Solar cell module

Abstract

The present invention relates to a solar cell module having: two substrates each including a conductive layer on at least one surface; and a plurality of sub-modules interposed between the conductive layers of the two substrates. The plurality of sub-modules each include a plurality of cells connected to each other by electrically connecting one of the conductive layers of the two substrates to the other by a conductive material. In addition, the two substrates each have a plurality of insulating grooves in the gaps between the plurality of sub-modules, and the plurality of insulating grooves formed in one of the two substrates and the plurality of insulating grooves formed in the other of the two substrates define at least one insulating space for preventing short circuits between adjacent sub-modules.

Description

Technical Field

[0001] The present invention relates to a solar cell module. Background Art

[0002] In recent years, as a photoelectric conversion element that converts light energy into electric energy, solar cells have attracted much attention. Among solar cells, there are dye-sensitized solar cells, organic thin-film solar cells, perovskite solar cells, and the like. These solar cells generally include a unit having the following structure, in which two electrodes supported by a substrate made of a resin film or the like sandwich a functional layer that facilitates the movement of electrons and holes. More specifically, in the case of a dye-sensitized solar cell, an electrolyte layer is provided as the functional layer. In addition, in the case of an organic thin-film solar cell or a perovskite solar cell, a donor layer and an acceptor layer are provided as the functional layer.

[0003] Moreover, a solar cell includes structural units such as a unit that is the smallest unit capable of generating an electromotive force, a sub-module formed by electrically connecting a plurality of units, and a module formed by electrically connecting a plurality of sub-modules.

[0004] As described above, in a solar cell, it is necessary to establish a plurality of electrical connections. Conventionally, various studies have been conducted on methods for efficiently manufacturing such solar cells. For example, in Patent Document 1, a solar cell module having only series wiring on a substrate and a method for manufacturing the same are proposed. According to the solar cell module and the manufacturing method disclosed in Patent Document 1, between adjacent sub-modules connected in series to each other, a welding portion is formed by welding the upper and lower film substrates to each other using ultrasonic vibration, and the welding portion functions as an insulating wire that prevents short circuits between sub-modules.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-82137 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] Here, the insulating wire disclosed in Patent Document 1 has room for further improvement. Therefore, an object of the present invention is to provide a solar cell module having a novel insulating structure between sub-modules.

[0010] Means for Solving the Problems

[0011] The object of the present invention is to effectively solve the above problems. The solar cell module of the present invention has: two substrates, each of which includes a conductive layer on at least one surface; a plurality of sub-modules, which are interposed between the conductive layers of the two substrates, and the plurality of sub-modules each include a plurality of units connected to each other by electrically connecting one of the conductive layers of the two substrates to the other by a conductive material. The two substrates each have a plurality of insulating grooves in the gaps between the plurality of sub-modules, and the plurality of insulating grooves formed in one of the two substrates and the plurality of insulating grooves formed in the other of the two substrates define at least one insulating space for preventing short circuits between adjacent sub-modules. The novel insulating structure is as follows: the two substrates each have a plurality of insulating grooves in the gaps between the plurality of sub-modules, and the insulating grooves can define at least one insulating space for preventing short circuits between adjacent sub-modules.

[0012] Here, the solar cell module of the present invention is preferably such that when the insulating groove in one of the two substrates is designated as insulating groove G1, the insulating groove in the other of the two substrates is designated as insulating groove G2, the width of the insulating groove G1 is designated as W1 (μm), the distance between the plurality of insulating grooves G1 is designated as D1 (μm), the number of the insulating grooves G1 is designated as N1 (pieces), the width of the insulating groove G2 is designated as W2 (μm), the distance between the plurality of insulating grooves G2 is designated as D2 (μm), the number of the insulating grooves G2 is designated as N2 (pieces), and the maximum size of the conductive material is designated as R (μm), the following relationships (1) to (5) are satisfied:

[0013] W1 > R and W2 > R (1);

[0014] (W1 + D1) > (W2 + D2) (2);

[0015] (W1 - D2) ≤ 2R (3);

[0016] (W1 + D1) / (W2 + D2) ≠ Z or (Z + 0.5) (where Z is an integer) (4);

[0017] N1 ≥ (A + 1) and N2 ≥ (B + 1) (where A and B are the smallest natural numbers that are independent of each other and satisfy the following relationship (α)) (5);

[0018] A × (W1 + D1) = B × (W2 + D2) (α).

[0019] If the solar cell module satisfies the above conditions, the manufacturing efficiency of the solar cell module is excellent. Here, the "maximum size" of the conductive material can be measured by the method described in the examples.

[0020] In addition, the solar cell module of the present invention preferably satisfies the following relationships (1), (6), and (7) when the insulating groove provided in one of the two substrates is defined as insulating groove G1, the insulating groove provided in the other of the two substrates is defined as insulating groove G2, the width of the insulating groove G1 is defined as W1 (μm), the distance between a plurality of the insulating grooves G1 is defined as D1 (μm), the width of the insulating groove G2 is defined as W2 (μm), the distance between a plurality of the insulating grooves G2 is defined as D2 (μm), and the maximum size of the conductive material is defined as R (μm):

[0021] W1 > R and W2 > R (1);

[0022] (W1 + D1) ≥ (W2 + D2) (6);

[0023] (W1 - D2) > 2R (7).

[0024] If the solar cell module satisfies the above conditions, the manufacturing efficiency of the solar cell module is excellent.

[0025] Advantages of the Invention

[0026] According to the present invention, a solar cell module having a novel inter-submodule insulation structure can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a top view showing a schematic structure of an example of a solar cell module according to an embodiment of the present invention.

[0028] Figure 2 is showing Figure 1 a schematic cross-sectional view taken along line I-I of the schematic structure of a submodule included in the solar cell module shown.

[0029] Figure 3 is a cross-sectional view showing the structure of an insulating space according to an embodiment of the present invention.

[0030] Figure 4 is Figure 3 a modified example of the structure shown.

[0031] Figure 5 is a cross-sectional view showing the structure of an insulating space according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. Herein, the solar cell module of the present invention is not particularly limited, and may be, for example, a solar cell module such as a dye-sensitized solar cell, an organic thin film solar cell, and a perovskite solar cell. Moreover, in the solar cell module of the present invention, a plurality of submodules formed by connecting a plurality of photoelectric conversion units (hereinafter referred to as "units") in series are included, for example, a submodule having a Z-type integrated structure. In addition, as an integrated structure of the submodule, in addition to the Z-type module, a series connection structure or a parallel connection structure such as a W-type module and a monolithic module are also exemplified, but it is not limited thereto.

[0033] (Solar cell module)

[0034] Furthermore, as an example of the present invention, the dye-sensitized solar cell module having a Z-type integrated structure is not particularly limited, and examples thereof include: Figure 1 The solar cell module 100 is shown in the top view. Figure 2 Shown in Figure 1 The submodule 101A as a component of the solar cell module 100 is shown in a cross-sectional view in the thickness direction (II cross-sectional view).

[0035] Here, in Figure 1 The solar cell module 100 shown in the top view in FIG. 1 comprises: two substrates each including a conductive layer on at least one side; and a plurality of submodules 101A and 101B interposed between the conductive layers of the two substrates. Furthermore, the plurality of submodules 101A and 101B each comprise a plurality of units connected to each other by electrically connecting one of the conductive layers of the two substrates to the other through a conductive material, and the two substrates each have a plurality of insulating grooves in the gaps between the plurality of submodules, and the plurality of insulating grooves formed in one of the two substrates and the plurality of insulating grooves formed in the other of the two substrates define at least one insulating space 120A and 120B for preventing short circuits between adjacent submodules.

[0036] More specifically, the solar cell module 100 includes two submodules 101A and 101B, two insulating spaces 120A and 120B for preventing short circuit between the two submodules 101A and 101B, and preferably includes a lead-out wiring 130. Figure 1 In the embodiment, the first substrate 1 on the front side, which corresponds to the upper surface side of the solar cell module 100, has a conductive layer ( Figure 1 The first substrate 1 and the conductive layer are transparent, and the porous semiconductor fine particle layer 22 and the catalyst layer 62 located inside the first substrate 1 can be visually confirmed.Figure 1 The drawings are omitted. Then, in Figure 1 , a conduction path P starting from the external device 200, passing through the solar cell module 100, and returning to the external device 200 again is indicated by a dashed line. As Figure 1 shown, in the solar cell module 100, a plurality of units arranged along the first direction X are connected in series with each other within the sub-modules 101A and 101B, and further, the two sub-modules 101A and 101B arranged along the second direction are connected in series with each other. It should be noted that in the illustrated example, the first direction is orthogonal to the second direction.

[0037] <Lead-out Wiring>

[0038] The lead-out wiring 130 included in the solar cell module 100 electrically connects Figure 1 the sub-module 101A shown on the upper side of Figure 1 and the sub-module 101B shown on the lower side of

[0039] <Insulation Space>

[0040] The adjacent insulation spaces 120A and 120B (hereinafter sometimes collectively referred to as "insulation space 120") are spaces provided inside the solar cell module to prevent short circuits between adjacent sub-modules 101A and 101B. Even when the conductive material that electrically connects between the units formed inside each of the sub-modules 101A and 101B exceeds the specified area of the sub-modules 101A and 101B due to manufacturing errors or the like, the insulation space 120 can prevent short circuits between the sub-modules 101A and 101B. Specifically, the space size of the insulation space 120 can accommodate at least one conductive material in a non-contact state, and the possibility of forming an electrical connection by at least one conductive material is extremely low. In addition, Figure 1 shows a case where the solar cell module 100 has two insulation spaces 120A and 120B. Of course, the number of insulation spaces that the solar cell module of the present invention can have is not limited to two. In addition, the insulation space 120 can be arranged in various ways. Details of the insulation space 120 will be described later. In this specification, for the sake of helping understanding, first, with reference to Figure 2 the detailed structure of the solar cell module 100 related to an example of the present invention will be described, and then, with reference to Figures 3 - 5 the insulation space 120 will be described in detail.

[0041] <Sub-module>

[0042] From Figure 2It can be clearly understood that the sub-module 101A is a sub-module of a dye-sensitized solar cell formed by connecting in series a plurality of (four in the illustrated example) units divided by the partition plate 8, and has a so-called Z-type integrated structure. Here, the sub-module 101A has the following structure: in a state where the partition plate 8 is interposed between the first substrate 3 and the second substrate 7, the photo-electrode 2 and the counter electrode 6 forming each unit are opposed to each other with the electrolyte layer 4 as a functional layer therebetween (i.e., a unit is formed), and the photo-electrode 2 of one unit and the counter electrode 6 of another unit are electrically connected by the conductive material 9 between adjacent units, and the first substrate 3 and the second substrate 7 are bonded together. The first substrate 3 has a first base material 1 and a plurality of (four in the illustrated example) photo-electrodes 2 as first electrodes disposed separately from each other on the first base material 1, and the second substrate 7 has a second base material 5 and a plurality of (four in the illustrated example) counter electrodes 6 as second electrodes disposed separately from each other on the second base material 5. Moreover, each unit of the sub-module 101A has a photo-electrode 2, a counter electrode 6 opposed to the photo-electrode 2, and an electrolyte layer 4 disposed between the photo-electrode 2 and the counter electrode 6. In addition, although not shown, the sub-module 101B can also have the same structure as the sub-module 101A.

[0043] Moreover, the sub-module 101A has: a counter electrode conductive layer 61 constituting the counter electrode 6; a first electrical connection portion 12A. In addition, the first electrical connection portion 12A is in contact with a conductive material (not shown), and an electrical connection with the sub-module 101B can be formed through this conductive material. Further, the sub-module 101A has: a photo-electrode conductive layer 21 constituting the photo-electrode 2; a second electrical connection portion 12B connected to the lead-out wiring 130. In the illustrated example, a structure in which these first electrical connection portions 12A and second electrical connection portions 12B are provided on different substrates is shown. However, not limited to the illustrated example, these first electrical connection portions 12A and second electrical connection portions 12B can also be provided on the same substrate by additionally providing a structure for lead wires. The structure for lead wires can be arbitrarily formed by, for example, the partition plate 8 and the conductive material 9.

[0044] <First Substrate>

[0045] Here, Figure 1 and Figure 2The first substrate 3 of the sub-module 101A shown has a first base material 1 and a plurality of photo electrodes 2 that are separately provided on the first base material 1. In addition, the photo electrode 2 has a conductive layer 21 for photo electrode provided on the first base material 1 and a part of a porous semiconductor particle layer 22 provided on the conductive layer 21 for photo electrode. Further, the conductive layer 21 for photo electrode is provided with a gap. Moreover, the adjacent photo electrodes 2 are provided in an electrically insulated manner. This insulation is not particularly limited. For example, it can be achieved by making a partition plate 8 exist in the gap between the adjacent conductive layers 21 for photo electrode.

[0046] Moreover, the first base material 1 is not particularly limited, and a known light-transmissive base material can be appropriately selected. For example, as the first base material 1, known transparent base materials such as transparent resin or glass that have transparency in the visible light region can be cited. It is particularly preferable to use a resin formed into a film shape, that is, a resin film, as the first base material 1. By using a resin film as the first base material 1, lightness and flexibility can be imparted to the sub-module 101A, and thus the solar cell module 100 including the sub-module 101A can be applied to various uses.

[0047] Examples of the transparent resin that can form the resin film include synthetic resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), polyethersulfone (PES), polyetherimide (PEI), transparent polyimide (PI), and cycloolefin polymer (COP).

[0048] Furthermore, the conductive layer 21 for photo electrode is not particularly limited, and can be formed by a conductive layer composed of a metal mesh made of Au, Ag, Cu, etc., a conductive layer formed by coating metal nanoparticles such as Ag nanoparticles, fine Ag wires, etc., a conductive layer composed of a composite metal oxide such as indium-tin oxide (ITO), indium-zinc oxide (IZO), fluorine-doped tin (FTO), etc., a carbon-based conductive layer containing carbon nanotubes, graphene, etc., or a conductive layer made of a conductive polymer such as PEDOT / PSS (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate). These materials can be appropriately selected according to compatibility with other materials. In addition, these conductive layers can be laminated in multiple layers on the base material, or the above various conductive materials capable of forming these conductive layers can be mixed to form a single conductive layer.

[0049] In addition, as a method for forming the conductive layer 21 for the photo electrode on the first substrate 1, known forming methods such as a method combining sputtering and etching, screen printing, etc. can be used.

[0050] Optionally, a primer layer (not shown) can be provided on the conductive layer 21 for the photo electrode. Here, when the electrolyte layer 4 described later is composed of a liquid, an internal short-circuit phenomenon called reverse electron transfer occurs, that is, the electrolyte reaches the conductive layer 21 for the photo electrode through the porous semiconductor particle layer 22, and electrons leak from the conductive layer 21 for the photo electrode to the electrolyte layer 4. Therefore, a reverse current unrelated to light irradiation may be generated, reducing the photoelectric conversion efficiency. Therefore, providing a primer layer on the conductive layer 21 for the photo electrode can prevent such an internal short-circuit phenomenon from occurring. Furthermore, by providing a primer layer on the conductive layer 21 for the photo electrode, the adhesion between the porous semiconductor particle layer 22 and the conductive layer 21 for the photo electrode can be improved.

[0051] The primer layer is not particularly limited as long as it is a substance that can prevent the internal short-circuit phenomenon (in other words, it is difficult for an interfacial reaction to occur). For example, it can be a layer containing materials such as titanium oxide, niobium oxide, tungsten oxide, etc. In addition, as a method for forming the primer layer, there is a method of directly sputtering the above materials onto the transparent conductive layer, or a method of applying, drying, and sintering as needed a solution in which the above materials are dissolved in a solvent, a solution in which a metal hydroxide that is a precursor of a metal oxide is dissolved, or a solution containing a metal hydroxide obtained by dissolving an organometallic compound in a water-containing mixed solvent on the conductive layer 21 for the photo electrode.

[0052] Furthermore, the porous semiconductor particle layer 22 that supports (adsorbs) the sensitizing dye is not particularly limited, and a porous semiconductor particle layer in which a porous semiconductor particle layer containing oxide semiconductor particles such as titanium oxide, zinc oxide, and tin oxide adsorbs a sensitizing dye such as an organic dye or a metal coordination dye can be used. Examples of the organic dye include cyanine dyes, merocyanine dyes, oxacyanine dyes, xanthene dyes, squaraine dyes, polymethine dyes, coumarin dyes, riboflavin dyes, perylene dyes, etc. In addition, examples of the metal coordination dye include bipyridine coordination compounds, phthalocyanine coordination compounds, or porphyrin coordination compounds of metals such as iron, copper, and ruthenium. Representative sensitizing dyes such as N3, N719, N749, D102, D131, D150, N205, HRS-1, and HRS-2 can be cited. In order to remove moisture and gas present in the solvent, it is preferable to degas and distill the organic solvent in which the sensitizing dye is dissolved in advance. As the organic solvent, alcohols such as methanol, ethanol, and propanol, nitriles such as acetonitrile, halogenated hydrocarbons, ethers, amides, esters, carbonates, ketones, hydrocarbons, aromatics, nitro methane, etc. are preferred. In addition, two or more of these solvents can be mixed and used.

[0053] In addition, as a method for forming the porous semiconductor particle layer 22 on the conductive layer 21 for the photo electrode, known forming methods such as screen printing or coating can be used. Further, as a method for adsorbing the sensitizing dye to the porous semiconductor particle layer, known methods such as immersing the porous semiconductor particle layer in a solution containing the sensitizing dye can be used.

[0054] <Second Substrate>

[0055] In addition, the second substrate 7 of the sub-module 101A has a second base material 5 and a plurality of counter electrodes 6 that are provided on the second base material 5 in a mutually separated manner. Further, the counter electrode 6 has a conductive layer 61 for the counter electrode provided on the second base material 5 and a catalyst layer 62 provided on a part of the conductive layer 61 for the counter electrode. In addition, the conductive layer 61 for the counter electrode is provided with a gap. Moreover, the catalyst layer 62 faces the porous semiconductor particle layer 22 of the photo electrode 2.

[0056] In addition, the adjacent counter electrodes 6 are provided in a mutually electrically insulated manner. This insulation is not particularly limited, and can be achieved, for example, by interposing a partition plate 8 in the gap between the adjacent counter electrodes 6.

[0057] Moreover, as the second base material 5, the same base material as the first base material 1 can be used, or a base material without transparency such as a foil or plate of titanium, SUS, or aluminum, etc., which is not corroded by other solar cell components, can be used. For the same reason as the first base material 1, it is particularly preferable to form the second base material 5 using a resin film.

[0058] In addition, as the conductive layer 61 for the counter electrode, the same conductive layer as the conductive layer 21 for the photo electrode can be used.

[0059] Furthermore, the catalyst layer 62 is not particularly limited, and any catalyst layer including components that can function as a solvent, such as a conductive polymer, a carbon nanostructure, a noble metal, and a mixture of a carbon nanostructure and a noble metal, etc., can be used.

[0060] Here, examples of the conductive polymer include polythiophenes such as poly(thiophene-2,5-diyl), poly(3-butylthiophene-2,5-diyl), poly(3-hexylthiophene-2,5-diyl), poly(2,3-dihydrothieno[3,4-b]-1,4-dioxin) (PEDOT); polyacetylene and its derivatives; polyaniline and its derivatives; polypyrrole and its derivatives; polythiophenium chloride p-xylene, poly[(2-methoxy-5-(2'-ethylhexyloxy))-1,4-phenylene vinylene], poly[(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene)], poly[[2-2',5'-bis(2''-ethylhexyloxy)phenyl]-1,4-phenylene vinylene] and other poly(phenylene vinylene) compounds, etc.

[0061] Examples of the carbon nanostructure include natural graphite, activated carbon, artificial graphite, graphene, carbon nanotubes, carbon nanobuds, etc.

[0062] There is no particular limitation on the noble metal as long as it has a catalytic effect, and well-known noble metals such as platinum metal, palladium metal, and ruthenium metal can be appropriately selected.

[0063] The method for forming the catalyst layer is not particularly limited, and a well-known method can be appropriately selected. For example, it can be carried out by coating or spraying a mixed solution obtained by dissolving or dispersing a conductive polymer, a carbon nanostructure, a noble metal, or both a carbon nanostructure and a noble metal in an appropriate solvent onto a conductive film, and drying the solvent of the mixed solution. In the case of using a carbon nanostructure and a noble metal, a binder can also be contained in the mixed solution. From the viewpoints of the dispersibility of the carbon nanostructure and the adhesion to the substrate, a polymer having functional groups such as hydroxyl, carboxyl, sulfonyl, and phosphate groups and sodium salts of these functional groups is preferably used as the binder. In addition, a known film-forming method such as screen printing, evaporation coating, or sputtering can be used to form the film.

[0064] The catalyst layer may also contain carbon nanotubes (hereinafter sometimes referred to as "specific carbon nanotubes"), and the average diameter (Av) of the carbon nanotubes and the standard deviation (σ) of the diameter satisfy 0.60 > 3σ / Av > 0.20 (hereinafter sometimes referred to as formula (A)). Here, the so-called "specific carbon nanotubes" refers to the general name of a collection of specified carbon nanotubes that make up it, and the meaning of "diameter" is the outer diameter of the specified carbon nanotubes.

[0065] The average diameter (Av) and the standard deviation (σ) of the diameter of the specific carbon nanotubes are the sample average value and the sample standard deviation, respectively. They are the average value and the standard deviation obtained when measuring the diameters of 100 randomly selected carbon nanotubes during observation using a transmission electron microscope. 3σ in formula (A) is obtained by multiplying the obtained standard deviation (σ) by 3.

[0066] By using specific carbon nanotubes, a counter electrode with excellent catalytic activity can be obtained. From the viewpoint of improving the characteristics of the obtained counter electrode, the carbon nanotubes preferably satisfy 0.60 > 3σ / Av > 0.25, and more preferably 0.60 > 3σ / Av > 0.50.

[0067] 3σ / Av represents the diameter distribution of specific carbon nanotubes. The larger this value, the wider the diameter distribution. The diameter distribution is preferably a normal distribution. In this case, the diameter distribution is obtained by measuring the diameters of 100 randomly selected carbon nanotubes that can be observed using a transmission electron microscope, and using the results to plot data with the horizontal axis as the diameter and the vertical axis as the frequency, and then performing Gaussian approximation. Although the value of 3σ / Av can also be increased by combining carbon nanotubes obtained by various different manufacturing methods, etc., it is difficult to obtain a normal distribution of the diameter distribution in this case. The specific carbon nanotubes can be composed of single carbon nanotubes, or can also be composed of a single carbon nanotube with an amount of other carbon nanotubes that does not affect its diameter distribution incorporated therein.

[0068] The specific carbon nanotubes can be obtained by a known method, for example, when synthesizing carbon nanotubes by chemical vapor deposition (CVD method) by supplying a raw material compound and a carrier gas to a substrate having a catalyst layer for manufacturing carbon nanotubes (hereinafter sometimes referred to as "CNT manufacturing catalyst layer") (hereinafter sometimes referred to as "CNT manufacturing substrate"), by making a trace amount of an oxidant present in the system, thereby significantly improving the catalytic activity of the CNT manufacturing catalyst layer (super growth method) (for example, International Publication No. 2006 / 011655). Hereinafter, the carbon nanotubes manufactured by the super growth method are sometimes referred to as SGCNT.

[0069] A counter electrode containing a catalyst layer composed of specific carbon nanotubes can be obtained, for example, by preparing a dispersion containing specific carbon nanotubes, coating the dispersion on a substrate, and drying the obtained coating film to form a catalyst layer.

[0070] <Separator>

[0071] In addition, the separator 8 of the sub-module 101A is disposed between the first substrate 3 and the second substrate 7, surrounding the electrolyte layer 4 and the conductive material 9 respectively. In other words, the space for disposing the electrolyte layer 4 and the space for the conductive material 9 are formed by partitioning with the first substrate 3, the second substrate 7, and the separator 8.

[0072] Specifically, in Figure 2 on one side in the width direction of each unit ( Figure 2On the right side (in the middle), the partition 8 is disposed between the first base material 1 of the first substrate 3 and the counter electrode conductive layer 61 of the counter electrode 6 of the second substrate 7. On the other side in the width direction of each unit ( Figure 2 On the left side (in the middle), the partition 8 is disposed between the photo electrode conductive layer 21 of the photo electrode 2 of the first substrate 3 and the second base material 5 of the second substrate 7. Further, an electrolyte layer 4 and a conductive material 9 are alternately disposed between the partitions 8.

[0073] Moreover, the substrate 8 is not particularly limited as long as it can bond the first substrate 3 and the second substrate 7 and seal the electrolyte layer 4. Preferably, the partition 8 preferably has excellent adhesiveness between substrates, resistance to electrolytes (chemical resistance), and high-temperature and high-humidity durability (moisture and heat resistance). Examples of the partition material capable of forming such a partition 8 include non-conductive thermoplastic resins, thermosetting resins, and active radiation (light, electron beam) curable resins. More specifically, (meth)acrylic resins, fluorine-based resins, silicone-based resins, olefin-based resins, and polyamide-based resins can be mentioned. In the present invention, (meth)acryloyl means "acryloyl" or "methacryloyl". From the viewpoint of operability, a photocurable acryloyl resin is particularly preferred.

[0074] In addition, from the viewpoint of ease of manufacture, it is of course possible to use a film formed by molding the above-mentioned various resins into a sheet to constitute the partition 8.

[0075] <Function layer>

[0076] In addition, the electrolyte layer 4 as a function layer of the sub-module 101A is disposed in a space surrounded by the porous semiconductor particle layer 22 of the photo electrode 2, the catalyst layer 62 of the counter electrode 6, and the partition 8. Moreover, the electrolyte layer 4 is not particularly limited, and any electrolyte, gel electrolyte, or solid electrolyte that can be used in a dye-sensitized solar cell can be used to form it.

[0077] <Conductive material>

[0078] The conductive material 9 of the sub-module 101A electrically connects the adjacent units in series. Specifically, the conductive material 9 Figure 2 electrically connects the photo electrode conductive layer 21 of the photo electrode 2 of the unit located on the right side Figure 2 to the counter electrode conductive layer 61 of the counter electrode 6 of the unit located on the left side.

[0079] Moreover, the conductive material 9 of the sub-module 101A is disposed in a space surrounded by the photo electrode conductive layer 21 of the photo electrode 2, the counter electrode conductive layer 61 of the counter electrode 6, and the two partitions 8. In addition, in Figure 2In the shown sub-module 101A, the conductive layer 21 for the photo-electrode is electrically connected to the conductive layer 61 for the counter electrode through the conductive material 9. However, in the sub-modules related to other examples, the electrical connection between the photo-electrode and the counter electrode can also be formed by the conductive material 9 and a wiring made of a conductive material such as a metal like silver or a metal oxide. In this case, the wiring can be formed on either the photo-electrode side or the counter electrode side.

[0080] There is no particular limitation on the conductive material 9. Metal particles such as Ag, Au, Cu, Al, In, Sn, Bi, Pb and their oxides, conductive carbon particles, and particles of organic compounds such as resin particles and inorganic compound particles covered with metal particles such as Ag, Au, Cu or conductive substances such as oxides of these metals on the surface can be used. For example, particles covered with an Au / Ni alloy. In addition, in this specification, the so-called "particle" means an object with an aspect ratio of 2.0 or less. Moreover, the aspect ratio of the particles of the conductive material 9 is more preferably 1.5 or less, further preferably 1.2 or less, particularly preferably 1.1 or less, and further particularly preferably 1.0 or less. In addition, the "aspect ratio" of the particles of the conductive material 9 is obtained by calculating the arithmetic mean of the major axis length and the minor axis length values obtained by observing 100 particles with a microscope for calculation, and calculating the value of (arithmetic mean major axis length / arithmetic mean minor axis length). If the aspect ratio is below the above upper limit value and further 1.0, the manufacturing efficiency of the solar cell module can be further improved.

[0081] In addition, the representative shape of the conductive material 9 is preferably spherical shapes such as oblate spherical and regular spherical. Particularly preferably, it is a regular spherical or an oblate spherical infinitely close to a regular sphere. This is because the manufacturing efficiency of the solar cell module can be further improved.

[0082] The maximum size of the conductive material 9 corresponds to the arithmetic mean major axis length of the conductive material 9 calculated in the above manner. Moreover, the maximum size R of the conductive material 9 is preferably 0.5 μm or more and 30 μm or less. If the maximum size R of the conductive material 9 is above the above lower limit value, the situation where the photo-electrode and the counter electrode are easily short-circuited in the sub-module can be effectively suppressed. In addition, if the maximum size R of the conductive material 9 is below the above upper limit value, the photoelectric conversion efficiency of the solar cell module can be improved.

[0083] In addition, the conductive material 9 is not particularly limited. It is preferably a conductive resin composition containing a resin and conductive particles, and is disposed in the specified space within the sub-module 101A. The resin that can be included in this conductive resin composition is not particularly limited, and examples thereof include: (meth)acrylic resins; epoxy resins such as bisphenol type epoxy resins, novolak type epoxy resins, cyclic epoxy resins, and alicyclic epoxy resins; silicone resins, etc. For this resin, any curing agent such as a radical initiator, cationic curing agent, or anionic curing agent can be used, and the polymerization form is not limited to addition polymerization, ring-opening polymerization, etc. In addition, the resin used as the separator material and the resin that can be used in combination when applying the conductive material 9 can be the same or different. Furthermore, the content ratio of the conductive particles in the conductive resin composition that can be used when applying the conductive material 9 is preferably 0.1% by volume or more and 90% by volume or less.

[0084] In addition, the method of disposing the conductive material 9 at a specified position within the sub-module 101A using the composition as described above is not particularly limited, and examples thereof include a method including the following steps: For example, an uncured composition containing the conductive material 9 and a resin is filled into the position where the conductive material 9 is to be disposed (for example, the space surrounded by the separator 8), and the filled uncured composition is cured.

[0085] <Electrical connection portion>

[0086] The first electrical connection portion 12A serially connects the conductive layer 61 for the counter electrode of the sub-module 101A and the conductive layer 21 for the optical electrode of the sub-module 101B ( Figure 2 not shown in the figure) through a structure for leads (not shown). The structure for leads can be arbitrarily formed by, for example, the separator 8 and the conductive material 9. The second electrical connection portion 12B connects the lead-out wiring 130 and the conductive layer 21 for the optical electrode. The first electrical connection portion 12A and the second electrical connection portion 12B are not particularly limited and can be formed of general electrical connection materials such as conductive resin compositions and solders. Moreover, as the conductive resin composition, a known composition containing a conductive material such as a metal, metal oxide, or conductive carbon material and an arbitrary resin can be used. In addition, as the solder, a solder containing tin, silver, copper, bismuth, lead, a flux component, etc. can be used.

[0087] <Arrangement of insulating grooves>

[0088] Here, regarding Figure 1 the insulating space 120 in the arrangement method related to an example illustrated, a detailed structure example thereof will be described with reference to Figure 3 ... Figure 3 is along Figure 1The cross-sectional view along the II-II section line shown is used to illustrate an example of the structure of the insulating space. Figure 2 The reference numerals of the components of the submodule 101B are marked with "A" to indicate that, for the components of the submodule 101B, Figure 2 The reference numerals of the structural parts are marked with "B". Figure 3 The conductive layer 21A for photoelectrodes, the conductive material 9A, and the conductive layer 61A for opposing electrodes shown ensure the series connection between the units in the submodule 101A, and the conductive layer 21B for photoelectrodes, the conductive material 9B, and the conductive layer 61B for opposing electrodes ensure the series connection between the units in the submodule 101B. Moreover, in the area corresponding to the gap between the submodules 101A and 101B on the first substrate 1, a plurality of areas lacking the conductive layer 21 for photoelectrodes, namely, the first insulating grooves G1, are provided. In addition, in the area corresponding to the gap between the submodules 101A and 101B on the second substrate 5, a plurality of areas lacking the conductive layer 61 for opposing electrodes, namely, the second insulating grooves G2, are provided. In other words, the conductive layer 21 for photoelectrodes is discontinuous through the first insulating grooves G1. In addition, the conductive layer 61 for opposing electrodes is discontinuous through the second insulating grooves G2.

[0089] The insulating spaces 120A and 120B are large enough to accommodate the conductive material 9C in a non-contact state. Therefore, the insulating spaces 120A and 120B can create a non-contact state between the conductive material 9C and at least one of the photoelectrode conductive layer 21 and the counter electrode conductive layer 61. Therefore, since the conductive material 9C is not electrically connected, the adjacent submodules 101A and 101B are as shown in FIG. Figure 1 As described above, the conduction is conducted at a position other than the conduction path P between the submodules, so that a short circuit between the submodules 101A and 101B can be prevented. In addition, the conductive material 9C contained in the insulating space 120A and the insulating space 120B, respectively, has the same material and properties as the conductive material 9A and the conductive material 9B. In addition, the conductive material 9D arranged in the region extending between the insulating space 120A and the insulating space 120B can be in contact with both the photoelectrode conductive layer 21 and the counter electrode conductive layer 61. However, even in such a case, the insulation between the adjacent submodules 101A and 101B can be ensured through the first insulating groove G1 and the second insulating groove G2, and then through the insulating spaces 120A and 120B.

[0090] Figure 3The insulating spaces 120A and 120B of the structure involved in the example shown are preferably divided by a plurality of first insulating grooves G1 and a plurality of second insulating grooves G2 arranged in a manner that satisfies the following conditions. That is, it is preferable to arrange the plurality of first insulating grooves G1 and the plurality of second insulating grooves G2 in the following manner: when the width of the first insulating groove G1 is set to W1 (μm), the distance between the first insulating grooves G1 is set to D1 (μm), the number of the first insulating grooves G1 is set to N1 (pieces), the width of the second insulating groove G2 is set to W2 (μm), the distance between the second insulating grooves G2 is set to D2 (μm), the number of the second insulating grooves G2 is set to N2 (pieces), and the maximum size of the conductive materials 9A, 9B, and 9C is set to R (μm), the relationships of the following conditions (1) to (5) are satisfied:

[0091] W1 > R and W2 > R (1);

[0092] (W1 + D1) > (W2 + D2) (2);

[0093] (W1 - D2) ≤ 2R (3);

[0094] (W1 + D1) / (W2 + D2) ≠ Z or (Z + 0.5) (where Z is an integer) (4);

[0095] N1 ≥ (A + 1) and N2 ≥ (B + 1) (where A and B are the smallest natural numbers that are independent of each other and satisfy the following relationship (α)) (5);

[0096] A × (W1 + D1) = B × (W2 + D2) (α).

[0097] In addition, in the present example described with reference to Figure 3 it is shown that: in Figure 3 the upper substrate serves as the first substrate 1, the lower substrate serves as the second substrate 5, the first insulating groove G1 serves as the first substrate 1 side, and the second insulating groove G2 serves as the second substrate 5 side. However, it is not limited to the illustrated example, and of course, the first insulating groove G1 can be provided on the second substrate 5 side and the second insulating groove G2 can be provided on the first substrate 1 side respectively.

[0098] In Figure 4 an example is shown where: the first substrate 1 having a plurality of first insulating grooves G1 and the second substrate 5 having a plurality of second insulating grooves G2 arranged in the same configuration have a relative position different from that Figure 3 shown. Figure 3 The deviation in the configuration as Figure 4 shown is caused by manufacturing errors during the manufacture of the solar cell module. As Figure 4As shown, even if the relative position relationship between the first substrate 1 and the second substrate 5 is Figure 3 In different ways, the insulating space 120C can also be created. Figure 4 In the manner shown, the insulation between the adjacent submodules 101A and 101B can also be ensured. Figures 3 - 4 The solar cell module of the structure shown can create an insulating space with high accuracy even when a manufacturing error occurs during manufacturing, resulting in a deviation in the bonding of the upper and lower substrates. Figures 3 - 4 The solar cell module having the structure shown has a high yield rate during manufacturing and is excellent in manufacturing efficiency.

[0099] Figure 5 Another example of an insulating space structure is shown. Figure 5 In terms of performance and Figures 3 - 4 The structures shown include various structural parts with the same functions as the various structural parts, and the markings are the same as those of the Figures 3 - 4 The same reference numerals are used to denote the components, and description thereof will be omitted. Figure 5 The structure shown includes insulating spaces 120D, 120E. Figure 5 The structure shown does not satisfy all of the above relationships (1) to (5). Figure 5 In the structure shown, the value of (W1+D1) is equal to the value of (W2+D2), and W1 is much larger than D2. Therefore, the above relationships (2) to (4) are not satisfied.

[0100] Figure 5 The results shown at least satisfy the following relationships (1), (6), and (7):

[0101] W1>R and W2>R (1);

[0102] (W1+D1)≥(W2+D2) (6);

[0103] (W1-D2)>2R (7).

[0104] By configuring the first insulating groove G1 and the second insulating groove G2 so as to satisfy the above-mentioned relationships (1), (6), and (7), it is possible to ensure good insulating space. Figure 5 Even when the first substrate 1 having a plurality of first insulating grooves G1 and the second substrate 5 having a plurality of second insulating grooves G2 are arranged in an offset manner, at least one insulating space can be ensured. Therefore, a solar cell module having such a structure has a high yield rate during manufacturing and excellent manufacturing efficiency.

[0105] Here, the width W1 of the first insulating groove G1 and the width W2 of the second insulating groove G2 are preferably 10 times or less, more preferably 8 times or less, and still more preferably 5 times or less of the maximum dimension R of the conductive materials 9A, 9B, and 9C. If the widths W1 and W2 are below the above upper limit values, it is not easy to see the insulating grooves from the outside of the solar cell module, so the appearance and transparency of the solar cell module can be further improved. In addition, it is more preferable that the widths W1 and W2 are greater than the maximum dimension R of the conductive materials 9A, 9B, and 9C and are 1.3 times or more of the maximum dimension R. If the widths W1 and W2 are above the above lower limit values, an insulating space with excellent insulating performance can be defined by the insulating grooves. In addition, when the number of insulating grooves provided on the two substrates is different, it is preferable that the number of insulating grooves provided on the substrate on the photo-electrode side is less than the number of insulating grooves provided on the substrate on the counter-electrode side. In the state where the solar cell module is installed, most observers visually observe the solar cell module from the photo-electrode side. If the number of insulating grooves formed on the photo-electrode side is smaller, the possibility that the observer clearly observes the insulating grooves is low, and the appearance of the solar cell module is good.

[0106] In addition, the depth of the first insulating groove G1 is not particularly limited as long as the depth of the deepest part of the groove is equal to or greater than the thickness of the photo-electrode conductive layer 21. In other words, the first insulating groove G1 only needs to make the photo-electrode conductive layer 21 include a discontinuous region in the sub-module arrangement direction ( Figure 1 the second direction Y shown). The same applies to the second insulating groove G2, as long as the depth of the deepest part of the groove is equal to or greater than the thickness of the counter-electrode conductive layer 61. In other words, the second insulating groove G2 only needs to make the counter-electrode conductive layer 61 include a discontinuous region in the sub-module arrangement direction ( Figure 1 the second direction Y shown). Furthermore, it is more preferable that the photo-electrode conductive layer 21 is entirely discontinuous within the first insulating groove G1, and the counter-electrode conductive layer 61 is entirely discontinuous within the second insulating groove G2.

[0107] Referring to the above Figures 3 - 5The structures of several insulating spaces are described. Like the various structures mentioned above, an insulating space is created by combining a plurality of insulating grooves respectively provided on the upper and lower substrates, and the insulation between sub-modules can be ensured without compromising the transparency of the solar cell module. Here, in the applications related to an example of a solar cell module, good appearance is sometimes pursued. However, since the refractive index of the part with the conductive layer for the photo electrode or the counter electrode on the substrate is different from that of the part without it, if the conductive layer for the photo electrode or the counter electrode is removed over a large area, in other words, if the width of the insulating groove is made too large, the good appearance and transparency of the solar cell module will be impaired. Therefore, like the present invention, by arranging a plurality of insulating grooves on the upper and lower substrates respectively, the insulation between sub-modules can be ensured without compromising the good appearance and transparency of the solar cell module.

[0108] (Method for manufacturing a solar cell module)

[0109] The sub-module having the above structure is not particularly limited and can be manufactured according to, for example, the following manufacturing method. This manufacturing method is a method for manufacturing a solar cell module, and the solar cell module has: two substrates, each of which includes a conductive layer on at least one surface; a plurality of sub-modules, which are interposed between the conductive layers on the two substrates, are formed by connecting a plurality of units arranged along a first direction in series, and are arranged along a second direction.

[0110] Specifically, the manufacturing method related to an example preferably includes:

[0111] · Insulating groove forming step (1): Prepare two substrates each including a conductive layer on at least one surface, and form a plurality of insulating grooves along the first direction on the side surfaces of the conductive layers of the two prepared substrates respectively, so as to obtain a first substrate with insulating grooves and a second substrate with insulating grooves;

[0112] · Electrode forming step (2): Form a plurality of first electrodes as the first substrate on the side surface of the conductive layer of the first substrate with insulating grooves, and form a plurality of second electrodes as the second substrate on the side surface of the conductive layer of the second substrate with insulating grooves;

[0113] · Conductive material arranging step (3): Arrange a conductive material for connecting adjacent units in series on at least one of the side surfaces of the conductive layers of the first substrate and the second substrate in the first direction;

[0114] · Laminating step (4): A first substrate (hereinafter simply referred to as "the first substrate with insulating grooves") including a first base material with insulating grooves obtained up to the above step (3) and a second substrate (hereinafter simply referred to as "the second substrate with insulating grooves") including a second base material with insulating grooves are laminated with the first electrode and the second electrode facing each other to obtain a laminate.

[0115] Moreover, in the above manufacturing method, in the laminating step (4), by arranging a plurality of insulating grooves of the first substrate and a plurality of insulating grooves of the second substrate opposite to each other in the gaps between adjacent sub-modules, at least one insulating space for preventing short circuits between adjacent sub-modules can be defined. In the above manufacturing method, the insulating groove forming step (1) is carried out at a stage before the laminating step (4) is implemented. Therefore, for example, when manufacturing a dye-sensitized solar cell module as a solar cell module, the insulating groove forming step (1) can be carried out at a stage before the dye is loaded on the photoanode. Thereby, the possibility of deterioration of the dye, which is an important structural element contributing to power generation, due to the heat generated in the insulating groove forming step (1) can be eliminated.

[0116] Hereinafter, regarding each of the steps (1) to (4) included in the manufacturing method related to the above example, with reference to Figures 1 - 2 ..., taking the case of manufacturing a dye-sensitized solar cell module having the same structure as the solar cell module 100 described above as an example, a detailed description will be given.

[0117] (1) Insulating groove forming step

[0118] In the insulating groove forming step, first, two base materials each including a conductive layer on at least one surface are prepared. There are no particular limitations on the base material and the conductive layer, and the first base material, the second base material, the conductive layer for photoanode, and the conductive layer for counter electrode respectively described in the <First Substrate> and <Second Substrate> items can be appropriately used. Then, a plurality of insulating grooves with the long side direction along the first direction are formed on the side surface of the conductive layer for photoanode of the first base material and the side surface of the conductive layer for counter electrode of the second base material respectively, to obtain a first base material with insulating grooves and a second base material with insulating grooves. There are no particular limitations on the method for forming the insulating grooves, and for example, laser processing, grooving by a tool, etc. can be cited. Regarding the arrangement mode of the insulating grooves, the arrangement mode detailed in the <Arrangement of Insulating Grooves> item can be appropriately used.

[0119] (2) Electrode forming step

[0120] The electrode forming step can be appropriately carried out according to the methods described in the <First Substrate> and <Second Substrate> items.

[0121] (3) Conductive material arranging step

[0122] The conductive material arranging step can be appropriately carried out according to the scheme described in the <Conductive Material> item. Specifically, as the conductive material is arranged, the region where the conductive material is arranged can be surrounded by a partition for preventing short circuits between adjacent cells.

[0123] (4) Laminating step

[0124] In the laminating step, a first substrate with an insulating groove and a second substrate with an insulating groove are laminated with the first electrode and the second electrode facing each other to obtain a laminate. In the laminate, a plurality of cells arranged in the first direction are electrically connected in series with each other.

[0125] By the manufacturing method according to an example described above, the solar cell module of the present invention can be manufactured well. Moreover, since this manufacturing method includes step (1), a solar cell module with excellent insulation reliability can be manufactured with high manufacturing efficiency.

[0126] [Examples]

[0127] Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In addition, in the following description, unless otherwise specified, "%" indicating a quantity is based on mass.

[0128] In the examples and reference examples, a dye-sensitized solar cell module composed of two sub-modules arranged in the second direction was manufactured. The two sub-modules were each formed by six cells connected in series with each other in the first direction, and the two sub-modules were connected in series with each other. It should be noted that the first direction is orthogonal to the second direction.

[0129] The size and shape of the conductive material used in the examples and reference examples were measured as follows. In addition, in the examples and reference examples, the manufacturing efficiency (manufacturing yield) of the solar cell module was calculated as follows. In addition, the appearance evaluation of the obtained solar cell module was carried out as follows.

[0130] <Size and shape of the conductive material>

[0131] For the conductive material used in the examples and reference examples, for 100 conductive materials, 100 conductive materials were observed using a scanning electron microscope. The shape of the conductive material was spherical. Then, for 100 conductive materials, the major axis length and the minor axis length were measured respectively, and the arithmetic mean value was obtained. The arithmetic mean major axis length value was divided by the arithmetic mean minor axis length to calculate the aspect ratio of the conductive material. Further, the arithmetic mean major axis length value was used as the "maximum size" of the conductive material.

[0132] In addition, the value of the arithmetic mean major axis length and the value of the arithmetic mean minor axis length of the conductive material used in all the examples and comparative examples are substantially the same, and the aspect ratio is 1.0.

[0133] <Manufacturing efficiency (manufacturing yield) of solar cell module>

[0134] Twenty solar cell modules with positional deviation occurring in the lamination process were selected from the solar cell modules manufactured in each example as the overall population for the manufacturing yield test. Then, for the 20 solar cell modules included in the overall population, under the condition of 1 sun illuminance, the voltage value of the extraction electrode was measured with a SourceMeter and compared with the theoretical value to determine whether there was a voltage drop of more than one unit. When there was no voltage drop, or even if there was a voltage drop, it was less than one unit, it was determined that the insulation was ensured in the solar cell module, and the proportion (%) of the number of solar cell modules in which the insulation was ensured among the 20 solar cell modules was calculated.

[0135] <Appearance evaluation of solar cell module>

[0136] Twenty solar cell modules manufactured in each of the examples and reference examples were visually observed. For the state of the insulating groove visually observed, the appearance evaluation was carried out according to the following criteria.

[0137] A: The insulating groove is not easily observable.

[0138] B: The insulating groove is slightly not easily visually observable.

[0139] (Example 1)

[0140] <Preparation of dye solution>

[0141] 72 mg of a ruthenium coordination compound dye (N719, manufactured by SOLARONIX) was placed in a 200 mL volumetric flask. 190 mL of dehydrated ethanol was mixed and stirred. After closing the volumetric flask, it was stirred for 60 minutes by the vibration of an ultrasonic cleaner. After keeping the solution at room temperature, dehydrated ethanol was added to make the total volume 200 mL, thereby preparing a dye solution.

[0142] <Fabrication of photoanode substrate>

[0143] On a transparent conductive substrate (thin film resistance: 13 ohm / sq) obtained by coating a transparent conductive layer (indium tin oxide (ITO)), which serves as a conductive layer for a photo electrode, on a transparent substrate (polyethylene naphthalate film, thickness: 200 μm) serving as a substrate for a photo electrode, a conductive silver paste (K3105, manufactured by Pelnox Co., Ltd.) is printed and coated at a specified position by a screen printing method, and then heated and dried in a hot air circulation oven at 150 °C for 15 minutes to fabricate an electrical connection portion. The transparent conductive substrate having the obtained electrical connection portion is placed on a coater with the surface on which the electrical connection portion is formed facing upward, and an ORGATIX PC-600 solution (manufactured by Matsumoto Fine Chemical Co., Ltd.) diluted to 1.6% is coated by a wire bar at a scanning speed of 10 mm / sec. After the obtained coating film is dried at room temperature for 10 minutes, it is further heated and dried at 150 °C for 10 minutes to fabricate a bottom coating layer on the transparent conductive substrate.

[0144] Laser processing is performed on the surface of the transparent conductive substrate where the bottom coating layer is formed at intervals corresponding to the width of the photo electrode unit to create a region where the conductive layer for the photo electrode does not exist in the gap between adjacent units, thereby forming an insulating line. Further, through laser processing, an insulating groove G1 is formed in such a manner that it is arranged in a configuration satisfying the conditions shown in Table 1 in the sub-module gap (insulating groove forming process).

[0145] Then, a mask sheet is obtained by overlapping two layers of a protective film coated with an adhesive layer on a polyester film (lower layer: PC-542PA manufactured by Fujimori Kogyo Co., Ltd.; upper layer: NBO-0424 manufactured by Fujimori Kogyo Co., Ltd.), and an opening (length: 60 mm, width: 5 mm) for forming a porous semiconductor particle layer is punched out in the mask sheet. In order to prevent air bubbles from entering, the processed mask sheet is attached to the surface of the transparent conductive substrate where the bottom coating layer is formed for collecting current. In addition, the purpose of the first layer of the mask sheet is to prevent dyes from adhering to unnecessary positions, and the purpose of the second layer is to prevent porous semiconductor particles from adhering to unnecessary positions.

[0146] A high-pressure mercury lamp (rated lamp power: 400 W) light source is placed at a position 10 cm away from the mask attachment surface, and after irradiating electromagnetic waves for 1 minute, anatase titanium oxide slurry (PECC-C01-06, manufactured by Peccell Technologies Co., Ltd.) is immediately coated using a Baker-type spreader. After the slurry is dried at room temperature for 10 minutes, the protective film (NBO-0424 manufactured by Fujimori Kogyo Co., Ltd.) on the upper side of the mask sheet is peeled off and removed, and it is further heated and dried at 150 °C for 5 minutes using a hot air circulation oven to form a porous semiconductor particle layer (length: 60 mm, width: 5 mm).

[0147] Then, the transparent conductive substrate formed with the porous semiconductor particle layer (length 60mm, width 5mm) was immersed in the prepared dye solution (40°C), and the dye was adsorbed while being gently stirred. After 90 minutes, the titanium oxide film adsorbed with the dye was taken out from the dye adsorption container, washed with ethanol and dried, and the remaining mask was peeled off to produce a photoelectrode.

[0148] <Fabrication of Counter Electrode Substrate>

[0149] A transparent conductive layer (indium tin oxide (ITO)) as a conductive layer for a counter electrode is coated on a transparent substrate (polyethylene naphthalate film, thickness 200 μm) as a substrate for a counter electrode to obtain a transparent conductive substrate (thin film resistance 13 ohm / sq), and laser processing is performed on the conductive surface of the transparent conductive substrate at intervals corresponding to the width of the platinum film pattern to form insulating lines. Furthermore, by laser processing, an insulating groove G2 is formed in the sub-module gap in a configuration method that satisfies the conditions shown in Table 1 (insulating groove forming process). Next, a metal mask with an opening (length 60 mm, width 5 mm) punched out is overlapped, and six platinum film patterns (catalyst layers) are formed by sputtering to obtain a counter electrode substrate with a light transmittance of about 72% in the catalyst layer forming portion. At this time, a structure is formed in which the porous semiconductor particle layer and the catalyst layer are consistent when the conductive surfaces of the above-mentioned photoelectrode substrate and the counter electrode substrate are overlapped facing each other.

[0150] <Production of dye-sensitized solar cell modules>

[0151] Micropearl AU (representative shape: true sphere, maximum size: 20 μm, aspect ratio: 1.0) manufactured by Sekisui Jushi Co., Ltd. was added to acrylic resin TB3035B as a resin material of the conductive resin composition to 13.5 mass %, and the mixture was uniformly mixed in a rotation and revolution mixer to prepare a conductive resin composition.

[0152] The catalyst layer forming surface of the opposing electrode substrate was fixed to an aluminum adsorption plate using a vacuum pump. Then, a conductive resin composition was applied in a line shape to a predetermined position between the catalyst layers by a dispensing device, and a liquid ultraviolet curing sealant TB3035B (manufactured by ThreeBond, absorption wavelength: 200nm to 420nm) as a separator material was applied to the outer peripheral portion of the catalyst layer sandwiching the line.

[0153] Then, a prescribed amount of electrolytic solution is applied to the catalyst layer portion, and in a reduced-pressure environment, the rectangular catalyst layer and the porous semiconductor particle layer having the same shape are superposed in such a manner that they face each other using an automatic laminating device, and light is irradiated from the photo-electrode substrate side by a metal halide lamp, and then light is irradiated from the counter-electrode substrate side (laminating step).

[0154] According to the above description, the manufacturing efficiency of the obtained solar cell module was calculated and the appearance was evaluated. The results are shown in Table 1.

[0155] (Examples 2 to Comparative Example 5)

[0156] A solar cell module was manufactured in the same manner as in Example 1, except that the insulating grooves G1 and G2 formed in the insulating groove forming step satisfied the conditions shown in Table 1. Then, in the same manner as in Example 1, the manufacturing efficiency was calculated and the appearance was evaluated. The results are shown in Table 1.

[0157] In Table 1, the conditions (1) to (7) are as follows:

[0158] W1 > R and W2 > R (1);

[0159] (W1 + D1) > (W2 + D2) (2);

[0160] (W1 - D2) ≤ 2R (3);

[0161] (W1 + D1) / (W2 + D2) ≠ Z or (Z + 0.5) (where Z is an integer) (4);

[0162] N1 ≥ (A + 1) and N2 ≥ (B + 1) (where A and B are the smallest natural numbers that are independent of each other and satisfy the following relationship (α)) (5);

[0163] A × (W1 + D1) = B × (W2 + D2) (α);

[0164] (W1 + D1) ≥ (W2 + D2) (6);

[0165] (W1 - D2) > 2R (7).

[0166] Moreover, in the above conditions (1) to (7), it is preferable to satisfy the following two condition combinations. When at least one of the following two condition combinations is satisfied, even if a lamination deviation occurs in the manufacturing process, insulation can be ensured with a high probability. Therefore, in the solar cell module that satisfies Combination 1 or Combination 2, the production yield of products with good insulation is high and the manufacturing efficiency is excellent.

[0167] Condition Combination 1 (Combination 1): (1) to (5)

[0168] Condition combination 2 (Combination 1): (1), (6), (7)

[0169] [Table 1]

[0170]

[0171] From Examples 1 to 4 and Comparative Examples 1 to 5 in Table 1, it can be seen that according to the present invention, a solar cell module having a novel inter-sub-module insulation structure can be provided. Further, from Table 1, it can be seen that in Examples 1 to 4, even in the case of bonding deviation occurring in the manufacturing process, a solar cell module capable of ensuring insulation can be efficiently manufactured.

[0172] Industrial applicability

[0173] According to the present invention, a solar cell module having a novel inter-sub-module insulation structure can be provided.

[0174] Explanation of reference numerals

[0175] 1: First substrate;

[0176] 2: Photoelectrode;

[0177] 3: First substrate;

[0178] 4: Electrolyte layer;

[0179] 5: Second substrate;

[0180] 6: Counter electrode;

[0181] 7: Second substrate;

[0182] 8: Partition;

[0183] 9, 9A - D: Conductive material;

[0184] 12A: First electrical connection portion;

[0185] 12B: Second electrical connection portion;

[0186] 21, 21A - B: Conductive layer for photoelectrode;

[0187] 22: Porous semiconductor particle layer;

[0188] 61, 61A - B: Conductive layer for counter electrode;

[0189] 62: Catalyst layer;

[0190] 100: Solar cell module;

[0191] 101A - B: Sub-module;

[0192] 120A~E: Insulation space;

[0193] 200: External device;

[0194] D1, D2: Distance;

[0195] G1, G2: Grooves for insulation;

[0196] P: Conductive path;

[0197] R: Maximum size;

[0198] W1, W2: Width

[0199] X: First direction;

[0200] Y: Second direction.

Claims

1. A solar cell module, comprising: Two substrates, each of which includes a conductive layer on at least one surface; and A plurality of sub-modules, which are interposed between the conductive layers of the two substrates, The plurality of sub-modules each include a plurality of photoelectric conversion units that are electrically connected to each other by electrically connecting one of the conductive layers of the two substrates to the other by a conductive material, the plurality of photoelectric conversion units are arranged along a first direction, and the plurality of sub-modules are arranged along a second direction orthogonal to the first direction, The two substrates each have a plurality of insulating grooves in the gaps between the plurality of sub-modules, The plurality of insulating grooves formed in one of the two substrates and the plurality of insulating grooves formed in the other of the two substrates define at least one insulating space for preventing short circuits between adjacent sub-modules, The shape of the conductive material is spherical, and its maximum size is 0.5 μm or more and 30 μm or less, and the space size of the insulating space can accommodate the conductive material and keep the conductive material non-contact with at least one of the conductive layers.

2. The solar cell module according to claim 1, wherein, When the insulating groove in one of the two substrates is set as insulating groove G1, the insulating groove in the other of the two substrates is set as insulating groove G2, the width of the insulating groove G1 is set as W1 μm, the distance between the plurality of insulating grooves G1 is set as D1 μm, the number of the insulating grooves G1 is set as N1, the width of the insulating groove G2 is set as W2 μm, the distance between the plurality of insulating grooves G2 is set as D2 μm, the number of the insulating grooves G2 is set as N2, and the maximum size of the conductive material is set as R μm, the following relationships (1) to (5) are satisfied: W1 > R and W2 > R (1); (W1 + D1) > (W2 + D2) (2); (W1 - D2) ≤ 2R (3); (W1 + D1) / (W2 + D2) ≠ Z or (Z + 0.5), where Z is an integer (4); N1 ≥ (A + 1) and N2 ≥ (B + 1), where A and B are the smallest natural numbers that are independent of each other and satisfy the following relationship (α) (5); A × (W1 + D1) = B × (W2 + D2) (α).

3. The solar cell module according to claim 1, wherein, When the insulating groove in one of the two substrates is set as insulating groove G1, the insulating groove in the other of the two substrates is set as insulating groove G2, the width of the insulating groove G1 is set as W1 μm, the distance between the plurality of insulating grooves G1 is set as D1 μm, the width of the insulating groove G2 is set as W2 μm, the distance between the plurality of insulating grooves G2 is set as D2 μm, and the maximum size of the conductive material is set as R μm, the following relationships (1), (6), and (7) are satisfied: W1 > R and W2 > R (1); (W1 + D1) ≥ (W2 + D2) (6); (W1 - D2) > 2R (7).

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