JP5621657B2 - Solar cell module - Google Patents

Description

  The present invention relates to a solar cell module, and more particularly to a solar cell module in which electric power is extracted from a solar cell by an electrode extraction portion formed by a component including a caulking member.

Solar cell modules including solar cells such as organic solar cells that use flexible substrates are produced using a highly productive roll-to-roll method, and the amount of semiconductor material used is small and lightweight. , Is promising.
In the roll-to-roll method, materials including a base material layer, a power generation layer, and upper and lower electrode layers are laminated by a series of processes. As a method of providing an electrode lead-out portion for taking out electric power from the laminate thus formed, conventionally, a protective film covering a part of the collector wire of the solar cell module is removed by a cutter or the like and exposed. A method of soldering the exposed portion to an external lead wire is known, but the working efficiency is poor, and there is a possibility that the current collector or the electrode may be damaged by a cutter.
On the other hand, a method of taking out electric power from a solar cell module by connecting the solar cell module and an external lead through a conductive metal fitting, instead of providing an electrode extraction portion, is also known. As the connection method, either the core wire of the external lead or the conductive terminal connected to the core wire of the external lead is electrically connected to the internal wiring via the conductive metal fitting, and is simultaneously crimped to the solar cell module with the conductive metal fitting. And fixing methods are known. In this method, the electrodes constituting the solar cell and the internal wiring are connected by auxiliary wiring, and the internal wiring and the external lead are connected by a conductive metal fitting on the protective film covering them. According to such a method, workability and appearance, which have been problems in the end treatment of the solar cell module, are improved, and weather resistance is also improved.

Japanese Patent Laid-Open No. 11-17206

  In the method described in Patent Document 1, the electrical connection using the conductive metal fitting is either the internal wiring of the solar cell module and the core wire of the external lead or the conductive terminal connected to the core wire of the external lead, In addition, since the connection part is outside the electrode of the solar cell module, there may be difficulty in electrical continuity between the inside and outside of the solar cell module, and the connection part is outside the solar cell module. However, there was a problem of being easily affected by the outside.

  Then, this invention is made | formed in view of the said conventional actual condition, Comprising: By producing the laminated body containing the solar cell element which consists of a solar cell element base material, an electric power generation layer, and an electrode by a roll-to-roll system. It is an object of the present invention to provide a solar cell module that ensures electrical continuity between the inside and outside of the solar cell module while ensuring high productivity and is excellent in durability.

As a result of intensive studies by the present inventors, a power generation layer, a base material that supports the power generation layer, and at least a pair of electrodes that are connected to the power generation layer on the light-receiving surface side and the non-light-receiving surface side of the power generation layer were laminated. A solar cell module comprising a solar cell in which a solar cell element and at least a pair of first current collectors stacked on the electrode are primarily sealed, wherein the first current collector and the primary seal are provided. And a second current collector fixed to the outer surface of the solar cell is electrically connected via a caulking member, and the caulking member and the second current collector are generated in the power generation layer. It has been found that a solar cell module in which a power extraction part for taking out electric power to the outside is formed and the electrode extraction part is secondarily sealed can solve the above-mentioned problems, and the present invention has been achieved.

That is, the present invention is as follows.
[1] A solar cell element in which a power generation layer, a base material that supports the power generation layer, and at least a pair of electrodes that are connected to the power generation layer on a light receiving surface side and a non-light receiving surface side of the power generation layer,
A solar cell module comprising a solar cell primarily sealed with at least a pair of first current collectors stacked on the electrode,
The first current collector and the second current collector fixed to the outer surface of the primary-sealed solar cell are electrically connected via a caulking member,
The caulking member and the second current collecting line form a power extraction portion for extracting the power generated in the power generation layer to the outside,
The electrode extraction part is secondary sealed,
A solar cell module characterized by that.
[2] The solar cell module according to [1], wherein electrical connection via the caulking member is performed between the electrode, the first current collector, and the second current collector.
[3] The solar cell module according to [1] or [2], wherein the current collector has a thickness of 10 μm or more and a width of 0.5 mm or more.
[4] The solar cell module according to any one of [1] to [3], wherein electrical connection between the electrode and the first current collecting wire is performed through a conductive adhesive layer.
[5] The sun according to any one of [1] to [4], wherein the caulking member is any one of a metal rivet, a pierced terminal, a metal rod, a stapler, a screw, a bolt, and an eyelet rod. Battery module.
[6] In any one of [1] to [5], the primary sealed solar cell includes a gas barrier layer on a light receiving surface side and / or a non-light receiving surface side of the solar cell element. The solar cell module described.
[7] The solar cell module according to any one of [1] to [6], wherein the power generation layer is made of an organic semiconductor material.
[8] A power generation layer, a base material that supports the power generation layer, and at least a pair of electrodes that are connected to the power generation layer on the light-receiving surface side and the non-light-receiving surface side of the power generation layer are stacked, Are further laminated to produce a laminate, and a first step of producing a solar cell by primary sealing of the laminate, a first current collector laminated on the electrode, and a first step. A second current collecting wire fixed to the outer surface of the formed solar cell through a caulking member to form an electrode extraction part in the solar cell, and an electrode extraction part in the second step The manufacturing method of the solar cell module characterized by including the 3rd process of carrying out secondary sealing of the solar cell in which this was formed.

  According to the present invention, the high productivity of the solar cell module is ensured, and electrical continuity between the inside and outside of the solar cell module is reliably obtained, and the solar cell module is long without being affected by the outside of the solar cell module. A solar cell module usable for a period can be provided.

Schematic diagram of a cross section showing a structural example of a solar cell element FIG. 1 is a schematic cross-sectional view showing a structural example of a primary sealed solar cell including the solar cell element of FIG. FIG. 2 is a schematic cross-sectional view showing a structural example of a secondary sealed solar cell module including the primary sealed solar cell in FIG. It is the figure which looked at the solar cell module of FIG. 3 from the light-receiving surface side. It is sectional drawing which shows the one aspect | mode of the fixing by a caulking member (metal cage). It is sectional drawing which shows the one aspect | mode of the fixing by a crimping member (pierce terminal). 10 is a diagram illustrating a structure manufactured in Manufacturing Example 1. FIG.

  Hereinafter, the present invention will be described in detail with reference to embodiments, examples, etc., but the present invention is not limited to the following embodiments, examples, etc., and can be arbitrarily set within the scope of the present invention. Can be changed and implemented.

An embodiment of a solar cell module of the present invention will be described with reference to the drawings.
The solar cell module of the present invention includes a first current collector 6 (also referred to as an internal current collector) that is primarily sealed together with a solar cell element substrate 1, a power generation layer 2, and a solar cell element comprising at least a pair of electrodes 3 and 4. ) And a second current collector 10 (also referred to as an external current collector) that is fixed to the primary sealed solar cell via a caulking member.
The first power collection line 6 is provided at the end of each of the upper electrode 3 provided on the non-light-receiving surface side of the power generation layer 2 and the lower electrode 4 provided on the light-receiving surface side of the power generation layer on the non-light-receiving surface side. Embodiments are preferred.
On the other hand, the second collector line 10 is preferably provided on the light-receiving surface side outside the primary-sealed solar cell in order to take out the electrode from the primary-sealed solar cell. Of course, the 2nd current collection line 10 may be provided in the non-light-receiving surface side.
In the embodiment described in FIG. 3, the upper electrode 3, the first current collector 6 and the second current collector 10, and the lower electrode 4, the first current collector 6 and the second current collector 10 are respectively connected via caulking members. As a result, the electrical connection of these members is ensured, and they are also physically connected. As a result, the power generated in the power generation layer can be efficiently extracted to the outside.
In particular, in the present invention, when electrical connection of the electrode, the first current collector line, and the second current collector line is performed by a caulking member, there is no problem with respect to electrical conduction due to a large number of connected portions. . Further, there is no need for auxiliary wiring for connecting the electrode and the current collector.
In the present invention, a structure portion that is formed on the outer surface of the primary sealed solar cell and includes the caulking member and the second current collector for taking out the electric power generated in the power generation layer is connected to the electrode extraction portion (in FIG. 3). This is referred to as an electrode extraction portion 14).

In the present invention, the caulking means that the surface of the caulking member around the press-fitted assembled component is deformed to fix the assembled component to the caulking member.
The member used as the caulking member may be any member as long as it has conductivity and can be deformed, but is preferably a metal fitting (terminal).
The caulking made of metal is formed by forming a pilot hole with a hole diameter of 0.5 to 50 mm in the portion of the first current collector laminated on the primary sealed solar cell electrode, Etc., and the connection may be made by inserting into a second current collector having a hole with a hole diameter of 0.5 to 50 mm (see FIG. 5). In addition to metal rivets and metal rods, screws, bolts, eyelets, etc. can also be used.
On the other hand, a connection may be made by inserting a metal fitting such as a stapler into a portion where the first and second current collectors overlap without penetrating the pilot hole. Moreover, you may use a piercing terminal instead of a stapler (refer FIG. 6). When using a pierced terminal, the pierced terminal is set in a press machine, and the part where the first current collection line of the primary sealed solar cell exists is applied to the press machine to perform alignment. Then press. At this time, the aspect which presses a 2nd current collector together is preferable. An embodiment in which a crimp terminal connection site is provided on the pierced terminal and the second current collecting line is taken out by the crimp terminal is also exemplified. The pierced terminal includes one in which a faston terminal is integrated.
The caulking member as described above preferably has a low resistance value, and examples thereof include copper, brass, and aluminum. Among them, it is preferable to use copper when considering the resistance value, cost, and durability in total.

The primary sealing referred to in the present invention is to seal the solar cell element and the first current collector, and the sealing at this time is preferably performed using at least an adhesive described later.
On the other hand, the secondary sealing referred to in the present invention is that the caulking member and a second current collector fixed to the outside of the solar cell that is primary-sealed by the caulking member are generated in the power generation layer. It means sealing at least a power extraction portion formed to extract electric power to the outside. As illustrated in FIG. 3, an embodiment in which not only the electrode extraction portion but also the primary sealed solar cell is sealed to form a stacked solar cell module is also preferable.
For secondary sealing, it is preferable to use at least a material for forming a sealing material and a weather resistant layer, which will be described later.

  The first and second current collectors only need to have a lower resistance value than the upper electrode and lower electrode to be connected. In particular, the resistance value is increased by increasing the thickness of the upper electrode and lower electrode of the power generation layer. Is preferably reduced. The thickness of the first and second current collectors is preferably 5 μm or more, more preferably 10 μm or more. Further, it is preferably 2 mm or less, more preferably 1 mm or less, and particularly preferably 300 μm or less. If the thickness is thinner than the above range, the resistance value of the current collector increases, and the generated power cannot be taken out efficiently. Further, if the thickness is larger than the above range, there is a risk that the solar cell module will increase in weight and the flexibility will decrease, the surface of the module will easily become uneven, and the production cost will increase. is there.

In addition, the width of the first and second current collectors 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 1st and 2nd collector wire 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 collecting line is narrower than the above range, the resistance value of the current collecting line increases, and the generated power cannot be efficiently taken out. 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.
As a material for the current collector, 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 solar cell module of the present invention preferably includes a solar cell element composed of a power generation layer, at least a pair of electrodes and a solar cell element substrate, and further laminates an adhesive layer and a gas barrier film during primary sealing.

<Adhesive layer>
In this invention, the aspect which performs primary sealing of a solar cell element and a 1st current collection line by providing the contact bonding layer which consists of an adhesive material is preferable. As an adhesive material constituting the adhesive layer according to the present invention, a hydrocarbon adhesive, an epoxy adhesive, an acrylic adhesive, a silicone adhesive, an ethylene-vinyl acetate copolymer adhesive, or the like is used. Can do. Among them, a hydrocarbon adhesive or an epoxy adhesive is preferable, a hydrocarbon adhesive or a thermosetting epoxy adhesive is more preferable, and a butyl rubber adhesive or a thermosetting epoxy system is particularly preferable. It is an adhesive.

An adhesive refers to a substance capable of bonding objects by being interposed between the objects as defined in, for example, JISK6800.
An adhesive is, for example, a substance that has adhesiveness at room temperature and adheres to an adherent at a light pressure as defined in JISK6800. An adhesive (pressure-sensitive type) that adheres only by applying pressure at room temperature. It is almost synonymous with adhesive.
The material of the adhesive layer is a hydrocarbon-based pressure-sensitive adhesive, which means that the water vapor transmission rate is low, the light transmission rate is high, and because it can be bonded without applying heat when bonding, damage to the solar cell element is avoided. This is preferable.

The film thickness (d ¹ ) of the adhesive layer is usually 1 × 10 ⁻⁶ m or more, preferably 5 × 10 ⁻⁶ m or more, while usually 5 × 10 ⁻³ m or less, preferably 1 × 10 ^−3. m or less, more preferably 1 × 10 ⁻⁴ m or less. It is preferable that the film thickness of the adhesive layer is 1 × 10 ⁻⁶ m or more from the viewpoint of improving the adhesive strength and filling the unevenness of the adherend substrate, lead wire, etc., and the film thickness of the adhesive layer is 5 ×. 10 ⁻³ m or less is preferable from the viewpoint of reducing the amount of water vapor permeated from the end face of the adhesive layer.

The water vapor transmission rate (A) at a film thickness of 1 m of the material of the adhesive layer is usually 1.0 × 10 ⁻⁶ g / m ² / day or more, preferably 1.0 × 10 ^{−5 in} a 40 degree 90% RH environment. g / m and a ² / day or more, whereas, typically ^{5.0 × 10 -2 g / m 2} / day or less, preferably ^{1.0 × 10 -2 g / m 2} / day or less, more preferably 5. 0 × 10 ⁻³ g / m ² / day or less. It is preferable that the water vapor permeability of the material of the adhesive layer is 1.0 × 10 ⁻⁶ g / m ² / day or more from the viewpoint that moisture held in the adhesive layer can be released from the inside of the module to the outside. In addition, the water vapor transmission rate of the adhesive layer material is preferably 5.0 × 10 ⁻³ g / m ² / day or less from the viewpoint of reducing the water vapor transmission rate from the end face of the adhesive layer. The water vapor transmission rate is measured in a 40 degree 90% RH environment by a measurement using an apparatus equipped with a humidity sensor, an infrared sensor, a gas chromatograph according to JIS K7129, or by a cup method (JIS Z0208).

Further, in the solar cell module of the present invention, when the electrode and the first current collector are electrically connected by the caulking member, as shown in FIGS. It is preferable to have the conductive adhesive layer 5 from the viewpoint of ensuring the electrical connection between the electrode and the first current collecting line.
Examples of the material constituting the conductive adhesive layer include a fiber-based double-sided conductive tape, a metal foil-based double-sided conductive tape, solder, ACF (Anisotropic Conductive Film), and the like. Among these, a double-sided conductive tape is preferably used because heating is unnecessary in the bonding step and the process is simple. Further, examples of the conductive adhesive layer include an embossed tape that is not conductive but is designed so that a part of the current collecting wire can penetrate the conductive adhesive layer and come into contact with the electrode.

<Solar cell element substrate>
A solar cell element substrate (hereinafter also simply referred to as a substrate) is a support member that supports the solar cell element. You may use the gas barrier film mentioned later. Examples of materials for forming the substrate include inorganic materials such as glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, and fluororesin film. , Vinyl chloride, polyethylene, polypropylene, cyclic polyolefin, cellulose, acetyl cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, poly (meth) acrylic resin, phenol resin, epoxy resin, polyarylate, polynorbornene, etc. Materials; Metal materials such as stainless steel, titanium, nickel, silver, gold, copper, and aluminum;

Among these, glass, polyethylene terephthalate, polyethylene naphthalate, polyimide, poly (meth) acrylic resin film, stainless steel, and aluminum are preferable from the viewpoint of easy formation of a solar cell element.
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. Further, these organic materials may contain reinforcing fibers such as carbon fibers and glass fibers to reinforce the mechanical strength. Moreover, it is good also as composite materials, such as what coat | coated or laminated the surface in order to provide insulation to these metal materials.

<Power generation layer>
As the power generation layer used in the solar cell module of the present invention, any power generation layer may be used as long as the effects of the present invention are not impaired, but thin film single crystal silicon, thin film polycrystalline silicon, amorphous silicon, A layer made of a silicon-based semiconductor material such as crystalline silicon or spherical silicon, a compound semiconductor material such as CIS, CIGS, or GaAs, an organic dye material, an organic semiconductor material, or the like is preferable. Among these, it is particularly preferable that it is made of an organic semiconductor material because it is particularly excellent in productivity and meets the object of the present invention.
Hereinafter, an organic solar cell element in which the material used for the power generation layer is an organic semiconductor will be specifically described.

<Solar cell element>
The organic solar cell element includes at least a substrate, at least a pair of electrodes, and an organic semiconductor layer containing an organic semiconductor provided therebetween. In addition, in this invention, what also contains a solar cell element base material is called a solar cell element for convenience. The organic semiconductor layer absorbs light to generate electric power, and the generated electric power is extracted from the electrode, and may include other layers such as a buffer layer as described later. In addition, an organic solar cell element is not limited to the example demonstrated below.

-Organic semiconductor layer It can form with arbitrary organic semiconductors. 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. Accordingly, examples of organic semiconductors will be given below. However, p-type and n-type may not always be clearly classified, and some of the same substances exhibit both p-type and n-type characteristics.

  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; polyacenes of tetracene and pentacene; Examples thereof include oligothiophene and derivatives containing these compounds as a skeleton. Furthermore, polymers such as polythiophene, polyfluorene, polyphenylene vinylene, polytriallylamine, polyacetylene, polyaniline, polypyrrole and the like including poly (3-alkylthiophene) are exemplified.

  Examples of n-type semiconductors include fullerene (C60, C70, C76); octaazaporphyrin; perfluoro compound of the above p-type semiconductor; naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, perylene. And aromatic carboxylic acid anhydrides such as tetracarboxylic acid diimides and imidized products thereof; and derivatives containing these compounds as a skeleton.

The specific configuration of the organic semiconductor layer is arbitrary as long as at least a p-type semiconductor and an n-type semiconductor are contained. It 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 organic semiconductor 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 p-type semiconductor (p 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 (p-i-n junction type) are preferable because they exhibit high performance.

Although there is no restriction | limiting in the thickness of each layer of the p layer of the organic-semiconductor layer, i layer, and n layer, Usually, it is preferable to set it as 3 nm or more, especially 10 nm or more, and usually 200 nm or less, especially 100 nm or less. Increasing the layer thickness tends to increase the uniformity of the film, and decreasing the thickness tends to improve the transmittance and decrease the series resistance.
-Electrode As an electrode, it is possible to form with arbitrary materials which have electroconductivity. Examples of electrode materials include metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, and alloys thereof; metal oxides such as indium oxide and tin oxide. Or an alloy thereof (ITO); conductive polymer such as polyaniline, polypyrrole, polythiophene, polyacetylene; the conductive polymer includes acids such as hydrochloric acid, sulfuric acid, sulfonic acid, Lewis acids such as FeCl ₃ , and halogens such as iodine Materials containing a dopant such as metal atoms such as atoms, sodium and potassium; 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 It is done. 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.

  Of the pair of electrodes, at least the electrode on the light receiving surface side is preferably light-transmitting for power generation. However, when the electrode is not transparent, such as the area of the electrode is smaller than the area of the power generation layer, the electrode does not necessarily have to be transparent if the power generation performance is not adversely affected. Examples of transparent electrode materials include oxides such as ITO and indium zinc oxide (IZO); and metal thin films. In this case, the specific range of the light transmittance is not limited, but considering the power generation efficiency of the solar cell element, 80% or more is preferable except for the loss due to partial reflection at the optical interface.

In addition, the material of an electrode may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
In addition, there is no restriction | limiting in the formation method of an electrode. For example, it can be formed by a dry process such as vacuum deposition or sputtering. Further, for example, it can be formed by a wet process using a conductive ink or the like. At this time, any conductive ink can be used. 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 such as electrical characteristics and wetting characteristics may be improved by surface treatment.

Further, as shown in FIG. 1, the electrodes used in the solar cell module of the present invention are arranged in the short direction of the power generation layer so that the area of the light receiving surface of the power generation layer is not reduced in both the upper electrode and the lower electrode. Use a material with a length (width) longer than the length (width), above the non-light-receiving surface of the power generation layer (both ends in the short direction of the primary sealed solar cell) The 1st current collection line is laminated on. However, in addition to this mode, the first current collecting line may include a mode in which the current collecting layer is stacked on the electrode that covers the non-light-receiving surface, while the second current collecting line also receives light from the power generation layer. The aspect which laminates | stacks a collector wire so that the part which covers a surface may be mentioned is also mentioned.

-Other layers The solar cell element shown in the above example may include other layers in addition to the organic semiconductor layers and electrodes described above. In addition, the position which forms other layers is arbitrary unless the electric power generation of a solar cell element is inhibited. As the other layers, buffer layers are exemplified.

  The buffer layer is a layer provided, for example, at the electrode interface facing the organic semiconductor layer in order to improve electrical characteristics. For example, poly (ethylenedioxythiophene): poly (styrenesulfonic acid) (PEDOT: PSS), molybdenum oxide, lithium fluoride, 2,9dimethyl-4,7-diphenyl-1,10-phenanthroline, and the like can be given.

<Gas barrier layer>
A barrier layer made of a gas barrier film is a layer that prevents permeation of water and oxygen.
Organic thin-film solar cells including organic solar cell elements tend to be vulnerable to moisture and oxygen, and the transparent electrode, metal electrode, and organic semiconductor layer may be deteriorated by moisture and oxygen. Therefore, it is preferable to protect the solar cell element from water and oxygen by covering the solar cell element with a gas barrier film, and to maintain high power generation capacity. In addition, it is preferable that the gas barrier film in this invention satisfy | fills the water vapor transmission rate as described below.

The water vapor permeability Pd at a thickness of 100 μm of the gas barrier film needs to be 10 ⁻¹ g / m ² / day or less in a 40 ° C. and 90% RH environment in order to block the ingress of moisture from the outside. Is 10 ⁻² g / m ² / day or less, more preferably 10 ⁻³ g / m ² / day or less, and 10 ⁻⁴ g / m ² / day or less. However, as the current technology is transparent and flexible and the barrier performance increases, the manufacturing cost also increases accordingly. Is in the range of 10 ⁻³ g / m ² / day to 10 ⁻⁴ g / m ² / day, which is the most preferable barrier performance in practice. Needless to say, if it is technically possible, it is more 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).
The degree of oxygen permeability required for the gas barrier film varies depending on the type of thin film solar cell element. For example, in general, the oxygen permeability per unit area (1 m ² ) per 100 μm thickness in a 25 ° C. environment is preferably 1 cc / m ² / day / atm or less, preferably 1 × 10 ⁻¹ cc / m ² / day / atm or less is more preferable, and 1 × 10 ⁻² cc / m ² / day / atm or less is further preferable, and 1 × 10 ⁻³ cc / m ² / day is more preferable. / Atm or less is preferable, 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. preferable. There is an advantage that the deterioration due to the oxidation of the element can be suppressed as the oxygen does not permeate. 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.

By applying such a gas barrier film, it becomes easy to implement a solar cell module taking advantage of excellent properties such as a thin-film solar cell element. Moreover, when a gas barrier film is used for the light-incidence / light-emitting surface of a solar cell module, what transmits visible light is preferable. 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, still more preferably 90% or more, particularly preferably 95% or more. Among these, 97% or more is particularly preferable. For example, a thin film solar cell module has an advantage of converting more sunlight into electric energy.
Further, when it is used on the surface opposite to the light incident / exit surface of the thin film solar cell module, it is not always necessary to transmit visible light, and therefore it may be opaque.

The thickness of the gas barrier film is not particularly defined, but is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and usually 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility.
Furthermore, since the solar cell module is often heated by receiving light, the gas barrier film preferably has resistance to heat. From this viewpoint, the melting point of the constituent material of the gas barrier film 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 300 It is below ℃. By increasing the melting point, it is possible to prevent the gas barrier film from melting and deteriorating when the solar cell module is used.

The specific configuration of the gas barrier film is arbitrary as long as the solar cell element can be protected from at least one of water and oxygen. However, since the manufacturing cost increases as the amount of water vapor or oxygen that can permeate the gas barrier film increases, it is preferable to use an appropriate film considering these points comprehensively.
Hereinafter, the configuration of the gas barrier film will be described with examples.

Two examples are preferable as the configuration of the gas barrier film.
The first example is a film in which an inorganic gas barrier film is disposed on a plastic film substrate.
At this time, the inorganic gas barrier film may be formed only on one side of the plastic film substrate, or may be formed on both sides of the plastic film substrate. When forming on both surfaces, the number of inorganic gas barrier films formed on both surfaces may be the same or different.

  The second example is a film in which a unit layer composed of two layers in which an inorganic gas barrier film and a polymer layer are laminated adjacent to each other is formed on a plastic film substrate. At this time, a unit layer composed of two layers in which an inorganic barrier layer and a polymer layer are laminated adjacent to each other is regarded as one unit, and this unit layer is composed of one unit (one inorganic gas barrier film and one polymer layer). Only one unit) may be formed, but two or more units may be formed. For example, 2 to 5 units may be laminated.

  The unit layer may be formed only on one side of the plastic film substrate, or may be formed on both sides of the plastic film substrate. When forming on both surfaces, the numbers of inorganic barrier layers and polymer layers formed on both surfaces may be the same or different. Moreover, when forming a unit layer on a plastic film base material, an inorganic barrier layer may be formed on the plastic film base material side, and a polymer layer may be formed on this inorganic barrier layer, or on the plastic film base material side. A polymer layer may be formed, and an inorganic barrier layer may be formed on the polymer layer.

Furthermore, for the purpose of protecting the gas barrier film, a protective film may be provided on the surface on which the gas barrier film is disposed. Such a protective film may be the same material as the gas barrier film substrate, or a different material. Moreover, it is good also as a laminated body which bonded together the surface which has arrange | positioned the gas barrier film, and turned the plastic film base material outside.
-Plastic film base material The plastic film base material used for the gas barrier film is not particularly limited as long as it is a film that can hold the above-described inorganic barrier layer and polymer layer, and may be appropriately selected from the intended use of the gas barrier film. it can.

  Examples of plastic film base materials include polyester resin, methacrylic resin, methacrylic acid-maleic acid copolymer, polystyrene, fluororesin, polyimide resin, fluorinated polyimide resin, polyamide resin, polyvinyl alcohol resin, polyamideimide resin. , Polyetherimide resin, cellulose acylate resin, polyurethane resin, polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyether sulfone resin, polysulfone resin, cycloolefin copolymer, fluorene ring modified polycarbonate resin And thermoplastic resins such as alicyclic modified polycarbonate resins and acryloyl compounds.

  Among these resins, preferred examples include polyester resins, polyarylate resins, polyethersulfone resins, fluorene ring-modified polycarbonate resins, alicyclic modified polycarbonate resins, and acryloyl compounds. It is also preferable to use a condensation polymer containing spirobiindane or spirobichroman. Among the polyester resins, biaxially stretched polyethylene terephthalate (PET) and biaxially stretched polyethylene naphthalate (PEN) are preferably used as the plastic film substrate in the present invention because of excellent thermal dimensional stability. It is done.

In addition, 1 type may be used for the material of a plastic film base material, and 2 or more types may be used together by arbitrary combinations and a ratio.
An anchor coat agent layer (anchor coat layer) may be formed on the plastic film substrate in order to improve adhesion to the inorganic gas barrier film. Usually, the anchor coat layer is formed by applying an anchor coat agent. Examples of the anchor coating agent include polyester resins, urethane resins, acrylic resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, isocyanate-containing resins, and copolymers thereof. In addition, an anchor coat agent may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The thickness of the anchor coat layer is usually 0.005 μm or more, preferably 0.01 μm or more, and usually 5 μm or less, preferably 1 μm or less. If the thickness is less than or equal to the upper limit of this range, the slipperiness is good, and there is almost no peeling from the plastic film substrate due to the internal stress of the anchor coat layer itself. Moreover, if it is the thickness more than the lower limit of this range, a uniform thickness can be maintained and it is preferable.

Inorganic gas barrier film An inorganic gas barrier film is usually a layer formed of a metal oxide, nitride or oxynitride. In addition, the metal oxide, nitride, and oxynitride which form an inorganic gas barrier film may be 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
Examples of the metal oxide include oxides such as Si, Al, Mg, In, Ni, Sn, Zn, Ti, Cu, Ce, and Ta, nitrides, and oxynitrides. Among these, in order to achieve both high barrier properties and high transparency, it is preferable to include aluminum oxide or silicon oxide, and it is particularly preferable to include silicon oxide from the viewpoint of moisture permeability and light transmittance. When the inorganic gas barrier film is composed of two or more kinds of metal oxides, it is desirable that the metal oxides include aluminum oxide and silicon oxide.

The ratio of each metal atom and oxygen atom is also arbitrary, but in order to improve the transparency of the inorganic gas barrier film and prevent coloring, the oxygen atom ratio should be extremely small from the stoichiometric ratio of the oxide. Is desirable. On the other hand, in order to improve the denseness of the inorganic gas barrier film and increase the barrier property, it is desirable to reduce oxygen atoms. From this viewpoint, for example, when SiO _x is used as the metal oxide, the value of x is particularly preferably 1.5 to 1.8. For example, when AlO _x is used as the metal oxide, the value of x is particularly preferably 1.0 to 1.4.

Increasing the thickness of the inorganic gas barrier film tends to increase the barrier property, but it is desirable to reduce the thickness in order to prevent cracking and prevent cracking when bent. Therefore, the appropriate thickness of the inorganic barrier layer is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably 200 nm or less.
Although there is no restriction | limiting in the film-forming method of an inorganic gas barrier film, Generally, it can carry out by sputtering method, a vacuum evaporation method, an ion plating method, plasma CVD method etc. For example, the sputtering method can be formed by a reactive sputtering method using plasma using one or more metal targets and oxygen gas as raw materials.

-Polymer layer Any polymer can be used for a polymer layer, for example, what can be formed into a film in a vacuum chamber can be used. In addition, the polymer which comprises a polymer layer may use 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
Examples of the compound that gives the polymer include the following. In addition, 1 type may be used for a monomer and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples thereof include siloxanes such as hexamethyldisiloxane, and polysiloxane is obtained as a polymer.
Moreover, paraxylylene, such as diparaxylylene, is mentioned, and polyparaxylylene is obtained as a polymer.
Moreover, the monomer which can carry out addition polymerization of two types of monomers alternately alternately is mentioned. According to this, a polyaddition polymer is obtained, and polyurethane (diisocyanate / glycol), polyurea (diisocyanate / diamine), polythiourea (dithioisocyanate / diamine), polythioether urethane (bisethyleneurethane / dithiol) And polyimine (bisepoxy / primary amine), polypeptide amide (bisazolactone / diamine), polyamide (diolefin / diamide) and the like.

  Furthermore, an acrylate monomer is mentioned. Either monofunctional, bifunctional, or polyfunctional acrylate monomers may be used, but in order to obtain an appropriate evaporation rate, curing degree, curing rate, etc., it is preferable to use a combination of two or more of the above acrylate monomers. . Examples of monofunctional acrylate monomers include aliphatic acrylate monomers, alicyclic acrylate monomers, ether acrylate monomers, cyclic ether acrylate monomers, aromatic acrylate monomers, hydroxyl group-containing acrylate monomers, carboxy group-containing acrylate monomers, and the like. .

Moreover, the monomer from which photocationic curing polymers, such as an epoxy type and an oxetane type, are obtained is mentioned.
Moreover, vinyl acetate is mentioned. Furthermore, polyvinyl alcohol is obtained by saponifying the polymer.
Furthermore, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride, itaconic anhydride and the like can be mentioned. Furthermore, a copolymer with ethylene can be constituted. Further, a mixture of these, a mixture of glycidyl ether compounds, and a mixture with an epoxy compound can also be used as the polymer.

  There is no restriction | limiting in the polymerization method of a monomer when superposing | polymerizing the said monomer and producing | generating a polymer. However, the polymerization is usually carried out after a composition containing a monomer is applied or deposited to form a film. As an example of the polymerization method, when a thermal polymerization initiator is used, polymerization is started by contact heating with a heater or the like; radiation heating with infrared rays, microwaves or the like. Moreover, when a photoinitiator is used, an active energy ray is irradiated and polymerization is started. Various light sources can be used when irradiating active energy rays, such as mercury arc lamps, xenon arc lamps, fluorescent lamps, carbon arc lamps, tungsten-halogen radiation lamps, and sunlight irradiation light. Can do. Further, electron beam irradiation or atmospheric pressure plasma treatment can also be performed.

Examples of the method for forming the polymer layer include a coating method and a vacuum film forming method.
When the polymer layer is formed by a coating method, for example, methods such as roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, and bar coating can be used.
On the other hand, when forming a polymer layer by a vacuum film-forming method, film-forming methods, such as vapor deposition and plasma CVD, are mentioned, for example.

  The thickness of the polymer layer is not particularly limited, but is usually 10 nm or more, and is usually 5000 nm or less, preferably 2000 nm or less, more preferably 1000 nm or less. By increasing the thickness of the polymer layer, the uniformity of the thickness can be easily obtained, and structural defects of the inorganic gas barrier film can be efficiently filled with the polymer layer, and the barrier property tends to be improved. In addition, by reducing the thickness of the polymer layer, the barrier property is improved because the polymer layer itself is less likely to crack due to external force such as bending. For this reason, it is desirable to determine from the said range as thickness which has barrier property and bending strength.

Among the above-described gas barrier films, as a more suitable gas barrier film, for example, a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is made of an inorganic material, preferably SiO _x or SiO _x N _y by vacuum film formation. The film etc. which vacuum-deposited by are mentioned. That is, the case where the gas barrier film is a film including a thermoplastic resin and SiO _x vacuum-deposited on the thermoplastic resin is included. (The value of x is particularly preferably 1.5 to 1.8, and Y is an integer.) SiO _x and SiO _x N _y do not absorb moisture or react with moisture, and are barriers by regulating the free volume. It is an inorganic material that achieves performance, and a dense thin film, particularly a SiO _x thin film formed by a vacuum deposition method or the like is more preferable. In particular, a film made of a thermoplastic resin having a SiO _x thin film is desirable because it has a higher barrier property.

In the case of organic barrier materials, in most cases, barrier properties are achieved mainly by the thickness of the barrier material while dissolving and diffusing a gas such as water vapor in the barrier material. In this case, the amount of dissolved gas in the barrier material is measured. In this case, gas saturation into the solar cell element cannot be performed, and this is not preferable.
The gas barrier film in the present invention defines the gas barrier performance by the water vapor transmission rate (that is, the water vapor barrier performance). This is because the water vapor barrier is one of the most important functions, and the water vapor barrier is usually used. This is because it is one of the most difficult gas to block (easily permeate) among low molecular weight components such as gases such as oxygen and volatile components, alkalis and acids.

Note that the gas barrier film may be formed of one material or two or more materials. The gas barrier film may be formed of a single layer film, but may be a laminated film including two or more layers.
It is preferable that the gas barrier film is laminated in the above-described order so that the solar cell element can be covered and protected from moisture and oxygen. Among these, it is a particularly preferable aspect that it is provided on the surface opposite to the substrate of the solar cell element. Moreover, you may cover the board | substrate installation surface back surface (surface on the opposite side to a light-receiving surface: non-light-receiving surface) of a solar cell element with the same gas barrier film. This is because the front and back surfaces of solar cell modules are often formed in a larger area than the other surfaces.

<Other layers>
In addition to the above structure, another substrate or an arbitrary functional layer may be included. For example, a layer containing a scavenger that absorbs at least one of moisture and oxygen, a sealing material, a weather resistant protective sheet, or a back protective sheet can be used.
<Layer containing a scavenger that absorbs at least one of moisture and oxygen>
The layer containing a scavenger that absorbs at least one of moisture and oxygen is a film that absorbs at least one of moisture and oxygen. Some components of solar cell elements are deteriorated by moisture as described above, and some are also deteriorated by oxygen. If these are not excluded as much as possible, it is difficult to extend the life while maintaining the power generation efficiency. .

Therefore, by covering the solar cell element with a layer containing a trapping agent that absorbs at least one of moisture and oxygen, the solar cell element and the like are protected from at least one of moisture and oxygen, and the power generation capacity is kept high. Is preferred.
Here, unlike the gas barrier film as described above, the layer containing a scavenger that absorbs at least one of moisture and oxygen does not hinder the permeation of at least one of moisture and oxygen, and absorbs at least one of moisture and oxygen. To do. By using a film that absorbs at least one of moisture and oxygen, when the solar cell element is covered with a gas barrier film or the like, at least one of moisture and oxygen that slightly enters the space formed by the gas barrier film and the adhesive layer The layer containing the trapping agent that absorbs at least one of moisture and oxygen can be trapped and the influence of moisture on the solar cell element can be eliminated.

Specifically, the moisture absorption capacity (also referred to as moisture absorption amount in the present invention) of a layer containing a scavenger that absorbs at least one of moisture and oxygen is usually 0.1 mg / cm ² or more per unit area with respect to the laminated surface. , 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 solar cell element can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, it is usually 15 mg / cm < ² > or less.

Further, the water absorption amount per unit volume of the layer containing the scavenger is usually 1 mg / cm ³ or more, preferably 5 mg / cm ³ or more, more preferably 10 mg / cm ³ or more. The higher the numerical value, the higher the water absorption capacity, and the deterioration of the solar cell element can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, it is usually 800 mg / cm < ³ > or less.
The method for measuring the amount of moisture absorbed is a method of calculating from the weight change of the test specimen before and after moisture absorption, a method of measuring the moisture content in the specimen with a moisture measuring device, and storing the specimen in a sealed container containing moisture. The water loss can be measured by a method of detecting with a moisture concentration meter. Since it can implement simply, the method of calculating from a weight change is preferable.

Specifically, after measuring the weight of the test specimen in a dry state, store the specimen in an environment where moisture exists, record the weight when there is no increase in weight, and calculate the difference as the amount of moisture absorbed. And
The storage environment in which moisture exists may be set as appropriate in terms of moisture absorption capacity as long as the conditions for the presence of moisture in excess of the moisture absorption amount of the specimen are satisfied. Specifically, for a test specimen with a large water absorption capacity, it may be performed in a humidity environment of 50 to 100% RH or more in order to shorten the test time. For a test specimen with a low water absorption capacity, the water concentration is appropriately controlled. In an environment, for example, in the range of 1 ppm to 1%. As for the environment for weight measurement, a test body that irreversibly absorbs water may be weighed in a humidity environment of 50% RH or more, but a test body that reversibly absorbs water has a humidity of 85% RH or more. It is necessary to measure the weight in a high humidity environment.

In addition, when a layer containing a scavenger that absorbs at least one of moisture and oxygen absorbs oxygen, when the solar cell element is covered with a gas barrier film or the like, the space formed by the gas barrier film and the adhesive layer is slightly increased. The layer containing the trapping agent that absorbs at least one of moisture and oxygen can trap the invading oxygen and eliminate the influence of oxygen on the solar cell element.
The oxygen absorption capacity of the layer containing a scavenger that absorbs at least one of moisture and oxygen is usually 0.01 ml / cm ² or more, preferably 0.05 ml / cm ² or more, more preferably 0 per unit area with respect to the laminated surface. .1 ml / cm ² or more. The higher this value, the higher the oxygen absorption capacity and the more the deterioration of the solar cell element can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, Usually, it is 20 ml / cm < ² > or less. In the present invention, oxygen absorption capacity and oxygen absorption are synonymous.

Moreover, the oxygen absorption amount per unit volume of the layer containing the scavenger is usually 0.1 ml / cm ³ or more, preferably 0.5 mg / cm ³ or more, more preferably 1 mg / cm ³ or more. The higher the numerical value, the higher the water absorption capacity, and the deterioration of the solar cell element can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, Usually, it is 200 mg / cm < ³ > or less.
In addition, the measuring method of oxygen absorption ability is calculated by the method of storing a test body in the airtight container containing oxygen, and detecting the oxygen reduction | decrease with an oxygen concentration meter. Record the oxygen concentration when there is no decrease in oxygen concentration, and use the difference from the oxygen concentration in the sealed container before the test as the oxygen absorption amount. The initial oxygen concentration in the sealed container may be set as appropriate so that oxygen exceeding the oxygen absorption amount of the test specimen exists and becomes a concentration suitable for the sensitivity of the oximeter. Further, the amount of the test body in the sealed container may be appropriately charged so that the oxygen decrease due to absorption is equal to or higher than the detection sensitivity of the oximeter.

  Furthermore, when a layer containing a scavenger that absorbs at least one of moisture and oxygen is used on the light-receiving side surface of the solar cell, it is preferable to transmit visible light from the viewpoint of not preventing light absorption of the solar cell element. 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, and still more preferably 90%, excluding loss due to partial reflection at the film interface. Above, particularly preferably 95% or more, and particularly preferably 97% or more. This is to convert more sunlight into electrical energy.

  Furthermore, since the solar cell module is often heated by receiving light, it is preferable that the layer including the trapping agent that absorbs at least one of moisture and oxygen also has resistance to heat. From this viewpoint, the melting point of the constituent material of the layer containing the scavenger that absorbs at least one of moisture and oxygen is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. The temperature is preferably 320 ° C. or lower, more preferably 300 ° C. or lower. By increasing the melting point, it is possible to reduce the possibility that the layer containing the trapping agent that absorbs at least one of moisture and oxygen when the solar cell module is used melts and deteriorates.

The material constituting the layer containing the scavenger that absorbs at least one of moisture and oxygen is arbitrary as long as it can absorb at least one of moisture and oxygen. Examples of the material include alkali metal, alkaline earth metal, alkaline earth metal oxide, alkali metal or alkaline earth metal hydroxide, silica gel as a substance that absorbs moisture (water absorbing agent, desiccant). , Zeolite compounds, sulfates such as magnesium sulfate, 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.
In addition, Zr-Al-BaO, an aluminum metal complex, etc. are also mentioned. Among these, alkaline earth metals Ca and Sr and their oxides CaO, SrO, and aluminum metal complexes are preferable, and CaO, SrO, and BaO are more preferable in terms of high moisture scavenging properties, and aluminum metal complexes are scavengers. Is more preferable in that it can be made transparent.

Among the more preferable, if a specific trade name is given, for example, it is more preferable to use OleDry (manufactured by Futaba Electronics Co., Ltd.) as a scavenger that absorbs moisture.
Inorganic materials such as Fe, Mn, Zn, and inorganic salts such as sulfates, chlorides and nitrates of these metals as substances that absorb oxygen (deoxygenating agents); ascorbic acid, hydrazine compounds, MXD6 nylon, ethylene Organic unsaturated hydrocarbons, polymers having a cyclohexene group, and the like.

Note that the layer including the scavenger that absorbs at least one of moisture and oxygen may be formed of one material or two or more materials.
As a preferable combination of the scavengers constituting the layer containing the scavenger that absorbs at least one of water and oxygen, in the case of the scavengers that absorb moisture, the alkaline earth metal Ca or Sr and the alkaline earth metal are oxidized. CaO or SrO; an alkaline earth metal oxide CaO or SrO and an aluminum metal complex are preferable from the viewpoint of moisture scavenging performance. In the case of a combination of a water absorbing scavenger and an oxygen absorbing scavenger, an alkaline earth metal oxide Oxide CaO or SrO and Fe; alkaline earth metal oxide CaO or SrO and ascorbic acid; alkaline earth metal oxide CaO or SrO and hydrazine compound; aluminum metal complex and ascorbic acid; aluminum metal complex and hydrazine compound This is preferable from the viewpoint of achieving both moisture and oxygen absorption. Furthermore, alkaline earth metal oxides CaO or SrO and ascorbic acid; alkaline earth metal oxides CaO or SrO and hydrazine compounds are preferred because they exhibit higher absorption performance.

In addition, the layer containing a scavenger that absorbs at least one of moisture and oxygen may be formed of a single layer film, but may be a laminated film including two or more layers.
The thickness of the layer containing a scavenger that absorbs at least one of moisture and oxygen is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 500 μm or less, preferably 400 μm or less, More preferably, it is 300 μm or less. Increasing the thickness tends to increase the mechanical strength, while decreasing the thickness tends to increase the flexibility, and further has the advantage that the device can be made thinner. For this reason, it is desirable to set it as the said range as a range which has both advantages.

In the solar cell module, the light receiving surface and the back surface are often formed in a larger area than the other surfaces, so that moisture and oxygen tend to enter through these surfaces. From this viewpoint, in the present invention, the layer containing the scavenger that absorbs at least one of moisture and oxygen is provided between the gas barrier film and the solar cell element.
In one embodiment, a layer containing a scavenger that absorbs at least one of moisture and oxygen is installed on the light-receiving surface side of the solar cell element. In addition to this embodiment, a layer containing a trapping agent that absorbs at least one of moisture and oxygen is installed on the back side of the solar cell element as necessary. Furthermore, as another embodiment, a layer containing a trapping agent that absorbs at least one of moisture and oxygen is provided on both the light-receiving surface and the back surface. In that case, it is preferable that a layer containing a scavenger that absorbs at least one of moisture and oxygen is positioned between the solar cell element and the gas barrier film on both the light receiving surface and the back surface.

The layer containing the trapping agent that absorbs at least one of moisture and oxygen is not limited in its installation position as long as it is in the space formed by the gas barrier film and the adhesive layer in addition to the above position. For example, it may be installed on a substrate where no solar cell element exists, on a gas barrier film other than the projection surface of at least one of the light-receiving surface and the back surface of the solar cell element, and at a position along the peripheral edge of the device, particularly the inner side of the adhesive layer. .

  The layer containing a trapping agent that absorbs at least one of moisture and oxygen can be formed by any method depending on the type of the trapping agent. For example, a method of attaching a film in which the trapping agent is dispersed with an adhesive, trapping A method of applying the agent solution by roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, bar coating, die coating, spin coating, ink jet, dispenser, or the like can be used. Further, a film forming method such as plasma CVD, vacuum deposition, ion plating, or sputtering may be used.

  Examples of the film for the scavenger include polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin). ), Polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, and the like. Among these, films of polyethylene resin, fluorine resin, cyclic polyolefin resin, and polycarbonate resin are preferable. In addition, the said resin may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  In addition, in the layer containing the trapping agent that absorbs at least one of moisture and oxygen arranged on the back surface of the solar cell element opposite to the light receiving surface, the constituent member on the back surface side of the solar cell element is necessarily required to transmit visible light. Therefore, it is possible to use one that does not transmit visible light. It is also possible to use a film that contains at least one of the moisture absorbent and the oxygen absorbent to be used in a larger amount than the layer containing the scavenger that absorbs at least one of moisture and oxygen. Examples of such an absorbent include CaO, BaO, and Zr—Al—BaO as moisture absorbents, and activated carbon as an oxygen absorbent.

In addition, you may provide the anticorrosion layer arrange | positioned between an electrode and the layer containing the capture | acquisition agent which absorbs at least one of a water | moisture content and oxygen which is the other side of the solar cell element of this electrode. That is, the anticorrosion layer is not particularly limited as long as the anticorrosive layer is disposed so that the layer containing the scavenger that absorbs at least one of moisture and oxygen does not directly contact the electrode.
Since the anticorrosion layer can sufficiently block moisture, oxygen, and alkali and acid generated by the reaction of the scavenger, which leaks from the layer containing the scavenger that absorbs at least one of water and oxygen, the solar cell Since deterioration of an element can be prevented, it is preferable. Moreover, by having an anticorrosive layer, it is possible to sufficiently block organic solvents and low molecular weight components volatilized from adhesives and pressure-sensitive adhesives used in the process in the production process of the solar cell module, The layer containing the trapping agent that absorbs at least one can be prevented from being altered, and the trapping agent after the solar cell module is assembled is preferable because it can sufficiently absorb at least one of moisture and oxygen.

The material which comprises the anticorrosion layer in this invention is arbitrary if it has the said characteristic. Specific examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, α-olefin maleic anhydride copolymer, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), styrene. -Butadiene copolymer (SB resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polyvinyl alcohol resin, ethylene- Vinyl alcohol copolymer, polyvinyl butyral resin, polyvinyl pyrrolidone resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, polyethylene terephthalate, polyester resin such as polyethylene naphthalate, polyimide resin, poly Doimide resin, polyaryl phthalate resin, polyamide resin, silicone resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyurethane resin, polybenzimidazole resin, phenol resin, melamine resin , Urea resins, resorcinol resins, xylene resins, epoxy resins, acetal resins, cellulose resins and the like. Preferably, resins such as polyethylene resins, cyclic polyolefin resins, ethylene-vinyl acetate copolymers, fluorine resins, poly (meth) acrylic resins, polycarbonate resins, polyester resins, polyimide resins, epoxy resins, etc. More preferred are polyethylene resins, fluorine resins, poly (meth) acrylic resins, polyester resins, polyimide resins, and epoxy resins. Among these, poly (meth) acrylic resins and epoxy resins are particularly preferable because they can provide an adhesive function.

This anticorrosion layer may be one or more, and may be composed of a plurality of layers. In the case of a plurality of layers, a combination such as a polyester resin and a poly (meth) acrylic resin, a polyester resin and an epoxy resin is preferable in that it has both transparency and heat resistance and can provide an adhesive function.
The thickness per layer of the anticorrosion layer is usually 20 μm or more, preferably 30 μm or more. Moreover, an upper limit is 500 micrometers, More preferably, it is 200 micrometers or less, More preferably, it is 100 micrometers or less. If the upper limit is exceeded, the flexible solar cell module is increased in thickness and difficult to bend. In addition, since there is a distance from the metal electrode of the element, there is a possibility that the trapping agent cannot efficiently absorb moisture, oxygen, etc. that have reached the periphery of the metal electrode. On the other hand, if the value is below the lower limit, the suppression of alkali diffusion becomes insufficient and there is a possibility that the deterioration of the electrode cannot be prevented.

  The anticorrosion layer can be formed by any method depending on the type of the compound to be used. For example, a method for producing a film or sheet, such as a melt extrusion molding method, a solution casting method, or a calendering method, constitutes the anticorrosion layer. A wet film forming method can be used in which a solution film is formed by roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, bar coating, die coating, spin coating, ink jetting, dispenser, or the like.

Further, a dry film forming method such as plasma CVD, vacuum deposition, ion plating, or sputtering may be used.
Furthermore, after the film or sheet is formed and after film formation, polymerization, crosslinking, and curing reaction may be performed by heating with a heater, infrared rays, microwaves, or the like, or irradiation with ultraviolet light and / or visible light.

[Encapsulant]
In the present invention, a sealing material may be used for the purpose of reinforcing the solar cell module or secondary sealing the above-described electrode extraction portion.
The sealing material preferably has a high strength from the viewpoint of maintaining the strength of the solar cell module. The specific strength is related to the strength of the weatherproof protective sheet and the back surface protective sheet other than the sealing material, and it is difficult to define in general, but the entire solar cell module has good bending workability and is bent. It is desirable to have a strength that does not cause partial peeling.

  Further, when the sealing material is used on the light receiving surface side of the solar cell element, 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 solar cell element, it is not always necessary to transmit visible light and may be opaque.
Furthermore, since the 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 solar cell module is used.

  The thickness of the sealing material is not particularly defined, but is usually 100 μm or more, preferably 150 μm or more, more preferably 200 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 solar cell module, and decreasing the thickness tends to increase flexibility and improve the visible light transmittance. For this reason, it is desirable to set it as the said range as a range which has both advantages.

As a material which comprises a sealing material, what used the ethylene-vinyl acetate copolymer (EVA) resin composition for the film (EVA film) etc. can be used, for example.
However, since the EVA resin cross-linking process requires a relatively long time, it may cause a reduction in the production speed and production efficiency of the solar cell module. In addition, when used for a long 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 solar cell element and reduce the power generation efficiency. Therefore, as the sealing material, a copolymer film made of a propylene / ethylene / α-olefin copolymer can be used in addition to the EVA film.

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.
About the position which provides a sealing material, it is preferable to provide so that the solar cell sealed primary may be inserted so that it may mention later.

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 a solar cell, it is preferable to have an ultraviolet blocking function because it is exposed to strong ultraviolet rays from sunlight.
As a method for imparting such a function, a layer having a function may be laminated on a sealing material by coating film formation or the like, or a material that exhibits a function is dissolved and dispersed in the sealing material. You may let them.

[Weather-resistant protective sheet]
The weather-resistant protective sheet is a sheet and film that protects the 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 a weather-resistant protective sheet, there is an advantage that a solar cell module constituent material, particularly a solar cell element, is protected and high power generation capability can be obtained without deterioration. In this invention, when secondary-sealing the electrode extraction part of a solar cell module, it seals using an above-described sealing material, and uses a light-resistant protective sheet as a weather-resistant layer which covers the surface of a sealing material. Is preferred.

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

On the other hand, when using a weatherproof protective sheet on the side opposite to the light receiving surface of the solar cell element, it is not always necessary to transmit visible light, and may be opaque.
Furthermore, since the solar cell element is often heated by receiving light, it is preferable that the weatherproof 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 solar cell element is used.

  The material which comprises a weather-resistant protective sheet is arbitrary as long as it can protect a 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 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, in the case of a solar cell, it is preferable to have an ultraviolet blocking function because it is exposed to strong ultraviolet rays from sunlight.

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 material that exhibits a function is dissolved and dispersed in the weather-resistant protective sheet. You may make it contain.
[Back protection sheet]
The back surface protective sheet is the same sheet and film as the above-described weather resistant protective sheet, and the same material as the weather resistant protective sheet can be used in the same manner except that the arrangement position is different. Moreover, if this back surface protection sheet cannot permeate | transmit water and oxygen, it is also possible to make a back surface protection sheet function as a gas barrier layer.

Moreover, since the constituent member on the back side of the solar cell element does not necessarily need to transmit visible light, a member that does not transmit visible light can be used. For this reason, the following examples are mentioned as a back surface protection sheet.
As the back surface protective sheet, various resin films and sheets having excellent strength, weather resistance, heat resistance, water resistance, and 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 Resins, poly (meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate or polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyarylphthalate resins Sheet of various resins such as silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin, etc. It is possible to use. Among these resin sheets, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), fluororesin such as tetrafluoroethylene and ethylene or propylene copolymer (ETFE), cyclic It is preferable to use a sheet of polyolefin resin, polycarbonate resin, poly (meth) acrylic resin, polyamide resin, or polyester resin. In addition, these may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

A metal material can also be used as the back surface protection sheet. For example, aluminum foil and a board, a stainless steel thin film, a steel plate, etc. are mentioned. Such a metal material is preferably subjected to corrosion prevention. In addition, as a metal used as this metal material, 1 type may be used and 2 or more types may be used together by arbitrary combinations and ratios.
Further, a composite material of resin and metal can be used. 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 vinylidene fluoride resin. (PVDF), vinyl fluoride resin (PVF) and the like. In addition, 1 type may be used for fluororesin and it may use 2 or more types together by arbitrary combinations and a ratio.

In addition, UV protection, heat ray blocking, antifouling properties, hydrophilicity, hydrophobicity, antifogging properties, abrasion resistance, electrical conductivity, antireflection, antiglare properties, light diffusion, light scattering, wavelength conversion, gas barrier You may give functions, such as sex. In particular, from the viewpoint of moisture resistance, it is preferable to provide a gas barrier layer by an inorganic oxide vapor deposition layer.
As a film thickness of a back surface protection sheet, it is 20 micrometers or more normally, Preferably it is 50 micrometers or more, More preferably, it is 100 micrometers or more. Moreover, it is 1000 micrometers or less normally, Preferably it is 500 micrometers or less, More preferably, it is 300 micrometers or less.

<Layer structure>
The layer configuration of the solar cell module of the present invention is preferably an embodiment in which a solar cell element, and if necessary, an adhesive layer and a gas barrier film are laminated in that order.
When glass, metal, or the like having gas barrier properties is used as the substrate, a gas barrier film is unnecessary on the substrate side of the solar cell element, so that the substrate / solar cell element (excluding the solar cell element substrate) / adhesion layer / It can be set as the structure of a gas barrier film. Similarly, when a gas barrier film is used as the substrate, it can be configured as glass barrier film (substrate) / solar cell element (excluding solar cell element substrate) / adhesive layer / gas barrier film.

When the substrate is a plastic film such as polyester, the structure of the substrate / gas barrier film / solar cell element (excluding the solar cell element substrate) / adhesion layer / gas barrier film, gas barrier film / adhesion layer / substrate / solar cell element (solar The battery element substrate may be excluded) / adhesive layer / gas barrier film.
A layer containing a trapping agent that absorbs at least one of moisture and oxygen is included between the solar cell element and the adhesive layer, between the adhesive layer and the gas barrier film, between the substrate and the adhesive layer, inside the substrate or inside the gas barrier film. May be.

<Method for manufacturing solar cell module>
Although there is no restriction | limiting in the manufacturing method of the solar cell module of this embodiment, The order to laminate | stack is important in this invention. Specifically, during primary sealing, a substrate, a solar cell element (excluding the solar cell element base material), an adhesive layer that covers the solar cell element, and a gas barrier film that covers the solar cell element as necessary. It is preferable to manufacture so that it may laminate in order.

Preferably, the following manufacturing procedures are mentioned.
Step 1: A solar cell element including a substrate, a power generation layer and an electrode is provided. The number of solar cells may be one, or a plurality of solar cell elements connected in series or in parallel. A first current collector is laminated on each of the electrodes on the light-receiving surface side and the non-light-receiving surface side through a conductive adhesive layer as necessary. The laminated body including the solar cell element and the current collector is primarily sealed to obtain a solar cell. In addition, this process 1 corresponds to a roll-to-roll system.
In step 1, in the case of providing an adhesive layer and a gas barrier layer at the time of primary sealing, a laminate in which one or more adhesive layers are laminated on the gas barrier film is manufactured, and the first current collector is laminated on the electrode. The solar cell element (including a pair of electrodes and a power generation layer) is a gas barrier film, an adhesive layer, and a solar cell element (so that the substrate is laminated on the light-receiving surface side) when the manufactured laminate is viewed from the non-light-receiving surface side. It is preferable to laminate in order. An adhesive layer or a gas barrier film may be further laminated on the light receiving surface side of the solar cell element.
Step 2: In the solar cell primarily sealed in Step 1, the first collector line and the second collector line are connected via a caulking member so as to be electrically connected to form an electrode extraction portion. To do. In this step 2, in addition to the first current collector and the second current collector, an embodiment in which the electrodes are simultaneously connected by the caulking member is particularly preferable.
Step 3: In the solar cell in which the first collector wire and the second collector wire are connected via the caulking member in Step 2 and the electrode extraction portion is formed, at least the electrode extraction portion is sealed. Next, sealing is performed to obtain a solar cell module.

Furthermore, as another preferable production procedure, the following method may be used in the case of laminating a layer containing the above-described scavenger during primary sealing.
A laminated body in which one or more adhesive layers are laminated on a gas barrier film is manufactured, and the solar battery element produced in step 1 has a gas barrier film, a layer containing a scavenger, The battery elements are stacked in this order (so that the substrate is stacked on the light receiving surface side).

  In the case of using a gas barrier film instead of the substrate, it can be manufactured by replacing the substrate of the above production method with a gas barrier film.

The order of the other layers is not particularly limited, but the completed solar cell module preferably has the following layer order. When the substrate side is a light receiving surface, a weathering protection sheet, a sealing material, a gas barrier film, an adhesive layer, a substrate, a solar cell element (excluding a solar cell element base material), a scavenger that absorbs at least one of moisture and oxygen Including layer, adhesive layer, gas barrier film, sealing material, back surface protective sheet; weatherproof protective sheet, sealing material, gas barrier film, adhesive layer, substrate, solar cell element (excluding solar cell element base material), moisture And a layer containing a scavenger that absorbs at least one of oxygen, an adhesive layer, a gas barrier film, a sealing material, and a back protective sheet. When the opposite side of the substrate is a light-receiving surface, a back surface protective sheet, a sealing material, a barrier film, an adhesive layer, a substrate, a solar cell element (excluding a solar cell element substrate), a trapping agent that absorbs at least one of moisture and oxygen In this order, the layer contains, an adhesive layer, a gas barrier film, a sealing material, and a weather-resistant protective sheet. A plurality of the above layers may be appropriately stacked as necessary, or may be omitted, and other functional layers may be inserted.

  The lamination method at the time of primary sealing is not particularly limited as long as the effects of the present invention are not impaired. For example, laminating with an adhesive, heat sealing by melt bonding, extrusion laminating, coextrusion molding, and wet deposition for coating film formation. Examples thereof include a film method, a laminating method using a photo-curing adhesive, a laminating method using a vacuum laminator, a laminating method using a roll laminator, and a wet film forming method using a coater. Among these, a laminating method using a photo-curing adhesive having a proven record in organic EL device sealing, a laminating method using a vacuum laminator having a proven record in solar cells, or a laminating method using a roll laminator is preferable in that general-purpose equipment can be used.

Secondary sealing is a method of sealing only a part so that the electrode extraction part is covered, and a sealing material so that all the primary sealed solar cells including the electrode extraction part are sealed. A method of using and laminating may be used.
As a method of secondary sealing only a part so as to cover the electrode extraction part, for example, a method of attaching a junction box and filling the inside with a silicone resin can be mentioned.
On the other hand, when the secondary sealing is performed by laminating the sealing material and the weathering protective film, the order of the layers is the weathering protection film as the weathering layer, the sealing material, the primary sealed solar cell, the sealing It is preferable to laminate | stack in order of a material and a weather-proof protective film. A method of laminating each layer can be a commonly used method, but it is preferable to laminate each constituent layer by thermal lamination (vacuum lamination) from the viewpoint of productivity and long-term durability.
As a procedure for integrating the solar cell module, there is a method in which a weather-resistant protective film, a sealing material, a primary-sealed solar cell, a sealing material, and a weather-resistant protective film are laminated in this order and thermally laminated. Further, any of the layers may be subjected to surface treatment such as corona treatment, plasma treatment, ozone treatment, UV irradiation, electron beam irradiation, or flame treatment.

The heat laminating conditions in the secondary sealing are not particularly limited, and heat laminating is possible under normal conditions.
The thermal lamination 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 is also improved, 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. Setting the vacuum time in the above range is preferable because the appearance of the solar cell module after heat lamination becomes good and generation of bubbles due to heat lamination conditions can be suppressed in each layer in the module.

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 conditions of the said range, since moderate adhesiveness can be acquired, without damaging a 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.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.

<Production Example 1>
(1) ITO was deposited on a 125 μm thick polyethylene terephthalate (PET) film by sputtering with 300 nm, and then silver (Ag) was deposited by vacuum deposition to a thickness of 100 nm.
(2) The sample made of PET / ITO / Ag prepared in (1) is cut into a size of 30 mm × 20 mm, and double-sided conductive tape (Sumitomo) is parallel to the short side direction at both ends in the long side direction of the sample. 3M CN4490) and a current collector (Hitachi Cable Cu-O-100-5) were attached by a rubber roller and laminated.
(3) A barrier film (VIEW-BARRIER manufactured by Mitsubishi Plastics) and an adhesive (Pomilan BB manufactured by Arakawa Chemical Co., Ltd.) were previously bonded with a roll laminator, and then created from below with a barrier film / adhesive / (2) It laminated | stacked so that it might become a laminated body / adhesive / barrier film, vacuum-laminated with the vacuum laminator (LM-30x30) by NPC, and was primarily sealed.
(4) The current collector portion was crimped using a metal fitting in which the Faston terminal and the pierce terminal were integrated, the connection current collector with a crimp terminal was joined to the Faston terminal portion, and the current collector was taken out to the outside.
(5) ETFE (manufactured by AGC 100HK-DCS) / EVA (manufactured by CI Kasei Co., Ltd.) / Stacked in the order of sample / EVA / ETFE prepared in (4), and a vacuum laminator (LM-30 × 30) manufactured by NPC Then, vacuum lamination was performed to prepare a test sample.

<Comparative Example 1>
A sample was prepared in the same manner as in Production Example 1 except that the conductive tape and the current collector used in (2) of Production Example 1 were not used.

<Comparative example 2>
A sample was produced in the same manner as in Production Example 1 except that the operation (5) of Production Example 1 was not performed.

<Durability test>
A high-temperature and high-humidity test (85 ° C., 85% RH) was conducted for a total of 50 hours using an environmental tester (a constant temperature and humidity chamber IG400 manufactured by Yamato Scientific Co., Ltd.).

<Evaluation method>
Using a digital multimeter (7461A manufactured by ADMTT), the resistance value between the two current collectors of each sample was measured by a four-terminal measurement method. The results are shown in Table 1. Moreover, about the result, the value of the result of an endurance test when the initial value of Table 1 was set to 1 was described in Table 2.

1 Solar cell element substrate (substrate)
2 Power generation layer 3 Upper electrode 4 Lower electrode 5 Conductive adhesive layer 6 First current collector 7 Adhesive layers 8 and 9 Barrier layer 10 Second current collector 11 Caulking member 12 Sealing layer 13 Weatherproof layer 14 Electrode extraction part 15 Primary sealing Stop region 16 Secondary sealed region 101 Primary sealed sample 102 Secondary sealed sample

Claims (14)

A solar cell element in which a power generation layer made of an organic semiconductor material , a base material supporting the power generation layer, and at least a pair of electrodes connected to the power generation layer on a light receiving surface side and a non-light receiving surface side of the power generation layer; ,
A solar cell module comprising a solar cell primarily sealed with a gas barrier layer, wherein at least a pair of first current collectors stacked on the electrode,
The first current collector and the second current collector fixed to the outer surface of the primary-sealed solar cell are electrically connected via a caulking member,
The caulking member and the second current collecting line form a power extraction portion for extracting the power generated in the power generation layer to the outside,
The electrode extraction part is secondary sealed,
A solar cell module characterized by that.   The solar cell module according to claim 1, wherein the solar cell has the gas barrier layer on a surface opposite to a base of the solar cell element.   The solar cell module according to claim 1 or 2, wherein the solar cell has the gas barrier layer on a surface of the solar cell element on a base material side.   The solar cell module according to any one of claims 1 to 3, wherein the primary sealed solar cell is primarily sealed by an adhesive layer and a gas barrier layer.   The adhesive layer has a thickness of 1 × 10 ^-6 m or more, 1 × 10 ^-Four The solar cell module according to claim 4, wherein the solar cell module is m or less.   The solar cell according to any one of claims 1 to 5, wherein the secondary sealing seals the entire surface of the primary sealed solar cell including the electrode extraction part. module.   7. The secondary sealing according to claim 6, wherein the secondary sealing is by thermal lamination.
Solar cell module. The electrical connection via the caulking member is performed between the electrode, the first current collector, and the second current collector , according to any one of claims 1 to 7. Solar cell module. 9. The solar cell module according to claim 1, wherein the current collector has a thickness of 10 μm or more and a width of 0.5 mm or more. The electrical connection of the electrodes and the first focusing wires, characterized by being carried out via a conductive adhesive layer, the solar cell module according to any one of claims 1-9. The crimping member is, metal rivets, pierce terminals, and characterized in that the metal rivets, staples, screws, or bolts and eyelet studs, solar cell module according to any one of claims 1-10. Said primary sealed solar cell, characterized in that it comprises a gas barrier layer on the light-receiving surface side and / or a non-light-receiving surface side of the solar cell element, the sun according to any one of claims 1 to 11 Battery module. A power generation layer made of an organic semiconductor material, a base material supporting the power generation layer, and at least a pair of electrodes connected to the power generation layer on the light-receiving surface side and the non-light-receiving surface side of the power generation layer are stacked, A current collector is further laminated to produce a laminate, a first step of producing a solar cell by primarily sealing the laminate with a gas barrier layer, a first current collector laminated on the electrode, A second step of connecting a second current collector line fixed to the outer surface of the solar cell produced in one step via a caulking member to form an electrode extraction portion in the solar cell; A method for producing a solar cell module, comprising a third step of secondarily sealing a solar cell in which an electrode extraction part is formed in the step.   The method for manufacturing a solar cell module according to claim 13, wherein a solar cell is manufactured by first sealing the laminate with an adhesive layer and a gas barrier layer.