WO2014003187A1

WO2014003187A1 - Organic thin film solar cell module

Info

Publication number: WO2014003187A1
Application number: PCT/JP2013/067943
Authority: WO
Inventors: 崇志藤原; 光敏小川
Original assignee: 三菱化学株式会社
Priority date: 2012-06-29
Filing date: 2013-06-28
Publication date: 2014-01-03
Also published as: JP2015167151A

Abstract

The purpose of the present invention is to provide an organic thin film solar cell module that experiences little degradation of the module, even with use for an extended period. This purpose is attained through an organic thin film solar cell module provided with: organic thin film solar cell elements in which are layered a photoelectric conversion layer (7), a substrate (1) for supporting the photoelectric conversion layer (7), and at least one pair of electrodes (2, 6) connecting to the photoelectric conversion layer (7) at the light-receiving surface side and at the non- light-receiving surface side of the photoelectric conversion layer (7); and at least one pair of current collection lines (8), wherein the current collection lines (8) are connected to the electrodes (2, 6) through an electrically conductive, thermosetting resin composition (9).

Description

Organic thin film solar cell module

The present invention relates to an organic thin film solar cell module.

In order to take out electricity from the organic thin film solar cell element, an electrode for electric extraction is usually installed on the upper electrode or lower electrode of each solar cell forming the thin film solar cell element, and the electrode and the collector are connected to each other. A connection method is known (see, for example, Patent Documents 1 and 2).

JP 2011-124582 A JP 2011-171707 A

As described above, although the method of connecting the electrode and the current collector is known, in the industrial production of the organic thin-film solar cell module, there is currently no specific method for installing the current collector. Therefore, the present inventors tried various installation methods such as solder, silver paste, pressure-sensitive adhesive, and conductive resin. However, it has been found that various problems occur depending on the installation method, such as complicated processes, low initial photoelectric conversion efficiency, low durability, and poor appearance.

The present invention solves such problems, can easily install a current collector, good initial photoelectric conversion efficiency, less module deterioration even after long-term use, excellent in appearance, It is an object to provide an organic thin film solar cell module and a method for efficiently producing the solar cell module.

As a result of intensive studies to solve the above problems, the present inventors have at least a photoelectric conversion layer, a substrate supporting the photoelectric conversion layer, and a light receiving surface side and a non-light receiving surface side of the photoelectric conversion layer. In an organic thin film solar cell module comprising an organic thin film solar cell having an organic thin film solar cell element in which at least a pair of electrodes connected to the photoelectric conversion layer is laminated, and at least a pair of collector wires connected to the electrodes, The present invention has been completed by finding that the above problem can be solved by connecting the current collector to the electrode via a conductive thermosetting resin composition. The outline of the present invention is as follows.

The present invention is an organic layer in which at least a photoelectric conversion layer, a substrate that supports the photoelectric conversion layer, and at least a pair of electrodes that are connected to the photoelectric conversion layer on a light receiving surface side and a non-light receiving surface side of the photoelectric conversion layer are stacked. In an organic thin film solar cell module comprising an organic thin film solar cell having a thin film solar cell element and at least a pair of current collectors connected to the electrodes, the current collector is interposed via a conductive thermosetting resin composition. The organic thin film solar cell module is connected to the electrode.
It is preferable that the thickness of the current collector is 200 μm or less.

The present invention also provides the following aspects.
[1] In an organic thin film solar cell element in which a lower electrode, a photoelectric conversion layer, and an upper electrode are sequentially laminated on a substrate, and an organic thin film solar cell module having a current collector electrically connected to the organic thin film solar cell element,
An organic thin film solar cell module, wherein the current collector is connected to an organic thin film solar cell element via a conductive thermosetting resin composition.
[2] The organic thin-film solar cell module according to [1], wherein the substrate is a resin substrate.
[3] The organic thin-film solar cell module according to [1], wherein the substrate is a flexible substrate.
[4] The organic thin film solar cell module according to [2] or [3], wherein the glass transition temperature (Tg) of the resin substrate is 400 ° C. or lower.
[5] The organic thin-film solar cell module according to [4], wherein the curing temperature of the conductive thermosetting resin composition is lower than the glass transition temperature (Tg) of the substrate.
[6] The organic thin-film solar cell module according to [5], wherein the curing temperature of the conductive thermosetting resin composition is less than 160 ° C.
[7] The organic thin film solar cell module according to any one of [1] to [6], wherein the organic thin film solar cell element has a monolithic structure.
[8] The organic thin-film solar cell module according to any one of [1] to [7], wherein two collector wires are respectively installed on the upper electrode.
[9] The organic thin film solar cell module according to any one of [1] to [8], wherein the upper electrode is ITO.
[10] The organic thin film solar cell module according to any one of [1] to [9], wherein the organic thin film solar cell module is sealed with a sealing material containing a thermosetting resin.
[11] The organic thin-film solar cell module according to [10], wherein the conductive thermosetting resin composition has a curing temperature equal to or lower than a temperature at which the thermosetting composition contained in the sealing material can be cured.
[12] The organic thin film solar cell module according to any one of [1] to [11], wherein the upper electrode is a metal thin film.
[13] A method for producing an organic thin film solar cell module, comprising the following steps 1 to 3 in sequence.
Step 1 Step 2 Step 1 of installing a current collector via a conductive thermosetting resin composition on an organic thin film solar cell element in which at least a lower electrode, a photoelectric conversion layer, and an upper electrode are sequentially laminated on a substrate Step 3 of installing the sealing material on the surface of the obtained organic thin-film solar cell element on which the current collector is installed. The laminate obtained in Step 2 is heated to cure the conductive thermosetting resin composition. The process of simultaneously performing sealing with a sealing material [14] The method for producing an organic thin-film solar cell module according to [13], wherein the sealing material includes a thermosetting resin.

According to the present invention, an organic thin-film solar cell module that can easily install a current collector, has good initial photoelectric conversion efficiency, has little deterioration even after long-term use, and has an excellent appearance, and a method for manufacturing the same Can be obtained.

It is a figure for demonstrating the monolithic structure of an organic thin-film solar cell element. (A)-(c) It is the conceptual diagram shown about the installation aspect of the collector wire in the organic thin-film solar cell element of this invention. It is a conceptual diagram which shows the layer structure of an organic thin film solar cell module. It is a schematic diagram showing the laminated constitution of the solar cell panel using an organic thin film solar cell module.

The present invention will be specifically described below.
The present invention includes at least a photoelectric conversion layer, a substrate supporting the photoelectric conversion layer, and at least a pair of electrodes (an upper electrode and a lower electrode) connected to the photoelectric conversion layer on a light receiving surface side and a non-light receiving surface side of the photoelectric conversion layer. In an organic thin film solar cell module comprising an organic thin film solar cell having an organic thin film solar cell element on which an electrode) is laminated and at least a pair of current collectors connected to the electrode, the current collector is electrically conductive. The electrode is connected to the electrode through a curable resin composition.
Further, another aspect of the present invention includes an organic thin film solar cell element in which a lower electrode, a photoelectric conversion layer, and an upper electrode are sequentially stacked on a substrate, and a current collector electrically connected to the organic thin film solar cell element The organic thin film solar cell module is an organic thin film solar cell module characterized in that the collector wire is connected to an organic thin film solar cell element via a conductive thermosetting resin composition.

1. Organic thin-film solar cell element The organic thin-film solar cell element according to the present invention usually has a structure in which a lower electrode, a photoelectric conversion layer, and an upper electrode are sequentially laminated on a substrate.
As long as the material of the photoelectric conversion layer of the organic thin film solar cell element used in the organic thin film solar cell module of the present invention does not impair the effects of the present invention, any material may be used. It is preferable to use an organic semiconductor material or the like. Among these, it is particularly preferable to use an organic semiconductor material because it is particularly excellent in productivity and easily obtains the effects of the present invention. Hereinafter, an example of an organic thin film solar cell element using an organic semiconductor material will be described.

1-1. Photoelectric conversion layer The photoelectric conversion layer is formed of an organic semiconductor. Organic semiconductors are classified into p-type and n-type depending on semiconductor characteristics. The p-type and n-type indicate whether it is a hole or an electron that contributes to electrical conduction, and depends on the electronic state, doping state, and trap state of the material. Therefore, there are cases where p-type and n-type cannot always be clearly classified, and there are cases where the same substance exhibits both p-type and n-type characteristics.

Examples of p-type semiconductors include high molecular organic semiconductor compounds and low molecular organic semiconductor compounds.
The polymer organic semiconductor compound is not particularly limited, and is a conjugated polymer semiconductor such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene or polyaniline; a polymer such as oligothiophene substituted with an alkyl group or other substituents Semiconductor; and the like. Moreover, the semiconductor polymer which copolymerized 2 or more types of monomer units is also mentioned. Examples of the conjugated polymer include Handbook of Conducting Polymers, 3rd Ed. (2 volumes), 2007, Materials Science and Engineering, 2001, 32, 1-40, Pure Appl. Chem. Use polymers described in 2002, 74, 2031-3044, Handbook of THIOPHENE-BASED MATERIALS (2 volumes in total), 2009, and the like and their derivatives, and polymers that can be synthesized by combinations of the described monomers. Can do. The polymer organic semiconductor compound used as the p-type semiconductor compound may be a single compound or a mixture of a plurality of compounds.

The low-molecular organic semiconductor compound is not particularly limited as long as it can function as a p-type semiconductor material. Specifically, it is a condensed aromatic hydrocarbon such as naphthacene, pentacene or pyrene; Oligothiophenes containing 4 or more thiophene rings; including at least one of thiophene ring, benzene ring, fluorene ring, naphthalene ring, anthracene ring, thiazole ring, thiadiazole ring and benzothiazole ring, and a total of 4 or more linked A phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin and a macrocycle such as a metal complex thereof. Preferably, they are a phthalocyanine compound and its metal complex, or a porphyrin compound and its metal complex. The molecular weight of the low-molecular organic semiconductor compound is not particularly limited both at the upper limit and the lower limit, but is usually 5000 or less, preferably 2000 or less, and is usually 100 or more, preferably 200 or more. In addition, when forming a p-type semiconductor layer by application | coating, a low molecular organic-semiconductor compound precursor can be converted into a low-molecular-weight organic semiconductor compound after application | coating. A method using a low molecular weight organic semiconductor compound precursor is more preferable in that coating film formation is easier. A low molecular organic semiconductor compound precursor is a compound that changes its chemical structure and is converted into a low molecular organic semiconductor compound by applying an external stimulus such as heating or light irradiation. A low molecular organic semiconductor compound precursor is preferable in that it has excellent film-forming properties.
Examples of p-type semiconductors include porphyrin compounds such as tetrabenzoporphyrin, tetrabenzocopper porphyrin, and tetrabenzozinc porphyrin; phthalocyanine compounds such as phthalocyanine, copper phthalocyanine, and zinc phthalocyanine; naphthalocyanine compounds; tetracene and pentacene polyacenes; And derivatives containing these compounds as a skeleton. Furthermore, polymers such as polythiophene including poly (3-alkylthiophene) and the like, polyfluorene, polyphenylene vinylene, polytriallylamine, polyacetylene, polyaniline, polypyrrole, and the like are also included.

The n-type semiconductor is not particularly limited, but specifically, a fullerene compound, a quinolinol derivative metal complex represented by 8-hydroxyquinoline aluminum; naphthalene tetracarboxylic acid anhydride; naphthalene tetracarboxylic acid diimide or perylene tetracarboxylic acid Condensed ring tetracarboxylic acid diimides such as acid diimides; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazol derivatives, benzothiadiazole derivatives, Oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxari Derivatives, benzoquinoline derivatives, bipyridine derivatives, borane derivatives, anthracene, pyrene, total fluoride condensed polycyclic aromatic hydrocarbons such as naphthacene or pentacene; single-walled carbon nanotubes, and the like.

Of these, fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl-substituted naphthalenetetracarboxylic acid diimides and N-alkyl-substituted perylene diimide derivatives are preferred, and fullerene compounds, N- Alkyl substituted perylene diimide derivatives and N-alkyl substituted naphthalene tetracarboxylic acid diimides are more preferred. One of the above compounds may be used, or a mixture of a plurality of compounds may be used. An n-type semiconductor is also included as an n-type semiconductor.

As long as at least a p-type semiconductor and an n-type semiconductor are contained, the specific configuration of the photoelectric conversion layer is arbitrary. The photoelectric conversion layer may be constituted only by a single layer film or may be constituted by two or more laminated films. For example, an n-type semiconductor and a p-type semiconductor may be contained in separate films, or an n-type semiconductor and a p-type semiconductor may be contained in the same film. In addition, each of the n-type semiconductor and the p-type semiconductor may be used alone or in combination of two or more in any combination and ratio.

As a specific configuration example of the photoelectric conversion layer, a bulk heterojunction type having a layer (i layer) in which a p-type semiconductor and an n-type semiconductor are phase-separated in the layer, a layer containing a p-type semiconductor (p layer) and n, respectively. Examples include a stacked type (hetero pn junction type) in which a layer containing a type semiconductor (n layer) has an interface, a Schottky type, and a combination thereof. Among these, a bulk heterojunction type and a combination of a bulk heterojunction type and a stacked type (pin junction type) are preferable because they exhibit high performance.

The method for producing the photoelectric conversion layer is not particularly limited, but a coating method, particularly a wet coating method is preferable. As the coating method, any method can be used, for example, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, Examples include the pipe doctor method, the impregnation / coating method, and the curtain coating method. In the case where the photoelectric conversion layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the photoelectric conversion layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

The thickness of each layer of the p-layer, i-layer and n-layer of the photoelectric conversion layer is usually 3 nm or more, preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm or more, particularly preferably 50 nm or more, and usually 1000 nm or less. Preferably it is 500 nm or less, More preferably, it is 300 nm or less. Increasing the thickness tends to increase the photocurrent, and decreasing the thickness tends to decrease the series resistance. Moreover, by setting it as the thickness more than the said lower limit, when installing a collector line on a cell especially, the short circuit of the cell by installation of a collector line can be prevented.

1-2. Electrode The organic thin film solar cell element has a lower electrode and an upper electrode. These electrodes have a function of collecting holes and electrons generated by light absorption. Therefore, as these electrodes, an electrode suitable for collecting holes (hereinafter also referred to as an anode) is used on one side, and an electrode suitable for collecting electrons (hereinafter also referred to as a cathode) on the other side. It is preferable to use The lower electrode may be an anode, the upper electrode may be a cathode, the lower electrode may be a cathode, and the upper electrode may be an anode. Any one of the lower electrode and the upper electrode may be translucent, and both may be translucent.

In the present invention, being translucent means that the transmittance of sunlight, that is, the proportion of sunlight that transmits light having a wavelength of 360 to 830 nm, is 40% or more. The solar ray transmittance is preferably 50% or more, more preferably 60% or more, and still more preferably 70% or more.
Moreover, it is preferable that the transparent electrode has a solar ray transmittance of usually 70% or more in order to allow light to reach the photoelectric conversion layer through the transparent electrode.
These light transmittances are values measured in accordance with JIS 7375: 2008.

The lower electrode and the upper electrode can be formed of a conductive material, for example, a metal such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, or the like Alloys thereof: metal oxides such as nickel oxide, indium oxide, tungsten oxide, tin oxide, zinc oxide, or indium-tin oxide (ITO), indium-zinc oxide (IZO), indium-tungsten oxide ( IWO) and the like; conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyacetylene; acids such as hydrochloric acid, sulfuric acid, and sulfonic acid; Lewis acids such as FeCl ₃ and halogens such as iodine Include dopants such as atoms, sodium, potassium and other metal atoms Examples thereof include conductive composite materials in which conductive particles such as metal particles, carbon black, fullerene, and carbon nanotubes are dispersed in a matrix such as a polymer binder.
Among these, a material having a deep work function such as Au or ITO is preferable for the electrode for collecting holes. On the other hand, for the electrode for collecting electrons, a material having a shallow work function such as Al is preferable. By optimizing the work function, there is an advantage of favorably collecting holes and electrons generated by light absorption.

At least the electrode on the light-receiving surface side has optical transparency and is preferably transparent. However, the electrode is not necessarily transparent if it does not significantly adversely affect the power generation performance. If the material of a transparent electrode is mentioned, said metal oxide, composite oxide, a metal thin film, etc. will be mentioned, A metal oxide and composite oxide are preferable. Further, the light transmittance of the upper electrode is preferably 80% or more, excluding loss due to partial reflection at the optical interface, considering the power generation efficiency of the organic thin film solar cell element.

The materials for the lower electrode and the upper electrode may be used alone or in combination of two or more in any combination and ratio.
In the present invention, a metal thin film made of metal or alloy can be preferably exemplified as the upper electrode. Since the metal thin film has high conductivity, it is preferable in that it requires less material than using other materials such as a conductive polymer. Moreover, film formation by vacuum film formation is possible, which is preferable in that damage to the organic thin film solar cell element can be suppressed as compared with a material that requires film formation by an application process.
In the present invention, when either one of the upper electrode and the lower electrode is translucent, it is preferable that the lower electrode formed on the substrate side has translucency. That is, by using a metal or alloy having a predetermined thickness as the upper electrode, it is easy to install the current collector with respect to the upper electrode, and the resistance between the current collector and the electrode can be easily lowered.
In addition, this invention can be used conveniently when the electrode which installs a current collection line is formed including the metal or the alloy. When a current collector is installed via a metal paste on a metal or alloy, especially an electrode formed containing a metal, the metal forming the electrode reacts with the components contained in the metal paste to deform the electrode. And problems such as discoloration may occur. According to the present invention, such a problem can be solved and an organic thin-film solar cell excellent in appearance can be provided.

There is no restriction | limiting in the formation method of a lower electrode and an upper electrode. For example, it can be formed by a dry process such as vacuum deposition or sputtering. It can also be formed by a wet process using conductive ink or the like. As this conductive ink, for example, a conductive polymer, a metal particle dispersion, or the like can be used. Furthermore, two or more electrodes may be laminated, and characteristics (electric characteristics, wetting characteristics, etc.) due to surface treatment may be improved.
The thicknesses of the upper electrode and the lower electrode are not particularly limited, but are usually 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and further preferably 50 nm or more. On the other hand, it is usually 400 μm or less, preferably 10 μm or less, more preferably 1 μm or less, and further preferably 500 nm or less. When the thickness of the electrode is equal to or more than the lower limit, sheet resistance is suppressed and sufficient conduction is possible. On the other hand, by being below the above upper limit, flexibility can be maintained. When the electrode is a transparent electrode, it is necessary to select a film thickness that can achieve both light transmittance and sheet resistance.
The sheet resistance of the electrode is not particularly limited, but is usually 1Ω / □ or more, on the other hand, 1000Ω / □ or less, preferably 500Ω / □ or less, more preferably 100Ω / □ or less.

1-3. Buffer layer (electron extraction layer, hole extraction layer)
The organic thin film solar cell element according to the present invention may include a buffer layer between the lower electrode and / or the upper electrode and the photoelectric conversion layer. The buffer layer refers to an electron extraction layer and / or a hole extraction layer. The buffer layer is not essential in the organic thin film solar cell element according to the present invention, and may include only one of an electron extraction layer and a hole extraction layer. The electron extraction layer is preferably present between the cathode and the photoelectric conversion layer, and the hole extraction layer is preferably present between the anode and the photoelectric conversion layer.

That is, the electron extraction layer and the hole extraction layer are preferably arranged so that the photoelectric conversion layer is sandwiched between the pair of electrodes. The stacking order of the electron extraction layer and the hole extraction layer may be appropriately selected as described above according to the functions of the upper electrode and the lower electrode, that is, each electrode is either an anode or a cathode.
Specifically, when the upper electrode is an anode and the lower electrode is a cathode and both the electron extraction layer and the hole extraction layer are included as buffer layers, the organic thin film solar cell element includes the lower electrode, the electron extraction layer, the photoelectric It is preferable to have a conversion layer, a hole extraction layer, and an upper electrode in this order. When the electron extraction layer is included and the hole extraction layer is not included, the organic thin film solar cell element preferably has a lower electrode, an electron extraction layer, a photoelectric conversion layer, and an upper electrode in this order. Similarly, when the hole extraction layer is included and the electron extraction layer is not included, the organic thin film solar cell element preferably has a lower electrode, a photoelectric conversion layer, a hole extraction layer, and an upper electrode in this order.
Further, at least one of the electron extraction layer and the hole extraction layer may be composed of a plurality of different layers.

[Electronic extraction layer]
The material of the electron extraction layer is not particularly limited as long as it is a material that improves the efficiency of extracting electrons from the photoelectric conversion layer to the cathode, and examples thereof include inorganic compounds and organic compounds.
Examples of the material of the inorganic compound include salts of alkali metals such as Li, Na, K or Cs; n-type semiconductor oxides such as titanium oxide (TiOx) and zinc oxide (ZnO). Among them, the alkali metal salt is preferably a fluoride salt such as LiF, NaF, KF or CsF, and the n-type semiconductor oxide is preferably zinc oxide (ZnO). Although the operation mechanism of such materials is unknown, it is possible to reduce the work function of the cathode when combined with a cathode made of Al or the like and increase the voltage applied to the inside of the organic thin film solar cell element. It is done.

Examples of organic compound materials include, for example, phosphine compounds having a double bond between a phosphorus atom and a group 16 element such as triarylphosphine oxide compounds; bathocuproin (BCP) or bathophenanthrene (Bphen), A phenanthrene compound which may have a substituent and may be substituted at the 1-position and the 10-position with a heteroatom; a boron compound such as triarylboron; such as (8-hydroxyquinolinato) aluminum (Alq3) Organometallic oxide; Compound having 1 or 2 ring structure which may have a substituent such as oxadiazole compound or benzimidazole compound; Naphthalenetetracarboxylic anhydride (NTCDA) or perylenetetracarboxylic acid Dicarboxylic anhydrides, such as anhydride (PTCDA) Aromatic compounds and the like having a condensed dicarboxylic acid structure, such as.

The thickness of the electron extraction layer is not particularly limited, but is usually 0.01 nm or more, preferably 0.1 nm or more, more preferably 0.5 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the thickness of the electron extraction layer is equal to or more than the above lower limit, the function as a buffer material is achieved. When the thickness of the electron extraction layer is not more than the above upper limit, electrons can be easily extracted and the photoelectric conversion efficiency can be improved.

There is no limitation on the method of forming the electron extraction layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. Specifically, for example, when an alkali metal salt is used as a material for the electron extraction layer, the electron extraction layer can be formed by using a vacuum film formation method such as vacuum deposition or sputtering. Especially, it is desirable to form an electron taking-out layer by vacuum vapor deposition by resistance heating. By using vacuum deposition, damage to other layers such as a photoelectric conversion layer can be reduced.

Further, for example, when using a material soluble in a solvent, the spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method are used in the same manner as the method for producing the photoelectric conversion layer described above. It can be formed by a wet coating method such as an air knife coating method, a wire barber coating method, a pipe doctor method, an impregnation / coating method, a curtain coating method, or the like.

On the other hand, for metal oxides of n-type semiconductors, for example, when zinc oxide ZnO is used as the material for the electron extraction layer, a vacuum film formation method such as sputtering can be used. It is desirable to form the extraction layer. For example, Sol-Gel Science, C.I. J. et al. Brinker, G.M. W. According to the sol-gel method described by Scherer, Academic Press (1990), an electron extraction layer composed of zinc oxide can be formed. In this case, the thickness is usually 0.1 nm or more, preferably 2 nm or more, more preferably 5 nm or more, and usually 1 μm or less, preferably 100 nm or less, more preferably 50 nm or less. If the electron extraction layer is too thin, the effect of improving the electron extraction efficiency is not sufficient, and if it is too thick, the electron extraction layer tends to deteriorate the characteristics of the device by acting as a series resistance component.
In the case where the electron extraction layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the electron extraction layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

[Hole extraction layer]
The material for the hole extraction layer is not particularly limited as long as it is a material that can improve the efficiency of extracting holes from the photoelectric conversion layer to the anode. Specifically, a conductive polymer in which polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline or the like is doped with sulfonic acid and / or iodine, etc .; a conductive organic material such as a polythiophene derivative having a sulfonyl group as a substituent, arylamine or the like Compound: Metal oxide such as copper oxide, nickel oxide, manganese oxide, molybdenum oxide, vanadium oxide or tungsten oxide; Nafion, p-type semiconductor described later, and the like. Among them, a conductive polymer doped with sulfonic acid is preferable, and (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) in which a polythiophene derivative is doped with polystyrene sulfonic acid is more preferable. It is. A thin film of metal such as gold, indium, silver or palladium can also be used. A thin film of metal or the like may be formed alone or in combination with the above organic material.

The thickness of the hole extraction layer is not particularly limited, but is usually 0.2 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the thickness of the hole extraction layer is 0.2 nm or more, it functions as a buffer material. When the thickness of the hole extraction layer is 400 nm or less, holes can be easily extracted and the photoelectric conversion efficiency can be improved.

There is no limitation on the method of forming the hole extraction layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. For example, when using a material soluble in a solvent, a spin coating method, a reverse roll coating method, a gravure coating method, a kiss coating method, a roll brush method, a spray coating method, an air knife coating method, a wire barber coating method, a pipe doctor It can be formed by a wet coating method such as a method, an impregnation / coating method, or a curtain coating method. The hole extraction layer is preferably formed by coating. When a semiconductor material is used for the hole extraction layer, the precursor may be converted into a semiconductor compound after the layer is formed using the precursor, similarly to the low-molecular organic semiconductor compound of the organic photoelectric conversion layer described later.

Especially, when using PEDOT: PSS as a material of a hole taking-out layer, it is preferable to form a hole taking-out layer by the method of apply | coating a dispersion liquid. Examples of the dispersion of PEDOT: PSS include CLEVIOSTM series manufactured by Heraeus, ORGACONTM series manufactured by Agfa, and the like.
When the hole extraction layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the hole extraction layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

1-4. Substrate An organic thin film solar cell element is usually manufactured by forming a plurality of organic thin film solar cells on a substrate.
A board | substrate is a member which supports an organic thin film photovoltaic cell. The material of the substrate is not particularly limited as long as the present invention can be applied, and known materials such as inorganic materials, organic materials, paper materials, and composite materials can be used. Specifically, inorganic materials such as quartz, glass, sapphire or titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, vinyl chloride Or polyolefin such as polyethylene; organic materials such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene or epoxy resin; paper materials such as paper or synthetic paper; stainless steel, titanium or aluminum Examples thereof include composite materials such as those obtained by coating or laminating the surface of a metal to impart insulating properties. Of these, resin substrates using organic materials can provide transparency to the substrate, so both superstrate and substrate structures can be created, and translucent see-through solar cells can be created. This is preferable because it is possible.

Among them, the substrate is preferably a flexible (flexible) substrate. This is because when the substrate is flexible, the organic thin film solar cell can be manufactured by a roll-to-roll method, and the degree of freedom in installing the organic thin film solar cell is improved. “Flexible” means, for example, that the material does not break (plastically deform) even when bent at a curvature radius of 170 mm.
Of the above materials, organic materials, paper materials, and composite materials are preferable as the material for the flexible substrate, more preferably organic materials and composite materials, and organic materials are particularly preferable in that a transparent flexible substrate can be obtained.
The organic material usually has a Tg (glass transition temperature), but deterioration of the appearance due to deformation of the substrate can be suppressed by sealing the organic thin film solar cell at less than Tg.
When the substrate is a resin substrate, the glass transition temperature (Tg) of the resin substrate is usually 30 ° C. or higher, preferably 50 ° C. or higher, usually 400 ° C. or lower, preferably 300 ° C. or lower, more preferably 200 ° C. or lower, More preferably, it is less than 160 degreeC. When the glass transition temperature (Tg) is in the above range, it is easy to perform molding when producing a resin substrate, and deformation is less likely to occur during the production of solar cells. The glass transition temperature in the present specification is a value obtained by differential scanning calorimetry (DSC) defined in JIS K-7121 1987 “Method for measuring transition temperature of plastic”.

The thickness of the substrate is not limited, but is usually 5 μm or more, preferably 20 μm or more, and is usually 20 mm or less, preferably 10 mm or less. It is preferable that the thickness of the substrate is 5 μm or more because the possibility that the strength of the organic thin film solar cell element is insufficient is reduced. It is preferable that the thickness of the substrate is 20 mm or less because the cost is suppressed and the weight does not increase. When the material of the substrate is glass, the thickness is usually 0.01 mm or more, preferably 0.1 mm or more, and is usually 1 cm or less, preferably 0.5 cm or less. It is preferable that the thickness of the substrate is 0.01 mm or more because mechanical strength is increased and cracking is difficult. Moreover, it is preferable that the thickness of the substrate is 0.5 cm or less because the weight does not increase.

Although there is no restriction | limiting in the length of a board | substrate, Usually, 10 cm or more, Preferably it is 1 m or more, More preferably, it is 10 m or more, More preferably, it is 50 m or more, Most preferably, it is 100 m or more. The upper limit is usually 10 km or less, preferably 5 km or less, more preferably 1 km or less, still more preferably 500 m or less.
When manufactured by a roll-to-roll method, it is usually 10 m or more, preferably 20 m or more, more preferably 50 m or more, still more preferably 100 m or more, and particularly preferably 200 m or more. Although an upper limit in particular is not restrict | limited, Usually, it is 10 km or less, Preferably it is 5 km or less, More preferably, it is 1 km or less. By setting the length within this range, efficient production by a roll-to-roll system can be performed. In the roll-to-roll method, since it takes time to switch the roll, in order to reduce the time loss due to the switching of the roll, it is preferable that the substrate of one roll is as long as the manufacturing apparatus allows. On the other hand, it should be noted that handling becomes difficult when the roll becomes heavy.

1-5. Structure of Organic Thin Film Solar Cell Element In the present invention, the organic thin film solar cell element preferably has a monolithic structure.
The organic thin film solar cell module of the present invention includes an organic thin film solar cell element having a structure in which a plurality of organic thin film solar cells are connected in series on the same substrate (hereinafter also referred to as a monolithic structure). The number and arrangement method of the organic thin film solar cells included in the organic thin film solar cell element can be determined by the potential and size required for the organic thin film solar cell module. That is, by having a monolithic structure, an organic thin film solar cell element having an arbitrary potential can be manufactured with high productivity.

As long as a plurality of organic thin-film solar cells are connected in series, the arrangement method and the number thereof are not particularly limited, but the number of organic thin-film solar cells connected in series is usually 3 or more, preferably 10 Above, more preferably 15 or more, still more preferably 30 or more, particularly preferably 100 or more. The upper limit is not limited as long as the effect of the present invention can be obtained, and is usually 500,000 or less, preferably 100,000 or less, more preferably 10,000 or less, still more preferably 1000 or less, and particularly preferably 600 or less. .
When organic thin film solar cells are connected in series in the longitudinal direction of the substrate, the number of cells connected in series should be set to the length of the substrate and the length of one organic thin film solar cell in the series connection direction. Can be arbitrarily determined. A solar cell element in which many organic thin film solar cells are directly connected may be formed on one substrate, or a plurality of solar cell elements in which a predetermined number of organic thin film solar cells are connected in series may be formed. It may be formed.

On the other hand, when the organic thin film solar cells are connected in series in the width direction of the substrate, the organic thin film solar cells are connected in series in a line depending on the length in the width direction of the substrate and the length in the serial connection direction of one organic thin film solar cell. The number that can be connected to is limited. The number of organic solar cells connected in series in a row is usually 3 or more, preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more, although the upper limit is not particularly limited. It is 600 or less, preferably 500 or less, more preferably 300 or less, and still more preferably 200 or less. On the other hand, if the adjacent cell rows are connected in series by the upper electrode or the lower electrode, the number of organic solar cells connected in series can be arbitrarily set, in this case usually 6 or more, preferably 10 or more, More preferably, it is 20 or more, more preferably 30 or more, and the upper limit is not particularly limited, but is usually 500,000 or less, preferably 100,000 or less, more preferably 10,000 or less, still more preferably 1000 or less. Particularly preferably, the number is 600 or less.
Among these, it is preferable to connect the organic thin-film solar cells in series in the longitudinal direction of the substrate in that a cell row having a desired potential can be easily cut out.

Further, the organic thin film solar cell includes at least a lower electrode, a photoelectric conversion layer, and an upper electrode. In the present invention, the electrode laminated on the substrate of the organic thin-film solar battery cell is usually called a lower electrode, and the electrode laminated after the photoelectric conversion layer is laminated on the lower electrode is called an upper electrode. The lower electrode may be directly laminated on the substrate or indirectly laminated.

1-6. Manufacturing method of organic thin-film solar cell Hereinafter, a monolithic structure in which organic thin-film solar cells (hereinafter also referred to as solar cells) including a photoelectric conversion layer, an upper electrode, and a lower electrode are connected in series on the same substrate. A method for producing an organic thin film solar cell element (hereinafter, also referred to as a solar cell element) having the same will be described with reference to FIG. A case where the photoelectric conversion layer is a pin junction type will be described as an example with reference to FIG. It can be manufactured by the method.

An organic thin film solar cell element is usually manufactured by forming a plurality of organic thin film solar cells on a substrate. When the light receiving surface of the organic thin film solar cell module is on the substrate 1 side, it is preferable to use a transparent substrate. When the light receiving surface is on the upper electrode 8 side, the substrate 1 may be transparent or opaque. (A) As shown in the figure, a lower electrode 2 having an open groove 11 is formed on a substrate 1. The electrode may be formed by either a dry method or a wet method. Examples of the dry method include known methods such as sputtering, vapor deposition, and CVD. Examples of the wet method include screen printing and die coating. The width of the first groove 11 is preferably about 50 to 1000 μm, particularly about 100 to 500 μm.

Next, a p layer 3 is formed on the lower electrode 2 as shown in FIG. When the p layer 3 is formed on the entire surface of the lower electrode 2, the first groove 11 is filled with the material of the p layer 3. When the p layer 3 is formed with a pattern on the lower electrode 2, the first groove 11 may not be filled with the material of the p layer 3.

Next, as shown in (c), an i layer 4 and an n layer 5 are sequentially formed on the lower electrode 2 and the p layer 3. Next, as shown in (d), the i layer 4 and the n layer 5 formed on the p layer 3 are separated by several tens to 100 μm in the vicinity so as not to overlap the first groove 11. A second groove 12 reaching the electrode 2 is formed by laser scribing. The width of the second groove is preferably about 50 to 1000 μm, particularly about 100 to 500 μm. The wavelength of the laser for forming the second groove 12 is 200 to 1200 nm, preferably about 250 to 900 nm, particularly about 250 to 600 nm. Thereby, the p layer 3, the i layer 4, and the n layer 5 are separated into strips.

Next, the upper electrode 6 is formed as shown in FIG. The second open groove 12 is filled with the material of the upper electrode 6. Since the second groove 12 is for connecting the upper electrode of the unit cell to the lower electrode 2 on the light receiving surface of the adjacent unit cell, it must reach the lower electrode 2.

Thereafter, as shown in FIG. 5 (f), the upper electrode 6, the n layer 5, the i layer 4 and the p layer 3 are laser scribed to form the third groove 13 and divided into unit cells. Since the open groove 13 divides the upper electrode 6 of the adjacent unit cell, it may stop in the middle of the i layer 4 without penetrating the i layer 4, and further penetrate the p layer 3 from the i layer 4 to the lower part. It may enter the electrode 2. The wavelength of the laser for forming the third groove 13 is 200 to 1200 nm, preferably about 250 to 900 nm, particularly about 250 to 600 nm. Since the upper electrode 6 of each unit cell is electrically connected to the lower electrode 2 of the adjacent unit cell by the material of the upper electrode 6 filling the inside of the open groove 12, the organic thin film solar cell element in which the unit cells are connected in series Is obtained.

The materials constituting the photoelectric conversion layer (in this embodiment, the p layer 3, the i layer 4, and the n layer 5) have good absorption of light having a wavelength of 200 to 1200 nm, particularly 250 to 900 nm, particularly 250 to 600 nm. The conversion layer is efficiently cut (scribed). The material constituting the upper electrode 6 may or may not absorb light having this wavelength. Even when the constituent material of the upper electrode 6 does not absorb light of this wavelength, when the underlying photoelectric conversion layer is removed by laser scribing, the upper electrode constituent material above the upper electrode 6 is removed together. 3 open grooves 13 are formed. Since the constituent material of the upper electrode 6 is not limited to the light absorbing material, options for the constituent material of the upper electrode are expanded.

2. Organic thin film solar cell module The organic thin film solar cell module of the present invention has a structure in which a current collector is connected to an organic thin film solar cell element via a conductive thermosetting resin composition.
The organic thin film solar cell module of the present invention is preferably such that at least the organic thin film solar cell element and the current collector are sealed with a sealing material. By sealing an organic thin film solar cell element, an organic thin film solar cell element can be reinforced and impact resistance can be improved.

2-1. Connecting the current collector The electrode and the current collector are connected to extract current from the organic thin-film solar cell element. In the present invention, the current collector is connected to the electrode via a conductive thermosetting resin composition.
The current collector and the electrode may be connected at a place where the electrode is not laminated with the photoelectric conversion layer, or may be connected at a place where the electrode is laminated with the photoelectric conversion layer.

When connecting the current collector and the electrode at a place where the photoelectric conversion layer is not stacked, for example, as shown in FIG. 2 a, the portion and the photoelectric conversion layer that are stacked with the photoelectric conversion layer 7 on the lower electrode 2 of the organic thin film solar cell. 7 is provided, and the upper electrode 6 is provided with a portion that is laminated with the photoelectric conversion layer 7 and a portion that is not laminated with the photoelectric conversion layer 7. And in the part which is not laminated | stacked with the photoelectric converting layer of each of the lower electrode 2 and the upper electrode 6 (both ends of FIG. 2a), a collector wire is connected through the contact bonding layer 9, and two collector wires are made into an organic thin film solar cell. Install in the cell. “Connecting” the current collector and the electrode means that at least the current collector and the electrode are electrically connected. Further, “installing” the current collector means that the electrode and the current collector are electrically connected.
2a, at both ends of the organic thin film solar cell, for example, by laminating a conductive material between the lower electrode and the current collector, or by laminating a material that does not affect current collection under the upper electrode, The installation work of the current collector may be facilitated by flattening the upper and lower surfaces of the organic thin film solar cells.

In general, in an organic thin film solar cell module, electricity is taken out by connecting a current collector to the upper electrode and lower electrode of the organic thin film solar cell element, but this is the case when the current collector is connected to only a plurality of upper electrodes. Even electricity can be taken out. This is because electricity flows between the upper electrode and the lower electrode of the organic thin film solar battery cell forming the organic thin film solar battery element across the photoelectric conversion layer, and the cells are connected in series. This is because electricity can be taken out even from the upper electrodes. When taking out electricity from upper electrodes, it is preferable to connect a current collection line to the upper electrode laminated | stacked with the photoelectric converting layer.
When the current collector is connected to the upper electrode laminated with the photoelectric conversion layer, for example, as shown in FIG. 2b, the current collector 8 may be installed on the upper electrode 6 of the organic thin film solar cell via the adhesive layer 9. . In addition, connecting a collector line with the electrode laminated | stacked with the photoelectric converting layer is installing in the range of 23 of the upper electrode 6 in FIG. 2c.
According to this method, even after the production of the organic thin-film solar cell element, the collector wire can be installed at an arbitrary position, and the potential can be freely adjusted. Accordingly, since the same organic thin film solar cell element can meet various required potential requirements, an organic thin film solar cell module can be manufactured without lowering the production efficiency. Specifically, a long organic thin-film solar cell element is manufactured by a roll-to-roll method, and can be used while being cut into a size (module width, series number) corresponding to the potential according to the demand. . In this case, an organic thin-film solar cell module in which two collector wires are respectively installed on the upper electrode is manufactured.
Specifically, as shown in FIG. 2c, in an organic thin-film solar battery element in which organic thin-film solar battery cells are connected monolithically, it is necessary to take out electricity by installing a collector wire 8 on an arbitrary upper electrode 6 It becomes possible to take out the electric potential according to. It is not necessary that all the current collectors are provided on the upper electrode of the organic thin film solar cell, and a region (for example, the rightmost region 24 in FIG. 2a) of the upper electrode that is not stacked with the photoelectric conversion layer is provided. A part of the current collecting line may be installed.

When the organic thin film solar cell element has a current collector connected to the lower electrode, electricity can be taken out by connecting the upper electrode 6 and the current collector 8 at one place. If connected at two locations, electricity can be taken out from the two current collectors connected to the upper electrode 6, or any of the current collector connected to the lower electrode and the two current collectors connected to the upper electrode 6 can be selected. It is also possible to take out electricity by selecting a current collector and selecting two potentials. Of course, it is also possible to connect the upper electrode and the current collector at three or more locations. For example, two types of potentials can be extracted from one organic thin film solar cell module when connected at three locations, and three types of potentials can be extracted from one organic thin film solar cell module when connected at four locations. In addition to being able to take out, it is possible to take out two systems of the same potential or two systems of different potentials.
In this way, by installing the current collector on the electrode laminated on the photoelectric conversion layer, the current collector can be installed at an arbitrary position, so the electric potential to be taken out from one organic thin film solar cell element can be freely set Can do.

In addition, the organic thin-film solar cell having the upper electrode on which the current collector is installed may be short-circuited or not short-circuited by the installation of the current-collector, but the organic thin-film solar cell element in which the current collector is installed It is preferable that all of the thin film solar cells are short-circuited or not all of them are short-circuited.
When the solar battery cell is short-circuited, electricity can be reliably flowed, so that stable electricity can be taken out. On the other hand, when the organic thin film solar cell is not short-circuited, even an organic thin film solar cell having an upper electrode on which the current collector is installed can generate power, It is preferable in that the amount of power generation, that is, the power generation efficiency can be increased. In particular, if the layer structure of the organic thin-film solar cell is designed so that the upper electrode on which the current collector is installed becomes the non-light-receiving surface of the organic thin-film solar cell, more power is generated because the current collector does not block the light reaching the photoelectric conversion layer. Efficiency can be increased.

The present invention is characterized in that the current collector is connected to the organic thin-film solar cell element via the conductive thermosetting resin composition, and in particular, the current collector is connected to the electrode laminated with the photoelectric conversion layer. In some cases, there are further advantageous effects.
In the organic thin film solar cell element, the photoelectric conversion layer containing an organic component has a lower strength than the other layers. Therefore, in order to prevent a decrease in power generation efficiency, it is preferable that the region where the current collector is installed be as far as possible from the photoelectric conversion layer that is easily affected by external force. In that respect, it is better to connect the current collector and the electrode at a place where the photoelectric conversion layer is not laminated, but the potential cannot be changed after the organic thin film solar cell element is manufactured.
On the other hand, since the conductive thermosetting resin composition has a three-dimensional crosslinked structure after curing, the linear expansion coefficient is low. Specifically, it is usually 100 ppm / ° C. or less, preferably 80 ppm / ° C. or less, more preferably 60 ppm / ° C. or less, usually 10 ppm / ° C. or more, preferably 20 ppm / ° C. or more, more preferably 30 ppm / ° C. or more. Therefore, there is little shrinkage | contraction and expansion | swelling by a heat | fever, and it can reduce the influence which acts on a photoelectric converting layer. That is, by connecting the current collector to the organic thin-film solar cell element via the conductive thermosetting resin composition, it is possible to secure the above-described degree of freedom of the extraction potential and improve the production efficiency.

2-2. Current collectors As materials for current collectors, metals, alloys and the like are often used, and among them, it is preferable to use copper, aluminum, silver, gold, nickel or the like having a low resistivity. Among these, copper and aluminum are particularly preferable because they are inexpensive. In order to prevent rust, the current collector may be plated with tin, silver or the like, the surface may be coated with resin, or a film may be laminated. As the shape of the current collecting wire, there are a rectangular wire, foil, flat plate, and wire shape, but for reasons such as securing a bonding area, it is preferable to use a flat wire, foil, or flat plate shape.
In the present invention, the “foil” refers to one having a thickness of less than 100 μm, and the “plate” refers to one having a thickness of 100 μm or more. Further, the “flat wire” refers to a wire whose cross section is rolled to make the cross section into a quadrangle.

The current collector is not particularly limited as long as it has conductivity, but preferably has a lower resistance value than the upper electrode and lower electrode to be connected, and in particular, by increasing the thickness of the upper electrode and lower electrode, It is preferable to reduce the resistance value. The thickness of the current collector is preferably 5 μm or more, more preferably 10 μm or more. Moreover, it is preferable that it is 2 mm or less, More preferably, it is 1 mm or less, More preferably, it is 300 micrometers or less, Most preferably, it is 200 micrometers or less. It is preferable for the thickness to be equal to or more than the above lower limit, since an increase in the resistance value of the current collecting line is suppressed and the generated power is easily taken out to the outside efficiently. Moreover, by being below the above upper limit, the increase in the weight of the organic thin film solar cell module can be suppressed and the flexibility can be maintained, and the occurrence of irregularities on the module surface can be suppressed, and the increase in production cost can be suppressed. Is preferable.

Further, the width of the current collecting line is preferably 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 2 mm or more. Moreover, it is preferable that the width | variety of a current collection line is 50 mm or less, More preferably, it is 20 mm or less, Most preferably, it is 10 mm or less. If the width of the current collection line is narrower than the above range, the resistance value of the current collection line will increase, and the generated power may not be taken out efficiently. In addition, the mechanical strength of the current collector decreases, which may cause breakage and the like. Moreover, when the width | variety of a current collection line is wider than the said range, the aperture ratio in the whole module will reduce, and there exists a possibility of leading to the fall of the power generation amount of a module.

In addition, the shape of the current collector line can be embossed. The embossed shape means a shape formed by embossing some uneven shape. By forming the current collector in an embossed shape, even if an adhesive layer is used, a portion of the embossed unevenness can be in direct contact with or very close to the electrode, so that conductivity is increased.
The emboss depth is usually 5 to 100 μm, and preferably 10 to 50 μm. The emboss depth means the height of the convex portion formed by embossing, and is specifically a value obtained by subtracting the thickness of the current collector from the thickness including the convex portion. Such an embossing depth is preferable because the embossed convex portion can directly contact the electrode.

2-3. Adhesive layer The present invention is characterized in that the current collector is connected to the electrode via a conductive thermosetting resin composition (adhesive layer 9 in FIG. 2a).
Conventionally, thermoplastic adhesives containing conductive particles, solder, metal paste, and the like are known as adhesive components for installing a current collector on an electrode of a solar cell.
ADVANTAGE OF THE INVENTION According to this invention, the organic thin film solar cell module with high durability with respect to the case where a thermoplastic resin plastic material is used can be obtained. Since the thermoplastic resin composition generally has a high coefficient of linear expansion, the ratio of the coefficient of linear expansion with the material used for the base material or the current collector is large. Therefore, when durability tests such as high-temperature and high-humidity tests, condensation freezing tests, and heat cycle tests are performed, film peeling of the power generation layer occurs, increasing the resistance between the current collector and the organic thin-film solar cell element, and output May cause decline.
In addition, when solder is used, a high temperature of 200 ° C. or higher is required for bonding, which may cause deformation of the base material and deterioration of the power generation layer. The metal paste has a high fluidity and may protrude when a collector wire is installed, resulting in poor appearance. In the case of a metal paste containing a solvent, outgas is generated at the time of curing, which may increase the resistance between the electrode of the organic thin film solar cell element and the current collector line and cause a decrease in output. Moreover, the electrode of an organic thin film solar cell element may be dissolved, and defects such as appearance may occur. For example, when silver is used for the electrode, a phenomenon called silver erosion that dissolves silver may occur.
The curing temperature of the conductive thermosetting resin composition is not particularly limited, but is preferably less than the glass transition temperature (Tg) of the substrate. This is because the deformation of the substrate during curing can be prevented, and the appearance failure of the module and the decrease in output can be prevented. Specifically, the curing temperature of the conductive thermosetting composition is usually 20 ° C. or higher, preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and usually 400 ° C. or lower, preferably 300 ° C. or lower, more preferably. 200 ° C. or less, particularly preferably less than 160 ° C. By being the said temperature range, the pot life of an electroconductive curable composition can be made more than fixed, and it can suppress that a board | substrate and an organic thin-film solar cell module are thermally deformed by the heat | fever at the time of making it harden | cure.
Moreover, when the sealing material used for the organic thin film solar cell module of the present invention contains a thermosetting resin, the curing temperature of the conductive thermosetting resin composition is such that the thermosetting resin contained in the sealing material is cured. It is preferable that the temperature is lower than the maximum temperature. After the current collector is installed, the encapsulant is installed, and the heating process for bonding and curing the encapsulant is performed at a temperature near the limit at which module deformation and output reduction do not occur in order to reduce module manufacturing time. Often done. Therefore, if the conductive thermosetting resin composition can be simultaneously cured at this time, not only the step of curing with the conductive curable resin alone can be omitted, but also the module deformation and output decrease are caused when the sealing material is cured. Absent.
Even when the sealing material is, for example, a thermoplastic resin and is sealed by thermal lamination, for the same reason, the curing temperature of the conductive thermosetting resin composition may be lower than the temperature at which thermal lamination is performed. preferable.

The curing temperature of the conductive thermosetting composition can be controlled, for example, by appropriately selecting the type of curing agent. In the case of an epoxy resin, it can be increased by using a curing agent such as an aromatic amine or a latent curing type curing agent such as dicyandiamide, and can be decreased by using a curing agent such as an aliphatic amine. be able to. In the case of an acrylic resin or a urethane resin, it can be increased by using a latent curing type curing agent such as block type isocyanate as the curing agent.
Further, in the present invention, the curing temperature of the conductive thermosetting composition is a temperature at which the calorific value becomes a peak when heated at 2 ° C./min from 25 ° C. to 400 ° C. with a DSC manufactured by Seiko Instruments Inc. .
In addition, after a conductive thermosetting composition hardens | cures, it can analogize by extracting a residual hardening | curing agent from hardened | cured material and identifying the structure of a hardening | curing agent using NMR etc.
Another layer may be laminated as long as the effect of the present invention is not impaired. Since the thermosetting resin composition applies heat when it is cured, the generation of gas after curing is less than that generated at room temperature. Therefore, even if the temperature of the organic thin film solar cell is increased after being installed outdoors after being sealed and exposed to sunlight for a long time, deterioration of the organic thin film solar cell module due to generation of gas can be prevented. Note that the term “conductive” means that at least electrical connection is possible, but the volume resistivity at room temperature (25 ° C.) is 10 Ωcm or less and 10 ⁻⁶ Ωcm or more.

As the conductive thermosetting resin composition used in the present invention, a conductive resin dispersed in a binder resin composition can be used. The conductive thermosetting resin composition may be in the form of a sheet or paste, but is preferably in the form of a sheet.

Conductive particles include metal particles such as gold, nickel, copper, silver, platinum, solder, palladium, aluminum, or alloys thereof, carbon-based particles such as carbon black, carbon tube, and carbon fiber, and gold-plated nickel particles. Composite metal particles such as gold- / nickel-plated resin particles, copper-plated resin particles, nickel-plated resin particles, and other metal-coated resin particles. From the viewpoint of conductivity, metal particles, composite metal particles, metal-coated resin Particles are preferred. Such conductive particles are used in the above-mentioned resin, usually 0.01% by volume or more, preferably 0.1% by volume or more, and usually 50% by volume or less, preferably 20% by volume or less. When the content of the conductive particles is equal to or more than the above lower limit, the connection stability due to the conductive particles can be easily increased, and a decrease in conductivity can be suppressed. Moreover, the moldability of a resin layer can be maintained and the fall of adhesive strength can be suppressed because content of electroconductive particle is below the said upper limit.

The shape of the conductive particles is not particularly limited, and examples thereof include a spherical shape, a needle shape, a fiber shape, a flake shape, a spike shape, and a coil shape. The size of the conductive particles is not particularly limited. For example, the particle size is 1 to 50 μm, preferably 2 to 20 μm. The particle size is a value measured by the BET method.

The binder resin composition can be appropriately selected from thermosetting binder resin compositions used in conventional conductive adhesives. For example, thermosetting acrylic resin, thermosetting epoxy resin, thermosetting urea resin, thermosetting melamine resin, polyimide resin, unsaturated polyester resin, polyurethane resin, bismaleimide resin, triazine-bismaleimide resin, thermosetting type A phenol resin etc. can be mentioned. Especially, when the point with the favorable adhesive strength after hardening is considered, the binder resin composition using a thermosetting epoxy resin can be used preferably.

The binder resin may contain a curing agent. Curing agents include imidazole curing agents, hydrazide curing agents, amine curing agents, phenol curing agents, acid anhydride curing agents, boron trifluoride-amine complexes, sulfonium salts, iodonium salts, polyamine salts, Examples include amine imide and dicyandiamide.

Such a thermosetting epoxy resin may be liquid or solid, and preferably has an epoxy equivalent of usually about 100 to 4000 and having two or more epoxy groups in the molecule. For example, a bisphenol A type epoxy compound, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, an ester type epoxy compound, an alicyclic epoxy compound, or the like can be preferably used. These compounds include monomers and oligomers.

ACF (Anisotropic Conductive Film, anisotropic conductive film) can also be used as the conductive thermosetting resin composition used in the present invention. ACF is a material in which conductive particles having a diameter of, for example, about 1 μm to 10 μm are dispersed in a thermosetting resin film, and has conductivity in the film thickness direction and insulation in the film surface direction. is there. The thermosetting resin composition used in the present invention may contain a filler such as silica and mica, a pigment, an antistatic agent, and the like as necessary. Coloring agents, preservatives, polyisocyanate crosslinking agents, silane coupling agents, and the like can also be blended.

When the conductivity of the thermosetting resin composition is low, fix the electrode and a part of the current collector with the thermosetting resin composition, and place the electrode and the current collector in direct contact with the remaining part. You can also.

2-4. Sealing material In the present invention, an organic thin film solar cell module is manufactured by connecting an organic thin film solar cell element and a collector wire, but it is preferable to seal at least the organic thin film solar cell element. The organic thin-film solar cell element is sealed in order to reinforce the organic thin-film solar cell element and increase impact resistance.
The sealing material used for sealing preferably has high strength from the viewpoint of maintaining the strength of the organic thin-film solar cell module. The specific strength is related to the strength of the layers other than the sealing material and is difficult to define in general, but the entire organic thin-film solar cell module has good bending workability and causes peeling of the bent portion. It is desirable to have such strength.

Further, when the sealing material is used on the light receiving surface side of the organic thin film solar battery cell, it is preferable to transmit visible light from the viewpoint of preventing light absorption. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. Particularly preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

On the other hand, when a sealing material is used on the side opposite to the light receiving surface of the organic thin film solar cell element, it is not always necessary to transmit visible light, and may be opaque.
Furthermore, since the organic thin film solar cell module is often heated by receiving light, it is preferable that the sealing material also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably It is 300 degrees C or less. By increasing the melting point, it is possible to prevent the sealing material from melting and deteriorating when the organic thin film solar cell module is used.

The thickness of the sealing material is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 30 μm or more, and usually 1000 μm or less, preferably 800 μm or less, more preferably 600 μm or less. Increasing the thickness tends to increase the strength of the entire organic thin-film solar cell module, and decreasing the thickness tends to increase flexibility and improve visible light transmittance. For this reason, it is desirable to set it as the said range as a range which has both advantages.

The material constituting the sealing material is not particularly limited, and is a thermosetting resin such as vinyl acetate ethylene copolymer containing a crosslinking agent, polyurethane or epoxy resin, a thermoplastic resin such as polyolefin, polyester or acrylic resin, or butyl rubber. Further, it may be an elastomeric resin such as silicone rubber, or the above composite.
The sealing material has a sealing temperature of usually 50 ° C. or higher, preferably 100 ° C. or higher, usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, more preferably 160 ° C. or lower, particularly preferably. Is 140 ° C. or lower. In the above temperature range, by heating at a temperature equal to or higher than the curing temperature of the conductive thermosetting resin composition, sealing and curing of the conductive thermosetting resin composition (that is, between the organic thin-film solar cell element and the current collector) Connection) at the same time.
In the present invention, when the sealing material contains the thermosetting resin, it is preferable in that the organic thin film solar cell module is not easily deformed even when exposed to high temperatures.
In the present invention, when the sealing material is a thermosetting resin, the curing temperature of the sealing material is higher than the curing temperature of the conductive thermosetting resin composition, that is, the curing of the conductive thermosetting resin composition. It is preferable that the temperature is equal to or lower than the temperature at which the thermosetting resin contained in the encapsulant can be cured, since the conductive thermosetting resin composition can be cured at the same time during the encapsulation.
The curing temperature of the thermosetting resin contained in the sealing material (that is, the curing temperature of the sealing material containing the thermosetting resin) is usually 50 ° C. or higher, preferably 100 ° C. or higher, and usually 250 ° C. or lower, preferably Is 200 ° C. or lower, more preferably 180 ° C. or lower, still more preferably 160 ° C. or lower, and particularly preferably 140 ° C. or lower.
In order to improve weather resistance, the EVA film is usually blended with a crosslinking agent to form a crosslinked structure. As the crosslinking agent, an organic peroxide that generates radicals at 100 ° C. or higher is generally used. Examples of such organic peroxides include 2,5-dimethylhexane, 2,5-dihydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and 3- Di-t-butyl peroxide or the like can be used. The compounding amount of these organic peroxides is usually 5 parts by weight or less, preferably 3 parts by weight or less, and usually 1 part by weight or more with respect to 100 parts by weight of EVA resin. In addition, 1 type may be used for a crosslinking agent and it may use 2 or more types together by arbitrary combinations and a ratio.

This EVA resin composition may contain a silane coupling agent for the purpose of improving the adhesive strength. Examples of silane coupling agents used for this purpose include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris- (β-methoxyethoxy) silane, γ-methacryloxypropyltri Mention may be made of methoxysilane or β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane. The compounding amount of these silane coupling agents is usually 5 parts by weight or less, preferably 2 parts by weight or less, and usually 0.1 parts by weight or more with respect to 100 parts by weight of the EVA resin. In addition, 1 type may be used for a silane coupling agent and it may use 2 or more types together by arbitrary combinations and a ratio.

Furthermore, in order to improve the gel fraction of the EVA resin and improve the durability, a crosslinking aid may be included in the EVA resin composition. Examples of the crosslinking aid provided for this purpose include monofunctional crosslinking aids such as trifunctional crosslinking aids such as triallyl isocyanurate or triallyl isocyanate. The amount of these crosslinking aids is usually 10 parts by weight or less, preferably 5 parts by weight or less, and usually 1 part by weight or more with respect to 100 parts by weight of the EVA resin. In addition, 1 type may be used for a crosslinking adjuvant, and 2 or more types may be used together by arbitrary combinations and a ratio. The temperature at which the crosslinking aid crosslinks is usually 50 ° C. or higher, preferably 100 ° C. or higher, usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, still more preferably 160 ° C. or lower, particularly preferably. 140 ° C. or lower. By being the said temperature range, sealing and hardening of a conductive thermosetting resin composition can be performed simultaneously.

Furthermore, for the purpose of improving the stability of the EVA resin, the EVA resin composition may contain, for example, hydroquinone, hydroquinone monomethyl ether, p-benzoquinone, or methylhydroquinone. These compounding quantities are normally 5 weight part or less with respect to 100 weight part of EVA resin.
However, since the EVA resin cross-linking process requires a relatively long time, it may cause a reduction in production speed and production efficiency of the organic thin-film solar cell module. In addition, when used for a long period of time, the decomposition gas (acetic acid gas) of the EVA resin composition or the vinyl acetate group of the EVA resin itself may adversely affect the organic thin film solar cell element and reduce the power generation efficiency. . Therefore, as the sealing material, in addition to the EVA film, a copolymer film made of a propylene / ethylene / α-olefin copolymer may be used.

Note that the sealing material may be formed of one kind of material or may be formed of two or more kinds of materials. Moreover, although the sealing material may be formed with the single layer film, the laminated | multilayer film provided with the film of two or more layers may be sufficient as it.
The sealing material is usually provided so as to sandwich the organic thin film solar cell element.
In addition, the sealing material may be provided with functions such as ultraviolet blocking, heat blocking, conductivity, antireflection, antiglare, light diffusion, light scattering, wavelength conversion, and gas barrier properties. In particular, in the case of an organic thin film solar cell, it is weak against water and oxygen, and is exposed to strong ultraviolet rays from sunlight, and therefore preferably has a gas barrier property and an ultraviolet blocking function.
As a method of imparting such a function, a layer having a function may be laminated on the sealing material by coating film formation or the like, or a material that exhibits the function is dissolved and dispersed in the sealing material. You may make it contain.

Examples of the gas barrier property include those satisfying the following water vapor permeability and oxygen permeability.
The water vapor transmission rate is typically 10 ⁻¹ g / m ² / day or less, preferably 10 ⁻² g / m ² / day, at 40 ° C. and 90% RH in a 100 μm-thick sealing material. Hereinafter, it is more preferably 10 ⁻³ g / m ² / day or less, and further preferably 10 ⁻⁴ g / m ² / day or less. The water vapor transmission rate is measured in an environment of 40 ° C. and 90% RH by a measurement using an apparatus equipped with a humidity sensor, an infrared sensor, and a gas chromatograph according to JIS K7129, or by a cup method (JIS Z0208).

As the oxygen permeability, for example, generally, the oxygen permeability per day of a unit area (1 m ² ) at a thickness of 100 μm in a 25 ° C. environment is usually 1 cc / m ² / day / atm or less. , 1 is preferably × ¹⁰ -1 or less ^{cc / m 2 / day / atm} , more preferably not more than ^{^{1 × 10 -2 cc / m 2}} / day / atm, 1 × 10 -3 cc / m ² / day / atm or less is more preferable, and 1 × 10 ⁻⁴ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day / atm or less. It is particularly preferred. There is an advantage that deterioration due to oxidation of the element can be suppressed as oxygen does not pass through. The oxygen permeability can be measured with an apparatus based on a differential pressure method according to JIS K7126A, or an apparatus equipped with an infrared sensor and a gas chromatograph based on an isobaric method according to JIS K7126B.

The sealing step of sealing the organic thin film solar cell element with the sealing material may be performed after the step (step 1) of installing the collector wire on the organic thin film solar cell element, or may be performed before step 1. .
When it has the process of sealing an organic thin film solar cell module after process 1, the whole organic thin film solar cell module including a current collection line is sealed, and after that among the sealing materials of an organic thin film solar cell module It is also possible to form a slit at a location where there is a current collecting wire from which electricity is to be taken out, and take out the current collecting wire from the slit.
In this case, the number of connection points of the collector line to the upper electrode is arbitrary as long as it is one or more, and the collector line may be connected to a position where a desired potential can be taken out.

When it has the process of sealing an organic thin-film solar cell module before the process 1, it forms an organic thin-film solar by forming a slit in the position which connects a current collection line with respect to the sealing material after sealing. The upper electrode is exposed on the surface of the battery module. And what is necessary is just to connect the upper electrode and collector wire of the position of a slit. Moreover, by providing a slit at a specific position in advance in the sealing material before sealing, the labor of forming the slit after sealing can be saved. Providing slits in advance in this way makes it possible to eliminate the possibility of damage to the organic thin film solar cells that occur when the slits are formed after sealing.

In the organic thin film solar cell module of the present invention, a weatherproof protective sheet can be further provided on the outermost surface after sealing. The weather-resistant protective sheet is a sheet and film that protects the organic thin-film solar cell module from a device installation environment such as temperature change, humidity change, light, and wind and rain. By covering the device surface with the weather-resistant protective sheet, there is an advantage that the organic thin-film solar cell module constituent material, particularly the organic thin-film solar cell element, is protected and high power generation capability can be obtained without deterioration.

Since the weather-resistant protective sheet is located on the outermost layer of the organic thin-film solar cell element, it is used as a surface covering material for organic thin-film solar cells such as weather resistance, heat resistance, transparency, water repellency, contamination resistance, and mechanical strength. It is preferable to have a suitable performance and to maintain it for a long period of time in outdoor exposure.
Moreover, when a weather-resistant protective sheet is used for the light-receiving surface side of the organic thin-film solar battery cell, it is preferable to transmit visible light from the viewpoint of not preventing light absorption. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. Particularly preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

On the other hand, when a weatherproof protective sheet is used on the side opposite to the light receiving surface of the organic thin film solar cell element, it is not always necessary to transmit visible light, and may be opaque.
Furthermore, since the organic thin-film solar cell element is often heated by receiving light, it is preferable that the weather-resistant protective sheet also has heat resistance. From this viewpoint, the melting point of the constituent material of the weatherproof protective sheet is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably. Is 300 ° C. or lower. By increasing the melting point, it is possible to reduce the possibility that the weatherproof protective sheet will melt and deteriorate when the organic thin film solar cell element is used.

The material constituting the weatherproof protective sheet is arbitrary as long as it can protect the organic thin film solar cell module. Examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyvinyl chloride resin, fluorine resin, polyethylene terephthalate, polyethylene Examples thereof include polyester resins such as naphthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicone resins, and polycarbonate resins.

Among them, fluorine resin is preferable, and specific examples thereof include polytetrafluoroethylene (PTFE), 4-fluoroethylene-perchloroalkoxy copolymer (PFA), 4-fluoroethylene-6-fluoride. Propylene copolymer (FEP), 2-ethylene-4-fluoroethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), etc. Can be mentioned.

In addition, the weather-resistant protective sheet may be formed of one type of material or may be formed of two or more types of materials. Moreover, the weather-resistant protective sheet may be formed of a single layer film, but may be a laminated film including two or more layers.
The thickness of the weatherproof protective sheet is not particularly defined, but is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and usually 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility. For this reason, it is desirable to set it as the said range as a range which has both advantages.

Moreover, you may perform surface treatments, such as a corona treatment and a plasma treatment, in order to improve the adhesiveness with another film to a weather-resistant protective sheet.
The weatherproof protective sheet is preferably provided on the outer side as much as possible in the organic thin film solar cell module. This is because more device components can be protected.
In addition, UV protection, heat ray blocking, antifouling properties, hydrophilicity, hydrophobicity, antifogging properties, abrasion resistance, conductivity, antireflection, antiglare properties, light diffusion, light scattering, wavelength conversion, Functions such as gas barrier properties may be imparted. In particular, the organic thin film solar cell is preferably exposed to strong ultraviolet rays from sunlight, and therefore has an ultraviolet blocking function.

As a method for imparting such a function, a layer having a function may be laminated on a weather-resistant protective sheet by coating film formation or the like, or a weather-resistant protection is achieved by dissolving or dispersing a material exhibiting the function. You may make it contain in a sheet | seat.

2-5. Layer Configuration of Organic Thin Film Solar Cell Module Hereinafter, an example of the layer configuration of the organic thin film solar cell module will be described with reference to FIG. .

FIG. 3 is a cross-sectional view schematically showing the configuration of an organic thin film solar cell module as one embodiment of the present invention. As shown in FIG. 3, the organic thin-film solar cell module 44 of this embodiment includes a weather-resistant protective sheet 31, an ultraviolet cut film 32, a gas barrier film 33, a getter material film 34, a sealing material 35, and an organic material. A thin film solar cell element 36, a sealing material 37, a getter material film 38, a gas barrier film 39, and a back sheet 40 are provided in this order. And light is irradiated from the side (downward in the figure) where the weatherproof protective sheet 31 is formed, and the organic thin film solar cell element 36 generates electric power. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 40 described later, the getter material film 38 and / or the gas barrier film 39 may not be used depending on the application. Good.

(Weather-resistant protective sheet 31)
The weatherproof protective sheet is as described above.

(UV cut film 32)
The ultraviolet cut film 32 is a film that prevents the transmission of ultraviolet rays.
Some components of the organic thin film solar cell module 44 are deteriorated by ultraviolet rays. Some of the

gas barrier films

33 and 39 and the like are deteriorated by ultraviolet rays depending on the type. Accordingly, the ultraviolet cut film 32 is provided on the light receiving portion of the organic thin film solar cell module 44, and the light receiving surface of the organic thin film solar cell element 36 is covered with the ultraviolet cut film 32, thereby allowing the organic thin film solar cell element 36 and, if necessary, a gas barrier. The

films

33, 39, etc. are protected from ultraviolet rays so that the power generation capacity can be kept high.

The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut film 32 is such that the transmittance of ultraviolet rays (for example, wavelength 300 nm) is preferably 50% or less, more preferably 30% or less, and particularly preferably. 10% or less.
Further, the ultraviolet cut film 32 is preferably one that transmits visible light from the viewpoint of not preventing the organic thin film solar cell element 36 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more.

Furthermore, since the organic thin film solar cell module 44 is often heated by receiving light, the ultraviolet cut film 32 preferably has resistance to heat. From this viewpoint, the melting point of the constituent material of the ultraviolet cut film 32 is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher. Moreover, it is 350 degrees C or less normally, Preferably it is 320 degrees C or less, More preferably, it is 300 degrees C or less. If the melting point is too low, the ultraviolet cut film 32 may melt when the organic thin film solar cell module 44 is used.

Moreover, the ultraviolet cut film 32 has a high softness | flexibility, its adhesiveness with an adjacent film is favorable, and what can cut water vapor | steam and oxygen is preferable.
The material constituting the ultraviolet cut film 32 is arbitrary as long as it can weaken the intensity of ultraviolet rays. Examples of the material include a film formed by blending an ultraviolet absorber with an epoxy, acrylic, urethane, or ester resin. Further, a film in which a layer of an ultraviolet absorbent dispersed or dissolved in a resin (hereinafter referred to as “ultraviolet absorbing layer” as appropriate) is formed on a base film may be used.

As the ultraviolet absorber, for example, salicylic acid-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ones can be used. Of these, benzophenone and benzotriazole are preferable. Examples of this include various aromatic organic compounds such as benzophenone and benzotriazole. In addition, a ultraviolet absorber may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
Specific examples of the ultraviolet cut film 32 include cut ace (MKV Plastic Co., Ltd.) and the like.

The ultraviolet cut film 32 may be formed of one type of material or may be formed of two or more types of materials. Further, the ultraviolet cut film 32 may be formed of a single layer film, but may be a laminated film including two or more layers.
The thickness of the ultraviolet cut film 32 is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more. Moreover, it is 200 micrometers or less normally, Preferably it is 180 micrometers or less, More preferably, it is 150 micrometers or less. Increasing the thickness tends to increase the absorption of ultraviolet rays, and decreasing the thickness tends to increase the transmittance of visible light.

The ultraviolet cut film 32 may be provided at a position covering at least a part of the light receiving surface of the organic thin film solar cell element 36. Preferably, the organic thin film solar cell element 36 is provided at a position covering the entire light receiving surface.
However, the ultraviolet cut film 32 may be provided at a position other than the position covering the light receiving surface of the organic thin film solar cell element 36.

(Gas barrier film 33)
The gas barrier film 33 is a film that prevents permeation of water and oxygen.

The organic thin film solar cell element 36 tends to be sensitive to moisture and oxygen. In particular, transparent electrodes such as ZnO: Al, compound semiconductor solar cell elements, and organic thin film solar cell elements may be deteriorated by moisture and oxygen. Therefore, by covering the organic thin film solar cell element 36 with the gas barrier film 33, the solar cell element 36 can be protected from water and oxygen, and the power generation capacity can be maintained high.
The degree of moisture-proof capability required for the gas barrier film 33 is such that the water vapor permeability per unit area (1 m ² ) per day is preferably 1 × 10 ⁻¹ g / m ² / day or less, and 1 × 10 It is more preferably ⁻² g / m ² / day or less, further preferably 1 × 10 ⁻³ g / m ² / day or less, and 1 × 10 ⁻⁴ g / m ² / day or less. Among them, it is particularly preferable, and it is particularly preferably 1 × 10 ⁻⁵ g / m ² / day or less, and particularly preferably 1 × 10 ⁻⁶ g / m ² / day or less. As the water vapor does not pass through, deterioration due to the reaction of the solar cell element 36 and the transparent electrode such as ZnO: Al of the element 36 with moisture is suppressed, so that the power generation efficiency is increased and the life is extended.

The degree of oxygen permeability required for the gas barrier film 33 is preferably such that the oxygen permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ cc / m ² / day / atm or less, It is more preferably 1 × 10 ⁻² cc / m ² / day / atm or less, further preferably 1 × 10 ⁻³ cc / m ² / day / atm or less, and further preferably 1 × 10 ⁻⁴ cc / m. ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁶ cc / m ² / day / atm or less. It is particularly preferred. The deterioration due to oxidation of the organic thin film solar cell element 36 and the transparent electrode such as ZnO: Al of the element 36 is suppressed as oxygen does not permeate.

Conventionally, since it was difficult to mount the gas barrier film 33 having such a high moisture-proof and oxygen-blocking capability, it was difficult to realize a solar cell including an excellent solar cell element such as an organic solar cell element. . However, application of such a gas barrier film 33 facilitates the implementation of the organic thin film solar cell module 44 utilizing the excellent properties of the organic solar cell element.

Further, the gas barrier film 33 is preferably one that transmits visible light from the viewpoint of not preventing the organic thin film solar cell element 36 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 85% or more, especially Preferably it is 90% or more, Especially preferably, it is 95% or more, Especially preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

Furthermore, since the organic thin film solar cell module 44 is often heated by receiving light, the gas barrier film 33 preferably has resistance to heat. From this viewpoint, the melting point of the constituent material of the gas barrier film 33 is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably. It is 300 degrees C or less. By increasing the melting point, it is possible to reduce the possibility that the gas barrier film 33 is melted and deteriorated when the organic thin film solar cell module 44 is used.

The specific configuration of the gas barrier film 33 is arbitrary as long as the organic thin film solar cell element 36 can be protected from water. However, since the production cost increases as the amount of water vapor or oxygen that can permeate the gas barrier film 33 increases, it is preferable to use an appropriate film considering these points comprehensively.

Particularly suitable gas barrier film 33 includes, for example, a film obtained by vacuum-depositing SiOx on a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).
The gas barrier film 33 may be formed of one type of material or may be formed of two or more types of materials. The gas barrier film 33 may be formed of a single layer film, but may be a laminated film including two or more layers.

The thickness of the gas barrier film 33 is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. Increasing the thickness tends to increase gas barrier properties, and decreasing the thickness tends to increase flexibility and improve visible light transmittance.

If the gas barrier film 33 can cover the organic thin film solar cell element 36 and protect it from moisture and oxygen, the formation position is not limited, but the front surface of the organic thin film solar cell element 36 (the surface on the light receiving surface side; the lower side in FIG. 3). And the back surface (surface opposite to the light receiving surface; upper surface in FIG. 3). This is because the front and back surfaces of the thin film solar cell module 44 are often formed in a larger area than the other surfaces. In this embodiment, the gas barrier film 33 covers the front surface of the organic thin film solar cell element 36, and a gas barrier film 39 described later covers the back surface of the organic thin film solar cell element 36. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 40 described later, the getter material film 38 and / or the gas barrier film 39 may not be used depending on the application. Good.

(Getter material film 34)
The getter material film 34 is a film that absorbs moisture and / or oxygen. Some of the components of the organic thin-film solar cell element 36 are deteriorated by moisture as described above, and some are deteriorated by oxygen. Therefore, by covering the organic thin film solar cell element 36 with the getter material film 34, the organic thin film solar cell element 36 and the like are protected from moisture and / or oxygen, and the power generation capacity is kept high.

Here, unlike the gas barrier film 33 as described above, the getter material film 34 does not prevent moisture permeation, but absorbs moisture. By using a film that absorbs moisture, when the organic thin film solar cell element 36 is covered with the gas barrier film 33 or the like, the getter material film 34 captures moisture that slightly enters the space formed by the

gas barrier films

33 and 9. Thus, the influence of moisture on the organic thin film solar cell element 36 can be eliminated.

The degree of water absorption capacity of the getter material film 34 is usually 0.1 mg / cm ² or more, preferably 0.5 mg / cm ² or more, more preferably 1 mg / cm ² or more. The higher the numerical value, the higher the water absorption capacity, and the deterioration of the organic thin film solar cell element 36 can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, it is usually 10 mg / cm < ² > or less.
Further, when the organic thin-film solar cell element 36 is covered with the

gas barrier films

33 and 39 or the like due to the absorption of oxygen by the getter material film 34, oxygen that slightly enters the space formed by the

gas barrier films

33 and 39 is absorbed. The getter material film 34 can capture and eliminate the influence of oxygen on the organic thin film solar cell element 36.

Furthermore, the getter material film 34 is preferably one that transmits visible light from the viewpoint of not preventing the organic thin-film solar cell element 36 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 85% or more, especially Preferably it is 90% or more, Especially preferably, it is 95% or more, Especially preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

Furthermore, since the organic thin-film solar cell module 44 is often heated by receiving light, the getter material film 34 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the getter material film 34 is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably. Is 300 ° C. or lower. By increasing the melting point, it is possible to reduce the possibility that the getter material film 34 melts and deteriorates when the organic thin film solar cell module 44 is used.

The material constituting the getter material film 34 is arbitrary as long as it can absorb moisture and / or oxygen. Examples of the material include alkali metal, alkaline earth metal or alkaline earth metal oxides; alkali metal or alkaline earth metal hydroxides; silica gel, zeolitic compounds, magnesium sulfate. And sulfates such as sodium sulfate and nickel sulfate; and organometallic compounds such as aluminum metal complexes and aluminum oxide octylates. Specifically, examples of the alkaline earth metal include Ca, Sr, and Ba. Examples of the alkaline earth metal oxide include CaO, SrO, and BaO. Other examples include Zr—Al—BaO and aluminum metal complexes. Specific product names include, for example, OleDry (Futaba Electronics).

Examples of the substance that absorbs oxygen include activated carbon, silica gel, activated alumina, molecular sieve, magnesium oxide, and iron oxide. In addition, Fe, Mn, Zn, and inorganic salts such as sulfates, chlorides, and nitrates of these metals are also included.
In addition, the getter material film 34 may be formed of one type of material or may be formed of two or more types of materials. The getter material film 34 may be formed of a single layer film, but may be a laminated film including two or more layers.

The thickness of the getter material film 34 is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility.
The getter material film 34 is not limited in its formation position as long as it is in the space formed by the

gas barrier films

33 and 39, but the front surface (light receiving surface side surface of the organic thin film solar cell element 36. Surface) and back surface (surface opposite to the light receiving surface; upper surface in FIG. 3) is preferably covered. This is because in the organic thin film solar cell module 44, the front and back surfaces are often formed in a larger area than the other surfaces, and therefore moisture and oxygen tend to enter through these surfaces. From this viewpoint, the getter material film 34 is preferably provided between the gas barrier film 33 and the organic thin film solar cell element 36. In this embodiment, the getter material film 34 covers the front surface of the organic thin film solar cell element 36, the getter material film 38 described later covers the back surface of the organic thin film solar cell element 36, and the

getter material films

34 and 38 are respectively organic thin film solar cells. It is located between the element 36 and the

gas barrier films

33 and 39. In addition, when using a highly waterproof sheet such as a sheet obtained by bonding a fluororesin film on both sides of an aluminum foil as the back sheet 40 described later, the getter material film 38 and / or the gas barrier film 39 may not be used depending on the application. .

The getter material film 34 can be formed by any method depending on the type of the water-absorbing agent or desiccant. For example, a method of attaching a film in which the water-absorbing agent or desiccant is dispersed with an adhesive, water-absorbing agent or desiccant The method of apply | coating this solution with a spin coat method, the inkjet method, or a dispenser method etc. can be used. Further, a film forming method such as a vacuum evaporation method or a sputtering method may be used.

Examples of the film for the water-absorbing agent or drying agent include polyethylene resins, polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), and acrylonitrile-butadiene-styrene copolymers. (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, or the like can be used. Among these, a film of polyethylene resin, fluorine resin, cyclic polyolefin resin or polycarbonate resin is preferable. In addition, the said resin may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Sealing material 35)
The sealing material 35 is as described above. In this embodiment, the sealing material 35 and the sealing material 37 are provided on the front surface and the back surface of the organic thin film solar cell element 36, respectively.

(Organic thin film solar cell element 36)
The organic thin film solar cell element 36 is the same as the organic thin film solar cell element described above.

-Connection between solar cell elements Although only one organic thin film solar cell element 36 may be provided per one organic thin film solar cell module 44 (for example, FIG. 3), normally, as shown in FIG. Two or more organic thin film solar cell elements 36 are provided. The specific number of thick organic thin film positive battery elements 36 may be set arbitrarily. When a plurality of organic thin film solar cell elements 36 are provided, the organic thin film solar cell elements 36 are often arranged in an array.

When a plurality of organic thin film solar cell elements 36 are provided, a current collector is already provided in each organic thin film solar cell element. Therefore, normally, the organic thin film solar cell elements 36 are the collectors of each organic thin film solar cell element. The electric wires are electrically connected using other conductive members as necessary. Then, electricity generated from the group of connected organic thin film solar cell elements 36 is taken out from a terminal (not shown). At this time, the organic thin film solar cell elements are usually connected in series in order to increase the voltage.
Thus, when connecting the organic thin film solar cell elements 36, it is preferable that the distance between the organic thin film solar cell elements 36 is small. As a result, it is preferable that the gap between the organic thin film solar cell element 36 and the organic thin film solar cell element 36 is narrow. This is because the light receiving area of the organic thin film solar cell element 36 is widened to increase the amount of received light, and the power generation amount of the organic thin film solar cell module 44 is increased.

(Encapsulant 37)
The sealing material 37 is as described above. The thing similar to the sealing material 35 can be used similarly except an arrangement position differing.
Moreover, since the constituent member on the back side of the organic thin film solar cell element 36 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

(Getter material film 38)
The getter material film 38 is the same film as the getter material film 34 described above, and the same getter material film 34 can be used as necessary except that the arrangement position is different.
Moreover, since the constituent member on the back side of the organic thin film solar cell element 36 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used. It is also possible to use a film containing more of the moisture or oxygen absorbent used than the getter material film 34. Examples of such absorbents include CaO, BaO, Zr—Al—BaO, and the like as moisture absorbents, and activated carbon, molecular sieves, and the like as oxygen absorbents.

(Gas barrier film 39)
The gas barrier film 39 is a film similar to the gas barrier film 33 described above, and the same material as the gas barrier film 39 can be used as necessary, except that the arrangement position is different.
Moreover, since the constituent member on the back side of the organic thin film solar cell element 36 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

(Backsheet 40)
The back sheet 40 is a film similar to the weather-resistant protective sheet 31 described above, and the same film as the weather-resistant protective sheet 31 can be used in the same manner except that the arrangement position is different. Further, if the back sheet 40 is difficult to permeate water and oxygen, the back sheet 40 can function as a gas barrier layer.

Moreover, since the constituent member on the back side of the organic thin film solar cell element 36 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used. Therefore, it is particularly preferable to use the following (i) to (iv) as the backsheet 40.
(I) As the back sheet 40, various resin films or sheets excellent in strength and excellent in weather resistance, heat resistance, water resistance and / or light resistance can be used. For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine Resin, poly (meth) acrylic resin, polycarbonate resin, polyester resin such as polyethylene terephthalate or polyethylene naphthalate, various polyamide resins such as nylon, polyimide resin, polyamideimide resin, polyaryl phthalate resin , Silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin or other resin It can be used. Among these resin sheets, it is preferable to use a fluorine resin, a cyclic polyolefin resin, a polycarbonate resin, a poly (meth) acrylic resin, a polyamide resin, or a polyester resin sheet. In addition, these may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Ii) As the back sheet 40, a metal thin film can also be used. For example, corrosion-resistant aluminum metal foil, stainless steel thin film, and the like can be mentioned. In addition, the said metal may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
(Iii) As the back sheet 40, for example, a highly waterproof sheet in which a fluorine resin film is bonded to both surfaces of an aluminum foil may be used. Examples of the fluorine resin include ethylene monofluoride (trade name: Tedlar, manufactured by DuPont), polytetrafluoroethylene (PTFE), a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), and a vinylidene fluoride resin. (PVDF) or vinyl fluoride resin (PVF). In addition, 1 type may be used for fluororesin and it may use 2 or more types together by arbitrary combinations and a ratio.

(Iv) As the back sheet 40, for example, a vapor deposition film of an inorganic oxide is provided on one side or both sides of the base film, and further, heat resistance is provided on both sides of the base film provided with the vapor deposition film of the inorganic oxide. What laminated | stacked the property polypropylene-type resin film may be used. Usually, when a polypropylene resin film is laminated on the base film, the lamination is performed by laminating with a laminating adhesive. By providing an inorganic oxide vapor-deposited film, it can be used as a back sheet 40 with excellent moisture resistance that prevents intrusion of moisture and / or oxygen.

・ Base film Basically, the base film is excellent in close adhesion with inorganic oxide deposition film, etc., excellent in strength, weather resistance, heat resistance, water resistance, and light resistance. Resin films can be used. For example, the resin described in (i) above can be used. Among these, it is preferable to use a film of a fluorine resin, a cyclic polyolefin resin, a polycarbonate resin, a poly (meth) acrylic resin, a polyamide resin, or a polyester resin.
As thickness of a base film, it is 12 micrometers or more normally, Preferably it is 20 micrometers or more, and is 300 micrometers or less normally, Preferably it is 200 micrometers or less.

-Vapor deposition film of an inorganic oxide As a vapor deposition film of an inorganic oxide, basically any thin film on which a metal oxide is deposited can be used. For example, a deposited film of an oxide of silicon (Si) or aluminum (Al) can be used. At this time, for example, SiOx (x = 1.0 to 2.0) can be used as the silicon oxide, and AlOx (x = 0.5 to 1.5) can be used as the aluminum oxide.

In addition, the kind of metal and inorganic oxide to be used may be 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The thickness of the deposited inorganic oxide film is usually 50 mm or more, preferably 100 mm or more, and usually 4000 mm or less, preferably 1000 mm or less.
As a method for forming the deposited film, a chemical vapor deposition method (chemical vapor deposition method, CVD method) such as a plasma chemical vapor deposition method, a thermal chemical vapor deposition method, or a photochemical vapor deposition method can be used.

Polypropylene resin film As the polypropylene resin, for example, a homopolymer of propylene or a copolymer of propylene and another monomer (for example, α-olefin) can be used. Moreover, an isotactic polymer can also be used as a polypropylene resin.

Polypropylene resins are largely controlled by their crystallinity, but high isotactic polymers have excellent tensile strength and impact strength, good heat resistance and bending fatigue strength, and workability. Is very good.

-Adhesive When laminating a polypropylene resin film on a base film, an adhesive for laminating is usually used. Thereby, a base film and a polypropylene resin film are laminated | stacked via the adhesive bond layer for lamination.

Examples of the adhesive constituting the adhesive layer for laminating include, for example, a polyvinyl acetate adhesive, a polyacrylate adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, a cellulose adhesive, and a polyester adhesive. Adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives, phenol resin adhesives, epoxy adhesives, polyurethane adhesives, reactive (meth) acrylic adhesives, silicone adhesives, etc. Is mentioned. In addition, 1 type may be used for an adhesive agent and it may use 2 or more types together by arbitrary combinations and a ratio.

(Dimensions etc.)
The organic thin film solar cell module 44 of the present invention is usually a thin film member. Thus, by forming the organic thin film solar cell module 44 as a film-like member, the organic thin film solar cell module 44 can be easily installed in a building material, an automobile, an interior, or the like. The organic thin film solar cell module 44 is light and difficult to break, and thus a highly safe solar cell can be obtained and can be applied to a curved surface, so that it can be used for more applications. Since it is thin and light, it is preferable in terms of distribution such as transportation and storage. Furthermore, since it is in the form of a film, it can be manufactured in a roll-to-roll manner, and a significant cost cut can be achieved.

Although there is no restriction | limiting in the specific dimension of the organic thin film solar cell module 44, The thickness is 50 micrometers or more normally, Preferably it is 100 micrometers or more, More preferably, it is 150 micrometers or more, Usually, 3000 micrometers or less, Preferably it is 2000 micrometers or less, More preferably, it is 1500 micrometers or less.

2-6. BACKGROUND OF THE INVENTION Since the present invention uses a conductive thermosetting resin composition for installing a current collector, the conductive curable resin composition is heated by sealing the organic thin film solar cell module. Can be cured simultaneously. By reducing the number of times of heating, efficient production of the organic thin film solar cell module can be realized. Moreover, deterioration of the photoelectric conversion layer can be suppressed with a decrease in the thermal history of the photoelectric conversion layer. That is, according to the manufacturing method of the present invention, a highly efficient organic thin film solar cell module can be obtained efficiently.
Specifically, it is preferable to sequentially include the following steps 1 to 3.

Step of installing a collector wire on the organic thin film solar cell element (Step 1)
A step of installing a current collector via a conductive thermosetting resin composition on an organic thin film solar cell element in which at least a lower electrode, a photoelectric conversion layer, and an upper electrode are sequentially laminated on a substrate. A current collector is installed at an arbitrary position of the battery element via the conductive thermosetting resin composition. At this time, the conductive thermosetting resin composition is previously installed on the current collector, and then the integrated current collector and the conductive thermosetting resin composition are used as the electrodes of the organic thin film solar cell element. After placing, it is preferable to install by applying pressure from above using a urethane roller or the like. In step 1, the conductive thermosetting resin composition is not cured. Arbitrary devices can be used for the installation of the current collector.

Sealing material installation process (process 2)
Step of installing a sealing material on the surface of the organic thin-film solar cell element in which the current collector obtained in Step 1 is installed, on the surface on which the current collector is installed In Step 2, the organic in which the current collector obtained in Step 1 is installed A sealing material is provided on the thin film solar cell element. Arbitrary apparatuses can be used for installation of the sealing material. Although the sealing material should just be installed in the surface which installed the electrical power collector of the organic thin film solar cell element at least, you may install it in both surfaces of an organic thin film solar cell element. The sealing material is preferably installed so as to cover the entire surface of the organic thin film solar cell element. For the above reasons, the sealing material is preferably a sealing material containing a thermosetting resin.

Heating process (process 3)
A step of heating the laminate obtained in step 2 and simultaneously curing the conductive thermosetting resin composition and sealing with a sealing material. In step 3, the current collector obtained in

steps

1 and 2 and The organic thin film solar cell provided with the sealing material is heated to cure the conductive thermosetting resin composition for adhering the current collector, and at the same time, sealing with the sealing material is performed. By these steps, the current collector can be bonded and sealed at the same time, and the manufacturing process can be made more efficient.
The heating conditions are not particularly limited as long as the conductive thermosetting resin composition and the sealing material containing the thermosetting resin are sufficiently cured and the module is not deformed. The heating temperature is usually 80 ° C. or higher, preferably 100 ° C. or higher, and is usually 180 ° C. or lower, preferably 160 ° C. or lower, more preferably 140 ° C. or lower. The heating time is usually 5 minutes or longer, preferably 10 minutes or longer, usually 180 minutes or shorter, preferably 120 minutes or shorter.
Other necessary layers may be laminated on the obtained organic thin film solar cell module by a laminating method as described below.

The organic thin film solar cell module of the present invention can also be produced by a known method. Specifically, it can be manufactured by laminating necessary layers and using a heat laminating method using a vacuum laminator or a roll laminator.

In the case of thermal lamination, it is preferably performed under vacuum conditions, and the degree of vacuum is usually 10 Pa or more, preferably 20 Pa or more, more preferably 30 Pa or more. On the other hand, the upper limit is usually 150 Pa or less, preferably 120 Pa or less, more preferably 100 Pa or less. By setting it as the said range, since generation | occurrence | production of a bubble can be suppressed in each layer in a module, and productivity improves, it is preferable.
The vacuum time is usually 1 minute or longer, preferably 2 minutes or longer, more preferably 3 minutes or longer. On the other hand, the upper limit is usually 20 minutes or less, preferably 18 minutes or less, more preferably 15 minutes or less. It is preferable to set the vacuum time in the above range since the appearance of the organic thin-film solar cell module after heat lamination becomes good and generation of bubbles due to heat lamination conditions in each layer in the module can be suppressed.

The pressurizing condition of the thermal laminate is usually a pressure of 50 kPa or more, preferably 70 kPa or more, more preferably 90 kPa or more. On the other hand, the upper limit value is preferably 101 kPa or less. By setting it as the pressurization condition of the said range, since moderate adhesiveness can be acquired, without damaging an organic thin-film solar cell module, it is preferable also from a durable viewpoint.
The holding time of the pressure is usually 1 minute or longer, preferably 3 minutes or longer, more preferably 5 minutes or longer. On the other hand, the upper limit is usually 50 minutes or less, preferably 40 minutes or less, more preferably 30 minutes or less. By setting it as the said holding time, since the gelling rate of a sealing material can be made appropriate, sufficient adhesive strength can be obtained.

The temperature condition of the thermal laminate is usually 115 ° C. or higher, preferably 120 ° C. or higher, more preferably 125 ° C. or higher. On the other hand, the upper limit is usually 180 ° C. or lower, preferably 165 ° C. or lower, more preferably 155 ° C. or lower. By setting the temperature range, sufficient adhesive strength can be obtained.
The temperature holding time is usually 1 minute or longer, preferably 3 minutes or longer, more preferably 5 minutes or longer. On the other hand, the upper limit is 50 minutes or less, preferably 40 minutes or less, more preferably 30 minutes or less. By setting it as the said holding time, since crosslinking of a sealing material is performed moderately, durability performance improves and it can have moderate softness | flexibility, and is preferable.

<Application>
There is no restriction | limiting in the use of the organic thin-film solar cell module 44 mentioned above, It is arbitrary. For example, as schematically shown in FIG. 4, an organic thin film solar cell panel 13 in which an organic thin film solar cell module 44 is provided on a certain base material 42 is prepared and used at a place of use. As a specific example, when a building material plate is used as the base material 42, an organic thin film solar cell module 44 is provided on the surface of the plate material to produce a solar cell panel as the solar cell panel 13. It can be used by installing it on the outer wall of the door.
Moreover, according to a use, you may further laminate | stack arbitrary layers with respect to an organic thin film solar cell module (not shown).

The base material 42 is a support member that supports the organic thin film solar cell element 36. Examples of the material for forming the base material 42 include inorganic materials such as glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluorine. Organic materials such as resin film, vinyl chloride, polyethylene, cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene; paper materials such as paper or synthetic paper; metals such as stainless steel, titanium or aluminum For example, a composite material such as a material whose surface is coated or laminated in order to impart insulating properties can be used. In addition, 1 type may be used for the material of a base material, and 2 or more types may be used together by arbitrary combinations and a ratio. Moreover, carbon fiber may be included in these organic materials or paper materials to reinforce the mechanical strength.

Examples of fields to which the organic thin film solar cell module of the present invention is applied include building material solar cells, automotive solar cells, interior solar cells, railway solar cells, marine solar cells, airplane solar cells, and spacecraft. It is suitable for use in solar cells for home use, solar cells for home appliances, solar cells for mobile phones, solar cells for toys and the like.

Hereinafter, the present invention will be described in more detail with reference to examples, but it goes without saying that the present invention is not limited to the following examples.

In this example, evaluation of the organic thin film solar cell module was performed by the following method.
(1) Appearance The appearance of the organic thin film solar cell module was observed, and ◎, ○, Δ, and × were determined according to the following criteria.
Appearance evaluation was performed according to the following criteria by observing whether the module was deformed and / or discolored.
The deformation of the module was evaluated by the maximum height of the deformed part from the surface of the table when the module was placed on a flat table.
A: The maximum deformation height of the organic thin film solar cell module is 2 mm or less and no discoloration of the organic thin film solar cell element is observed. ○: The maximum deformation height of the organic thin film solar cell module is 2 mm or more. No discoloration is observed.
(Triangle | delta): The maximum height of a deformation | transformation of an organic thin film solar cell module is 2 mm or less, and discoloration of an organic thin film solar cell element is observed.
X: The maximum deformation height of the organic thin film solar cell module is 2 mm or more, and discoloration of the organic thin film solar cell element is observed.
(2) Moisture and heat resistance test test method: using a thermo-hygrostat PL-1J manufactured by Espec, in accordance with the conditions of JIS C8991-2011 10.12, the high-temperature and high-humidity test is performed at a temperature of 85 ° C. and a humidity of 85% for 200 hours. It was performed according to the conditions.
Evaluation method: The photoelectric conversion efficiency after 200 hours with respect to the photoelectric conversion efficiency before the wet heat resistance test was determined.
(3) Condensation freezing test test method: 10 cycles of 85 ° C. and 85% RH −40 ° C. were performed according to the conditions of JIS C8991-2011 10.13 using a constant temperature and humidity chamber PL-1J manufactured by Espec. It was.
Evaluation method: The photoelectric conversion efficiency after 10 cycles with respect to the photoelectric conversion efficiency before the wet heat resistance test was determined.
(4) Photoelectric conversion efficiency After irradiating light to the module for 20 minutes or more under a light source with AM 1.5 and incident energy of 100 mW / cm ² , the following measurements were performed within 3 hours. Based on JIS C 8935 “Amorphous Solar Cell Module Output Measurement Method”, the sampling period was set to 100 μsec, the waiting time from application of the set voltage to actual measurement was set to 50 μsec, and measurement was performed in the direction from Isc to Voc.

<Example 1>
<Manufacture of organic thin film solar cell element>
ITO40nm, Ag10nm, ITO40nm are sequentially laminated, thickness 50 [mu] m, a polyethylene naphthalate substrate (Tm260 ℃, Tg155 ℃) of 60mm square hand, subjected to laser patterning in a YVO ₄ laser (wavelength 532 nm), to form a lower electrode .
A zinc oxide solution was prepared by diluting zinc oxide (BYK-3841 manufactured by Big Chemie Japan) seven times by weight with isopropanol. A zinc oxide layer of 120 nm was formed on the lower electrode by applying the zinc oxide solution with a # 2 wire bar.
P3HT (Rieke) and C60 bisindene adduct were dissolved in a solution of toluene: tetralin (weight ratio 19: 1) to make a 3.5 weight percent solution. On the zinc oxide layer, a P3HT: C60 bisindene adduct 200 nm was laminated as an organic photoelectric conversion layer by applying the solution using a # 4 wire bar. PEDOT: PSS was laminated | stacked 160nm by apply | coating PH1000 (clevieus made from Heraeus) with a # 5 wire bar on the organic photoelectric converting layer of the previous period, and it heat-dried at 150 degreeC for 10 minutes in nitrogen atmosphere. Next, laser patterning was performed with a YVO ₄ laser (wavelength 532 nm), and then 100 nm of Ag was laminated as an upper electrode by a sputtering method. Laser patterning was performed on Ag with a YVO ₄ laser (wavelength 355 nm), thereby manufacturing an organic thin film solar cell element having a monolithic structure in which four organic thin film solar cells were connected in series.

<Installation of current collector>
On the upper electrode of the organic thin-film solar battery cell at both ends of the obtained organic thin-film solar battery element, a collector wire with a conductive thermosetting resin composition (DT101C4 manufactured by Dexerals, Inc. (epoxy system containing nickel particles as conductive particles) Conductive curable resin, curing temperature 120 ° C.) 15 μm + copper foil 35 μm thickness, width 4 mm).
<Sealing>
Sealed with a barrier film (trade name: View Barrier, thickness 100 μm) made by Mitsubishi Plastics Co., Ltd., with B-Stage epoxy sheet adhesive (curing temperature 120 ° C, thickness 30 μm) bonded in advance After laminating on the light-receiving surface side and non-light-receiving surface side of the solar cell element with the stop material inside, after vacuuming at 120 ° C. for 10 minutes using an NPC vacuum laminator, bonding is performed by applying pressure for 3 minutes, and then the oven At 120 ° C. for 1 hour. The photoelectric conversion efficiency of the organic thin film solar cell module obtained in this way was 1.32%.

<Example 2>
In Example 1, the collected electric wire with the conductive thermosetting resin composition was made of conductive paste ECA100 (curing temperature 90 ° C., thickness 30 μm) manufactured by Nihon Solder Co., Ltd. and tin-plated copper wire A-TPS (SN) 0.18 × manufactured by Hitachi Cable, Ltd. An organic thin film solar cell module was produced in the same manner except that the thickness was 5.0 (thickness 180 μm, width 5 mm). The photoelectric conversion efficiency of the organic thin film solar cell module thus obtained was 1.55%.
<Comparative Example 1>
In Example 1, the collected electric wire with the conductive thermosetting resin composition is Sumitomo 3M conductive tape # 4305 (thickness 50 μm, width 5 mm) and Hitachi Cable tin-plated copper wire A-TPS (SN) 0.18 × 5 An organic thin-film solar cell module was manufactured in the same manner except that it was changed to 0.0. The photoelectric conversion efficiency of the organic thin film solar cell module thus obtained was 1.22%.
<Comparative Example 2>
In Example 1, the collected electric wire with the conductive thermosetting resin composition is made of Sparkle Solder HA60A-1a2N-F2-1.2-B (thickness 30 μm) manufactured by Senju Metal Industry Co., Ltd. and tin-plated copper wire A-TPS manufactured by Nitto Hitachi Cable, Ltd. (SN) The organic thin-film solar cell module was manufactured by the same method except having set it as 0.18 * 5.0. The photoelectric conversion efficiency of the organic thin film solar cell module obtained in this way was 1.41%.
<Comparative Example 3>
In Example 1, the collected electric wire with the conductive thermosetting resin composition was used as conductive paste LS-411AW (thickness 30 μm) manufactured by Asahi Chemical Research Laboratories and tin-plated copper wire A-TPS (SN) 0.18 × 5 manufactured by Hitachi Cable, Ltd. An organic thin-film solar cell module was manufactured in the same manner except that it was set to 0.0. The photoelectric conversion efficiency of the organic thin film solar cell module thus obtained was 1.04%.
<Comparative example 4>
An organic thin-film solar cell was produced in the same manner as in Example 1 except that the collected electric wire with the conductive thermosetting resin composition was tin-plated copper wire A-TPS (SN) 0.18 × 5.0 manufactured by Hitachi Cable, Ltd. A module was manufactured. The photoelectric conversion efficiency of the organic thin film solar cell module obtained in this way was 1.87%.

Table 1 shows the appearance and heat resistance test results of the organic thin-film solar cell modules obtained in Example 1 and Comparative Examples 1 to 3. In Table 1, durability is the ratio of the photoelectric conversion efficiency after the high temperature and high humidity test to the initial efficiency.

From the experimental results shown in Table 1, the following can be considered.
In Example 1, both durability and appearance were good. This is probably because the thermosetting resin composition has less residual solvent outgas and is less affected by the outgas in the organic thin film solar cell module.
The comparison between Example 1 and Comparative Example 1 shows that the thermosetting conductive resin has higher durability than the conductive adhesive tape. The reason why Comparative Example 1 has lower durability than Example 1 is that the conductive adhesive tape has a larger coefficient of linear expansion than that of the conductive thermosetting resin, so that the deformation during the durability test is large, and the organic thin film solar This is considered to be due to the film peeling of the photoelectric conversion layer of the battery element.
In Comparative Example 2, it is shown that when solder is used to connect the electrode of the organic thin film solar cell element and the collector line, the output is reduced after the durability test. This is thought to be because conduction was unstable because the electrodes of the organic thin-film solar cell element were dissolved in the solder and deformed during solder connection. Moreover, since the high temperature (200 degreeC or more) was required in the case of a connection, the base material of the organic thin film solar cell element deform | transformed.
In Comparative Example 3, when a conductive paste is used to connect the electrode of the organic thin film solar cell element and the collector line, the output is reduced after the durability test. This is presumably because outgas due to the residual solvent was generated, resulting in poor connection between the electrode of the organic thin film solar cell element and the current collector, and deterioration of the power generation layer of the organic thin film solar cell element. In addition, since the conductive paste has fluidity, an appearance defect occurred due to protrusion from the connecting portion.
In Comparative Example 4, when the conductive adhesive was not used to connect the electrode of the organic thin film solar cell element and the collector line, the output decreased after the durability test. This is thought to be due to the fact that floating or the like occurred between the current collector and the upper electrode, and the resistance value increased.

<Example 3>
An organic thin-film solar cell module was prepared in the same manner except that the heating temperature at the time of sealing was set to 100 ° C. in Example 1.
<Example 4>
An organic thin film solar cell module was prepared in the same manner as in Example 2.
<Example 5>
In Example 2, an organic thin film solar cell module was similarly produced except that the heating temperature at the time of sealing was 140 ° C.
<Example 6>
In Example 2, an organic thin film solar cell module was similarly produced except that the heating temperature at the time of sealing was 160 ° C.
Table 2 below shows the condensation freezing test and appearance evaluation results of the organic thin film solar cell modules of Examples 3 to 6.
As the result of the condensation freezing test, the ratio of the photoelectric conversion efficiency after the condensation freezing test with respect to the initial efficiency was obtained, and when it was 1 or more, it was evaluated as ◯, and when it was 1 or less, it was evaluated as ×.

The results shown in Table 2 show that the organic thin-film solar cell module of the present invention is not easily deformed during the manufacturing process, does not cause discoloration, etc., and thus has an excellent appearance and high durability in the use environment. Has been. The appearance of Example 6 is inferior to that of Examples 3 to 5, but the module was deformed because the heat treatment was performed at 160 ° C. or higher. This is probably because the solar cell module is processed at a temperature exceeding the Tg of the substrate during the manufacturing process.
From the above, it has been shown that the solar cell module of the present invention is less likely to undergo module deformation during the manufacturing process, and further has high durability in the use environment.

DESCRIPTION OF SYMBOLS 1 Translucent board | substrate 2 Lower electrode 3 p layer 4 i layer 5 n layer 6 Upper electrode 7 Photoelectric conversion layer 8 Current collector 9 Adhesive layer 11 1st groove | channel 12 2nd groove 13 3rd groove 23 Upper part Electrode: Region 24 laminated with the photoelectric conversion layer Upper electrode: Region 31 not laminated with the photoelectric conversion layer 31 Weatherproof protective sheet 32

UV cut film

33, 39

Gas barrier film

34, 38

Getter material film

35, 37 Sealing material 36 Organic Thin Film Solar Cell Element 40 Back Sheet 42 Base Material 43 Organic Thin Film Solar Cell Panel 44 Organic Thin Film Solar Cell Module

Claims

An organic thin film solar cell element in which at least a photoelectric conversion layer, a substrate that supports the photoelectric conversion layer, and at least a pair of electrodes that are connected to the photoelectric conversion layer on a light receiving surface side and a non-light receiving surface side of the photoelectric conversion layer are stacked. When,
In an organic thin film solar cell module comprising an organic thin film solar cell having at least a pair of current collectors connected to the electrodes,
The said collector wire is connected to the said electrode through the electroconductive thermosetting resin composition, The solar cell module characterized by the above-mentioned.
The organic thin-film solar cell module according to claim 1, wherein the thickness of the collector line is 200 µm or less.