferably 1 to 10, not including the carbon atom number of the substituent. The carbon atom number of the branched or cyclic alkoxy group is usually 3 to 40, preferably 4 to 10, not including the carbon atom number of the substituent.

The alkoxy group may have a substituent. Specific examples of the alkoxy group include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, isobutyloxy group, tert-butyloxy group, n-pentyloxy group, n-hexyloxy group, And cyclohexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, n-nonyloxy, n-decyloxy, 3,7-dimethyloctyloxy, and lauryloxy groups.

The number of carbon atoms of the “aryloxy group” is usually 6 to 60, preferably 6 to 48, not including the number of carbon atoms of the substituent.

The aryloxy group may have a substituent. Specific examples of the aryloxy group include phenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, 1-anthracenyloxy group, 9-anthracenyloxy group, 1-pyrenyloxy group, and these groups And the hydrogen atom in is substituted by an alkyl group, an alkoxy group, a fluorine atom and the like.

The "alkylthio group" may be linear, branched or cyclic. The carbon atom number of the linear alkylthio group is usually 1 to 40, preferably 1 to 10, not including the carbon atom number of the substituent. The carbon atom number of the branched and cyclic alkylthio group is usually 3 to 40, preferably 4 to 10, not including the carbon atom number of the substituent.

The alkylthio group may have a substituent. Specific examples of the alkylthio group are methylthio group, ethylthio group, propylthio group, isopropylthio group, butylthio group, isobutylthio group, tert-butylthio group, pentylthio group, hexylthio group, cyclohexylthio group, heptylthio group, octylthio group, 2 And -ethylhexylthio group, nonylthio group, decylthio group, 3,7-dimethyloctylthio group, laurylthio group, and trifluoromethylthio group.

The number of carbon atoms of the “arylthio group” is usually 6 to 60, preferably 6 to 48, not including the number of carbon atoms of the substituent.

The arylthio group may have a substituent. Examples of the arylthio group include phenylthio group and C1 to C12 alkyloxyphenylthio group (C1 to C12 indicate that the number of carbon atoms of the group described immediately thereafter is 1 to 12. The same applies to the following. And C1-C12 alkylphenylthio group, 1-naphthylthio group, 2-naphthylthio group, and pentafluorophenylthio group.

The “p-valent heterocyclic group” (p represents an integer of 1 or more) is a direct bond from a heterocyclic compound which may have a substituent to a carbon atom or a heteroatom constituting a ring. It means the remaining atomic groups excluding p hydrogen atoms among the hydrogen atoms. Among p-valent heterocyclic groups, “p-valent aromatic heterocyclic group” is preferable. The “p-valent aromatic heterocyclic group” is a p-membered hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring, from the aromatic heterocyclic compound which may have a substituent. Means the remaining atomic groups excluding the hydrogen atom of

Examples of the substituent which the heterocyclic compound may have include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a monovalent heterocyclic group, and a substituted amino group. And an acyl group, an imine residue, an amido group, an acid imide group, a substituted oxycarbonyl group, an alkenyl group, an alkynyl group, a cyano group, and a nitro group.

Aromatic heterocyclic compounds include, in addition to compounds in which the heterocycle itself exhibits aromaticity, compounds in which an aromatic ring is fused to the heterocycle even if the heterocycle itself exhibits no aromaticity are included Ru.

Among the aromatic heterocyclic compounds, specific examples of compounds in which the heterocycle itself exhibits aromaticity include oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine And pyridazine, quinoline, isoquinoline, carbazole, and dibenzophosphole.

Among the aromatic heterocyclic compounds, specific examples of compounds in which the aromatic heterocycle itself does not exhibit aromaticity and in which an aromatic ring is fused to the heterocycle include phenoxazine, phenothiazine, dibenzoborole, and dibenzo. And silole and benzopyran.

The carbon atom number of the monovalent heterocyclic group is usually 2 to 60, preferably 4 to 20, not including the carbon atom number of the substituent.

The monovalent heterocyclic group may have a substituent, and examples of the monovalent heterocyclic group include, for example, thienyl group, pyrrolyl group, furyl group, pyridyl group, piperidyl group, quinolyl group, and the like. Examples include an isoquinolyl group, a pyrimidinyl group, a triazinyl group, and a group in which a hydrogen atom in these groups is substituted with an alkyl group, an alkoxy group or the like.

The “substituted amino group” means an amino group having two substituents. An alkyl group, an aryl group, and a monovalent | monohydric heterocyclic group are mentioned as an example of the substituent which an amino group has, An alkyl group, an aryl group, or a monovalent | monohydric heterocyclic group is preferable. The carbon atom number of the substituted amino group is usually 2-30.

Examples of the substituted amino group include dialkylamino groups such as dimethylamino and diethylamino; diphenylamino, bis (4-methylphenyl) amino, bis (4-tert-butylphenyl) amino, bis (3, And diarylamino groups such as 5-di-tert-butylphenyl) amino group.

The "acyl group" usually has about 2 to 20 carbon atoms, and preferably 2 to 18 carbon atoms. Specific examples of the acyl group include acetyl group, propionyl group, butyryl group, isobutyryl group, pivaloyl group, benzoyl group, trifluoroacetyl group, and pentafluorobenzoyl group.

The “imine residue” refers to an atomic group obtained by removing one hydrogen atom directly bonded to a carbon atom or a nitrogen atom constituting a carbon atom-nitrogen atom double bond from an imine compound. The "imine compound" means an organic compound having a carbon atom-nitrogen atom double bond in the molecule. Examples of the imine compound include aldimine, ketimine, and a compound in which a hydrogen atom bonded to a nitrogen atom constituting a carbon atom-nitrogen atom double bond in the aldimine is substituted with an alkyl group or the like.

The imine residue usually has about 2 to 20 carbon atoms, and preferably 2 to 18 carbon atoms. Examples of imine residues include groups represented by the following structural formula.

The "amide group" means the remaining group except one hydrogen atom bonded to the nitrogen atom from the amide. The carbon atom number of the amide group is usually about 1 to 20, preferably 1 to 18. Specific examples of the amide group include formamide group, acetamide group, propioamide group, butyroamide group, benzamide group, trifluoroacetamide group, pentafluorobenzamide group, diformamide group, diacetamide group, dipropioamide group, dibutyroamide group, dibenzamide group , Ditrifluoroacetamide group, and dipentafluorobenzamide group.

The "acid imide group" refers to the remaining atomic group from acid imide except one hydrogen atom bonded to a nitrogen atom. The number of carbon atoms of the acid imide group is usually about 4 to 20. Specific examples of the acid imide group include the groups shown below.

The “substituted oxycarbonyl group” means a group represented by R′—O— (C = O) —. Here, R ′ represents an alkyl group, an aryl group, an arylalkyl group, or a monovalent heterocyclic group.
The substituted oxycarbonyl group usually has about 2 to 60 carbon atoms, and preferably 2 to 48 carbon atoms.

Specific examples of the substituted oxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, isobutoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group Group, cyclohexyloxycarbonyl group, heptyloxycarbonyl group, octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3, 7-dimethyloctyloxycarbonyl group, dodecyloxycarbonyl group, tri Fluoromethoxycarbonyl group, pentafluoroethoxycarbonyl group, perfluorobutoxycarbonyl group, perfluorohexyloxycarbonyl , Perfluorooctyl group, phenoxycarbonyl group, naphthoxycarbonyl group, and a pyridyloxycarbonyl group.

The "alkenyl group" may be linear, branched or cyclic. The carbon atom number of the linear alkenyl group is usually 2 to 30, preferably 3 to 20, not including the carbon atom number of the substituent. The carbon atom number of the branched or cyclic alkenyl group is usually 3 to 30, preferably 4 to 20, not including the carbon atom number of the substituent.

The alkenyl group may have a substituent. Specific examples of the alkenyl group include vinyl group, 1-propenyl group, 2-propenyl group, 2-butenyl group, 3-butenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5-hexenyl group And 7-octenyl groups, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, an alkoxy group or the like.

The "alkynyl group" may be linear, branched or cyclic. The carbon atom number of the linear alkenyl group is usually 2 to 20, preferably 3 to 20, not including the carbon atom number of the substituent. The carbon atom number of the branched or cyclic alkenyl group is usually 4 to 30, preferably 4 to 20, not including the carbon atom number of the substituent.

The alkynyl group may have a substituent. Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, 3-pentynyl group, 4-pentynyl group, 4-pentynyl group, 1-hexynyl group, 5-hexynyl group And groups in which a hydrogen atom in these groups is substituted with an alkyl group, an alkoxy group or the like.

As used herein, the term "ink" means a liquid used in a coating method and is not limited to colored liquids. In addition, the term "coating method" includes a method of forming a film using a liquid substance, for example, slit coating method, knife coating method, spin coating method, casting method, microgravure coating method, gravure coating method, bar Coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, gravure printing method, flexographic printing method, offset printing method, ink jet coating method, dispenser printing method, nozzle coating method, capillary The coat method is mentioned.

The "ink" may be a solution, or may be a dispersion, such as a dispersion, an emulsion (emulsion), a suspension (suspension) or the like.

[2. ink]
The ink of the present invention comprises a p-type semiconductor material, an n-type semiconductor material, a first solvent, and a second solvent.

[Ink component]
(First solvent)
The first solvent is a nitrogen-containing heterocyclic compound. When the ink of the present invention contains a nitrogen-containing heterocyclic compound as the first solvent, the external quantum efficiency of the photoelectric conversion element can be improved. Although the reason is not to limit the present invention, the following mechanism is presumed.

It is considered that the nitrogen-containing heterocyclic compound as the first solvent and the n-type semiconductor material such as the fullerene derivative strongly interact with each other due to a hydrogen bond, a dispersing force and the like. When a coating is formed from the ink and the solvent is removed from the coating by drying or the like, the strong interaction between the nitrogen-containing heterocyclic compound and the n-type semiconductor material causes the n-type semiconductor material to be coated as well as removing the solvent. It is thought that it becomes possible to move (migration) easily in the middle. As a result, in the solidified film obtained by removing the solvent from the coating film, it is considered that a network of n-type semiconductor material functioning as a charge transfer path is sufficiently formed to improve the external quantum efficiency.

The nitrogen-containing heterocyclic compound includes, for example, pyridine which may have a substituent, quinoline which may have a substituent, quinoxaline which may have a substituent, and the like. And 1,2,3,4-tetrahydroquinoline, pyrimidine which may have a substituent, pyrazine which may have a substituent, and quinazoline which may have a substituent. . The first solvent may be composed of one type of nitrogen-containing heterocyclic compound or may be composed of two or more types of nitrogen-containing heterocyclic compounds. Preferably, the first solvent is composed of one nitrogen-containing heterocyclic compound.

The nitrogen-containing heterocyclic compound may have a substituent on the ring structure.
As a substituent which the ring structure (eg, quinoline ring structure, 1,2,3,4-tetrahydroquinoline ring structure, quinoxaline ring structure) of the nitrogen-containing heterocyclic compound may have, for example, the number of carbon atoms There may be mentioned an alkyl group of 1 to 5, an alkoxy group of 1 to 5 carbon atoms, a halogen group and an alkylthio group.

The nitrogen-containing heterocyclic compound as the first solvent contains a six-membered ring structure, and the six-membered ring structure contains one or two hetero atoms, and the one or two hetero atoms are respectively nitrogen atoms Is preferred. Examples of the 6-membered ring structure containing one hetero atom and wherein one hetero atom is a nitrogen atom include a pyridine ring structure, a tetrahydropyridine ring structure, and a piperidine ring structure. Examples of the 6-membered ring structure containing two hetero atoms, wherein the two hetero atoms are nitrogen atoms include a pyrazine ring structure and a pyrimidine ring structure.

As the nitrogen-containing heterocyclic compound containing a pyridine ring structure, for example, pyridine which may have a substituent, quinoline which may have a substituent, and isoquinoline which may have a substituent are exemplified. It can be mentioned.

Examples of the nitrogen-containing cyclic compound containing a tetrahydropyridine ring structure include optionally substituted 1,2,3,4-tetrahydroquinoline and optionally substituted 1,2,3 3,4- tetrahydroisoquinoline is mentioned.

Examples of the nitrogen-containing cyclic compound containing a pyrazine ring structure include pyrazine which may have a substituent and quinoxaline which may have a substituent.

Examples of the nitrogen-containing cyclic compound containing a pyrimidine ring structure include pyrimidine which may have a substituent, and quinazoline which may have a substituent.

The first solvent is
Preferably, it is a nitrogen-containing heterocyclic compound containing a pyridine ring structure, a tetrahydropyridine ring structure, a piperidine ring structure or a pyrazine ring structure, and more preferably a nitrogen-containing heterocyclic compound containing a pyridine ring structure, a tetrahydropyridine ring or a pyrazine ring structure A heterocyclic compound,
More preferably, it is selected from the group consisting of quinoline which may have a substituent, 1,2,3,4-tetrahydroquinoline which may have a substituent, and quinoxaline which may have a substituent. At least one of
More preferably, it is one or more selected from the group consisting of quinoline having an alkyl group, 1,2,3,4-tetrahydroquinoline having an alkyl group, and quinoxaline having an alkyl group,
More preferably, one kind selected from the group consisting of 2-methylquinoline, 3-methylquinoline, 6-methylquinoline, 8-methylquinoline, 1,2,3,4-tetrahydroquinaldine, and 2-methylquinoxaline It is above.

In another aspect, the first solvent is
Preferably, quinoline which may have a substituent, 1,2,3,4-tetrahydroquinoline which may have a substituent, or quinoxaline which may have a substituent is preferable.
More preferably, quinoline having an alkyl group, 1,2,3,4-tetrahydroquinoline having an alkyl group, or quinoxaline having an alkyl group,
More preferably, 2-methylquinoline, 3-methylquinoline, 6-methylquinoline, 8-methylquinoline, 1,2,3,4-tetrahydroquinaldine, or 2-methylquinoxaline.

(Second solvent)
The second solvent is an aromatic hydrocarbon. As the second solvent, a solvent capable of dissolving the p-type semiconductor material is preferable.

As the aromatic hydrocarbon, for example, toluene, xylene (eg, o-xylene, m-xylene, p-xylene), trimethylbenzene (eg, mesitylene, 1,2,4-trimethylbenzene (pseudocumene)), butylbenzene Examples are (for example, n-butylbenzene, sec-butylbenzene, tert-butylbenzene), methylnaphthalene (eg 1-methylnaphthalene), tetralin and indane.

The second solvent may be composed of one aromatic hydrocarbon or may be composed of two or more aromatic hydrocarbons. Preferably, the second solvent is composed of one aromatic hydrocarbon.

The second solvent is preferably toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methyl At least one selected from the group consisting of naphthalene, tetralin and indane,
More preferably, toluene, o-xylene, m-xylene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, methyl naphthalene, tetralin or indane It is.

(Combination of the first solvent and the second solvent)
As a combination of a 1st solvent and a 2nd solvent, the combination shown, for example in the following table | surface is mentioned.

(Weight ratio of first solvent and second solvent)
The weight ratio of the first solvent to the second solvent (first solvent / second solvent) is preferably 1/99 from the viewpoint of improving the solubility of the p-type semiconductor material and the n-type semiconductor material. Or more, more preferably 3/97 or more, still more preferably 5/95 or more, preferably 20/80 or less, more preferably 15/85 or less, more preferably 10/90 or less, preferably 1/99 20/80 or less, more preferably 3/97 or more and 15/85 or less, still more preferably 5/95 or more and 10/90 or less.

(Weight percentage of the sum of the first solvent and the second solvent in the ink)
The total weight of the first solvent and the second solvent contained in the ink is preferably from the viewpoint of making the solubility of the p-type semiconductor material and the n-type semiconductor material better with respect to 100% by weight of the total weight of the ink. Is 90% by weight or more, more preferably 92% by weight or more, still more preferably 95% by weight, and from the viewpoint of facilitating formation of a film having a certain thickness or more, preferably 99% by weight or less, more preferably 98% by weight % Or less, more preferably 97.5% by weight or less.

(Any solvent)
The ink may comprise any solvent other than the first solvent and the second solvent. The content of the optional solvent is preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 1% by weight or less, based on 100% by weight of the total weight of all the solvents contained in the ink. Particularly preferably, it is 0% by weight.

(P-type semiconductor material)
The p-type semiconductor material may be a low molecular weight compound or a high molecular weight compound.

Examples of p-type semiconductor materials which are low molecular weight compounds include phthalocyanines, metal phthalocyanines, porphyrins, metal porphyrins, oligothiophenes, tetracenes, pentacenes, and rubrenes.

As the p-type semiconductor material which is a polymer compound, for example, polyvinylcarbazole and its derivative, polysilane and its derivative, polysiloxane derivative having aromatic amine structure in side chain or main chain, polyaniline and its derivative, polythiophene and its derivative And polypyrrole and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, polyfluorene and derivatives thereof and the like.

The p-type semiconductor material is preferably a polymer compound from the viewpoint of making the stability of the ink excellent, and from the viewpoint of making the external quantum efficiency of the photoelectric conversion device excellent, the following formula (I) It is preferable that it is a high molecular compound containing the structural unit represented by the structural unit represented by, and / or following formula (II).

In formula (I), Ar ¹ and Ar ² each represent a trivalent aromatic heterocyclic group, and Z is a group represented by any one of the following formulas (Z-1) to (Z-7) Represents

In formula (II), Ar ³ represents a divalent aromatic heterocyclic group.

In formulas (Z-1) to (Z-7), R represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a monovalent heterocyclic group, a substituted group It represents an amino group, an acyl group, an imine residue, an amido group, an acid imide group, a substituted oxycarbonyl group, an alkenyl group, an alkynyl group, a cyano group or a nitro group. When two R's are present in each of Formula (Z-1) to Formula (Z-7), two R's may be the same as or different from each other.

The constitutional unit represented by the formula (I) is preferably a constitutional unit represented by the following formula (I-1).

In formula (I-1), Z represents the same meaning as described above.

Examples of the structural unit represented by the formula (I-1) include structural units represented by the following formulas (501) to (505).

In the above formulas (501) to (505), R represents the same meaning as described above. When two R's are present, two R's may be the same or different.

The number of carbon atoms of the divalent aromatic heterocyclic group represented by Ar ³ is generally 2 to 60, preferably 4 to 60, and more preferably 4 to 20. The divalent aromatic heterocyclic group represented by Ar ³ may have a substituent. Examples of the substituent which the divalent aromatic heterocyclic group represented by Ar ³ may have include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, Examples thereof include monovalent heterocyclic groups, substituted amino groups, acyl groups, imine residues, amide groups, acid imide groups, substituted oxycarbonyl groups, alkenyl groups, alkynyl groups, cyano groups, and nitro groups.

Examples of the divalent aromatic heterocyclic group represented by Ar ³ include groups represented by the following formulas (101) to (185).

In formulas (101) to (185), R represents the same meaning as described above. When a plurality of R's are present, the plurality of R's may be the same or different.

As the constitutional unit represented by the formula (II), constitutional units represented by the following formulas (II-1) to (II-6) are preferable.

In formulas (II-1) to (II-6), X ¹ and X ² each independently represent an oxygen atom or a sulfur atom, and R represents the same meaning as described above. When a plurality of R's are present, the plurality of R's may be the same or different.

It is preferable that each of X ¹ and X ² in the formulas (II-1) to (II-6) is a sulfur atom because the raw material compounds are easily available.

The polymer compound which is a p-type semiconductor material may contain two or more structural units of the formula (I), and may contain two or more structural units of the formula (II).

In order to improve the solubility in a solvent, the polymer compound which is a p-type semiconductor material may contain a constitutional unit represented by the following formula (III).

In formula (III), Ar ⁴ represents an arylene group.

The arylene group represented by Ar ⁴ means an atomic group remaining after removing two hydrogen atoms from an aromatic hydrocarbon which may have a substituent. The aromatic hydrocarbon also includes a compound having a condensed ring, and a compound in which two or more members selected from the group consisting of independent benzene rings and condensed rings are directly or linked via a divalent group such as vinylene.

Examples of the substituent which the aromatic hydrocarbon may have include the same substituents as the examples mentioned above as the substituent which the heterocyclic compound may have.

The carbon atom number of the arylene group excluding the substituent is usually 6 to 60, and preferably 6 to 20. The number of carbon atoms of the arylene group including the substituent is usually about 6 to 100.

Examples of arylene groups include phenylene (for example, the following formulas 1 to 3), naphthalene-diyl (for example, the following formulas 4 to 13), anthracene-diyl (for example, the following formulas 14 to 19), Biphenyl-diyl group (for example, the following formulas 20 to 25), terphenyl-diyl group (for example, the following formulas 26 to 28), fused ring compound group (for example, the following formulas 29 to 35), fluorene-diyl group (For example, the following formulas 36 to 38), and a benzofluorene-diyl group (for example, the following formulas 39 to 46).

When the polymer compound as the p-type semiconductor material contains the constitutional unit represented by the formula (I) and / or the constitutional unit represented by the formula (II), the constitutional unit represented by the formula (I) and the formula The total amount of the constituent units represented by (II) is usually 20 to 100 mol%, assuming that the amount of all constituent units contained in the polymer compound is 100 mol%, and the charge transportability as a p-type semiconductor material Preferably from 40 to 100 mol%, more preferably from 50 to 100 mol%.

Examples of the polymer compound as the p-type semiconductor material include polymer compounds represented by the following formula

The polymer compound as a p-type semiconductor material has a polystyrene equivalent weight average molecular weight of usually 1 × 10 ³ to 1 × 10 ⁸ and is preferably 1 × 10 ³ to ^{3 in} view of improving the solubility in a solvent. It is 1 × 10 ⁶ .

The ink may contain only one p-type semiconductor material, or may contain two or more arbitrary proportions.

(N-type semiconductor material)
The n-type semiconductor material may be a low molecular weight compound or a high molecular weight compound.

Examples of n-type semiconductor materials (electron accepting compounds) which are low molecular weight compounds include oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyano Anthraquinodimethane and derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, fullerenes such as C ₆₀ fullerene and derivatives thereof, and phenanthrene derivatives such as vasocuproin Can be mentioned.

Examples of n-type semiconductor materials (electron accepting compounds) which are high molecular compounds include polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having an aromatic amine structure in the side chain or main chain, polyaniline and the like Derivatives, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, and polyfluorene and derivatives thereof can be mentioned.

The n-type semiconductor material is preferably at least one selected from fullerenes and fullerene derivatives, and more preferably fullerene derivatives.

Examples of _{fullerene, C 60} _{fullerene, C 70} _{fullerene, C 76} _{fullerene, C 78} fullerene, and include _{C 84} fullerene. Examples of fullerene derivatives include derivatives of these fullerenes. The fullerene derivative means a compound in which at least a part of the fullerene is modified.

Examples of the fullerene derivative include compounds represented by the following formulas (N-1) to (N-4).

In formulas (N-1) to (N-4),
R ^a represents an alkyl group, an aryl group, a monovalent heterocyclic group, or a group having an ester structure. The plurality of ^Ras may be the same as or different from each other.
R ^b represents an alkyl group or an aryl group. Plural R ^{b 's} may be the same as or different from each other.

Examples of the group having an ester structure represented by ^Ra include a group represented by the following formula (19).

In formula (19), u1 represents an integer of 1 to 6. u2 represents an integer of 0 to 6; R ^c represents an alkyl group, an aryl group or a monovalent heterocyclic group.

Examples of C ₆₀ fullerene derivatives include the following compounds.

The following compounds may be mentioned as examples of C ₇₀ fullerene derivatives.

Specific examples of the fullerene derivative include [6,6] -phenyl-C61 butyric acid methyl ester (C60PCBM, [6,6] -phenyl C61 butyric acid methyl ester), [6,6] -phenyl-C71 butyric acid methyl ester ( C70PCBM, [6,6] -Phenyl C71 butyric acid methyl ester, [6,6] -phenyl-C85 butyric acid methyl ester (C84PCBM, [6,6] -phenyl C85 butyric acid methyl ester), and [6,6] ] -Thienyl-C61 butyric acid methyl ester ([6,6] -Thienyl C61 butyric acid methyl ester).

The ink may contain only one n-type semiconductor material, or may contain two or more arbitrary proportions of combinations.

(Composition ratio of p-type semiconductor material and n-type semiconductor material)
The weight ratio of the p-type semiconductor material to the n-type semiconductor material in the ink (p-type semiconductor material: n-type semiconductor material) is preferably 1: 9 to 9: 1, and 1: 9 to 2: 1. Is more preferable, 1: 9 or more and 1: 1 or less is further preferable, and 1: 5 or more and 1: 1 or less is particularly preferable.

(Any ingredient)
The ink may contain any component other than the first solvent, the second solvent, the p-type semiconductor material, and the n-type semiconductor material as long as the effects of the present invention are not impaired.
Optional components include, for example, solvents other than the first solvent and the second solvent as described above, propiophenone, methyl benzoate, ethyl benzoate and benzyl benzoate.

(Concentration of p-type semiconductor material and n-type semiconductor material in ink)
The total concentration of the p-type semiconductor material and the n-type semiconductor material in the ink is preferably 0.01% by weight or more and 20% by weight or less, and more preferably 0.01% by weight or more and 10% by weight or less More preferably, it is 0.01% by weight or more and 5% by weight or less, and particularly preferably 0.1% by weight or more and 5% by weight or less. In the ink, the p-type semiconductor material and the n-type semiconductor material may be dissolved or dispersed, but preferably at least a part is dissolved, and more preferably all is dissolved.

[Method of producing ink]
The ink can be produced by a known method. For example, a method of preparing a mixed solvent by mixing a first solvent and a second solvent, and adding a p-type semiconductor material and an n-type semiconductor material to the mixed solvent for production; a p-type semiconductor material in the first solvent And the n-type semiconductor material is added to the second solvent, and then the mixture is manufactured by mixing the first solvent and the second solvent to which each material is added; .

The first solvent and the second solvent, and the p-type semiconductor material and the n-type semiconductor material may be heated to a temperature equal to or lower than the boiling point of the solvent and mixed.

After mixing the first solvent and the second solvent with the p-type semiconductor material and the n-type semiconductor material, the resulting composition may be filtered using a filter, and the filtrate may be used as an ink. As the filter, for example, a filter formed of a fluorine resin such as polytetrafluoroethylene (PTFE) can be used.

[Use of ink]
The application of the ink of the present invention is optional. The ink of the present invention can be used to form a film containing a p-type semiconductor material and an n-type semiconductor material.
The ink of the present invention is suitably used to form an active layer contained in a photoelectric conversion element. In particular, the light detection element including the active layer formed using the ink of the present invention has improved EQE when a reverse bias voltage is applied. Therefore, the ink of the present invention is particularly suitably used to form an active layer contained in a light detection element.

[3. Solidified film of ink]
After the film is formed by the ink, the solvent is removed from the film and the film is solidified to obtain a solidified film of the ink.

The dimensions, such as thickness, of the solidified film of the ink are not particularly limited.

The solidified film of the ink is suitably used for the application described as the application of the ink.

[4. Method of producing solidified film of ink]
The solidified film of the ink can be manufactured by any manufacturing method. One embodiment of a method for producing a solidified film of ink includes a step (i) of applying an ink to an application target to obtain a coating, and a step (ii) of removing a solvent from the obtained coating.

[Step (i)]
Any application method can be used as a method of applying the ink to the application target. The coating method is preferably a slit coating method, a knife coating method, a spin coating method, a microgravure coating method, a gravure coating method, a bar coating method, an ink jet coating method, a nozzle coating method or a capillary coating method. The coating method, the capillary coating method, or the bar coating method is more preferable, and the slit coating method or the spin coating method is more preferable.

The ink is applied to any application target. For example, the ink may be applied on a functional layer of a photoelectric conversion element, such as an electrode (anode or cathode), an electron transport layer, or a hole transport layer, in a manufacturing process of the photoelectric conversion element.

[Step (ii)]
Arbitrary methods can be used as a method of removing a solvent from a coating film. Examples of the method of removing the solvent include drying methods such as a hot air drying method, an infrared heat drying method, a flash lamp annealing drying method, and a reduced pressure drying method.

[5. Photoelectric conversion element]
The photoelectric conversion element of the present invention comprises a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode in this order, and the active layer is a solidified film of ink. .

[Elements of photoelectric conversion element]
(Active layer)
The active layer includes p-type semiconductor material and n-type semiconductor material. The active layer is a solidified film of the above-mentioned ink. Examples and preferred examples of the p-type semiconductor material, the n-type semiconductor material, and the ink are the same as those described in [2. Ink] is the same as the example described in the section.

In the photoelectric conversion element, the EQE is improved by the active layer being a solidified film of the ink. In particular, EQE improves when a reverse bias voltage is applied to the photoelectric conversion element. Therefore, the photoelectric conversion element of the present invention is suitable as a light detection element.

The photoelectric conversion element may have a plurality of active layers.

(electrode)
Preferably, at least one of the first electrode and the second electrode is a transparent or translucent electrode. When the substrate is opaque, it is preferable that one of the first electrode and the second electrode which is farther from the substrate is transparent or translucent.

Examples of transparent or translucent electrodes include conductive metal oxide films and translucent metal thin films. Specific examples of the transparent or translucent electrode material include, for example, indium oxide, zinc oxide, tin oxide, and a complex thereof (eg, indium tin oxide (ITO), indium zinc oxide), These include NESA, gold, platinum, silver and copper. Among them, as the transparent or translucent electrode material, one or more selected from ITO, indium zinc oxide and tin oxide are preferable.

Examples of the method for producing the electrode include a vacuum evaporation method, a sputtering method, an ion plating method, and a plating method.

A transparent conductive film composed of an organic compound such as polyaniline and a derivative thereof and polythiophene and a derivative thereof may be used as the transparent or translucent electrode.

One of the first electrode and the second electrode may be an electrode with low light transmittance. Examples of the material of the low light transmitting electrode include metals and conductive polymers. Specific examples of the electrode material include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium and the like And alloys of two or more of them; one or more of the above metals and one or more metals selected from the group consisting of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten and tin Graphite; graphite intercalation compounds; polyaniline and its derivatives; polythiophene and its derivatives.

More specifically, as the alloy, for example, magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminium alloy, indium-silver alloy, lithium-aluminium alloy, lithium-magnesium alloy, lithium-indium alloy, calcium- Aluminum alloy is mentioned.

[Any element]
The photoelectric conversion element may include elements other than the first electrode, the active layer, and the second electrode. Optional elements include, for example, a substrate, a hole transport layer, an electron transport layer, and a sealing layer.

(substrate)
The photoelectric conversion element is usually formed on a substrate (supporting substrate). The substrate is preferably formed of a material that does not change chemically when forming the electrode and forming the organic layer. Examples of substrate materials include glass, plastic, polymer films, and silicon.

The substrate may have low light transmittance, but in the photoelectric conversion element, for example, when taking in light from the substrate, the substrate is preferably transparent or translucent. In the case of manufacturing a photoelectric conversion element on a substrate with low light transmittance, light can not be taken in from the electrode side closer to the substrate, so a transparent or semitransparent electrode is used for the electrode far from the substrate. It is preferred to use. By using a transparent or translucent electrode for the electrode far from the substrate, light can be taken in from the electrode far from the substrate, even if a substrate with low light transmittance is used.

(Hole transport layer)
In the photoelectric conversion element, a hole transport layer may be provided between an electrode which is an anode and an active layer. The hole transport layer has a function of transporting holes from the active layer to the electrode.

The hole transport layer provided in contact with the electrode may be particularly referred to as a hole injection layer. The hole transport layer (hole injection layer) provided in contact with the electrode has a function of promoting the injection of holes into the electrode. The hole transport layer (hole injection layer) may be in contact with the active layer.

The hole transport layer contains a hole transport material. Examples of the hole transporting material include polythiophene and derivatives thereof, an aromatic amine compound, a polymer compound containing a constitutional unit having an aromatic amine residue, CuSCN, CuI, NiO, and molybdenum oxide (MoOx). .

(Electron transport layer)
In the photoelectric conversion element, an electron transport layer may be provided between an electrode which is a cathode and an active layer. The electron transport layer has a function of transporting electrons from the active layer to the electrode. The electron transport layer may be in contact with the electrode. The electron transport layer may be in contact with the active layer.

The electron transport layer contains an electron transport material. Examples of electron transporting materials include zinc oxide nanoparticles, gallium-doped zinc oxide nanoparticles, aluminum-doped zinc oxide nanoparticles, polyethyleneimine, polyethyleneimine ethoxylated, and PFN-P2.

(Sealing layer)
The photoelectric conversion element may include a sealing layer. The sealing layer is provided, for example, on the electrode side far from the substrate. The sealing layer can be formed of a material having a moisture blocking property (water vapor barrier property) or an oxygen blocking property (oxygen barrier property).

Below, one Embodiment of the photoelectric conversion element of this invention is described using figures.
FIG. 1 is a schematic view showing an embodiment of the photoelectric conversion element of the present invention.
The photoelectric conversion element 10 of the present embodiment is provided on the support substrate 11 and includes the first electrode 12 as an anode, the hole transport layer 13, the active layer 14, the electron transport layer 15, And the two electrodes 16 in this order. The first electrode 12 is provided to be in contact with one of two main surfaces of the support substrate 10. A hole transport layer 13 is provided in contact with the first electrode 12. An active layer 14 is provided in contact with the hole transport layer 13. An electron transport layer 15 is provided in contact with the active layer 14. A second electrode 16 as a cathode is provided in contact with the electron transport layer 15. The material constituting the supporting substrate 11 and the material constituting each element (the first electrode 12, the hole transport layer 13, the active layer 14, the electron transport layer 15, the second electrode 16) included in the photoelectric conversion element 10 are as follows. The material mentioned as an example as a material which constitutes each above-mentioned element may be sufficient.

The photoelectric conversion element of the present invention can be produced by any method. The photoelectric conversion element of the present invention is, for example, the above item [4. Method of Producing Solidified Film of Ink] The method can be produced by the method including the method of producing a solidified film of ink described in the above. Specifically, for example, the photoelectric conversion element of the present invention can be manufactured by a method including the above-mentioned step (i) and step (ii).

[Use of photoelectric conversion element]
The photoelectric conversion element of the present invention generates photovoltaic power between electrodes by being irradiated with light such as sunlight, and can be operated as a solar cell. Further, by integrating a plurality of solar cells, it can also be used as a thin film solar cell module.

Further, the photoelectric conversion element of the present invention can flow a photocurrent by irradiating light to a transparent or semi-transparent electrode in a state where a voltage is applied between the electrodes, and as a light sensor (light detection element) It can be operated. It can also be used as an image sensor by integrating a plurality of light sensors.

(Application example of photoelectric conversion element)
The photoelectric conversion device according to the embodiment of the present invention described above is suitably applied to detection units included in various electronic devices such as workstations, personal computers, portable information terminals, room access control systems, digital cameras, and medical devices. can do.

The photoelectric conversion element (light detection element) of the present invention is included in the electronic device illustrated above, for example, an image detection unit (image sensor) for a solid-state imaging device such as an X-ray imaging device and a CMOS image sensor, a fingerprint detection unit The present invention can be suitably applied to a detection unit that detects predetermined features of a part of a living body such as a face detection unit, a vein detection unit, and an iris detection unit, and a detection unit of an optical biosensor such as a pulse oximeter.

Hereinafter, among detection units to which the photoelectric conversion element according to the embodiment of the present invention can be suitably applied, an example configuration of an image detection unit for a solid-state imaging device and a fingerprint detection unit for a biometric information authentication device (fingerprint authentication device) Will be described with reference to the drawings.

(Image detection unit)
FIG. 2 is a view schematically showing a configuration example of an image detection unit for a solid-state imaging device.

The image detection unit 1 includes a CMOS transistor substrate 20, an interlayer insulating film 30 provided so as to cover the CMOS transistor substrate 20, and photoelectric conversion according to an embodiment of the present invention provided on the interlayer insulating film 30. It is provided so as to penetrate element 10 and interlayer insulating film 30, and is provided so as to cover photoelectric conversion element 10 and interlayer wiring portion 32 electrically connecting CMOS transistor substrate 20 and photoelectric conversion element 10. And a color filter 50 provided on the sealing layer.

The CMOS transistor substrate 20 has any suitable configuration known in the art according to the design.

The CMOS transistor substrate 20 includes transistors, capacitors and the like formed within the thickness of the substrate, and is equipped with functional elements such as a CMOS transistor circuit (MOS transistor circuit) for realizing various functions.

Examples of the functional element include a floating diffusion, a reset transistor, an output transistor, and a selection transistor.
A signal readout circuit or the like is built in the CMOS transistor substrate 20 by such functional elements, wirings, and the like.

The interlayer insulating film 30 can be made of, for example, any conventionally known suitable insulating material such as silicon oxide or insulating resin. The interlayer wiring portion 32 can be made of, for example, any conventionally known suitable conductive material (wiring material) such as copper, tungsten or the like. The interlayer wiring section 32 may be, for example, an in-hole wiring formed simultaneously with the formation of the wiring layer, or may be a buried plug formed separately from the wiring layer.

The sealing layer 40 is made of any conventionally known suitable material, on the condition that penetration of harmful substances such as oxygen and water which may cause the photoelectric conversion element 10 to be functionally deteriorated can be prevented or suppressed. Can.

As the color filter 50, for example, a primary color filter that is made of any suitable material known in the related art and corresponds to the design of the image detection unit 1 can be used. Further, as the color filter 50, a complementary color filter which can be thinner than the primary color filter can be used. As complementary color filters, for example, 3 types of (yellow, cyan, magenta), 3 types of (yellow, cyan, transparent), 3 types of (yellow, transparent, magenta), and 3 of (transparent, cyan, magenta) Color filters of different types can be used. These can be arranged in any suitable manner corresponding to the design of the photoelectric conversion element 10 and the CMOS transistor substrate 20, provided that color image data can be generated.

The light received by the photoelectric conversion element 10 through the color filter 50 is converted by the photoelectric conversion element 10 into an electrical signal according to the amount of light received, and the light reception signal outside the photoelectric conversion element 10 through the electrode, ie, an imaging target Is output as an electrical signal corresponding to

Next, the light reception signal output from the photoelectric conversion element 10 is input to the CMOS transistor substrate 20 through the interlayer wiring portion 32, and is read by a signal readout circuit built in the CMOS transistor substrate 20, and further not shown. Signal processing is performed by any suitable conventional known functional unit to generate image information based on an imaging target.

(Fingerprint detection unit)
FIG. 3 is a view schematically showing a configuration example of a fingerprint detection unit configured integrally with the display device.

The display device 2 of the portable information terminal includes a fingerprint detection unit 100 including the photoelectric conversion element 10 according to the embodiment of the present invention as a main component, and a display panel provided on the fingerprint detection unit 100 and displaying a predetermined image. And a unit 200.

In this configuration example, the fingerprint detection unit 100 is provided in an area substantially corresponding to the display area 200 a of the display panel unit 200. In other words, the display panel unit 200 is integrally stacked above the fingerprint detection unit 100.

In the case of performing fingerprint detection only in a part of the display area 200a, the fingerprint detection unit 100 may be provided in correspondence with only the part of the display area 200a.

The fingerprint detection unit 100 includes the photoelectric conversion element 10 according to the embodiment of the present invention as a functional unit that performs essential functions. The fingerprint detection unit 100 may be any desired conventionally known member such as a protection film (protection film), a support substrate, a sealing substrate, a sealing member, a barrier film, a band pass filter, an infrared cut film, etc. not shown. It can be provided in a manner corresponding to the design to obtain the characteristics. The fingerprint detection unit 100 may adopt the configuration of the image detection unit described above.

The photoelectric conversion element 10 can be included in any mode in the display area 200a. For example, a plurality of photoelectric conversion elements 10 may be arranged in a matrix.

As described above, the photoelectric conversion element 10 is provided on the support substrate 11 or the sealing substrate, and the support substrate 11 is provided with an electrode (anode or cathode) in a matrix, for example.

The light received by the photoelectric conversion element 10 is converted by the photoelectric conversion element 10 into an electric signal according to the amount of light received, and the light reception signal outside the photoelectric conversion element 10 through the electrodes, that is, the electric corresponding to the captured fingerprint It is output as a signal.

The display panel unit 200 is configured as an organic electroluminescence display panel (organic EL display panel) including a touch sensor panel in this configuration example. The display panel unit 200 may be configured of, for example, a display panel having an arbitrary suitable conventionally known configuration such as a liquid crystal display panel including a light source such as a backlight instead of the organic EL display panel.

The display panel unit 200 is provided on the fingerprint detection unit 100 described above. The display panel unit 200 includes an organic electroluminescent element (organic EL element) 220 as a functional part that performs essential functions. The display panel unit 200 further includes any substrate such as a conventionally known glass substrate (support substrate 210 or sealing substrate 240), sealing member, barrier film, polarizing plate such as circular polarizing plate, touch sensor panel 230, etc. Suitable previously known components can be provided in a manner corresponding to the desired properties.

In the configuration example described above, the organic EL element 220 is used not only as a light source for pixels in the display area 200 a but also as a light source for capturing a fingerprint in the fingerprint detection unit 100.

Here, the operation of the fingerprint detection unit 100 will be briefly described.
When fingerprint authentication is performed, the fingerprint detection unit 100 detects a fingerprint using light emitted from the organic EL element 220 of the display panel unit 200. Specifically, light emitted from the organic EL element 220 is transmitted through components existing between the organic EL element 220 and the photoelectric conversion element 10 of the fingerprint detection unit 100, and the display is in the display region 200a. The light is reflected by the skin (finger surface) of the fingertip of the finger placed in contact with the surface of the panel unit 200. At least a part of the light reflected by the finger surface is transmitted through the component present between them, received by the photoelectric conversion element 10, and converted into an electrical signal according to the amount of light received by the photoelectric conversion element 10. Then, from the converted electrical signal, image information on the fingerprint on the finger surface is constructed.

The portable information terminal provided with the display device 2 performs fingerprint authentication by comparing the obtained image information with fingerprint data for fingerprint authentication recorded in advance by any conventionally known and suitable steps.

[6. Method of manufacturing photoelectric conversion element]
The method for producing a photoelectric conversion element of the present invention is a method for producing a photoelectric conversion element comprising, in order, a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode. And the step of forming the active layer, wherein the step of forming the active layer is a step (i) of applying the ink to a target to be coated to obtain a coating, and removing the solvent from the coating obtained Step (ii) is included.

In the method for producing a photoelectric conversion element of the present invention, the step of forming an active layer preferably includes step (i) and step (ii) in this order.

Regarding examples and preferable examples of the p-type semiconductor material, the n-type semiconductor material, and the ink, the items [2. The same as the example described in [Ink]

Any application method can be used as a method of applying the ink to the application target. As a preferable coating method, a more preferable coating method, and a further preferable coating method, the items [4. Method of Producing Solidified Film of Ink] The same method as the method described in [Step (i)] may be mentioned.

Arbitrary methods can be used as a method of removing a solvent from the obtained coating film. As an example of the method of removing the solvent, the above item [4. Method of Producing Solidified Film of Ink] The same method as the method described in [Step (ii)] may be mentioned.

The step of forming the active layer may include an optional step other than the above step (ii) and step (ii).

The ink is applied over the layer to form the active layer. Therefore, the application object of the ink differs depending on the layer configuration of the photoelectric conversion element to be manufactured and the order of lamination. For example, when the photoelectric conversion element has a layer configuration of substrate / anode / hole transport layer / active layer / electron transport layer / cathode and is laminated in the order of the elements described on the left, the application of the ink The subject is usually a hole transport layer. Also, for example, when the photoelectric conversion element has a layer configuration of substrate / cathode / electron transport layer / active layer / hole transport layer / anode, and is stacked in the order of the elements described on the left, the ink The object of application is usually the electron transport layer.

The method of manufacturing a photoelectric conversion device according to an embodiment may be a method of manufacturing a photoelectric conversion device having a plurality of active layers, and even if step (i) and step (ii) are repeated a plurality of times. Good.

The method of manufacturing a photoelectric conversion element of the present invention can improve the EQE of the photoelectric conversion element. In particular, EQE can be improved when a reverse bias voltage is applied to the photoelectric conversion element. Therefore, the method for producing a photoelectric conversion element of the present invention is suitable as a method for producing a light detection element.

The following examples are provided to further illustrate the present invention. The invention is not limited to the following examples.

[Evaluation method]
(Method of measuring external quantum efficiency (EQE))
While applying a reverse bias voltage of 3 V to the photoelectric conversion element, using a solar simulator (trade name: CEP-2000 type), a fixed number of photons (1 per 10 nm) in the wavelength range of 300 nm to 1200 nm the light .0 × ^{10 16)} is irradiated to the photoelectric conversion element, to measure the current value of the current generated to determine the EQE spectrum at 1200nm wavelength 300nm by a known method.

[Semiconductor material used in the embodiment]
In this embodiment, p-type semiconductor materials and n-type semiconductor materials described in the following table are used.

As the material P-1, a material synthesized with reference to the method described in WO2013 / 051676 was used.
As the material P-2, a product manufactured by 1-material, product name: PCE10 is used.
As a material P-3, a 1-material company make, brand name: PDTSTPD is used.
As the material P-4, Lumtec's product name: PDPP3T is used.
As the material P-5, a material synthesized with reference to the method described in JP-A-2010-74127 is used.
As the material P-6, a material synthesized using the method described in WO 2011/052709 as a reference was used.
A trade name: E100 manufactured by Frontier Carbon, Inc. was used as the material N-1.
As the material N-2, a product manufactured by American Die Source, trade name: ADS71 BFA is used.

The solvents used in this example and their boiling points (bp) are as shown in the table below.

Example 1
[A. Preparation of ink]
A mixed solvent was prepared using 2-methylquinoline as the first solvent, pseudocumene as the second solvent, and a weight ratio of the first solvent to the second solvent of 10:90. In the mixed solvent, 2 wt% of the material P-1 as p-type semiconductor material with respect to the total weight of the composition and 3 wt% of the material N-1 as n-type semiconductor material with respect to the total weight of the composition are mixed. After stirring at 12 ° C. for 12 hours, the mixture was filtered through a PTFE filter with a pore size of 5 μm to obtain a composition (I-1) as an ink.

[B. Fabrication and evaluation of photoelectric conversion element]
A glass substrate on which an ITO film was formed to a thickness of 150 nm by sputtering was prepared. The glass substrate on which the ITO film was formed was subjected to surface treatment by ozone UV treatment.

(Formation of hole transport layer)
A suspension of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid in water (Clevios P VP AI4083 manufactured by Heraeus) was filtered through a filter with a pore size of 0.45 μm. The filtered suspension was spin-coated on the surface of the surface-treated substrate on the ITO side to form a 40 nm thick film. Next, the substrate on which the film was formed was placed on a hot plate in the air, and the film was dried at 200 ° C. for 10 minutes to form a hole transport layer.

(Formation of active layer)
Next, the composition (I-1) was spin-coated on the hole transport layer and then dried in a vacuum dryer (0.1 mbar) to form an active layer. The thickness of the active layer after drying was about 400 nm.

(Formation of electron transport layer)
Subsequently, a 45 wt% isopropanol dispersion (manufactured by Tayca, HTD-711Z) of zinc oxide nanoparticles (particle size 20 to 30 nm) is diluted with 10 times by weight of the dispersion, 3-pentanol, and the coating liquid Was prepared. The coating liquid was applied by spin coating to a thickness of 40 nm on the active layer, and dried under a nitrogen gas atmosphere to form an electron transport layer.

(Formation of electrode and formation of sealing layer)
Thereafter, in the resistance heating vapor deposition apparatus, an Ag film was formed to a thickness of about 80 nm on the electron transporting layer to form an electrode. Next, a UV curable sealant was applied to the periphery of the substrate on which the electrode was formed, and a glass plate was laminated, and then sealed by irradiation with UV light to obtain a photoelectric conversion element. The shape of the obtained photoelectric conversion element was a square of 1 cm × 1 cm.

(Evaluation of photoelectric conversion element)
The external quantum efficiency of the resulting device was measured by the method described above. In the wavelength range of 300 nm to 1200 nm, the maximum external quantum efficiency (EQE) was 68%. The results are shown in Table 6.

Examples 2 to 6 and Comparative Examples 1 to 3
[A.1 in Example 1] except that the solvents shown in Table 5 were used as the first solvent and the second solvent. Preparation of Ink] Compositions (I-2) to (I-6) and (C-1) to (C-3) were prepared in the same manner as the procedure described in the following.

In (Formation of Active Layer), the procedure is carried out except that the compositions (I-2) to (I-6) and (C-1) to (C-3) are used instead of the composition (I-1). Example 1 [B. Production and Evaluation of Photoelectric Conversion Element] The photoelectric conversion element was produced and evaluated in the same manner as the procedure described in the section. The results are shown in Table 6.

The photoelectric conversion elements of Examples 1 to 6 had higher external quantum efficiency when a reverse bias voltage of 3 V was applied, as compared with the photoelectric conversion elements of Comparative Examples 1 to 3.

Examples 7 to 11 and Comparative Examples 4 to 6
The solvents listed in the table below were used as the first solvent and the second solvent, and the material P-6 was used instead of the material P-1 as the p-type semiconductor material [A. Preparation of Inks] Compositions (I-7) to (I-11) and (C-4) to (C-6) as inks were prepared in the same manner as the procedure described in the following.

In (Formation of Active Layer), the compositions (I-7) to (I-11) and (C-4) to (C-6) were used instead of the composition (I-1), [B. Production and Evaluation of Photoelectric Conversion Element] The photoelectric conversion element was produced and evaluated in the same manner as the procedure described in the section. The results are shown in Table 8.

The photoelectric conversion elements of Examples 7 to 11 had higher external quantum efficiency when a reverse bias voltage of 3 V was applied, as compared with the photoelectric conversion elements of Comparative Examples 4 to 6.

DESCRIPTION OF SYMBOLS 1 image detection part 2 display 10

photoelectric conversion element

11 and 210 support substrate 12 1st electrode 13 hole transport layer 14 active layer 15 electron transport layer 16 2nd electrode 20 CMOS transistor substrate 30 interlayer insulation film 32 interlayer wiring part 40 sealing layer 50 color filter 100 fingerprint detection unit 200 display panel unit 200a display area 220 organic EL element 230 touch sensor panel 240 sealing substrate

Claims

An ink comprising a p-type semiconductor material, an n-type semiconductor material, a first solvent which is a nitrogen-containing heterocyclic compound, and a second solvent which is an aromatic hydrocarbon.
The ink according to claim 1, wherein the n-type semiconductor material is a fullerene derivative.
The nitrogen-containing heterocyclic compound comprises a six-membered ring structure, wherein the six-membered ring structure comprises one or two hetero atoms, and the one or two hetero atoms are each a nitrogen atom. Or the ink as described in 2.
The ink according to claim 3, wherein the six-membered ring structure is a pyridine ring structure, a tetrahydropyridine ring structure, a piperidine ring structure, or a pyrazine ring structure.
The first solvent comprises quinoline which may have a substituent, 1,2,3,4-tetrahydroquinoline which may have a substituent, and quinoxaline which may have a substituent. The ink according to any one of claims 1 to 4, which is one or more selected from the group.
The ink according to any one of claims 1 to 5, wherein a weight ratio of the first solvent to the second solvent (first solvent / second solvent) is 1/99 or more and 20/80 or less. .
The ink according to any one of claims 1 to 6, wherein the weight percentage of the total of the first solvent and the second solvent in the ink is 95 wt% or more and 99 wt% or less.
The ink according to any one of claims 1 to 7, which is for forming an active layer of a photoelectric conversion element.
A solidified film of the ink according to any one of claims 1 to 8.
A photoelectric conversion device comprising a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode in this order, the active layer being a solidified film according to claim 9 .
The photoelectric conversion element according to claim 10, which is a light detection element.
An image sensor comprising the photoelectric conversion element according to claim 10.
A fingerprint authentication apparatus, comprising the photoelectric conversion device according to claim 10.
A solidified film comprising the step (i) of applying the ink according to any one of claims 1 to 8 to a coating target to obtain a coating, and removing the solvent from the obtained coating (ii). Manufacturing method.
A method of manufacturing a photoelectric conversion element, comprising a first electrode, an active layer containing a p-type semiconductor material and an n-type semiconductor material, and a second electrode in this order,
A process (i) of applying the ink according to any one of claims 1 to 8 to a coating object to obtain a coating film, including the process of forming the active layer, and the process of forming the active layer The manufacturing method of a photoelectric conversion element including the process (ii) of removing a solvent from the obtained coating film.