JP6562398B2 - Semiconductor device, solar cell, solar cell module, and composition - Google Patents

Description

  The present invention relates to a semiconductor device, a solar cell, a solar cell module, and a composition.

  In semiconductor devices such as field effect transistors, electroluminescent elements (LEDs), and photoelectric conversion elements, deterioration of the semiconductor material over time causes a decrease in performance of the semiconductor devices. In particular, it is known that the perovskite semiconductor used in Non-Patent Documents 1 and 2 is easily deteriorated by moisture. In order to solve such a problem, for example, a method of providing a barrier layer such as a moisture-proof layer has been sought (Patent Document 1).

JP2011-77425A

Wang et al. Nanoscale, 2014, 6, 12287-12297. Boix et al. Materials today, 2014, 17, 16-23.

  In order to further improve the durability of a semiconductor device, it is required not only to provide a barrier layer but also to improve the durability of the semiconductor device by devising the configuration of the semiconductor layer itself.

  An object of this invention is to improve the durability of a semiconductor device.

  The present inventors have surprisingly found that the durability of a semiconductor device is improved by mixing an insulating polymer in a semiconductor layer, and the present invention has been completed based on this finding.

That is, the gist of the present invention is as follows.
[1] A semiconductor device having a pair of electrodes and a semiconductor layer disposed between the pair of electrodes, wherein the semiconductor layer includes a semiconductor compound and a repeating unit represented by the following formula (Ia) A semiconductor device comprising an insulating polymer.
(In Formula (Ia), R ¹ and R ² each independently represent a hydrocarbon group or a hydrogen atom, and R ¹ and R ² may be bonded to each other to form a ring.)
^[2], wherein R ¹ and the R ² is bonded to each other to form a ring, the semiconductor device according to [1].
[ 3 ] The ratio of the repeating unit represented by the formula (Ia) among the repeating units constituting the insulating polymer is 50 mol% or more, either [1] or [ 2 ] A semiconductor device according to 1.
[ 4 ] The ratio of the insulating polymer to the semiconductor compound in the semiconductor layer is 0.1% by mass or more and 10% by mass or less, according to any one of [1] to [ 3 ] Semiconductor device.
[ 5 ] The semiconductor device according to any one of [1] to [ 4 ], wherein the insulating polymer has a weight average molecular weight of 10 × 10 ³ or more and 400 × 10 ³ or less.
[ 6 ] The semiconductor device according to any one of [1] to [ 5 ], wherein the insulating polymer is an amorphous polymer and has a refractive index of 1.5 or less.
[ 7 ] The semiconductor device according to any one of [1] to [ 6 ], wherein a solubility of the insulating polymer in 1 g of N, N-dimethylformamide at 25 ° C. is 0.5 mg or more.
[ 8 ] The semiconductor device according to any one of [1] to [ 7 ], wherein the semiconductor compound contains a perovskite semiconductor compound.
[ 9 ] The semiconductor device according to any one of [1] to [ 8 ], which is a photoelectric conversion element.
[ 10 ] The semiconductor device according to [ 9 ], wherein a fill factor is 0.7 or more.
[ 11 ] A solar cell having the semiconductor device according to [ 9 ] or [ 10 ].
[ 12 ] A solar cell module having the solar cell according to [ 11 ].

  The durability of the semiconductor device can be improved.

It is sectional drawing which represents typically the field effect transistor element which concerns on one Embodiment. It is sectional drawing which represents typically the electroluminescent element which concerns on one Embodiment. It is sectional drawing which represents typically the photoelectric conversion element as one Embodiment. It is sectional drawing which represents typically the solar cell as one Embodiment. It is sectional drawing which represents typically the solar cell module as one Embodiment. It is an XRD measurement result which concerns on Example 3-1. It is an XRD measurement result concerning Comparative Example 3-1.

  Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

<1. Semiconductor devices>
A semiconductor device according to the present invention includes a pair of electrodes and a semiconductor layer disposed between the pair of electrodes. The semiconductor layer contains a semiconductor compound and an insulating polymer.

  When an insulating compound is added to the semiconductor layer, it is assumed that the function of the semiconductor layer is impaired. However, according to the present inventors, it has been found that even if an insulating polymer is added to the semiconductor layer, the function of the semiconductor layer is not significantly impaired, and the function of the semiconductor layer is improved in some cases. It has also been found that adding an insulating polymer to the semiconductor layer improves the durability of the semiconductor device.

  The reason why the durability is improved by the addition of the insulating polymer to the active layer is not clear, but the inventors of the present application presume the reason as follows. That is, when a semiconductor layer is formed using only a semiconductor compound, the crystal size tends to be non-uniform when the crystal size of the semiconductor compound increases. For this reason, it is conceivable that current leakage occurs as a result of poor morphology of the semiconductor layer and insufficient bonding between the semiconductor layer and other layers. On the other hand, by adding an insulating polymer, the semiconductor compound crystal can be prevented from growing non-uniformly, and a semiconductor layer having a good morphology can be obtained, thereby suppressing current leakage. It is thought that you can. As a result, it is estimated that the durability of the semiconductor device is improved.

  Further, it is considered that the light transmittance of the semiconductor layer is improved by making the size of the semiconductor compound crystal in the semiconductor layer uniform. Therefore, when light moves through the semiconductor layer like a photoelectric conversion element or an electroluminescence element, it is considered that light utilization efficiency or emission efficiency is improved.

  On the other hand, Masi et al. Scientific Reports, 5, 7758. describes that a semiconductor layer can be easily formed by adding a conductive polymer to the semiconductor layer. However, according to the study by the present inventors, it has been found that when a conductive polymer is added to the semiconductor layer, the function of the semiconductor layer is impaired. This is because the addition of the conductive polymer inhibits the fast charge separation function of the semiconductor compound itself in the active layer, or the semiconductor over time due to the relationship between the energy level of the semiconductor compound and the conductive polymer. This is thought to be due to changes in the properties of the layers.

  In this specification, a semiconductor device refers to an electronic device provided with a semiconductor layer containing a semiconductor compound. An electronic device is a device that has two or more electrodes and controls the current flowing between the electrodes or the voltage generated by electricity, light, magnetism, or a chemical substance, or the voltage applied between the electrodes or A device that generates light, an electric field, a magnetic field, or the like by an electric current. Specific examples include an element that controls current or voltage by applying voltage or current, an element that controls voltage or current by applying a magnetic field, or an element that controls voltage or current by applying a chemical substance. Specific examples of control include rectification, switching, amplification, or oscillation.

In this specification, “semiconductor” is defined by the magnitude of carrier mobility in a solid state. As is well known, the carrier mobility is an index indicating how fast (or many) charges (electrons or holes) can be transferred. Specifically, the “semiconductor” in this specification preferably has a carrier mobility at room temperature of preferably 1.0 × 10 ⁻⁶ cm ² / V · s or more, more preferably 1.0 × 10 ⁻⁵ cm ² / V · s or more. More preferably, it is 5.0 × 10 ⁻⁵ cm ² / V · s or more, and particularly preferably 1.0 × 10 ⁻⁴ cm ² / V · s or more. The carrier mobility can be measured, for example, by measuring the IV characteristics of the field effect transistor or the time-of-flight method.

  Examples of semiconductor devices include resistors, rectifiers (diodes), switching elements (transistors, thyristors), amplifier elements (transistors), memory elements, chemical sensors, etc., or devices obtained by combining or integrating these elements Is mentioned. Further, as a further example of a semiconductor device, there is an optical element. In the optical element, a photodiode or a phototransistor that generates a photocurrent, an electroluminescent element that emits light by applying an electric field, or a photoelectric conversion that generates electromotive force by light An element or a solar cell is included.

  As a more specific example of the semiconductor device, S.A. M.M. Examples include those described in Sze, Physics of Semiconductor Devices, 2nd Edition (Wiley Interscience 1981). Especially, as a preferable example of the semiconductor device which concerns on one Embodiment, a field effect transistor element (FET), an electroluminescent element (LED), a photoelectric conversion element, or a solar cell is mentioned.

  The kind of electrode is not specifically limited. Depending on the type of semiconductor device, an electrode can be manufactured using an appropriate material. Specific examples of electrodes will be described later with respect to some semiconductor devices.

  A semiconductor compound refers to a compound that becomes a material of a semiconductor. The kind of semiconductor compound is not particularly limited. For example, the semiconductor layer may contain a p-type semiconductor compound, may contain an n-type semiconductor compound, or may contain both of them. The semiconductor layer may contain a perovskite semiconductor compound.

  Examples of the p-type semiconductor compound include polymer semiconductor compounds such as conjugated copolymer semiconductors such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene, and polyaniline. Further, as a p-type semiconductor compound, condensed aromatic hydrocarbons such as naphthacene, pentacene or pyrene; oligothiophenes containing 4 or more thiophene rings such as α-sexithiophene; thiophene ring, benzene ring, fluorene ring, naphthalene ring , An anthracene ring, a thiazole ring, a thiadiazole ring, and a benzothiazole ring, and a total of four or more connected; a phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin and a metal complex thereof And low molecular semiconductor compounds such as macrocyclic compounds. Single-walled carbon nanotubes or graphene can also be used as the p-type semiconductor compound.

  Examples of the n-type semiconductor compound include fullerene compounds, quinolinol derivative metal complexes such as 8-hydroxyquinoline aluminum, condensed ring tetracarboxylic acid diimides such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide, perylene diimide derivatives, and terpyridine. Metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, Pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzoquinoline derivatives, bipyridine derivatives, borane Conductor anthracene, a pyrene, total fluoride condensed polycyclic aromatic hydrocarbon such as naphthacene or pentacene, and graphene, or n-type polymers and the like.

A perovskite semiconductor compound refers to a semiconductor compound having a perovskite structure. The perovskite semiconductor compound is not particularly limited, and can be selected from, for example, those listed in Galasso et al. Structure and Properties of Inorganic Solids, Chapter 7-Perovskite type and related structures. For example, examples of the perovskite compound include those represented by the general formula AMX ₃ and those represented by the general formula A ₂ MX ₄ . Here, M represents a divalent cation, A represents a monovalent cation, and X represents a monovalent anion.

  On the other hand, perovskite semiconductors are known to be easily deteriorated by moisture and have low durability. Adding an insulating polymer to the semiconductor layer as in this embodiment is very advantageous in that the durability of the perovskite semiconductor having such characteristics can be improved. Thus, in one embodiment, the semiconductor compound contained in the semiconductor layer contains a perovskite semiconductor compound.

  As the semiconductor compound contained in the semiconductor layer, an appropriate compound can be selected according to the type of the semiconductor device. Specific examples of semiconductor compounds will be described later with respect to several semiconductor devices.

The insulating polymer is a polymer having insulating properties. In the present specification, the electrical resistivity of the insulating polymer alone is 1 × 10 ⁶ Ω · m or more, preferably 1 × 10 ⁸ Ω · m or more, and more preferably 1 × 10 ¹⁰ Ω · m or more. is there. It is considered that the leakage current flowing in the semiconductor layer can be suppressed when the electric resistivity of the insulating polymer alone is 1 × 10 ⁶ Ω · m or more.

  The kind of insulating polymer is not particularly limited as long as a semiconductor layer can be formed together with a semiconductor compound. In one embodiment, as the insulating polymer, a polymer having a higher stability and a main chain composed of carbon atoms is used.

  The insulating polymer is preferably a soluble polymer, and preferably exhibits solubility in an aprotic polar solvent so that a semiconductor layer containing the insulating polymer can be formed by a coating method. Specifically, the solubility of the insulating polymer in 1 g of N, N-dimethylformamide at 25 ° C. is preferably 0.5 mg or more, more preferably 1.0 mg or more, and 2.0 mg or more. More preferably.

  There are no particular restrictions on the type of insulating polymer, for example, nonionic polymers such as polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone, polyvinyl polypyrrolidone, polyethylene glycol, polymethyl vinyl ether, polyisopropyl acrylamide; sodium polyacrylate, polystyrene Cationic polymers such as sodium sulfonate, sodium polyisopropylenesulfonate, polynaphthalenesulfonic acid condensate salt, polyethyleneimine xanthate salt; dimethylaminomethyl (meth) acrylate quaternary salt, dimethyldiallylammonium chloride, polyamidine, polyvinylimidazoline Anionic polymers such as dicyandiamide condensate, epichlorohydrin dimethylamine condensate, polyethyleneimine; Chill aminoethyl (meth) acrylate quaternary salt of acrylic acid copolymer, amphoteric polymers of Hofmann degradation products of polyacrylamide.

  As such an insulating polymer, a polyvinyl polymer having a hydrophilic substituent is particularly preferable. The hydrophilic substituent includes a hydroxy group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group (—COOR), an alkylcarbonyloxy group (—OCOR), an amino group which may have a substituent, and a substituent. An amide group (-NRCOR), a nitro group, a sulfo group, a sulfonyloxy group, a phospho group, a phosphonooxy group, a heterocyclic group having 2 to 10 carbon atoms (for example, a pyrrolyl group, a pyrrolidinyl group, or a thienyl group), and Examples thereof include a hydrocarbon group having 1 to 10 carbon atoms having these hydrophilic substituents.

More specifically, the insulating polymer preferably has a repeating unit represented by the following formula (I).
In the formula (I), Z represents a hydrophilic substituent. As the hydrophilic substituent, those described above are preferable.

In one embodiment, the insulating polymer has a repeating unit represented by the following formula (Ia).
In the formula (Ia), R ¹ and R ² each independently represent a hydrocarbon group or a hydrogen atom, and R ¹ and R ² may be bonded to each other to form a ring. As a hydrocarbon group, Preferably it is a C1-C10 hydrocarbon group, More specifically, a C1-C10 alkyl group, a C1-C10 alkenyl group, and a C1-C10 Examples include alkynyl groups and aromatic hydrocarbon groups having 6 to 10 carbon atoms.

In a further embodiment, in the repeating unit represented by formula (Ia), R ¹ and R ² are bonded to each other to form a ring. For example, R ¹ and R ² may constitute an alkanediyl group having 2 to 5 carbon atoms.

  The repeating units represented by formulas (I) and (Ia) may have further substituents. Further substituents include a halogen group, a hydroxy group, a cyano group, a silyl group, a boryl group, an amino group optionally substituted with an alkyl group, an alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. , An alkylcarbonyl group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, an alkynyl group having 1 to 10 carbon atoms, an ester group, an arylcarbonyl group, an arylthio group, an aryloxy group Group, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a heterocyclic group having 2 to 10 carbon atoms.

As a specific example, the insulating polymer may have a repeating unit represented by the following formula (Ib).

In formula (Ib), R ^{3 to} R ⁸ are each independently a hydrogen atom or a monovalent substituent. The monovalent substituent is not particularly limited, and examples thereof include the substituents listed as examples of the further substituent of the formula (Ia). That is, a halogen group, a hydroxy group, a cyano group, a silyl group, a boryl group, an amino group optionally substituted with an alkyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or 1 carbon atom -10 alkylcarbonyl group, C1-C10 alkylthio group, C1-C10 alkenyl group, C1-C10 alkynyl group, ester group, arylcarbonyl group, arylthio group, aryloxy group, carbon number A 6-10 aromatic hydrocarbon group or a C2-C10 heterocyclic group is mentioned. Among these, R ^{3 to} R ⁸ are each independently preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and among them, R ^{3 to} R ⁸ are preferably each a hydrogen atom. .

  The insulating polymer may contain two or more different repeating units represented by the formula (I), (Ia) or (Ib), and may be further crosslinked to form a crosslinked polymer. Further, it may form a complex with a compound such as iodine. The insulating polymer may contain a repeating unit other than the repeating unit represented by the formula (I), (Ia) or (Ib), for example, a vinyl acetate unit. A copolymer containing a repeating unit represented by formula (I), (Ia) or (Ib) may also be used. The ratio of the repeating unit represented by the formula (I), (Ia) or (Ib) among the repeating units constituting the insulating polymer is preferably 30 mol% or more, more preferably 50 mol% or more. More preferably, it is 70 mol% or more, and particularly preferably 90 mol% or more. When the ratio of the repeating unit represented by the formula (I), (Ia) or (Ib) is 30 mol% or more, it becomes easier to produce a coating liquid containing an insulating polymer.

  The terminal group of the insulating polymer is not particularly limited, and examples thereof include a hydrogen atom, a hydroxyl group, a trialkylsilyl group, a triarylsilyl group, and a vinyl group.

The weight average molecular weight of the insulating polymer is not particularly limited as long as the effect of improving the durability of the semiconductor layer can be obtained, but is preferably 5 × 10 ³ or more, and more preferably 10 × 10 ³ or more. Moreover, it is preferably 1000 × 10 ³ or less, more preferably 400 × 10 ³ or less. It is considered that the crystal growth of the semiconductor compound can be appropriately controlled when the weight average molecular weight is in this range.

  The ratio between the semiconductor compound and the insulating polymer contained in the semiconductor layer is not particularly limited. The ratio of the insulating polymer to the semiconductor compound is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, more preferably 1 so that the effect of improving durability can be obtained more. .2% by mass or more. Further, the ratio of the insulating polymer to the semiconductor compound is preferably 20% by mass or less, more preferably 10% by mass or less, more preferably 5.0% so that the performance of the semiconductor device is sufficiently maintained. It is not more than mass%, particularly preferably not more than 3.0 mass%.

  It is preferable that the insulating polymer is uniformly dispersed in the semiconductor layer. From this viewpoint, it is preferable that the crystallinity of the insulating polymer is not high. Specifically, the insulating polymer is preferably an amorphous polymer that becomes amorphous when used alone. Specific examples of the amorphous polymer include polyvinyl pyrrolidone or acrylic resin. Amorphous polymers tend to be highly light transmissive. Therefore, when light moves in a semiconductor layer like a photoelectric conversion element or an electroluminescence element, the insulating polymer is in an amorphous state, so that reflection and refraction of light are suppressed, and thus it has high light transmittance. It is preferable at the point which can obtain a device. Therefore, the refractive index of the insulating polymer when used alone is preferably 1.8 or less, and more preferably 1.5 or less.

  The thickness of the semiconductor layer is not particularly limited, and can be appropriately selected according to the use of the semiconductor layer. As an example, the thickness of the semiconductor layer may be not less than 0.5 nm and not more than 500 nm.

  In addition to the semiconductor compound and the insulating polymer, other compounds may be added to the semiconductor layer. In this case, the ratio of the semiconductor compound and the insulating polymer in the semiconductor layer is preferably 50% by mass or more, more preferably 70% by mass or more, so that the semiconductor characteristics of the semiconductor layer are well exhibited. Preferably it is 90 mass% or more. The semiconductor layer may have a stacked structure including a plurality of layers containing different materials or having different components.

  The method for forming the semiconductor layer is not particularly limited, and any method can be used. Specific examples include a coating method in which a semiconductor layer is formed by coating a coating solution containing a semiconductor compound or a semiconductor compound precursor and an insulating polymer, and a vapor deposition method in which the semiconductor compound and the insulating polymer are co-evaporated. Etc. It is preferable to use a coating method because a semiconductor layer can be easily formed.

  The semiconductor compound precursor refers to a material that can be converted into a semiconductor compound after coating a coating solution. A specific example is a semiconductor compound precursor that can be converted into a semiconductor compound by heating. For example, by heating a film obtained by applying a coating liquid, a semiconductor compound precursor can be converted into a semiconductor compound, and a semiconductor layer containing a semiconductor compound and an insulating polymer can be formed.

  Specific examples of the semiconductor compound precursor include a compound represented by the formula (2) described below and / or a formula (described later) which can be converted into a perovskite semiconductor compound represented by the formula (1) described below by heating. Examples of the compound represented by 3) include metal halides and alkylammonium salt halides. Moreover, the bicycloporphyrin compound etc. which can be converted into a porphyrin compound by heating are also mentioned.

  The coating liquid used for the coating method can be prepared by dissolving a semiconductor compound or a semiconductor compound precursor and an insulating polymer in a solvent. The solvent is not particularly limited as long as the semiconductor compound and the insulating polymer are dissolved. Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane or decane; aromatic hydrocarbons such as toluene, xylene, mesitylene, cyclohexylbenzene, chlorobenzene, or orthodichlorobenzene; cyclopentane, Cycloaliphatic hydrocarbons such as cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin or decalin; lower alcohols such as methanol, ethanol or propanol; fats such as acetone, methyl ethyl ketone, cyclopentanone, dimethyl sulfoxide or cyclohexanone Aromatic ketones such as acetophenone or propiophenone; S such as ethyl acetate, butyl acetate, γ-butyrolactone, or methyl lactate Le ethers; chloroform, methylene chloride, dichloroethane, halogenated hydrocarbons such as trichloroethane or trichlorethylene; ethers such as ethyl ether and tetrahydrofuran or dioxane; or an amide such as dimethylformamide or dimethylacetamide, and the like.

  When a perovskite semiconductor compound is used, as a solvent for the coating solution, Brandrup, J. et al. The solubility parameter (SP value) described in et al. “Polymer Handbook, 4th Ed.” Is preferably 9 or more, and more preferably 10 or more. Examples thereof include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, pyridine, and γ-butyrolactone. As the solvent, a mixed solvent of two or more kinds of solvents may be used. Even when a mixed solvent is used, the solubility parameter of at least one of the mixed solvents is preferably 10 or more.

  Such a coating liquid containing a semiconductor compound or a semiconductor compound precursor, an insulating polymer, and a solvent can be used as a composition for forming a semiconductor layer. In particular, a composition containing a perovskite semiconductor compound or a perovskite semiconductor compound precursor, an insulating polymer, and a solvent is useful for forming a perovskite semiconductor layer having durability. Such a composition is also useful for forming a perovskite semiconductor layer having high light transmittance. The composition may further contain an additive, but the main component of the composition is preferably a semiconductor compound or a semiconductor compound precursor, an insulating polymer, and a solvent.

  The ratio of the semiconductor compound or semiconductor compound precursor contained in the composition and the insulating polymer is not particularly limited. Included in the composition with respect to the mass of the semiconductor compound contained in the composition or the mass of the semiconductor compound that can be formed by the semiconductor compound precursor contained in the composition so that the effect of improving durability can be obtained more The ratio of the mass of the insulating polymer is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 1.2% by mass or more. Further, the ratio of the insulating polymer to the semiconductor compound or the semiconductor compound precursor is preferably 20% by mass or less, more preferably 10% by mass or less, so that the performance of the semiconductor device is sufficiently maintained. Preferably it is 5.0 mass% or less, Most preferably, it is 3.0 mass% or less.

  Further, the concentration of the semiconductor compound or the semiconductor compound precursor contained in the composition is not particularly limited, and can be appropriately selected so that a semiconductor layer having an appropriate thickness is formed. The concentration of the semiconductor compound or semiconductor compound precursor is preferably 10% by weight or more, more preferably 15% by weight or more, while preferably 60% by weight or less, so that the coating film formation proceeds smoothly. More preferably, it is 45 weight% or less.

  Although any method can be used as a coating method of the coating solution, for example, spin coating method, ink jet method, doctor blade method, drop casting method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, Examples thereof include a spray coating method, an air knife coating method, a wire barber coating method, a pipe doctor method, an impregnation / coating method, and a curtain coating method.

  A semiconductor layer can be formed by performing drying after applying the coating solution and performing a process of converting the semiconductor compound precursor into a semiconductor compound as necessary. The drying method is not particularly limited, and for example, heat drying may be performed.

  Hereinafter, a field effect transistor element, an electroluminescence element, a photoelectric conversion element, and a solar cell will be described in detail as examples of the semiconductor device according to the present invention.

<2. Field Effect Transistor (FET)>
A field effect transistor (FET) device according to the present invention includes a semiconductor layer, a pair of electrodes, a source electrode and a drain electrode, and a gate electrode. This semiconductor layer contains the semiconductor compound and the insulating polymer as described above.

  Hereinafter, the FET element according to an embodiment will be described in detail. FIG. 1 is a diagram schematically showing a structural example of an FET element according to the present invention. In FIG. 1, 51 is a semiconductor layer, 52 is an insulator layer, 53 and 54 are source and drain electrodes, 55 is a gate electrode, and 56 is a substrate. The semiconductor layer 51 contains a semiconductor compound and an insulating polymer. However, in another embodiment, the FET element has a semiconductor layer containing a semiconductor compound and an insulating polymer, which is different from the semiconductor layer 51 acting as a channel between the source electrode 53 and the drain electrode 54. Also good. Although FIGS. 1A to 1D show FET elements having different structures, each of them shows a structure example of an FET element according to the present invention. There is no particular limitation on these constituent members constituting the FET element and the manufacturing method thereof, and well-known techniques can be used. For example, techniques described in publicly known documents such as International Publication No. 2013/180230 or Japanese Patent Application Laid-Open No. 2012-191194 can be used.

  In the FET element according to one embodiment, the semiconductor layer 51 is produced by forming a semiconductor film on the substrate 56 directly or via another layer. The film thickness of the semiconductor layer 51 is not limited. For example, in the case of a horizontal field effect transistor element, the element characteristics do not depend on the film thickness of the semiconductor layer 51 as long as the film thickness is equal to or greater than a predetermined film thickness. However, since the leakage current often increases when the film thickness becomes too thick, the film thickness of the semiconductor layer is preferably 0.5 nm or more, more preferably 10 nm or more, and preferably 1 μm from the viewpoint of cost. Hereinafter, it is more preferably 200 nm or less.

As the characteristics of the semiconductor layer 51, the carrier mobility at room temperature is preferably 1.0 × 10 ⁻⁶ cm ² / V · s or more, more preferably 1.0 × 10 ⁻⁵ cm ² / V · s or more, more preferably 5. 0 × 10 ⁻⁵ cm ² / V · s or more, particularly preferably 1.0 × 10 ⁻⁴ cm ² / V · s or more.

<3. Electroluminescent device (LED)>
An electroluminescent element (LED) according to the present invention includes an anode and a cathode that are a pair of electrodes, and a light emitting layer that is a semiconductor layer disposed between the electrodes. An electroluminescent element is a self-luminous element that utilizes the principle that a fluorescent substance emits light by recombination energy between holes injected from an anode and electrons injected from a cathode when an electric field is applied. In one embodiment, the light emitting layer contains a semiconductor compound and an insulating polymer as described above. However, in another embodiment, the electroluminescent element may have a semiconductor layer containing a semiconductor compound and an insulating polymer, which is different from the light emitting layer. For example, the electron transport layer or the hole transport layer may be a semiconductor layer containing a semiconductor compound and an insulating polymer.

  FIG. 2 is a cross-sectional view schematically showing one embodiment of the electroluminescent element according to the present invention. In FIG. 2, reference numeral 31 is a base material, 32 is an anode, 33 is a hole injection layer, 34 is a hole transport layer, 35 is a light emitting layer, 36 is an electron transport layer, 37 is an electron injection layer, 38 is a cathode, 39 Indicates an electroluminescent element. The light emitting layer 35 contains a semiconductor compound and an insulating polymer. Note that the electroluminescent element does not need to have all of these constituent members, and the necessary constituent members can be arbitrarily selected. For example, the hole injection layer 33, the hole transport layer 34, the electron transport layer 36, and the electron injection layer 37 are not necessarily provided. There are no particular restrictions on these constituent members constituting the electroluminescent element and the manufacturing method thereof, and well-known techniques can be used. For example, techniques described in publicly known documents such as International Publication No. 2013/180230 or Japanese Patent Application Laid-Open No. 2012-191194 can be used.

There is no restriction | limiting in the formation method of the light emitting layer 35. FIG. For example, a wet film formation method or a dry film formation method can be used. In addition, for the purpose of improving the light emission efficiency of the device, changing the emission color, and improving the drive life of the device, the host material emits light by doping with another compound such as a fluorescent dye or a phosphorescent metal complex. Layer 35 may be made. For example, by doping with a fluorescent dye,
1) Improvement of luminous efficiency by high-efficiency fluorescent dyes 2) Variable emission wavelength by selection of fluorescent dyes 3) Use of fluorescent dyes that cause concentration quenching 4) Use of fluorescent dyes with poor thin film properties 5) It is expected that driving stability is improved by eliminating charge traps.

  In addition, mixing a hole transport material in the light emitting layer 35 is also effective for the purpose of improving the driving stability of the device. The amount of the hole transport material mixed in the light emitting layer 35 is preferably in the range of 5 to 50% by mass.

  The thickness of the light emitting layer 35 is not limited, and is preferably 3 nm or more, more preferably 10 nm or more, preferably 300 nm or less, more preferably so that the amount of light emission can be secured while satisfying the conditions desired for the light emitting layer 35. 100 nm or less.

  2 shows only one embodiment of the electroluminescent element according to the present invention, and the electroluminescent element according to the present invention is not limited to the illustrated configuration. For example, a stacked structure opposite to that shown in FIG. 2 is adopted, that is, a cathode 38, an electron injection layer 37, an electron transport layer 36, a light emitting layer 35, a hole transport layer 34, a hole injection layer 33, and an anode It is also possible to stack 32 in this order.

  The configuration of the electroluminescent device according to the present invention is not particularly limited, and the anode and the cathode are arranged in an XY matrix, whether it is a single device or an element having a structure arranged in an array. It may be an element having an arranged structure.

<4. Photoelectric conversion element>
The photoelectric conversion element according to the present invention includes a cathode and an anode that are a pair of electrodes, and an active layer that is a semiconductor layer disposed between the electrodes. In addition, the photoelectric conversion element according to an embodiment may include other components including a base material, an electron extraction layer, and a hole extraction layer. In one embodiment, the active layer contains a semiconductor compound and an insulating polymer as described above. However, in another embodiment, the photoelectric conversion element may have a semiconductor layer containing a semiconductor compound and an insulating polymer different from the active layer. For example, the electron extraction layer or the hole extraction layer may be a semiconductor layer containing a semiconductor compound and an insulating polymer.

  FIG. 3 is a cross-sectional view schematically showing an embodiment of the photoelectric conversion element according to the present invention. The photoelectric conversion element shown in FIG. 3 is a photoelectric conversion element used in a general thin-film solar cell, but the photoelectric conversion element according to the present invention is not limited to that shown in FIG. A photoelectric conversion element 100 according to an embodiment of the present invention includes a base material 107, a cathode (electrode) 101, an electron extraction layer (buffer layer) 102, an active layer 103, a hole extraction layer (buffer layer) 104, work function tuning. The layer 105 and the anode (electrode) 106 have a layer structure formed in this order. The active layer 103 contains a semiconductor compound and an insulating polymer. Note that the electron extraction layer 102, the hole extraction layer 104, and the work function tuning layer 105 are not necessarily provided. A work function tuning layer may be present between the cathode 101 and the electron extraction layer 102.

<4-1. Active layer (103)>
The active layer 103 is a layer where photoelectric conversion is performed. When the photoelectric conversion element 100 receives light, the light is absorbed by the active layer 103 to generate carriers, and the generated carriers are extracted from the cathode 101 and the anode 106.

  The structure of the active layer 103 is not particularly limited. For example, the active layer 103 may be a heterojunction type active layer including a layer containing a p-type semiconductor compound and a layer containing an n-type semiconductor compound. When light enters such an active layer 103, carrier separation occurs at the layer interface, and the generated carriers (holes and electrons) are transported to the cathode 101 and the anode 106. In this case, any layer may contain an insulating polymer. For example, all the layers may contain an insulating polymer.

  In one embodiment, the active layer 103 is a bulk hetero active layer having a layer (i layer) in which a p-type semiconductor compound and an n-type semiconductor compound are mixed. In the i layer, the p-type semiconductor compound and the n-type semiconductor compound are phase-separated. When light enters the i layer, carrier separation occurs at the phase interface, and the generated carriers (holes and electrons) are transported to the cathode 101 and the anode 106. In the i layer, at least one of a layer containing a p-type semiconductor compound and a layer containing an n-type semiconductor compound may be laminated. Again, any layer may contain an insulating polymer.

  In other embodiments, the active layer 103 is a layer containing a perovskite semiconductor compound, and a solar cell having such an active layer 103 is known as a perovskite solar cell. In the perovskite semiconductor, a perovskite semiconductor compound having a perovskite structure forms a crystal. In such crystals, fast charge separation occurs and the diffusion distance of holes and electrons is long, so that efficient charge separation occurs.

  There is no particular limitation on the thickness of the active layer 103. In terms of the ability to absorb more light, the thickness of the active layer 103 is preferably 5 nm or more, more preferably 10 nm or more, more preferably 50 nm or more, and particularly preferably 120 nm or more. On the other hand, the thickness of the active layer 103 is preferably 500 nm or less, more preferably 400 nm or less, and more preferably 300 nm or less in that the series resistance decreases.

(Heterojunction type active layer and bulk hetero type active layer)
The p-type semiconductor compound contained in the heterojunction type or bulk hetero type active layer 103 is not particularly limited and may be a low-molecular semiconductor compound or a high-molecular semiconductor compound. Two or more p-type semiconductor compounds may be used. From the viewpoint of promoting charge separation, it is preferable to use a p-type semiconductor compound having an energy band gap of 1.0 eV to 1.8 eV. In addition, it is preferable to use a polymer semiconductor compound that can be dissolved in a solvent in that the active layer 103 can be formed using a simple coating process.

  The p-type polymer semiconductor compound is not particularly limited, but a polymer semiconductor compound that is a copolymer of two or more monomer units is preferably used. Examples of such optoelectronic semiconductor compounds include Accounts of Chemical Research, 2012, 45, 723-733, Macromolecules, 2012, 45, 607-632, Chemistry of Materials, 2011, 23, 456-469, Energy & Environmental Science. , 2011, 4, 1225-1237, Progress in Polymer Science, 2011, 36, 1326-1414, Journal of Materials Chemistry, 2012, 22, 10416-10434, and Progress in Polymer Science, 2012, 37, 1292-1331. What is done. Moreover, the derivative | guide_body of these high molecular semiconductor compounds can also be used, and the high molecular semiconductor compound obtained by copolymerization of the monomer described in said literature can also be used. Furthermore, in order to control solubility, crystallinity, film formability, HOMO energy level, LUMO energy level, and the like, substituents may be introduced into these polymer semiconductor compounds.

  There is no particular limitation on the n-type semiconductor compound contained in the heterojunction type or bulk hetero type active layer 103. For example, those exemplified as the n-type semiconductor compound that may be contained in the semiconductor layer can be used.

Among these, fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl-substituted naphthalenetetracarboxylic acid diimides or N-alkyl-substituted perylene diimide derivatives are preferable, fullerene compounds, N- Alkyl substituted perylene diimide derivatives, N-alkyl substituted naphthalene tetracarboxylic acid diimides or n-type polymers are more preferred, and fullerene compounds are particularly preferred. The fullerene compound, but no particular _restriction, particularly preferably _{C 60} derivatives or _{C 70 derivatives,} C 61 PCBM or _C 71 PCBM is particularly preferred. Two or more n-type semiconductor compounds may be used.

  In the bulk hetero type active layer 103, the mass ratio of the p-type semiconductor compound to the n-type semiconductor compound in the i layer (p-type semiconductor compound / n-type semiconductor compound) is not particularly limited, but a good phase separation structure is obtained. In view of improving the photoelectric conversion efficiency, it is preferably 0.15 or more, more preferably 0.3 or more, on the other hand, preferably 4 or less, and more preferably 2 or less. Is particularly preferably 0.8 or less.

(Active layer containing perovskite semiconductor compound)
The perovskite semiconductor compound is not particularly limited, and those described above can be used. Preferred structures of the perovskite compound include those represented by the general formula AMX ₃ and those represented by the general formula A ₂ MX ₄ .

  Although the monovalent cation A is not particularly limited, for example, those described in the above-mentioned book of Galasso can be used. More specific examples include cations including Group 1 and Group 13 to Group 16 elements of the periodic table. Among these, cesium ion, rubidium ion, ammonium ion which may have a substituent, or phosphonium ion which may have a substituent are preferable. As an example of the ammonium ion which may have a substituent, a primary ammonium ion or a secondary ammonium ion is mentioned. There is no particular limitation on the substituent. Specific examples of the ammonium ion that may have a substituent include alkylammonium ions and arylammonium ions. In particular, in order to avoid steric hindrance, a monoalkylammonium ion having a three-dimensional crystal structure is preferable. From the viewpoint of improving stability, it is preferable to use an alkylammonium ion substituted with one or more fluorine groups. Moreover, the combination of 2 or more types of cations can also be used as the cation A.

  Specific examples of the monovalent cation A include methylammonium ion, methylammonium monofluoride ion, methylammonium difluoride ion, methylammonium trifluoride ion, ethylammonium ion, isopropylammonium ion, n-propylammonium ion, and isobutylammonium ion. N-butylammonium ion, t-butylammonium ion, dimethylammonium ion, diethylammonium ion, phenylammonium ion, benzylammonium ion, guanidinium ion, formamidinium ion, acetamidinium ion or imidazolium And ions.

The divalent cation M is not particularly limited, but is preferably a divalent metal cation or a semimetal cation. Specific examples include cations of Group 14 elements of the periodic table, and more specific examples include lead cations (Pb ²⁺ ), tin cations (Sn ²⁺ ), and germanium cations (Ge ²⁺ ). Moreover, the combination of 2 or more types of cations can also be used as the cation M. From the viewpoint of obtaining a stable photoelectric conversion element, it is particularly preferable to use a lead cation or two or more cations including a lead cation.

  Examples of monovalent anions X include halide ion, acetate ion, nitrate ion, sulfate ion, borate ion, acetylacetonate ion, carbonate ion, citrate ion, sulfur ion, tellurium ion, thiocyanate ion, titanate. An ion, a zirconate ion, a 2,4-pentanedionate ion, or a silicofluorine ion. In order to adjust the band gap, X may be one type of anion or a combination of two or more types of anions. Among these, X is preferably a halide ion or a combination of a halide ion and other anions. Examples of the halide ion X include chloride ion, bromide ion or iodide ion. From the viewpoint of not excessively widening the band gap of the semiconductor, it is preferable to use iodide ions.

Preferable examples of the perovskite semiconductor compound include organic-inorganic perovskite semiconductor compounds, and particularly halide organic-inorganic perovskite semiconductor compounds. Specific examples of the perovskite semiconductor compound include CH ₃ NH ₃ PbI ₃ , CH ₃ NH ₃ PbBr ₃ , CH ₃ NH ₃ PbCl ₃ , CH ₃ NH ₃ SnI ₃ , CH ₃ NH ₃ SnBr ₃ , and CH ₃ NH ₃ Sn _3. CH ₃ NH ₃ PbI _(3-x) Cl _x , CH ₃ NH ₃ PbI _(3-x) Br _x , CH ₃ NH ₃ PbBr _(3-x) Cl _x , CH ₃ NH ₃ Pb _(1-y) Sn _y I ₃ , CH ₃ NH ₃ Pb _(1-y) Sn _y Br ₃ , CH ₃ NH ₃ Pb _(1-y) Sn _y Cl ₃ , CH ₃ NH ₃ Pb _(1-y) Sn _y I _{(3 -x) Cl x, CH 3 NH} 3 Pb (1-y) Sn y I (3-x) Br x, and _{CH 3 NH 3 Pb (1-} y) Sn y Br (3-x) Cl x, and , _CFH 2 _NH 3 instead of _CH 3 NH ₃ in serial of _compounds, CF 2 HNH _3, or those using _CF 3 NH _3, include like. Note that x is an arbitrary value from 0 to 3, and y is an arbitrary value from 0 to 1.

  From the viewpoint of improving the photoelectric conversion efficiency, it is preferable to use a semiconductor compound having an energy band gap of 1.0 eV to 3.5 eV as the perovskite semiconductor compound.

  The active layer 103 may contain two or more types of perovskite semiconductor compounds. For example, two or more types of perovskite semiconductor compounds in which at least one of A, B, and X is different may be included in the active layer 103.

  The amount of the perovskite semiconductor compound contained in the active layer 103 is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more so that good photoelectric conversion characteristics can be obtained. It is. There is no restriction | limiting in an upper limit, and it is 100 mass% or less.

  The active layer 103 may contain an additive in addition to the perovskite semiconductor compound. The additive is not particularly limited, and examples of the additive include inorganic compounds such as halides, oxides, or inorganic salts such as sulfides, sulfates, nitrates, and ammonium salts. The amount of the additive in the active layer 103 is preferably 50% by mass or less, more preferably 30% by mass or less, and more preferably 20% by mass or less so that good photoelectric conversion characteristics can be obtained. . There is no restriction | limiting in a lower limit, and it is 0 mass% or more.

(Method for forming active layer)
The formation method of the active layer 103 is not particularly limited, and any method can be used. Specific examples include a coating method and a vapor deposition method (or a co-evaporation method). It is preferable to use a coating method because the active layer 103 can be easily formed. Hereinafter, a method for forming the active layer 103 by a coating method will be described.

  The bulk hetero type active layer 103 can be formed by preparing a coating liquid containing a p-type semiconductor compound, an n-type semiconductor compound, an insulating polymer, and a solvent, and applying the coating liquid. This coating solution may further contain an additive. Moreover, you may use the mixed solvent of a high boiling point solvent and a low boiling point solvent as a solvent. By using such an additive or mixed solvent, the volatilization rate of the solvent can be adjusted, and the organization of the semiconductor compound can be promoted to optimize the phase separation structure.

  Although any method can be used as a coating method of the coating solution, for example, spin coating method, ink jet method, doctor blade method, drop casting method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, Examples thereof include a spray coating method, an air knife coating method, a wire barber coating method, a pipe doctor method, an impregnation / coating method, and a curtain coating method.

  You may heat-dry after apply | coating a coating liquid. By heating the bulk hetero active layer 103, self-organization of the active layer can be promoted. The heating temperature is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, so that the effect of self-organization can be obtained. On the other hand, preferably no higher than 300 ° C., more preferably so as not to cause damage due to heat. It is 280 degrees C or less, More preferably, it is 250 degrees C or less. The heating time is preferably 1 minute or more, more preferably 3 minutes or more, so that the effect of self-organization can be obtained. On the other hand, from the viewpoint of improving the processing efficiency, preferably 3 hours or less, more preferably Is less than 1 hour.

  The solvent of the coating solution is not particularly limited as long as it can uniformly dissolve the p-type semiconductor compound, the n-type semiconductor compound, and the insulating polymer. For example, what was mentioned as a solvent which can be used when forming a semiconductor layer by the apply | coating method can be used. Among them, aromatic hydrocarbons such as toluene, xylene, mesitylene, cyclohexylbenzene, chlorobenzene or orthodichlorobenzene; cycloaliphatic carbonization such as cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin or decalin Hydrogen; ketones such as acetone, methyl ethyl ketone, cyclopentanone or cyclohexanone; or ethers such as ethyl ether, tetrahydrofuran or dioxane. On the other hand, it is preferable to use a non-halogen solvent from the viewpoint of environmental burden.

  More preferably, non-halogen aromatic hydrocarbons such as toluene, xylene, mesitylene or cyclohexylbenzene; non-halogen ketones such as acetone, methyl ethyl ketone, cyclopentanone or cyclohexanone; aromatic ketones such as acetophenone or propiophenone Non-halogen alicyclic hydrocarbons such as tetrahydrofuran, cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin or decalin; or non-halogen aliphatic ethers such as 1,4-dioxane; . Particularly preferred are non-halogen aromatic hydrocarbons such as toluene, xylene, mesitylene or cyclohexylbenzene. As the solvent, one kind of solvent may be used alone, or any two or more kinds of solvents may be used in any ratio.

  As the high boiling point solvent, it is preferable to use a solvent having a boiling point of 180 ° C. or higher and 250 ° C. or lower under normal pressure, and specific examples include tetralin, decalin, acetophenone, and the like. As the low boiling point solvent, a solvent having a boiling point of 60 ° C. or higher and 150 ° C. or lower under normal pressure is preferably used, and specific examples include toluene, xylene, tetrahydrofuran, ethyl methyl ketone, and the like. By combining solvents having such boiling points, the organization of the semiconductor compound can be promoted. From the viewpoint of environmental burden, these high-boiling solvents and low-boiling solvents are preferably non-halogen solvents.

  The ratio between the high boiling point solvent and the low boiling point solvent is not particularly limited. In terms of facilitating the organization of the semiconductor compound, the weight ratio (high boiling point solvent / low boiling point solvent) is preferably 1/20 or more, more preferably 1/15 or more, and 1/10 or more. More preferably. On the other hand, the weight ratio (high boiling point solvent / low boiling point solvent) is preferably 10/1 or less, more preferably 2/1 or less, more preferably 1/1 or less, and more preferably 1/2 or less. It is particularly preferred that

  Examples of combinations of low and high boiling solvents include non-halogen aromatic hydrocarbons and alicyclic hydrocarbons, non-halogen aromatic hydrocarbons and aromatic ketones, ethers and alicyclic carbonization. Examples thereof include hydrogens, ethers and aromatic ketones, aliphatic ketones and alicyclic hydrocarbons, or aliphatic ketones and aromatic ketones. Specific examples of preferred combinations include toluene and tetralin, xylene and tetralin, toluene and acetophenone, xylene and acetophenone, tetrahydrofuran and tetralin, tetrahydrofuran and acetophenone, methyl ethyl ketone and tetralin, methyl ethyl ketone and acetophenone, and the like.

  When the coating solution contains an additive, the amount of the additive with respect to the entire coating solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more in terms of facilitating the organization of the semiconductor compound. More preferably, it is preferably 10% by mass or less, more preferably 5% by mass or less.

  The coating solution can be prepared by preparing a solution of a p-type semiconductor compound, a solution of an n-type semiconductor compound, and a solution of an insulating polymer, and then mixing these solutions. The coating liquid can also be prepared by dissolving a p-type semiconductor compound, an n-type semiconductor compound, and an insulating polymer in a solvent.

  The total concentration of the p-type semiconductor compound and the n-type semiconductor compound in the coating solution is not particularly limited. From the viewpoint of forming an active layer having a sufficient thickness, the total concentration is preferably 0.3% by mass or more based on the entire coating solution. Further, from the viewpoint of sufficiently dissolving the semiconductor compound, the total concentration is preferably 20% by mass or less with respect to the entire coating solution.

  The heterojunction active layer 103 is formed by preparing a coating solution containing a p-type semiconductor compound and a solvent and a coating solution containing an n-type semiconductor compound and a solvent, and sequentially applying these coating solutions. can do. At least one of the coating liquid containing the p-type semiconductor compound and the coating liquid containing the n-type semiconductor compound further contains an insulating polymer. There is no particular limitation on the solvent and the coating method, and the solvent and the coating method described in the method for forming the bulk hetero type active layer can be used. As in the case of producing a bulk hetero type active layer, it is preferable to heat-dry after applying each coating solution. In addition, as in the case of producing a bulk hetero type active layer, each coating solution may contain an additive.

  Even when the active layer 103 containing the perovskite semiconductor compound is formed, there is no particular limitation on the method of forming the active layer 103. As an example, a coating solution containing a compound represented by the following formula (2), a compound represented by the following formula (3), an insulating polymer, and a solvent is prepared, and this coating solution is applied. A method is mentioned. Such a coating solution can be prepared by heating and stirring the compound in the solution. According to this method, an active layer 103 containing a compound represented by the following formula (1) and an insulating polymer can be produced.

  As another example, after applying a coating liquid containing a compound represented by the following formula (3) and a solvent, a coating liquid containing a compound represented by the following formula (2) and a solvent was applied. And a method of heat annealing. At least one of the coating liquid containing the compound represented by Formula (3) and the coating liquid containing the compound represented by Formula (2) further contains an insulating polymer. Also by this method, the active layer 103 containing the compound represented by the following formula (1) and the insulating polymer can be produced.

AMX ₃ (1)
AX (2)
MX ₂ (3)
The definitions of A, M and X are as described above. Specific examples of the AX include halogenated alkyl ammonium salts, metal halides Examples of MX _2. AX and MX ₂ are precursors of the velovskite semiconductor compound AMX ₃ .

  The heating temperature at the time of heating and stirring or heating annealing is preferably 60 ° C. or higher from the viewpoint of sufficiently promoting the reaction of the compound, and is preferably 150 ° C. or lower from the viewpoint of avoiding side reactions. The heating and stirring time is preferably 2 hours or longer from the viewpoint of sufficiently promoting the reaction of the compound, and preferably 24 hours or shorter from the viewpoint of improving production efficiency. The annealing method is not particularly limited, and may be performed with a hot plate under normal pressure or reduced pressure, or may be performed with a near infrared heating device (NIR).

The molar fraction (2/3) of the compound represented by the formula (2) with respect to the compound represented by the formula (3) is not particularly limited. However, when BX ₂ remains in the active layer, the conversion efficiency of the photoelectric conversion element tends to decrease. Moreover, even if the compound represented by Formula (2) can be removed by the heat treatment described later, the compound represented by Formula (3) is often difficult to remove by heating. Therefore, it is preferable to form the active layer 103 so that the compound represented by the formula (3) does not remain in the layer. From this point, the molar fraction (2/3) of the compound represented by the formula (2) with respect to the compound represented by the formula (3) is preferably 100 mol% or more, while it is 600 mol% or less. It is preferable that it is 400 mol% or less.

  The total amount of the compound represented by the formula (2) and / or the compound represented by the formula (3) with respect to the total amount of the coating solution is preferably 10 masses in order to produce the active layer 103 having a sufficient thickness. % Or more, more preferably 15% by mass or more, and particularly preferably 20% by mass or more. On the other hand, in order to avoid precipitation in a solvent, it is preferably 50% by mass or less, more preferably 45% by mass or less, and particularly preferably 40% by mass or less.

  Moreover, in order to accelerate | stimulate crystal formation, the coating liquid may contain the additive further. In this case, the amount of the additive is preferably 50 with respect to the total amount of the compound represented by the formula (2) and / or the compound represented by (3) so that good photoelectric conversion performance can be obtained. It is not more than mass%, more preferably not more than 30 mass%, particularly preferably not more than 10 mass%.

  Also when forming the active layer 103 containing a perovskite semiconductor compound, it is preferable to heat-dry after apply | coating a coating liquid. The solvent coordinated by heating and the remaining compound represented by the formula (2) are removed from the layer, crystallization is promoted, and the photoelectric conversion efficiency tends to be improved. Since the progress of crystallization depends on the concentration of the coating solution, it is preferable to shorten the heating time when the concentration of the coating solution is low or the content of the solvent is small.

  The heating temperature at this time is not particularly limited, but is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, from the viewpoint of sufficiently promoting crystallization. On the other hand, decomposition and side reactions of the perovskite semiconductor compound are performed. In order to suppress, it is preferably 150 ° C. or lower, more preferably 130 ° C. or lower, more preferably 120 ° C. or lower. The heating time is not particularly limited, but is preferably 10 minutes or longer, more preferably 30 minutes or longer, more preferably 1 hour or longer from the viewpoint of sufficiently promoting crystallization, while improving the production efficiency. From the viewpoint of making it, it is preferably 3 hours or less, more preferably 2 hours or less. These heating may be performed under normal pressure or under reduced pressure.

<4-2. Buffer layer (102, 104)>
The buffer layer can be generally classified into an electron extraction layer and a hole extraction layer. In one embodiment, the photoelectric conversion element 100 includes an electron extraction layer 102 between the cathode 101 and the active layer 103, and a hole extraction layer 104 between the active layer 103 and the anode 106. However, the photoelectric conversion element 100 may have only one of the electron extraction layer 102 and the hole extraction layer 104, or may not include either the electron extraction layer 102 or the hole extraction layer 104. Good.

  The electron extraction layer 102 and the hole extraction layer 104 are preferably disposed so as to sandwich the active layer 103 between a pair of electrodes (101, 106). That is, when the photoelectric conversion element 100 includes both the electron extraction layer 102 and the hole extraction layer 104, the anode (electrode) 106, the hole extraction layer 104, the active layer 103, the electron extraction layer 102, and the cathode (electrode) 101. Can be arranged in this order. When the photoelectric conversion element 100 includes the electron extraction layer 102 and does not include the hole extraction layer 104, the anode (electrode) 106, the active layer 103, the electron extraction layer 102, and the cathode (electrode) 101 may be arranged in this order. it can. The stacking order of the electron extraction layer 102 and the hole extraction layer 104 may be reversed. Further, at least one of the electron extraction layer 102 and the hole extraction layer 104 may be composed of a plurality of different films.

(Electronic extraction layer)
There is no particular limitation on the material of the electron extraction layer 102, and any material can be used as long as it can improve the efficiency of extracting electrons from the active layer 103 to the cathode 101. Specifically, inorganic compounds, organic compounds, or organic / inorganic perovskite compounds according to the present invention described in publicly known documents such as International Publication Nos. 2013/171517, 2013/180230, and 2012-191194. Is mentioned. For example, examples of the inorganic compound include salts of alkali metals such as lithium, sodium, potassium, and cesium, and metal oxides such as zinc oxide, titanium oxide, aluminum oxide, and indium oxide. Examples of the organic compound include bathocuproin (BCP), bathophenanthrene (Bphen), (8-hydroxyquinolinato) aluminum (Alq3), boron compound, oxadiazole compound, benzimidazole compound, naphthalenetetracarboxylic anhydride (NTCDA), Examples include perylene tetracarboxylic acid anhydride (PTCDA), fullerene compounds, or phosphine compounds having a double bond with a Group 16 element of the periodic table such as phosphine oxide compounds or phosphine sulfide compounds.

  There is no particular limitation on the method for forming the electron extraction layer 102. When a compound having sublimation properties is used as a material, it can be formed by a dry film formation method such as a vacuum evaporation method. Further, when a compound soluble in a solvent is used as a material, it can be formed by a wet film forming method such as a spin coating method or an ink jet method. Note that as the solvent, the solvents described in the description of the method for forming the active layer 103 can be used. In the case of using the wet film forming method, any method can be used as a coating method of the coating liquid containing the material of the electron extraction layer 102. Examples thereof include spin coating, gravure coating, kiss coating, roll brushing, spray coating, air knife coating, wire barber coating, pipe doctor method, impregnation / coating method, and curtain coating method. Moreover, only 1 type of method may be used as a coating method, and it can also be used in combination of 2 or more types.

  The total film thickness of the electron extraction layer 102 is not particularly limited, but is preferably 0.5 nm or more, more preferably 1 nm or more, more preferably 5 nm or more, and particularly preferably 10 nm or more. On the other hand, it is preferably 1 μm or less, more preferably 700 nm or less, more preferably 400 nm or less, and particularly preferably 200 nm or less. When the film thickness of the electron extraction layer 102 is within the above range, uniform application is facilitated, and the electron extraction function can be exhibited well.

(Hole extraction layer)
The material of the hole extraction layer 104 is not particularly limited as long as it is a material capable of improving the efficiency of extracting holes from the active layer 103 to the anode 106. Specifically, inorganic compounds, organic compounds, or organic / inorganic perovskite compounds according to the present invention described in publicly known documents such as International Publication Nos. 2013/171517, 2013/180230, and 2012-191194. Is mentioned. For example, examples of the inorganic compound include metal oxides such as copper oxide, nickel oxide, manganese oxide, iron oxide, molybdenum oxide, vanadium oxide, and tungsten oxide. In addition, as an organic compound, a conductive polymer in which polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline, or the like is doped with sulfonic acid, iodine, or the like (for example, PEDOT: PSS or doped P3HT), a sulfonyl group as a substituent And polythiophene derivatives, conductive organic compounds such as arylamine, Nafion, or lithium-doped spiro-OMeTAD.

  The total film thickness of the hole extraction layer 104 is not particularly limited, but is preferably 0.5 nm or more. On the other hand, it is preferably 400 nm or less, more preferably 200 nm or less. When the thickness of the hole extraction layer 104 is 0.5 nm or more, the function as a buffer material is performed well, and when the thickness of the hole extraction layer 104 is 400 nm or less, holes are easily extracted. Thus, the photoelectric conversion efficiency can be improved.

  There is no limitation on the formation method of the hole extraction layer 104. When a compound having sublimation property is used, it can be formed by a dry film forming method such as a vacuum vapor deposition method. Further, when a compound soluble in a solvent is used, it can be formed by a wet film forming method such as a spin coating method or an ink jet method. Note that as the solvent, the solvents described in the description of the method for forming the active layer 103 can be used.

<4-3. Electrode (101, 106)>
The electrode has a function of collecting holes and electrons generated by light absorption. Therefore, it is preferable to use the anode 106 suitable for collecting holes and the cathode 101 suitable for collecting electrons as the pair of electrodes. Any one of the pair of electrodes may be translucent, and both may be translucent. Translucency means that sunlight passes through 40% or more. Moreover, it is preferable that the transparent electrode has a solar ray transmittance of 70% or more because more light passes through the transparent electrode and reaches the active layer 103. The light transmittance can be measured with a spectrophotometer (for example, U-4100 manufactured by Hitachi High-Tech).

  There are no particular limitations on the constituent members of the cathode 101 and the anode 106 and the manufacturing method thereof, and well-known techniques can be used. For example, members described in publicly known documents such as International Publication No. 2013/171517, International Publication No. 2013/180230, or Japanese Patent Application Laid-Open No. 2012-191194 and a manufacturing method thereof can be used.

<4-4. Work function tuning layer (105)>
The work function tuning layer 105 adjusts the work function of the cathode 101 or the anode 106. However, if the cathode 101 or the anode 106 can function properly, it is not necessary to provide the work function tuning layer 105.

  The kind of the work function tuning layer 105 is not particularly limited, and a known one can be used. As an example of the material of the work function tuning layer 105, an amine polymer or an oligomer such as polyethyleneimine ethoxylate (PEIE) or branched polyethyleneimine (PEI) is preferable from the viewpoint of easy film formation by coating. In this case, from the viewpoint of increasing the solubility in an organic solvent, the molecular weight of the material of the work function tuning layer 105 is preferably 100 or more, more preferably 1000 or more, particularly preferably 10,000, while preferably 1,000,000 or less. , Preferably 500,000 or less, particularly preferably 200,000 or less.

  There is no limitation on the method of forming the work function tuning layer 105. When a compound having sublimation property is used, it can be formed by a dry film forming method such as a vacuum vapor deposition method. Further, when a compound soluble in a solvent is used, it can be formed by a wet film forming method such as a spin coating method or an ink jet method. Note that as the solvent, the solvents described in the description of the method for forming the active layer 103 can be used.

<4-5. Other layers>
The photoelectric conversion element 110 may have components other than the components shown in FIG. For example, the photoelectric conversion element 110 may have an insulator layer between the active layer 103 and the electrodes (101, 106). As a specific example, an insulator layer can be provided between the active layer 103 and the electron extraction layer 104. The insulator layer refers to a layer containing an insulator that does not pass a direct current. By providing such an insulator layer, it is possible to effectively suppress substances such as moisture from reaching the active layer 103. On the other hand, even if a thin insulator layer is provided, the function of the photoelectric conversion element 110 is maintained. This is thought to be because carriers that are electrons or holes pass through the insulator layer due to the tunnel effect.

  Although there is no restriction | limiting in particular in the material of an insulator layer, For example, a fluororesin or a silicon resin can be used. From the viewpoint of improving moisture resistance due to the insulator layer, the thickness of the insulator layer is preferably 1.0 nm or more, more preferably 5.0 nm or more, and particularly preferably 10 nm or more. Further, from the viewpoint of promoting the movement of carriers due to the tunnel effect, the thickness of the insulator layer is preferably 30 nm or less, more preferably 25 nm or less, and particularly preferably 20 nm or less.

<4-6. Substrate (107)>
The photoelectric conversion element 100 has the base material 107 used as a support body normally. But the photoelectric conversion element which concerns on this invention does not need to have the base material 107. FIG. The material of the base material 107 is not particularly limited as long as the effects of the present invention are not significantly impaired. For example, publicly known documents such as International Publication No. 2013/171517, International Publication No. 2013/180230, or Japanese Unexamined Patent Application Publication No. 2012-191194. The materials described in can be used.

<4-7. Method for manufacturing photoelectric conversion element>
The photoelectric conversion element 100 can be manufactured by forming each layer constituting the photoelectric conversion element 100 in accordance with the above-described method. There is no particular limitation on the method of forming each layer constituting the photoelectric conversion element 100, and the layers can be formed by a sheet-to-sheet (manyoba) method or a roll-to-roll method.

  The roll-to-roll method is a method in which a flexible base material wound in a roll shape is fed out and processed intermittently or continuously while being wound up by a take-up roll. is there. According to the roll-to-roll method, it is possible to batch-process long substrates of the order of km, and the roll-to-roll method is more suitable for mass production than the sheet-to-sheet method. On the other hand, when attempting to form each layer by the roll-to-roll method, the film may be damaged or partially peeled due to the contact between the film-forming surface and the roll due to its structure.

  The size of the roll that can be used in the roll-to-roll method is not particularly limited as long as it can be handled by a roll-to-roll manufacturing apparatus, but the upper limit of the outer diameter is preferably 5 m or less, more preferably 3 m or less, and more preferably 1 m or less. On the other hand, the lower limit is preferably 10 cm or more, more preferably 20 cm or more, more preferably 30 cm or more. The upper limit of the outer diameter of the roll core is preferably 4 m or less, more preferably 3 m or less, and more preferably 0.5 m or less. On the other hand, the lower limit is preferably 1 cm or more, more preferably 3 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and particularly preferably 20 cm or more. It is preferable that these diameters are not more than the above upper limit from the viewpoint of high handleability of the roll, and it is preferable that the diameter is not less than the lower limit from the viewpoint that the layer formed in each step is less likely to be broken by bending stress. . The lower limit of the width of the roll is preferably 5 cm or more, more preferably 10 cm or more, more preferably 20 cm or more. On the other hand, the upper limit is preferably 5 m or less, more preferably 3 m or less, more preferably 2 m or less. It is preferable that the width is equal to or less than the upper limit in terms of high handleability of the roll.

  Further, after the cathode 101 or the anode 106 is laminated, the photoelectric conversion element 100 is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, on the other hand, preferably 300 ° C. or lower, more preferably 280 ° C. or lower, more preferably 250 ° C. Heating is preferably performed in the following temperature range (this step may be referred to as an annealing treatment step). By performing the annealing process at a temperature of 50 ° C. or higher, the adhesion between the layers of the photoelectric conversion element 100, for example, the adhesion between the layers such as the electron extraction layer 102 and the cathode 101 and the electron extraction layer 102 and the active layer 103 is improved. This is preferable because the effect of By improving the adhesion between the layers, the thermal stability and durability of the photoelectric conversion element can be improved. It is preferable to set the temperature of the annealing treatment step to 300 ° C. or lower because the organic compound contained in the photoelectric conversion element 100 is less likely to be thermally decomposed. In the annealing process, stepwise heating using different temperatures within the above temperature range may be performed.

  The heating time is preferably 1 minute or more, more preferably 3 minutes or more, on the other hand, preferably 180 minutes or less, more preferably 60 minutes or less in order to improve adhesion while suppressing thermal decomposition. The annealing treatment step is preferably terminated when the open-circuit voltage, the short-circuit current, and the fill factor, which are parameters of the solar cell performance, reach a constant value. Further, the annealing treatment step is preferably performed under normal pressure and in an inert gas atmosphere in order to prevent thermal oxidation of the constituent materials. As a heating method, the photoelectric conversion element may be placed on a heat source such as a hot plate, or the photoelectric conversion element may be placed in a heating atmosphere such as an oven. The heating may be performed batchwise or continuously.

<4-8. Photoelectric conversion characteristics>
The photoelectric conversion characteristics of the photoelectric conversion element 100 can be obtained as follows. The photoelectric conversion element 100 is irradiated with light having an AM1.5G condition at an irradiation intensity of 100 mW / cm ^{2 using a} solar simulator, and current-voltage characteristics are measured. From the obtained current-voltage curve, photoelectric conversion characteristics such as photoelectric conversion efficiency (PCE), short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), series resistance, and shunt resistance can be obtained.

  The photoelectric conversion efficiency of the photoelectric conversion element 100 is not particularly limited, but is preferably 1% or more, more preferably 1.5% or more, and more preferably 2% or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better. Further, the fill factor of the photoelectric conversion element 100 is not particularly limited, but is preferably 0.6 or more, more preferably 0.7 or more, and more preferably 0.9 or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better.

Moreover, in order to put a photoelectric conversion element into practical use, it is important to have high photoelectric conversion efficiency and high durability in addition to simple and inexpensive manufacture. From this viewpoint, the durability of the photoelectric conversion efficiency before and after exposing the photoelectric conversion element 100 to the atmosphere for one week is preferably 60% or more, more preferably 80% or more, and the higher the better. The durability of the photoelectric conversion efficiency can be calculated as follows based on the photoelectric conversion efficiency before and after the photoelectric conversion element 100 is exposed to the atmosphere.
Durability (%) = ((photoelectric conversion efficiency after N hours exposure to air) / (photoelectric conversion efficiency immediately before exposure to air)) × 100

<5. Solar cell>
The photoelectric conversion element 100 according to the present invention is preferably used as a solar cell, particularly a solar cell element of a thin film solar cell. FIG. 4 is a cross-sectional view schematically showing a configuration of a solar cell according to an embodiment of the present invention. FIG. 4 shows a thin-film solar cell that is a solar cell according to an embodiment of the present invention. As shown in FIG. 4, the thin-film solar cell 14 according to this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and a solar cell. The element 6, the sealing material 7, the getter material film 8, the gas barrier film 9, and the back sheet 10 are provided in this order. The thin film solar cell 14 according to the present embodiment has the photoelectric conversion element according to the present invention as the solar cell element 6. And light is irradiated from the side (downward in Drawing 4) in which weatherproof protective film 1 was formed, and solar cell element 6 generates electricity. In addition, the thin film solar cell 14 does not need to have all these structural members, and can select a required structural member arbitrarily.

  There are no particular restrictions on these constituent members constituting the thin-film solar cell and the manufacturing method thereof, and well-known techniques can be used. For example, techniques described in publicly known documents such as International Publication No. 2013/171517, International Publication No. 2013/180230, or Japanese Patent Application Laid-Open No. 2012-191194 can be used.

  There is no restriction | limiting in the use of the solar cell which concerns on this invention, especially the thin film solar cell 14 mentioned above, It can use for arbitrary uses. For example, a solar cell according to one embodiment includes a solar cell for building materials, a solar cell for automobiles, a solar cell for interiors, a solar cell for railways, a solar cell for ships, a solar cell for airplanes, a solar cell for spacecraft, and a solar cell for home appliances. It can be used as a battery, a solar cell for mobile phones or a solar cell for toys.

  The solar cell according to the present invention, particularly the thin film solar cell 14 described above, may be used as it is, or may be used as a component of the solar cell module. For example, as shown in FIG. 5, a solar cell according to the present invention, in particular, a solar cell module 13 provided with the above-described thin film solar cell 14 on a substrate 12 is manufactured, and the solar cell module 13 is installed at a place of use. Can be used. A well-known technique can be used as the base material 12, for example, as the material of the base material 12, a material described in International Publication No. 2013/171517, International Publication No. 2013/180230, or Japanese Patent Application Laid-Open No. 2012-191194. Can be used. For example, when a building material plate is used as the substrate 12, a solar cell panel for an outer wall of a building can be produced as the solar cell module 13 by providing the thin film solar cell 14 on the surface of the plate.

<6. Further Semiconductor Device According to the Present Invention>
A further semiconductor device according to the present invention includes a pair of electrodes and a semiconductor layer disposed between the pair of electrodes. In one embodiment, the semiconductor layer has a lattice size of 25 nm or less. Here, the lattice size means the size of the semiconductor compound crystal contained in the semiconductor layer, and can be calculated using the Scherrer equation based on the X-ray diffraction measurement. By reducing the lattice size of the semiconductor layer, the surface roughness of the semiconductor layer is reduced and the layer interface becomes smoother, so that it is possible to suppress performance deterioration due to a short circuit or the like. Further, the semiconductor layer becomes denser and durability can be improved.

  Moreover, when using a semiconductor device as an optical device, it may be preferable that the light transmittance of a semiconductor layer is high. For example, in a photoelectric conversion element, the light reaching the active layer can be increased by increasing the light transmittance of the active layer. Here, by reducing the lattice size of the semiconductor layer, light reflection and / or scattering in the semiconductor layer can be suppressed, so that the light transmittance of the semiconductor layer can also be increased. Further, by reducing the lattice size of the semiconductor layer, the surface roughness of the semiconductor layer can be reduced, and light reflection and / or scattering on the surface of the semiconductor layer can be suppressed. Can also be increased.

  Such a semiconductor device can be produced, for example, by adding an insulating polymer to the semiconductor layer as described above. However, the manufacturing method is not limited to this method, and the above effect can be obtained by reducing the lattice size of the semiconductor layer. In one embodiment, in order to obtain the above effect, the lattice size of the semiconductor layer is particularly preferably 20 nm or less. Moreover, although there is no special restriction | limiting in the minimum of a lattice size, in order to prevent a conductive fall, it is preferable that it is 5 nm or more, and it is preferable that it is 10 nm or more.

  Further, the surface roughness (Rq) of the semiconductor layer is not particularly limited, but is preferably 10 nm or less, and more preferably 5 nm or less in order to obtain the above effect. On the other hand, the lower limit is not particularly limited. The surface roughness (Rq, root mean square roughness) can be measured according to JIS B 0601: 2013. About another structure, the structure similar to the semiconductor device mentioned above can be employ | adopted, for example, the semiconductor layer may contain the perovskite semiconductor compound.

  Hereinafter, embodiments of the present invention will be described by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

[Example 1]
(Preparation of active layer coating solution)
Lead (II) iodide (0.84 g), lead (II) chloride (0.51 g) and methylammonium iodide (CH ₃ NH ₃ I, 1.16 g) so that the molar ratio is 1: 1: 4 Was weighed into a vial and polyvinylpyrrolidone (PVP, 49.4 mg, weight average molecular weight Mw = 40 × 10 ³ ) and N, N-dimethylformamide (8 mL) were added. Next, the obtained mixed liquid was heated and stirred at 67 ° C. for 6 hours. Thereafter, the resulting solution was filtered through a polytetrafluoroethylene (PTFE) filter (pore size: 0.2 μm) to prepare an active layer coating solution. The total concentration of lead (II) iodide, lead (II) chloride and methylammonium iodide in the resulting active layer coating solution was 25% by mass. By using the active layer coating solution thus prepared, a perovskite semiconductor compound (1.93 g) composed of lead (II) iodide, lead (II) chloride and methylammonium iodide in a molar ratio of 1: 1: 2. ). The mass ratio of polyvinyl pyrrolidone contained in the active layer coating solution to the perovskite semiconductor compound that can be formed was 2.6% by mass.

(Preparation of photoelectric conversion element)
For a glass substrate (manufactured by Geomat Co., Ltd.) with a patterned indium tin oxide (ITO) transparent conductive film, use a detergent (Yokohama Yushi Kogyo Co., Ltd., Semi-clean M-LO, 15 mL). Ultrasonic cleaning, ultrasonic cleaning using ultrapure water, drying by nitrogen blowing, and UV-ozone treatment were performed.

  Next, after filtering a poly (3,4-ethylenedioxythiophene) poly (styrene sulfonic acid) dispersion (PEDOT: PSS, manufactured by Heraeus) with a motorcycle al (pore diameter 0.45 μm), at room temperature, the above-mentioned A hole extraction layer having a thickness of about 35 nm was formed by spin coating on the substrate at a speed of 3000 rpm. The obtained substrate was heated at 120 ° C. for 30 minutes.

  Next, the substrate was introduced into a glove box and heat-treated at 115 ° C. for 20 minutes in a nitrogen atmosphere. After cooling, an active layer coating solution (0.1 mL) was spin-coated on the substrate at a speed of 6000 rpm to form a layer having a thickness of about 100 nm, and further heat-annealed on a hot plate at 100 ° C. for 25 minutes. As described above, an active layer was formed. The active layer thus formed contains a halide organic-inorganic perovskite semiconductor compound and polyvinylpyrrolidone which is an insulating polymer.

  Next, an amorphous fluororesin polymer solution CYTOP (manufactured by Asahi Glass Co., Ltd., prepared to 0.4% by mass, 0.1 mL) was added on the active layer at a rotation of 6000 rpm to form an insulator layer. The thickness of the insulator layer was 15 nm.

The characteristics of CYTOP are: volume resistivity:> 10 ¹⁷ Ωcm (JIS K6911), relative dielectric constant: 2.0 to 2.1 (100 Hz to 1 MHz, room temperature, JEC-6150), refractive index: 1.34 ( JIS K7142, 25 ° C.-), water contact angle: 110 °, glass transition temperature: 108 ° C. The visible light transmittance of the 200 μm thick CYTOP film is 95%. Furthermore, the water vapor transmission rate of the CYTOP film having a thickness of 100 μm was 0.2 g / m ² (24 hours).

Next, a solution in which phenyl C ₆₁ butyric acid methyl ester (PCBM, manufactured by Frontier Carbon Co., Ltd., 20 mg) was dissolved in chlorobenzene (1 mL) was filtered through a polytetrafluoroethylene (PTFE) filter (pore diameter: 0.2 μm). The obtained solution (0.1 mL) was spin-coated on the active layer at a speed of 2000 rpm, thereby forming an electron extraction layer having a thickness of about 70 nm.

  Next, a methanol solution (0.2% by mass, 0.1 mL) of polyethyleneimine ethoxylate (PEIE) is added on the electron extraction layer at a rotation of 6000 rpm, thereby tuning the work function with a thickness of about 10 nm. A layer was formed.

  Next, a silver film having a thickness of about 150 nm was deposited on the work function tuning layer by a resistance heating type vacuum deposition method using a patterning mask to form an electrode. Thus, a 25 × 30 mm square photoelectric conversion element was produced.

[Example 2]
Except that the mass of polyvinyl pyrrolidone used in preparing the active layer coating solution was 19.8 mg (1.0 mass% (mass ratio to the perovskite semiconductor compound, the same shall apply hereinafter)), A conversion element was produced.

[Example 3]
A photoelectric conversion element was produced in the same manner as in Example 1 except that the mass of polyvinyl pyrrolidone used in preparing the active layer coating solution was 39.5 mg (2.0 mass%).

[Example 4]
A photoelectric conversion element was produced in the same manner as in Example 1 except that the mass of polyvinyl pyrrolidone used in preparing the active layer coating solution was 59.3 mg (3.1 mass%).

[Example 5]
The polyvinyl pyrrolidone used in preparing the active layer coating solution had a weight average molecular weight of 10 × 10 ³ and a mass of 29.6 mg (1.5% by mass), as in Example 1. A photoelectric conversion element was produced.

[Example 6]
The polyvinyl pyrrolidone used in preparing the active layer coating solution had a weight average molecular weight of 10 × 10 ³ and a mass of 59.3 mg (3.1% by mass), as in Example 1. A photoelectric conversion element was produced.

[Example 7]
The polyvinyl pyrrolidone used in preparing the active layer coating solution had a weight average molecular weight of 360 × 10 ³ and a mass of 29.6 mg (1.5% by mass), as in Example 1. A photoelectric conversion element was produced.

[Example 8]
In preparing the active layer coating solution, a polyvinylpyrrolidone-vinyl acetate copolymer (70:30, 29.6 mg, 1.5 mass%) having a weight average molecular weight of 66 × 10 ³ was used instead of polyvinylpyrrolidone. A photoelectric conversion element was produced in the same manner as in Example 1 except for.

[Example 9]
When preparing the active layer coating solution, a polyvinylpyrrolidone-vinyl acetate copolymer (50:50, 29.6 mg, 1.5 mass%) having a weight average molecular weight of 45 × 10 ³ was used instead of polyvinylpyrrolidone. A photoelectric conversion element was produced in the same manner as in Example 1 except for.

[Example 10]
Except for using polyvinylpyrrolidone-iodine complex (Aldrich, 29.6 mg, 1.5 mass%) having a weight average molecular weight of 45 × 10 ³ instead of polyvinylpyrrolidone when preparing the active layer coating solution, A photoelectric conversion element was produced in the same manner as in Example 1.

[Example 11]
When preparing the active layer coating solution, a photoelectric conversion element was prepared in the same manner as in Example 1 except that crosslinked polyvinylpyrrolidone (Alfa, 29.6 mg, 1.5 mass%) was used instead of polyvinylpyrrolidone. Produced.

[Example 12]
Except that poly (4-vinylpyridine) (29.6 mg, 1.5% by mass) having a weight average molecular weight of 60 × 10 ³ was used instead of polyvinylpyrrolidone in preparing the active layer coating solution. The photoelectric conversion element was produced similarly to 1.

[Example 13]
Except that poly (4-vinylpyridine) (29.6 mg, 1.5% by mass) having a weight average molecular weight of 160 × 10 ³ was used instead of polyvinylpyrrolidone in preparing the active layer coating solution. The photoelectric conversion element was produced similarly to 1.

[Comparative Example 1]
A photoelectric conversion element was produced in the same manner as in Example 1 except that polyvinylpyrrolidone was not added to the active layer coating solution.

[Comparative Example 2]
A photoelectric conversion element was produced in the same manner as in Example 1 except that polyvinylpyrrolidone was not added to the active layer coating solution and an insulator layer was not formed on the active layer.

[Comparative Example 3]
In preparing the active layer coating solution, poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene] (MEH-PPV, 29.6 mg) which is a conductive polymer instead of polyvinylpyrrolidone. , 1.5 mass%) was used, and a photoelectric conversion element was produced in the same manner as in Example 1.

[Evaluation of photoelectric conversion element]
A 1 mm square metal mask was attached to the photoelectric conversion elements obtained in Examples 1 to 13 and Comparative Examples 1 to 3, and current-voltage characteristics between the ITO electrode and the silver electrode were measured. A source meter (manufactured by Keithley, Model 2400) was used for the measurement, and a solar simulator having an air mass (AM) of 1.5 G and an irradiance of 100 mW / cm ² was used as the irradiation light source. From this measurement result, open circuit voltage Voc (V), short circuit current density Jsc (mA / cm ² ), form factor FF, and photoelectric conversion efficiency PCE (%) were calculated. Table 1 shows these values calculated based on the measurement results immediately after producing the photoelectric conversion element.

Here, the open circuit voltage Voc is a voltage value when the current value = 0 (mA / cm ² ), and the short circuit current density Jsc is a current density when the voltage value = 0 (V). The form factor FF is a factor representing the internal resistance, and is represented by the following expression when the maximum output is Pmax.
FF = Pmax / (Voc × Jsc)
Further, the photoelectric conversion efficiency PCE is given by the following equation when the incident energy is Pin.
PCE = (Pmax / Pin) × 100
= (Voc x Jsc x FF / Pin) x 100

  Moreover, durability of the photoelectric conversion element obtained in Examples 1-13 and Comparative Examples 1-3 was evaluated. The results are shown in Table 1. Durability depends on the time until the conversion efficiency reaches 80% with respect to the conversion efficiency (initial conversion efficiency) immediately after production when measurement is repeatedly performed under conditions of 21 to 22 ° C. and humidity of 35 to 45%. evaluated. In Table 1, x indicates that the conversion efficiency is 80% or less of the initial conversion efficiency in less than 24 hours. Further, Δ indicates that the conversion efficiency is 80% or less of the initial conversion efficiency in 24 hours or more and less than 48 hours. Moreover, (circle) shows that conversion efficiency became 80% or less of initial stage conversion efficiency in 48 hours or more and less than 500 hours. Further, ◎ indicates that the conversion efficiency did not become 80% or less of the initial conversion efficiency even after 500 hours.

  Moreover, the transmittance | permeability of the photoelectric conversion element obtained in Examples 1-13 and Comparative Examples 1-3 was evaluated. The permeability was evaluated according to the transmission spectrum of the photoelectric conversion element before forming the upper electrode (silver electrode). That is, a transmission spectrum was measured using a blank as air, and an average transmittance in a wavelength range of 400 to 800 nm was calculated. The obtained results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 13 in which the active layer contains an insulating polymer, it was confirmed that the durability was significantly improved as compared with Comparative Examples 1 to 3. Moreover, it turned out that the value of a fill factor (FF) improves significantly in Examples 1-13 in which an active layer contains an insulating polymer. Furthermore, it has been found that the light transmittance of the photoelectric conversion element is improved by the addition of the insulating polymer. Further, in Examples 1 to 13, despite the fact that the active layer contains an insulating polymer, the photoelectric conversion efficiency immediately after the production was hardly lowered, but a number of improvements were confirmed.

[Example 14]
For a glass substrate (manufactured by Geomat Co., Ltd.) with a patterned indium tin oxide (ITO) transparent conductive film, use a detergent (Yokohama Yushi Kogyo Co., Ltd., Semi-clean M-LO, 15 mL). Ultrasonic cleaning, ultrasonic cleaning using ultrapure water, drying by nitrogen blowing, and UV-ozone treatment were performed. Next, Example 1 except that the mass of polyvinyl pyrrolidone used in preparing the active layer coating solution was 57.0 mg (3.0 mass% (mass ratio to the perovskite semiconductor compound, the same shall apply hereinafter)). An active layer coating solution was prepared in the same manner, and the active layer coating solution (0.1 mL) was spin-coated on the substrate at a speed of 6000 rpm / 45 seconds, and then heat-annealed on a hot plate at 100 ° C. for 25 minutes. .

  The lattice size and surface roughness of the film thus obtained were measured. The lattice size was calculated by the following Scherrer equation after measuring the X-ray diffraction peak under the following conditions. Also, the surface roughness was measured by using an atomic force microscope (AFM) to bring the cantilever with the probe attached to the tip of the spring plate to a distance of several nanometers from the sample surface. The unevenness of the sample was measured by the interatomic force acting between them, and the difference was obtained.

(Measurement condition)
Measuring device SmartLab manufactured by SmartLab
Optical system Oblique incident X-ray diffraction optical system Measurement conditions out of plane method X-ray output 45 kV, 200 mA (CuKα)
Scanning axis 2θ
Incident angle (θ) 0.02 °
Scanning range (2θ) 3-40 °
Scanning speed 3 ° / min

(Scherrer's formula)
T = Kλ / β · cos θ
(T = lattice size, K = form factor, λ = X-ray wavelength, β = peak full width at half maximum, θ = Bragg angle)
The shape factor used was 0.94.

[Example 15]
The same method as in Example 14 except that the mass of polyvinylpyrrolidone used in preparing the active layer coating solution was 114.0 mg (5.9 mass% (mass ratio to the perovskite semiconductor compound, the same applies hereinafter)). The active layer was formed by, and the lattice size and the surface roughness were measured. The obtained results are shown in Table 2.

[Example 16]
The same method as in Example 14 except that the mass of polyvinylpyrrolidone used in preparing the active layer coating solution was 190.0 mg (9.8 mass% (mass ratio to the perovskite semiconductor compound, the same applies hereinafter)). The active layer was formed by, and the lattice size and the surface roughness were measured. The obtained results are shown in Table 2.

[Comparative Example 4]
An active layer was formed by the same method as in Example 14 except that polyvinylpyrrolidone was not added, and the lattice size and the surface roughness were measured. The obtained results are shown in Table 2.

  From the results in Table 2, the lattice size of the active layer according to Comparative Example 4 to which no insulating polymer was added was 38 nm. On the other hand, it was confirmed that the lattice size of the active layers according to Examples 14 to 16 was as small as 16 nm to 17 nm. That is, when considering the results in Tables 1 and 2, when no insulating polymer is added, the active layer has a large lattice size, so that when light is incident on the device, reflection and / or scattering of light occurs. It is considered that the light transmittance of the element has been lowered. On the other hand, by adding an insulating polymer, the lattice size of the active layer is reduced, so that reflection and scattering of light can be suppressed, and as a result, the transmittance of the element is considered to be improved.

  The surface roughness of the active layer according to Comparative Example 4 was 14.55 nm, whereas the surface roughness of the active layer according to Examples 14 to 16 was 2.85 nm to 3.11 nm. It was confirmed that it was significantly smaller than 4. That is, when considering the results of Tables 1 and 2, when no insulating polymer is added, the active layer has a large surface roughness, so that when light is incident on the device, the light is reflected and / or scattered. Therefore, it is considered that the light transmittance of the element has been lowered. On the other hand, when the insulating polymer is added, the surface roughness of the active layer is reduced, so that reflection, scattering, etc. of light can be suppressed, and as a result, the transmittance of the element is considered to be improved. Thus, in Examples 14-16, it is thought that the surface roughness of an active layer becomes small reflecting that the lattice size of the active layer became small. Moreover, it is thought that the characteristics regarding the lattice size and the surface roughness as described above have a good influence on the durability of the photoelectric conversion element according to each example.

[Example 17]
In order to confirm the crystal structure of the active layer containing the perovskite semiconductor compound, XRD measurement was performed as follows. That is, the active layer coating solution was applied onto the substrate by the same method as in Example 14, heat treatment was performed, and XRD measurement was performed at 26 ° C. or 60 ° C., respectively. The XRD measurement was performed under the same conditions as in Example 14 except for the temperature. The obtained result is shown in FIG.

[Comparative Example 5]
The active layer coating solution was applied onto the substrate by the same method as in Comparative Example 4, heat treatment was performed, and XRD measurement was performed at 26 ° C. or 60 ° C., respectively. The XRD measurement was performed under the same conditions as in Example 14 except for the temperature. The obtained results are shown in FIG.

  Referring to the results in FIG. 7, it can be confirmed that in Comparative Example 5, the active layer had a cubic structure at 60 ° C., whereas it had a tetragonal structure at 26 ° C. On the other hand, referring to the results of FIG. 6, in Example 17, it can be confirmed that the active layer has a cubic structure at both 26 ° C. and 60 ° C. When these results are evaluated, it is considered that the perovskite compound-containing active layer to which no insulating polymer is added has a low durability because the perovskite compound-containing active layer changes from a cubic system to a tetragonal system when the temperature decreases. On the other hand, the perovskite compound-containing active layer to which an insulating polymer is added can maintain a cubic system even when the temperature is lowered, so that the structure does not change with temperature change and is considered to have high durability. It is done.

DESCRIPTION OF SYMBOLS 1 Weatherproof protective film 2 Ultraviolet cut film 3,9 Gas barrier film 4,8 Getter material film 5,7 Sealing material 6 Solar cell element 10 Back sheet 12 Base material 13 Solar cell module 14 Thin film solar cell 31 Base material 32 Anode 33 Hole injection layer 34 Hole transport layer 35 Light emitting layer 36 Electron transport layer 37 Electron injection layer 38 Cathode 39 Electroluminescent device 51 Semiconductor layer 52 Insulator layers 53 and 54 Source electrode and drain electrode 55 Gate electrode 56 Base material 100 Photoelectric conversion Element 101 Cathode 102 Electron extraction layer 103 Active layer 104 Hole extraction layer 105 Work function tuning layer 106 Anode 107 Base material

Claims (12)

An insulating polymer comprising a pair of electrodes and a semiconductor layer disposed between the pair of electrodes, wherein the semiconductor layer includes a semiconductor compound and a repeating unit represented by the following formula (Ia) A semiconductor device comprising:
(In Formula (Ia), R ¹ and R ² each independently represent a hydrocarbon group or a hydrogen atom, and R ¹ and R ² may be bonded to each other to form a ring.) Characterized in that R ¹ and R ² are bonded to each other to form a ring, the semiconductor device according to claim 1. 3. The semiconductor device according to claim 1, wherein a ratio of the repeating unit represented by the formula (Ia) among the repeating units constituting the insulating polymer is 50 mol% or more. Wherein in the semiconductor layer, the ratio of the insulating polymer to the semiconductor compound is equal to or less than 10 mass% 0.1 mass% or more, the semiconductor device according to any one of claims 1 to 3. Characterized in that said weight average molecular weight of the insulating polymer is 10 × 10 ³ or more 400 × 10 ³ or less, the semiconductor device according to any one of claims 1 to 4. The insulating polymer is amorphous polymer, and wherein the refractive index of 1.5 or less, the semiconductor device according to any one of claims 1 to 5. 1g of N, N-solubility at 25 ° C. of the insulating polymer to dimethyl formamide and wherein the at least 0.5 mg, the semiconductor device according to any one of claims 1 to 6. It said semiconductor compound is characterized by containing a perovskite semiconductor compound, a semiconductor device according to any one of claims 1 to 7. Characterized in that it is a photoelectric conversion element, a semiconductor device according to any one of claims 1 to 8. The semiconductor device according to claim 9 , wherein a fill factor is 0.7 or more. A solar cell comprising the semiconductor device according to claim 9 or 10 . A solar cell module comprising the solar cell according to claim 11 .