Photovoltaic power generation sheet and installation structure for photovoltaic power generation sheet

Abstract

To provide an installation structure for a photovoltaic power generation sheet that can reduce an influence of thermal expansion and contraction after installation, and the photovoltaic power generation sheet.SOLUTION: An installation structure 11 comprises a photovoltaic power generation sheet 1, an installation surface 12, and an adhesion layer 13 interposed between one principal surface of the photovoltaic power generation sheet 1 and the installation surface 12 to bond a part of the photovoltaic power generation sheet 1 to the installation surface 12. The principal surface of the photovoltaic power generation sheet 1 includes a plurality of first regions 7 on which a plurality of power generation parts 3 are projected and at least one second region 8 between two adjacent first regions 7. The adhesion layer 13 is interposed between the principal surface and installation surface 12 to bond at least the first region 7 to the installation surface 12, and a non-adhesion space 14 which does not bond at least a part of a second region 8 to the installation surface 12 is present between the principal surface and installation surface 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a photovoltaic sheet having a plurality of power generation sections, and an installation structure for the photovoltaic sheet in which a photovoltaic sheet having a plurality of power generation sections is installed on an installation surface. [Background technology]

[0002] As a photovoltaic power generation device, for example, rigid solar cell modules that use monocrystalline silicon or polycrystalline silicon for the solar cell are known, and in recent years, flexible photovoltaic sheets have become popular. Due to their inherent flexibility, photovoltaic sheets can be installed directly on the mounting surface without using a stand, and can be installed not only on flat roofs and walls, but also on curved roofs such as tents and domes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-135914 A Summary of the Invention [Problem to be solved by the invention]

[0004] When installing a photovoltaic sheet on a mounting surface, a method is used in which the photovoltaic sheet is adhered to the mounting surface using an adhesive. Specifically, a method is used in which the entire photovoltaic sheet is adhered to the mounting surface using an adhesive.

[0005] After the photovoltaic sheet is installed on the installation surface, when the temperature rises due to the influence of sunlight or drops in winter, the photovoltaic sheet and the installation surface undergo thermal expansion and contraction due to temperature changes. Here, a difference in the amount of thermal expansion occurs between the photovoltaic sheet and the installation surface due to the difference in the linear expansion coefficient. When the entire photovoltaic sheet is attached to the installation surface with an adhesive, a shear stress occurs between the two based on the difference in the amount of thermal expansion and contraction described above. Then, due to this shear stress, parts of the photovoltaic sheet peel off from the installation surface in places, and the photovoltaic sheet bends at the peeled parts, and if the bending occurs near the power generation section, the power generation section may be damaged. In addition, when the photovoltaic sheet bends, unevenness occurs at the bent parts, and if dirt accumulates on the unevenness, the dirt may suppress the incidence of sunlight on the photovoltaic sheet, thereby reducing the power generation efficiency of the photovoltaic sheet.

[0006] An object of the present invention is to provide a photovoltaic sheet that can mitigate the effects of thermal expansion and contraction after installation on an installation surface by means of an adhesive layer, and an installation structure for the photovoltaic sheet. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention includes as its subject the installation structure for a photovoltaic sheet described in the following item 1.

[0008] Item 1. A photovoltaic sheet including a plurality of power generation units that generate electricity by receiving sunlight; An installation surface on which the solar power generation sheet is installed; an adhesive layer interposed between one main surface of the photovoltaic sheet and the installation surface to adhere a portion of the photovoltaic sheet to the installation surface; Equipped with the main surface of the photovoltaic sheet includes a plurality of first regions which are regions onto which the plurality of power generating portions are projected, and at least one second region which is a region between two adjacent first regions, The adhesive layer is interposed between the main surface and the installation surface so as to adhere at least the first region to the installation surface, An installation structure for a solar power generation sheet, wherein a non-adhesive space exists between the main surface and the installation surface, in which at least a portion of the second region is not adhered to the installation surface, or a weak adhesive layer is interposed, which adheres at least a portion of the second region to the installation surface with an adhesive force weaker than the adhesive force of the adhesive layer.

[0009] The present invention encompasses a photovoltaic sheet installation structure described in the following item 2 as a preferred embodiment of the photovoltaic sheet installation structure described in item 1 above.

[0010] Item 2. The solar power generation sheet installation structure according to claim 1, wherein the non-adhesive space or the weakly adhesive layer extends over the entire length of the second region in a direction perpendicular to the direction in which the first regions are adjacent to each other.

[0011] The present invention encompasses a photovoltaic sheet installation structure described in the following item 3 as a preferred embodiment of the photovoltaic sheet installation structure described in item 1 or 2 above.

[0012] Item 3. The photovoltaic sheet installation structure according to item 1 or 2, wherein the adhesive layer has elasticity.

[0013] The present invention encompasses a photovoltaic sheet installation structure described in the following item 4 as a preferred embodiment of the photovoltaic sheet installation structure described in item 3 above.

[0014] Item 4. The solar cell installation structure according to item 3, wherein the adhesive layer has a transverse elastic modulus of 0.1 MPa or more and 10,000 MPa or less.

[0015] The present invention encompasses the installation structure for a photovoltaic sheet described in the following item 5 as a preferred embodiment of the installation structure for a photovoltaic sheet described in item 1 or 2 above.

[0016] Item 5. The installation structure for a photovoltaic sheet according to item 1 or 2, wherein the adhesive layer includes an elastic body having elasticity.

[0017] The present invention encompasses a photovoltaic sheet installation structure described in the following item 6 as a preferred embodiment of the photovoltaic sheet installation structure described in item 5 above.

[0018] Item 6. The solar cell installation structure according to item 3, wherein the elastic body has a transverse elastic modulus of 0.1 MPa or more and 10,000 MPa or less.

[0019] The present invention encompasses the installation structure for a photovoltaic sheet described in the following item 7 as a preferred embodiment of the installation structure for a photovoltaic sheet described in the above item 2, and any one of items 3, 4, 5, and 6 which refer to item 2.

[0020] Item 7. The installation surface is an inclined surface that intersects with a horizontal plane at an angle, The plurality of power generating sections of the photovoltaic sheet are aligned in one direction, The solar power generation sheet is installed on the installation surface so that a direction perpendicular to a direction in which the plurality of power generation units are arranged coincides with a tilt direction of the tilted surface.

[0021] In order to achieve the above object, the present invention includes as its subject the photovoltaic sheet described in the following item 8.

[0022] Item 8. A photovoltaic sheet including a plurality of power generating units that generate electricity by receiving sunlight, one main surface of the photovoltaic sheet that faces an installation surface when the photovoltaic sheet is installed on the installation surface includes a plurality of first regions that are regions onto which the plurality of power generating units are projected, and at least one second region that is a region between two adjacent first regions, a photovoltaic sheet having an adhesive region mark on the main surface, the adhesive region mark indicating a region where an adhesive layer is to be provided for adhering a portion of the photovoltaic sheet to the installation surface, the adhesive layer being provided so as to include at least the first region and not include at least a portion of the second region; Effect of the Invention

[0023] According to the present invention, there is an advantage that the influence of thermal expansion and contraction can be alleviated by the adhesive layer after the device is placed on the placement surface. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view of an installation structure in which a photovoltaic sheet is installed on the surface of a roof. [Diagram 2] 2(A) is a schematic cross-sectional view taken along the line AA in FIG. 1, and FIG. 2(B) is a schematic cross-sectional view showing an enlarged portion of FIG. 2(A). [Diagram 3] FIG. 3 is a schematic cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a schematic back view showing a state in which an adhesive layer is provided on the photovoltaic sheet. [Diagram 5] Fig. 5(A) is a cross-sectional view of a photovoltaic sheet, Fig. 5(B) is an enlarged view of part a in Fig. 5(A), and Fig. 5(C) is a cross-sectional view showing the power generating section cut along line CC in Fig. 5(A). [Figure 6] FIG. 6 is a schematic rear view of the photovoltaic sheet. [Figure 7] FIG. 7 is a schematic back view of a photovoltaic sheet on which adhesive area marks are displayed. [Figure 8] FIG. 8 is a schematic back view showing a modified example in which an adhesive layer is provided on a photovoltaic sheet. [Figure 9] FIG. 9 is a schematic back view showing a modified example in which an adhesive layer is provided on a photovoltaic sheet. [Figure 10] FIG. 10 is a schematic back view showing a modified example in which an adhesive layer is provided on a photovoltaic sheet. [Figure 11] FIG. 11(A) is a schematic cross-sectional view of a modified installation structure in which a solar power generation sheet is installed on the surface of a roof, and FIG. 11(B) is a schematic back view showing the solar power generation sheet with an adhesive layer and a weak adhesive layer provided thereon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0026] Figures 1 to 3 show a photovoltaic sheet installation structure 11 according to one embodiment of the present invention. The installation structure 11 includes an installation surface 12, a photovoltaic sheet 1 to be installed on the installation surface 12, and an adhesive layer 13 for adhering a portion of the photovoltaic sheet 1 to the installation surface 12. Figures 5 to 7 show the photovoltaic sheet 1 according to one embodiment of the present invention. The photovoltaic sheet 1 and installation structure 11 of this embodiment will be described below.

[0027] (Installation surface) The installation surface 12 is one surface of the installation target on which the photovoltaic sheet 1 is installed. The installation surface 12 is, for example, constituted by the surface of a building material. Examples of building materials include roofing materials, wall materials (metal siding materials, ceramic siding materials, sandwich panels, etc.), partitions, door materials, fence materials, and floor materials. Examples of roofing materials include roofing materials used for folded plate roofs, slate roofs, roof decks, tile roofing, and vertical flat roofing. The roof may be vertically or horizontally roofed. The building material may be for a non-residential building or for a residential building. Examples of non-residential buildings include stores, warehouses, factories, vinyl greenhouses, greenhouses, assembly halls, gymnasiums, and parking lots. The installation surface 12 may be constituted by the surface of other structures, for example, the surface of a road, ground, or embankment, or may be constituted by the surface of an automobile, train, or ship.

[0028] The installation surface 12 is formed of, for example, metal, resin, asphalt, or concrete. The installation surface 12 may be, for example, a surface on which soil, sand, or gravel has accumulated. The installation surface 12 may also include the surface of, for example, a resin sheet material laid and fixed on the surface of the above-mentioned structure.

[0029] The installation surface 12 is preferably made of a material with a low linear expansion coefficient. The low linear expansion coefficient of the installation surface 12 can reduce the degree of thermal expansion of the installation surface 12 even if the temperature rises due to sunlight or drops in winter after the photovoltaic sheet 1 is installed.

[0030] The installation surface 12 may be a horizontal surface perpendicular to the direction of gravity, or a surface intersecting the horizontal surface at an angle. The installation surface 12 intersecting the horizontal surface at an angle includes an inclined surface that forms a predetermined inclination angle θ (0°<θ<90°) with respect to the horizontal surface, and a vertical surface that is perpendicular to the horizontal surface. The installation surface 12 may be a flat surface or a curved surface, and the surface state may be smooth or may be rough or uneven. The installation surface 12 may also be a corrugated surface that is curved so that multiple peaks and multiple valleys are arranged alternately.

[0031] In this embodiment, the installation surface 12 is the surface (roof surface) of the roofing material, and is an inclined surface. Here, as shown in Fig. 1, the highest part of one roof surface is defined as "above water" and the lowest part as "below water". In addition, the direction parallel to the line segment connecting above water and below water at the shortest distance is defined as the "water flow direction". In this embodiment, above water is the ridge, below water is the eaves, and the water flow direction is parallel to the eaves-ridge direction.

[0032] (Photovoltaic power generation sheet) The photovoltaic sheet 1 is flexible and formed into a flexible sheet. In the present disclosure, "sheet-like" refers to a shape in which the thickness of the object is 10% or less of the maximum length between the outer peripheries in a planar view. When the shape in a planar view is rectangular, "the maximum length between the outer peripheries in a planar view" refers to the length of the diagonal. When the shape in a planar view is circular, "the maximum length between the outer peripheries in a planar view" refers to the length of the diameter. In the present disclosure, "sheet-like" also includes membrane-like, foil-like, and film-like shapes.

[0033] In the photovoltaic sheet 1, one main surface in the thickness direction (front surface) is a surface that receives sunlight (light-receiving surface). In the photovoltaic sheet 1, the other main surface in the thickness direction (reverse surface) is a surface that faces the installation surface 12 when the photovoltaic sheet 1 is installed on the installation surface 12.

[0034] The photovoltaic sheet 1 is formed in a rectangular shape in plan view with the width being longer than the length, however, the shape of the photovoltaic sheet 1 may be, for example, a square shape in plan view, a roughly circular shape in plan view, an elliptical shape in plan view, or a polygonal shape in plan view, and is not particularly limited.

[0035] The bending strength of the photovoltaic sheet 1 is preferably 10 MPa or more, more preferably 20 MPa or more, more preferably 50 MPa or more, and more preferably 100 MPa or more. Meanwhile, the bending strength of the photovoltaic sheet 1 is preferably 200 MPa or less, more preferably 150 MPa or less, more preferably 130 MPa or less, and more preferably 100 MPa or less. All of the numerical ranges that combine the above-mentioned lower and upper limits are preferred ranges for the bending strength of the photovoltaic sheet 1.

[0036] The flexibility of the photovoltaic sheet 1 may also be defined by its flexural modulus. The flexural modulus of the photovoltaic sheet 1 is preferably 100 MPa or more, more preferably 200 MPa or more, more preferably 500 MPa or more, and more preferably 1000 MPa or more. On the other hand, the flexural modulus of the photovoltaic sheet 1 is preferably 10000 MPa or less, more preferably 7500 MPa or less, and more preferably 5000 MPa or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways are preferred ranges for the flexural modulus of the photovoltaic sheet 1. When the photovoltaic sheet 1 is defined by its flexural modulus, the flexural strength does not have to be included in the above range.

[0037] If the photovoltaic sheet 1 has a bending strength in the range of 10 MPa to 200 MPa or a bending modulus in the range of 100 MPa to 10,000 MPa, it conforms well to the shape of the installation surface 12, improving workability on the installation surface 12. Furthermore, it is less likely to flap in the wind when installed, which effectively prevents damage such as cracks. The bending strength and bending modulus of the photovoltaic sheet 1 are measured, for example, by a measurement method conforming to JIS K7171.

[0038] 5, the photovoltaic sheet 1 includes a back sheet 2, a plurality of power generating units 3, a barrier sheet 4, a sealing layer 5, and a sealing edge material 6. The plurality of power generating units 3 and the sealing layer 5 are disposed between the back sheet 2 and the barrier sheet 4. The sealing edge material 6 provides a seal between the outer periphery of the back sheet 2 and the outer periphery of the barrier sheet 4 over the entire length.

[0039] In the photovoltaic sheet 1, the multiple power generating units 3 are arranged at intervals from each other, as shown in FIG. 1 and FIG. 6. In this embodiment, the multiple power generating units 3 are arranged in a row in one direction, and the direction in which the multiple power generating units 3 are arranged coincides with the longitudinal direction of the photovoltaic sheet 1. The multiple power generating units 3 are electrically connected in series or parallel. The distance between two adjacent power generating units 3 may be more than 0 mm, and is preferably 2 mm or more, more preferably 10 mm or more, and more preferably 15 mm or more. On the other hand, the distance between two adjacent power generating units 3 is preferably 100 mm or less, more preferably 50 mm or less, and more preferably 20 mm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways is a preferred range for the distance between two adjacent power generating units 3.

[0040] As shown in Fig. 6, the main surface of the photovoltaic sheet 1 includes a plurality of first regions 7, which are regions onto which a plurality of power generating sections 3 are projected, and at least one second region 8, which is a region between adjacent first regions 7. The main surface of the photovoltaic sheet 1 also includes a third region 9, which is a region along the outer edge of the photovoltaic sheet 1. The third region 9 is a region that has a certain range inward from the outer edge of the photovoltaic sheet 1, and extends along the entire length of the outer edge of the photovoltaic sheet 1.

[0041] (Back seat) As shown in Fig. 5(A), the back sheet 2 is disposed on the side opposite the light-receiving surface of the photovoltaic sheet 1, and protects the back side of the multiple power generation sections 3. The back sheet 2 constitutes the main surface (back surface) of the photovoltaic sheet 1 that faces the installation surface 12. The back sheet 2 has barrier properties against water vapor and protective properties against external forces. The back sheet 2 may be light-transmitting or non-light-transmitting.

[0042] In the present disclosure, "having light-transmitting properties" means that the light transmittance is 10% or more with respect to the peak wavelength of light before incidence.

[0043] The back sheet 2 has flexibility. The modulus of longitudinal elasticity of the back sheet 2 is preferably 100 MPa or more, more preferably 1000 MPa or more, more preferably 2400 MPa or more, and more preferably 3000 MPa or more. On the other hand, the modulus of longitudinal elasticity of the back sheet 2 is preferably 10000 MPa or less, more preferably 5000 MPa or less, more preferably 4200 MPa or less, and more preferably 4000 MPa or less. The numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways are all preferred ranges for the modulus of longitudinal elasticity of the back sheet 2.

[0044] Examples of materials for the back sheet 2 include synthetic resins such as thermoplastic resins, thermosetting resins, general-purpose plastics, engineering plastics, and vinyl resins (e.g., polyvinyl chloride). Examples of materials for the back sheet 2 include synthetic resins, as well as natural resins, rubber, metals, carbon, and pulp.

[0045] The thickness of the back sheet 2 is preferably 50 μm or more, more preferably 100 μm or more, and more preferably 200 μm or more. On the other hand, the thickness of the back sheet 2 is preferably 2000 μm or less, more preferably 1000 μm or less, more preferably 800 μm or less, and more preferably 600 μm or less. All of the numerical ranges obtained by combining the above-mentioned lower and upper limits are preferred ranges for the thickness of the back sheet 2. If the thickness of the back sheet 2 is within the range of 50 μm or more and 2000 μm or less, it is easy to set the bending strength of the photovoltaic sheet 1 to the above range.

[0046] (Power Generation Division) The power generating unit 3 generates electricity from sunlight by utilizing the photovoltaic effect. The power generating unit 3 is flexible. As shown in FIG. 5(A), the power generating unit 3 includes at least one power generating cell 30. In the power generating unit 3 of this embodiment, as shown in FIG. 5(C), the multiple power generating cells 30 are arranged in one direction among the surface directions of the photovoltaic sheet 1, and are formed in a strip shape. In one power generating unit 3, the multiple power generating cells 30 are arranged in one direction among the surface directions of the photovoltaic sheet 1 and are monolithically integrated. In other words, the power generating unit 3 has a monolithic structure in which the multiple power generating cells 30 form one module.

[0047] The power generating cell 30 is a photoelectric conversion element that utilizes the photovoltaic effect, and is the smallest unit element capable of generating power. In the power generating unit 3 having a monolithic structure, a plurality of power generating cells 30 are mechanically joined together and electrically connected. The amount of power generated in one power generating unit 3 can be changed by increasing or decreasing the number of power generating cells 30.

[0048] 5(A), the power generating cell 30 includes a light-transmitting substrate 31, a light-transmitting conductive layer 32, a power generating layer 33, and an electrode 34. The light-transmitting substrate 31, the light-transmitting conductive layer 32, the power generating layer 33, and the electrode 34 are laminated in this order along a direction from the barrier sheet 4 toward the back sheet 2. In other words, they are disposed so that the light-transmitting substrate 31 faces the barrier sheet 4, and the electrode 34 faces the back sheet 2.

[0049] (Translucent base material) As shown in Fig. 5(A), the light-transmitting base material 31 supports the light-transmitting conductive layer 32, the power generation layer 33, and the electrode 34. The light-transmitting base material 31 has light-transmitting properties. The light-transmitting properties of the light-transmitting base material 31 may be such that the light transmittance is 10% or more with respect to the peak wavelength of the light before incidence, but is preferably 50% or more, and more preferably 80% or more. In the present disclosure, a light transmittance of 80% or more with respect to the peak wavelength of the light before incidence is considered to be "transparent."

[0050] Examples of materials for the light-transmitting substrate 31 include inorganic materials, organic materials, and metal materials. Examples of inorganic materials include quartz glass and non-alkali glass. Examples of organic materials include plastics and polymer films such as polyethylene terephthalate (PET), polyethylene naphthalene (PEN), polyethylene, polyimide, polyamide, polyamideimide, liquid crystal polymer, and cycloolefin polymer. Examples of metal materials include stainless steel, aluminum, titanium, and silicon.

[0051] There are no particular limitations on the thickness of the light-transmitting base material 31 as long as it can support the light-transmitting conductive layer 32, the power generation layer 33, and the electrodes 34, and the thickness is, for example, 10 μm or more and 300 μm or less.

[0052] The light-transmitting substrate 31 is a substrate that is required during the manufacturing process of the power generating cells 30. Therefore, it is not necessarily a necessary component of the product, the photovoltaic sheet 1. The light-transmitting substrate 31 may be used, for example, only during the manufacturing process of the photovoltaic sheet 1, or may be removed after or during manufacturing. When removed, a substrate that does not have light-transmitting properties may be used instead of the light-transmitting substrate 31.

[0053] (Transparent conductive layer) The transparent conductive layer 32 has electrical conductivity and functions as a cathode. The transparent conductive layer 32 has light transmitting properties. The transparent conductive layer 32 is preferably transparent.

[0054] Examples of materials for the translucent conductive layer 32 include transparent materials such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and NESA film. The translucent conductive layer 32 is formed on the surface of the translucent base material 31 by, for example, a sputtering method, an ion plating method, a plating method, or a coating method.

[0055] The light-transmitting conductive layer 32 may be configured to have light-transmitting properties by forming a light-transmitting pattern using an opaque material. Examples of the opaque material include platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, nickel, tin, zinc, and alloys containing these. Examples of the light-transmitting pattern include a lattice shape, a line shape, a wavy line shape, a honeycomb shape, and a round hole shape.

[0056] The thickness of the transparent conductive layer 32 is preferably 30 nm or more and 300 nm or less. When the thickness of the transparent conductive layer 32 is within the range of 30 nm or more and 300 nm or less, good conductivity can be obtained while maintaining high flexibility.

[0057] (Power generation layer) The power generation layer 33 is a layer that causes photoelectric conversion by irradiation with light, and generates electrons and holes from excitons generated by absorbing light. As shown in Fig. 5(B), the power generation layer 33 includes a hole transport layer 330, a photoelectric conversion layer 331, and an electron transport layer 332. The hole transport layer 330, the photoelectric conversion layer 331, and the electron transport layer 332 are laminated in this order along the direction from the translucent conductive layer 32 toward the electrode 34.

[0058] (Hole transport layer) The hole transport layer 330 extracts holes generated in the photoelectric conversion layer 331 to the light-transmitting conductive layer 32, and prevents electrons generated in the photoelectric conversion layer 331 from moving to the light-transmitting conductive layer 32. Examples of the material of the hole transport layer 330 include metal oxides. Examples of the metal oxides include titanium oxide, molybdenum oxide, vanadium oxide, zinc oxide, nickel oxide, lithium oxide, calcium oxide, cesium oxide, and aluminum oxide. Other examples include delafossite-type compound semiconductors (CuGaO2), copper oxide, copper thiocyanate (CuSCN), vanadium pentoxide (V2O5), and graphene oxide. Examples of the material of the hole transport layer 330 include p-type organic semiconductors and p-type inorganic semiconductors.

[0059] The thickness of the hole transport layer 330 is preferably 1 nm or more, more preferably 10 nm or more. On the other hand, the thickness of the hole transport layer 330 is preferably 1000 nm or less, more preferably 500 nm or less, more preferably 50 nm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range of the thickness of the hole transport layer 330. If the thickness of the hole transport layer 131 is within the range of 1 nm or more and 1000 nm or less, the hole transport can be satisfactorily realized.

[0060] (Photoelectric conversion layer) The photoelectric conversion layer 331 (photoactive layer) is a layer that photoelectrically converts absorbed light. The material of the photoelectric conversion layer 331 may be any material that can photoelectrically convert absorbed light, such as amorphous silicon, perovskite, and non-silicon materials (semiconductor material CIGS). The photoelectric conversion layer 331 may also have a tandem laminated structure that combines these materials. The photoelectric conversion layer 331 using a non-silicon material uses the semiconductor material CIGS containing copper (Cu), indium (In), gallium (Ga), and selenium (Se), which makes it easy to reduce the thickness of the photoelectric conversion layer.

[0061] In the following, a photoelectric conversion layer 331 using perovskite will be described as an example of the photoelectric conversion layer 331. The photoelectric conversion layer 331 containing a perovskite compound has the advantage that the power generation efficiency has a relatively low dependency on the angle of incident light (hereinafter, sometimes referred to as incident angle dependency). As a result, the photovoltaic sheet 1 of this embodiment has a low dependency on the gradient of the installation surface 12, so it can be installed in a wider area than other solar cell modules and a higher power generation efficiency can be obtained.

[0062] A perovskite compound is a structure having a perovskite crystal structure or a crystal similar thereto. The perovskite crystal structure is represented by the composition formula ABX3. In this composition formula, for example, A represents an organic cation, B represents a metal cation, and X represents a halogen anion. However, the A site, B site, and X site are not limited to these.

[0063] Examples of the organic group of the organic cation constituting the A site include alkylammonium derivatives and formamidinium derivatives. The organic cation constituting the A site may be one type or two or more types.

[0064] Examples of metals in the metal cations constituting the B site include Cu, Ni, Mn, Fe, Co, Pd, Ge, Sn, Pb, and Eu. The metal cations constituting the B site may be of one type or of two or more types.

[0065] Examples of halogens in the halogen anion constituting the X site include F, Cl, Br, and I. The halogen anion constituting the X site may be of one type, or of two or more types.

[0066] The thickness of the photoelectric conversion layer 331 is preferably 1 nm or more, more preferably 5 nm or more, more preferably 10 nm or more, more preferably 100 nm or more, and more preferably 300 nm or more. On the other hand, the thickness of the photoelectric conversion layer 331 is preferably 1,000,000 nm or less, more preferably 50,000 nm or less, and more preferably 1,000 nm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range for the thickness of the photoelectric conversion layer 331. When the thickness of the photoelectric conversion layer 132 is within the range of 1 nm or more and 1,000,000 nm or less, the photoelectric conversion efficiency is improved satisfactorily.

[0067] (electron transport layer) The electron transport layer 332 extracts electrons generated in the photoelectric conversion layer 331 to the electrode 34, and prevents holes generated in the photoelectric conversion layer 331 from moving to the electrode 34. The electron transport layer 332 preferably contains, for example, either a halogen compound or a metal oxide.

[0068] Examples of halogen compounds include lithium halides (LiF, LiCl, LiBr, LiI) and sodium halides (NaF, NaCl, NaBr, NaI). Examples of elements constituting metal oxides include titanium, molybdenum, vanadium, zinc, nickel, lithium, potassium, cesium, aluminum, niobium, tin, and barium. Examples of materials for the electron transport layer 332 include n-type organic semiconductors and n-type inorganic semiconductors.

[0069] The thickness of the electron transport layer 332 is preferably 1 nm or more, and more preferably 10 nm or more. On the other hand, the thickness of the electron transport layer 332 is preferably 1000 nm or less, more preferably 500 nm or less, and more preferably 50 nm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range for the thickness of the electron transport layer 332. If the thickness of the electron transport layer 133 is within the range of 1 nm or more and 1000 nm or less, the electron transport layer 133 can satisfactorily transport electrons.

[0070] (electrode) The electrode 34 is conductive and functions as an anode. The electrode 34 extracts electrons from the photoelectric conversion layer 331 in response to photoelectric conversion caused by the photoelectric conversion layer 331. The electrode 34 may be made of either a light-transmitting material or a light-opaque material. Examples of materials for the electrode 34 include platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, nickel, tin, zinc, and alloys containing these metals.

[0071] (Barrier sheet) As shown in FIG. 5(A), the barrier sheet 4 is disposed on the opposite side of the back sheet 2 with respect to the power generation sections 3 in the thickness direction of the photovoltaic sheet 1, and protects the front sides of the multiple power generation sections 3. The barrier sheet 4 constitutes the main surface (front surface) of the photovoltaic sheet 1 that faces sunlight. The barrier sheet 4 includes the light receiving surface of the photovoltaic sheet 1. The barrier sheet 4 is light transmissive. The barrier sheet 4 is preferably transparent. The barrier sheet 4 has barrier properties against water vapor and protective properties against external forces.

[0072] The barrier sheet 4 is flexible. The Young's modulus of the barrier sheet 4 is preferably 100 Pa or more, more preferably 1000 MPa or more, more preferably 2400 MPa or more, and more preferably 3000 MPa or more. On the other hand, the Young's modulus of the barrier sheet 4 is preferably 10000 MPa or less, more preferably 5000 MPa or less, more preferably 4200 MPa or less, and more preferably 4000 MPa or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways are preferred ranges for the Young's modulus of the barrier sheet 4.

[0073] Examples of materials for the barrier sheet 4 include synthetic resins such as thermoplastic resins, thermosetting resins, general-purpose plastics, engineering plastics, and vinyl resins (e.g., polyvinyl chloride). Examples of materials for the barrier sheet 4 include synthetic resins, as well as natural resins, rubber, metal, and pulp.

[0074] The thickness of the barrier sheet 4 is preferably 50 μm or more, more preferably 100 μm or more, and more preferably 200 μm or more. On the other hand, the thickness of the barrier sheet 4 is preferably 2000 μm or less, more preferably 1000 μm or less, more preferably 800 μm or less, and more preferably 600 μm or less. All of the numerical ranges that combine the above-mentioned lower and upper limits are preferred ranges for the thickness of the barrier sheet 4. If the thickness of the barrier sheet 4 is within the range of 50 μm or more and 2000 μm or less, the bending strength of the photovoltaic sheet 1 can be easily set within the above range.

[0075] When the photovoltaic sheet 1 is heated or cooled, the amount of thermal expansion and contraction of the barrier sheet 4 is preferably close to that of the back sheet 2. That is, the ratio of the thermal expansion coefficient (linear expansion coefficient) of the barrier sheet 4 to the back sheet 2 is preferably 6.0 or less, more preferably 3.0 or less, and more preferably 1.0 or less. On the other hand, the ratio of the thermal expansion coefficient of the barrier sheet 4 to the back sheet 2 is preferably 0.8 or more, more preferably 0.9 or more, and more preferably 0.95 or more. All of the numerical ranges obtained by combining the above-mentioned lower and upper limits are preferred ranges for the ratio of the thermal expansion coefficient of the barrier sheet 4 to the back sheet 2. If the ratio of the thermal expansion coefficient of the barrier sheet 4 to the back sheet 2 is within the range of 0.8 or more and 6.0 or less, the effects of thermal expansion and contraction occurring in the photovoltaic sheet 1 can be effectively reduced even if the temperature rises due to the influence of sunlight or falls in winter after the photovoltaic sheet 1 is installed.

[0076] (Sealing layer) As shown in FIG. 5(A), the sealing layer 5 is filled between the barrier sheet 4 and the back sheet 2 with a plurality of power generating units 3 disposed between the barrier sheet 4 and the back sheet 2. The power generating units 3 are embedded in the sealing layer 5 and covered by the sealing layer 5. The sealing layer 5 therefore prevents water from entering the plurality of power generating units 3 from around the respective power generating units 3. The sealing layer 5 is light-transmitting and is preferably transparent. Note that the sealing layer 5 does not necessarily need to cover all of the plurality of power generating units 3. For example, if a portion of the power generating units 3 is exposed from the sealing layer 5, the exposed portion may be covered with, for example, a sealing edge material 6.

[0077] Examples of materials for the sealing layer 5 include ethylene vinyl acetate (EVA), polyolefin, butyl rubber, silicone resin, polyvinyl butyral, acrylic resin, polyisobutylene resin, SBS resin, SIBS resin, and epoxy resin.

[0078] The transverse elastic modulus of the sealing layer 5 is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, and more preferably 0.1 MPa or less. On the other hand, the transverse elastic modulus of the sealing layer 5 is preferably 500 MPa or less, more preferably 250 MPa or less, and more preferably 100 MPa or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range of the transverse elastic modulus of the sealing layer 5. When the transverse elastic modulus of the sealing layer 5 is in the range of 0.01 MPa or more and 500 MPa or less, the sealing layer 5 can well absorb the shear stress in the surface direction generated in the back sheet 2 and the barrier sheet 4 by deforming in the surface direction. This can effectively suppress peeling caused by the shear stress generated in the back sheet 2 and the barrier sheet 4.

[0079] The back sheet 2 and the barrier sheet 4 are bonded via the sealing layer 5, and the adhesive strength is preferably 0.1 N / 10 mm or more and 10 N / 10 mm or less in a peel test. In particular, when the photovoltaic sheet 1 is installed in a bent state, the shear stress generated in the photovoltaic sheet 1 becomes larger, so by adopting an adhesive strength in the above range in the peel test, peeling can be effectively suppressed for a long period of time. The peel test is performed in accordance with JIS Z 0237.

[0080] The thickness of the sealing layer 5 is preferably 10 μm or more, more preferably 30 μm or more, and more preferably 50 μm or more. On the other hand, the thickness of the sealing layer 5 is preferably 300 μm or less, more preferably 200 μm or less, and more preferably 100 μm or less. The numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways are all preferred ranges for the thickness of the sealing layer 5. By having the thickness of the sealing layer 5 within the range of 10 μm or more and 300 μm or less, it is possible to sufficiently secure the escape allowance for shear stress during thermal expansion and contraction, and the effect of preventing peeling can be favorably improved. In addition, the weight of the photovoltaic sheet 1 can be reduced, and the workability and workability can be improved.

[0081] (Sealing edge material) As shown in Fig. 5(A), the sealing edge material 6 seals the outer periphery of the back sheet 2 and the barrier sheet 4 over their entire length with a plurality of power generation units 3 and sealing layers 5 disposed between them. The sealing edge material 6 has a first adhesive portion 61, a second adhesive portion 62, and a sealing portion 63 connecting the first adhesive portion 61 and the second adhesive portion 62. The first adhesive portion 61 is adhered to the front surface (upper surface in the figure) of the barrier sheet 4. The second adhesive portion 62 is adhered to the rear surface (lower surface in the figure) of the back sheet 2. The first adhesive portion 61, the sealing portion 63, and the second adhesive portion 62 are integrally formed.

[0082] The material of the sealing edge material 6 may be, for example, a tape material made of butyl rubber, silicone rubber, or the like.

[0083] In this embodiment, the sealing edge material 6 is not necessarily required. For example, instead of the sealing edge material 6, the edge of the barrier sheet 4 may be folded toward the back sheet 2 and the folded end may be joined to the back sheet 2. This makes the sealing edge material 6 unnecessary.

[0084] (Power generation) When light is irradiated onto the power generating cells 30 from the front surface side (barrier sheet 4 side) of the solar power generating sheet 1, the photoelectric conversion layer 331 of the power generating layer 33 absorbs the light and performs photoelectric conversion, generating electrons and holes in the photoelectric conversion layer 331. The electrons are extracted to the electrode 34 (anode) via the electron transport layer 332, and the holes are extracted to the translucent conductive layer 32 (cathode) via the hole transport layer 330, resulting in the extraction of a current from the translucent conductive layer 32 and the electrode 34 (i.e., power generation).

[0085] In the power generating unit 3, a plurality of power generating cells 30 are joined in one direction. Here, as shown in FIG. 5(C), the electrode 34 (anode) of each power generating cell 30 has an extension 340 extending from a portion laminated on the electron transport layer 332. The extension 340 extends to the translucent conductive layer 32 of the adjacent power generating cell 30, and is mechanically joined and electrically connected to the translucent conductive layer 32 of the adjacent power generating cell 30. By joining the adjacent power generating cells 30 by the extension 340, the translucent conductive layer 32 at one end of the power generating unit 3 and the electrode 34 at the other end of the power generating unit 3 are electrically connected. By including a plurality of power generating cells 30 in the power generating unit 3, the amount of electricity taken out from the power generating unit 3 can be stabilized even if a malfunction occurs in some of the power generating cells 30.

[0086] Although the electrode has the extension 340, the light-transmitting conductive layer 32 (cathode) may have the extension 340 that extends to the adjacent electrode .

[0087] Furthermore, when the power generation unit 3 is provided with a translucent base material 31, from the viewpoint of facilitating the manufacture of the power generation unit 3, it is preferable to support the translucent conductive layer 32, the power generation layer 33 and the electrodes 34 of each power generation cell 30 on a common translucent base material 31, as shown in FIG. 5(C).

[0088] The multiple power generating units 3 are electrically connected by a distribution line disposed between the back sheet 2 and the barrier sheet 4. When the multiple power generating units 3 are connected in series, the translucent conductive layer 32 at an end of one of the two adjacent power generating units 3 is connected via a distribution line to the electrode 34 at the end of the other power generating unit 3. When the multiple power generating units 3 are connected in parallel, the translucent conductive layers 32 of the two adjacent power generating units 3 are connected to each other via a distribution line, and the electrodes 34 are connected to each other via a distribution line.

[0089] (first area) In the main surface of the photovoltaic sheet 1, the first region 7 shown in FIG. 6 is a region including the back sheet 2, the power generation section 3, the barrier sheet 4, and the sealing layer 5 in the thickness direction of the photovoltaic sheet 1. As shown in FIG. 4, the photovoltaic sheet 1 is adhered to the installation surface 12 by providing an adhesive layer 13 at least in the first region 7. In this embodiment, a part of the photovoltaic sheet 1 is adhered to the installation surface 12 by the adhesive layer 13 interposed between the main surface (rear surface) of the photovoltaic sheet 1 on the back sheet 2 side and the installation surface 12. The adhesive layer 13 is interposed between the main surface (rear surface) of the photovoltaic sheet 1 and the installation surface 12 so as to adhere at least the first region 7 to the installation surface 12. This fixes the power generation section 3 onto the installation surface 12. Therefore, even if the photovoltaic sheet 1 vibrates due to wind or the like, the power generation section 3 is restrained by the installation surface 12, so that the vibration of the power generation section 3 can be reduced, and a decrease in the power generation efficiency of the installed photovoltaic sheet 1 due to vibration can be suppressed.

[0090] (Second area) On the main surface of the photovoltaic sheet 1, the second region 8 shown in Fig. 6 is located between two adjacent first regions 7 and is a portion that, in the thickness direction of the photovoltaic sheet 1, includes the back sheet 2, barrier sheet 4, and sealing layer 5 but does not include the power generating section 3. The photovoltaic sheet 1 is installed on the installation surface 12 without at least a portion of the second region 8 being adhered to the installation surface 12 by an adhesive layer 13. In other words, in this embodiment, a non-adhesive space 14 exists between the main surface (reverse surface) of the photovoltaic sheet 1 on the back sheet 2 side and the installation surface 12, as shown in Fig. 2(A) , where at least a portion of the second region 8 is not adhered to the installation surface 12.

[0091] 2(A) and 4, the photovoltaic sheet 1 has a non-adhesive portion 80 that is not adhered to the installation surface 12 in the second region 8 between two adjacent first regions 7, and this non-adhesive portion 80 can absorb part of the thermal expansion and contraction that occurs in the photovoltaic sheet 1. In other words, when the photovoltaic sheet 1 is placed on the installation surface 12, even if the first region 7 including the power generation unit 3 expands or contracts, the non-adhesive portion 80 between the two adjacent first regions 7 absorbs the expansion or contraction of the first region 7 and bends (shrinks or stretches), thereby preventing the first region 7 including the power generation unit 3 from bending and peeling off from the installation surface 12. This prevents the photovoltaic sheet 1 from bending in the first region 7, causing damage to the power generation unit 3.

[0092] In particular, when the photovoltaic sheet 1 is formed in an elongated shape that is long in one direction, as in this embodiment, the effect of thermal expansion in the longitudinal direction is more likely to be evident. Therefore, if there is a non-adhesive portion 80 between two adjacent power generating units 3 that is not adhered to the installation surface 12, damage to the power generating units 3 can be effectively suppressed.

[0093] As shown in FIG. 2(B), the bending of the photovoltaic sheet 1 due to thermal expansion and contraction occurs mainly in the non-adhesive portions 80 of the second region 8, and unevenness 81 due to the bending may occur in the second region 8.

[0094] The width of the non-adhesive portion 80 (the size in the longitudinal direction of the photovoltaic sheet 1) may be more than 0 mm, and does not necessarily have to be the same as the width of the second region 8. The width of the non-adhesive portion 80 is preferably 10 mm or more, more preferably 25 mm or more, and more preferably 50 mm or more. On the other hand, the width of the non-adhesive portion 80 is preferably 150 mm or less, more preferably 100 mm or less, and more preferably 50 mm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range for the width of the non-adhesive portion 80. By having the width of the non-adhesive portion 80 within the range of 10 mm or more and 150 mm or less, the above-mentioned effect of the non-adhesive portion 80 can be satisfactorily exhibited, and further, the adhesive layer 13 can firmly fix the power generating unit 3 to the installation surface 12, effectively suppressing a decrease in the power generating efficiency of the power generating unit 3 due to vibration.

[0095] In order to effectively utilize the effects of the non-adhesive portions 80 described above, it is preferable that the non-adhesive portions 80 extend across the entire length of the second region 8 (the entire length of the power generating section 3) in the width direction of the solar power generating sheet 1 (the direction perpendicular to the direction in which the first regions 7 are adjacent to each other), as shown in Figure 4.

[0096] (Third area) On the main surface of the photovoltaic sheet 1, the third region 9 shown in FIG. 6 is a region that surrounds the first region 7 and the second region 8, and is a region that includes the back sheet 2, the barrier sheet 4, the sealing layer 5, and the sealing edge material 6 in the thickness direction of the photovoltaic sheet 1, but does not include the power generating section 3. When the photovoltaic sheet 1 is installed on the installation surface 12, the third region 9 may be adhered to the installation surface 12 by an adhesive layer 13. This makes it possible to prevent a gap from being generated between the outer peripheral edge of the photovoltaic sheet 1 and the installation surface 12 after the photovoltaic sheet 1 is installed on the installation surface 12. This makes it possible to prevent wind from entering between the photovoltaic sheet 1 and the installation surface 12. This makes it possible to prevent the photovoltaic sheet 1 from vibrating due to wind, so that the power generation efficiency of the photovoltaic sheet 1 can be stably maintained.

[0097] When the third region 9 of the photovoltaic sheet 1 is adhered to the installation surface 12 by the adhesive layer 13, at least one non-adhered portion may be present in part of the third region 9. This allows the water to be discharged from between the photovoltaic sheet 1 and the installation surface 12 via the non-fixed portion, even if water such as rainwater seeps in between the photovoltaic sheet 1 and the installation surface 12. This makes it possible to prevent deterioration of the photovoltaic sheet 1 due to water remaining between the photovoltaic sheet 1 and the installation surface 12.

[0098] The width of the third region 9 (the length in the direction from the outer periphery of the photovoltaic sheet 1 toward the inside) is preferably 5 mm or more, more preferably 100 mm or more, and more preferably 150 mm or more. Meanwhile, the width of the third region 9 is preferably 250 mm or less, more preferably 200 mm or less, and more preferably 175 mm or less. All of the numerical ranges that combine the above-mentioned lower and upper limits are preferred ranges for the width of the third region 9. By having the width of the third region 9 within the range of 5 mm or more and 250 mm or less, vibrations of the photovoltaic sheet 1 caused by the influence of wind, etc., can be effectively suppressed by the adhesive layer 13.

[0099] (adhesive layer) As shown in FIG. 2(A), the adhesive layer 13 is interposed between one main surface of the photovoltaic sheet 1 (in this embodiment, the main surface (rear surface) on the back sheet 2 side) and the installation surface 12, and adheres a part of the photovoltaic sheet 1 to the installation surface 12. As shown in FIG. 4, the adhesive layer 13 is provided on one main surface of the photovoltaic sheet 1 so as to cover at least a plurality of first regions 7 onto which the plurality of power generation units 3 are projected. Covering the first regions 7 preferably means that the first regions 7 are completely hidden by the adhesive layer 13, but also allows the case where only a small part of the first region 7 is not hidden by the adhesive layer 13. The adhesive layer 13 is preferably provided so as to cover a size larger than the first region 7 so that the plurality of power generation units 3 can be reliably fixed to the installation surface 12 by the adhesive layer 13.

[0100] The adhesive layer 13 may be provided on one main surface of the solar power generating sheet 1 in a portion of the second region 8 between two adjacent first regions 7 and / or in at least a portion of the third region 9 surrounding the first region 7 and the second region 8.

[0101] The adhesive layer 13 can be formed using an adhesive, a pressure sensitive adhesive, an adhesive sheet, a double-sided tape, or the like. In particular, it is preferable to form the adhesive layer 13 using an adhesive. The viscosity of the adhesive is preferably 800 cP or more, and more preferably 1000 cP or more. On the other hand, the viscosity of the adhesive is preferably 10×10 7 cP or less, more preferably 10×10 6 cP or less, more preferably 10×10 4 The viscosity of the adhesive is preferably in the range of 800 cP or more and 10×10 7 By being in the range of 800 cP or less, the photovoltaic sheet 1 can be strongly adhered to the installation surface 12 without impairing the handleability of the adhesive. The viscosity of the adhesive may be less than 800 cP, but is preferably 100 cP or more.

[0102] The loss factor (tan δ) of the adhesive layer 13 with respect to vibration is preferably 0.01 or more, more preferably 0.05 or more, and more preferably 0.07 or more. On the other hand, the loss factor of the adhesive layer 13 with respect to vibration is preferably 0.3 or less, more preferably 0.25 or less, and more preferably 0.2 or less. All of the numerical ranges obtained by combining the above-mentioned lower and upper limits are preferred ranges for the loss factor of the adhesive layer 13. The loss factor of the adhesive layer 13 indicates the amount of vibration energy transmitted from the installation surface 12 to the photovoltaic sheet 1 through the adhesive layer 13. The loss factor is calculated by the storage modulus / loss modulus of the adhesive layer 13. The loss factor can be measured using a rheometer in accordance with JIS K7244-10.

[0103] When the photovoltaic sheet 1 is installed on an installation surface 12 such as a roofing material or wall material, the photovoltaic sheet 1 may vibrate due to the vibration of the installation surface 12 in addition to the effects of wind. If the photovoltaic sheet 1 vibrates due to the vibration of the installation surface 12, there is a risk of a decrease in the power generation efficiency of the photovoltaic sheet 1. In particular, when the photovoltaic sheet 1 is made large, the vibration of the photovoltaic sheet 1 caused by the vibration of the installation surface 12 becomes large, and the problem of a decrease in the power generation efficiency of the photovoltaic sheet 1 due to vibration becomes more pronounced.

[0104] By having the loss coefficient of the adhesive layer 13 within the range of 0.01 or more and 0.3 or less, the vibration of the installation surface 12 can be effectively treated as elastic loss and energy can be consumed in the adhesive layer 13, thereby suppressing vibration of the photovoltaic sheet 1. In addition, the photovoltaic sheet 1 can be firmly fixed to the installation surface 12 by the adhesive layer 13, and in particular, even if the installation surface 12 is inclined and the installation angle of the photovoltaic sheet 1 approaches vertical with respect to the horizontal plane, the photovoltaic sheet 1 can be suppressed from sliding down the installation surface 12.

[0105] The thickness of the adhesive layer 13 is preferably 0.1 mm or more, more preferably 1 mm or more, and more preferably 3 mm or more. On the other hand, the thickness of the adhesive layer 13 is preferably 20 mm or less, more preferably 15 mm or less, and more preferably 10 mm or less. Any of the numerical ranges obtained by combining the above-mentioned lower and upper limits is a preferred range for the thickness of the adhesive layer 13. By having the thickness of the adhesive layer 13 be in the range of 0.1 mm or more and 20 mm or less, the vibration of the installation surface 12 can be effectively suppressed by the adhesive layer 13, the vibration of the photovoltaic sheet 1 can be suppressed, and the weight load on the installation surface 12 can be reduced.

[0106] The adhesive layer 13 preferably has a male. The modulus of transverse elasticity of the adhesive layer 13 is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, more preferably 1 MPa or more, and more preferably 10 MPa or more. The modulus of transverse elasticity of the adhesive layer 13 is preferably 10,000 MPa or less, more preferably 1000 MPa or less, more preferably 100 MPa or less, more preferably 50 MPa or less, and more preferably 10 MPa or less. The numerical ranges obtained by combining the above-mentioned lower and upper limits are all preferred ranges of the modulus of transverse elasticity of the adhesive layer 13. Since the modulus of transverse elasticity of the adhesive layer 13 is within the range of 0.1 MPa or more and 10,000 MPa or less, the photovoltaic sheet 1 can be applied to the installation surface 12 along the shape of the installation surface 12, so that the area can be effectively utilized. In addition, since the adhesive layer 13 is easily deformed in the shear direction, it is possible to easily cause deflection in the second region 8 adjacent to the first region 7 in which the adhesive layer 13 is provided when the photovoltaic sheet 1 is thermally expanded or contracted.

[0107] The peel strength of the photovoltaic sheet 1 to the mounting surface 12 via the adhesive layer 13 is preferably 0.1 N / cm or more. The peel strength is a measurement result obtained in a 90° peel test conforming to JIS K6854-1, and in the case of deterioration over time, the peel strength at the time of construction is used.

[0108] Examples of materials for the adhesive layer 13 include resin compositions containing at least one selected from vinyl acetate resin, ethylene vinyl acetate resin, epoxy resin, cyanoacrylate resin, acrylic resin, chloroprene rubber, styrene, butadiene rubber, polyurethane resin, silicone resin, and modified silicone resin.

[0109] The adhesive layer 13 may be formed at the construction site by applying an adhesive or the like to the photovoltaic sheet 1, or may be formed in advance by attaching an adhesive sheet or double-sided tape to the photovoltaic sheet 1. The adhesive surfaces of the adhesive sheet or double-sided tape may be covered with a release protective sheet when transporting them to the construction site, and the release protective sheet may be peeled off after the sheet arrives at the construction site.

[0110] (Glue area mark) The adhesive layer 13 may be formed on the photovoltaic sheet 1 at the construction site. When the adhesive layer 13 is provided on the main surface (rear surface) of the photovoltaic sheet 1 on the back sheet 2 side and attached to the installation surface 12, if the back sheet 2 is opaque, there is a risk that the position of the first region 7 onto which the power generation unit 3 is projected cannot be grasped on the main surface (rear surface) on the back sheet 2 side. Since the main surface (front surface) on the barrier sheet 4 side of the photovoltaic sheet 1 is translucent, the position of the power generation unit 3 can be grasped from the front side. However, when the photovoltaic sheet 1 is large, it is not easy to identify the position of the first region 7 onto which the power generation unit 3 is projected on the main surface (rear surface) on the back sheet 2 side based on the position of the power generation unit 3 confirmed from the front side, and forming the adhesive layer 13 requires a great deal of effort.

[0111] 7, it is preferable to display an adhesive area mark 10 indicating the location where the adhesive layer 13 is to be provided on the main surface (rear surface) of the photovoltaic sheet 1 facing the back sheet 2. This makes it possible to easily provide the adhesive layer 13 on the main surface (rear surface) of the photovoltaic sheet 1 facing the back sheet 2 by simply applying adhesive or pressure-sensitive adhesive or attaching an adhesive sheet or double-sided tape to the location where the adhesive area mark 10 is displayed.

[0112] On the main surface (reverse surface) of the photovoltaic sheet 1 facing the back sheet 2, the first region 7 is provided with an adhesive layer 13, and therefore the adhesive region mark 10 is displayed. On the main surface (reverse surface) of the photovoltaic sheet 1 facing the back sheet 2, the second region 8 is not provided with an adhesive layer 13 in at least a portion thereof, and therefore the adhesive region mark 10 is not displayed over the entire region, or the adhesive region mark 10 may be displayed only in a portion thereof. On the main surface (reverse surface) of the photovoltaic sheet 1 facing the back sheet 2, the third region 9 may or may not be provided with an adhesive layer 13, and therefore the adhesive region mark 10 is not displayed over the entire region, or the adhesive region mark 10 may be displayed at least in a portion thereof. From the above, the adhesive region mark 10 is displayed on the main surface (reverse surface) of the photovoltaic sheet 1 facing the back sheet 2, so as to include at least the first region 7 and not include at least a portion of the second region 8.

[0113] The adhesive area mark 10 can be represented by, for example, a rectangular frame. The method of displaying the adhesive area mark 10 is not particularly limited, and various marks can be used as long as they can indicate to an installer or the like that this is the location where the adhesive layer 13 is to be provided.

[0114] (Installation example) The installer forms an adhesive layer 13 on the main surface (reverse surface) of the photovoltaic sheet 1 on the back sheet 2 side, for example by applying an adhesive according to the adhesive area marks 10. Then, the photovoltaic sheet 1 is placed on the installation surface 12, and a part of the photovoltaic sheet 1 is adhered to the installation surface 12 by the adhesive layer 13, thereby installing the photovoltaic sheet 1 on the installation surface 12.

[0115] In the case where the installation surface 12 is an inclined surface that intersects with the horizontal plane at an angle as in this embodiment, the photovoltaic sheet 1 is installed on the installation surface 12 so that the direction perpendicular to the arrangement of the multiple power generating units 3 (in other words, the multiple adhesive layers 13 provided in the first region 7) coincides with the inclination direction of the inclined surface, as shown in Fig. 1. As a result, when the photovoltaic sheet 1 is installed on the installation surface 12 as shown in Fig. 1, the second regions 8 of the photovoltaic sheet 1 are arranged such that the direction perpendicular to the direction in which the first regions 7 are adjacent coincides with the inclination direction of the inclined surface.

[0116] In the second region 8 of the photovoltaic sheet 1, as shown in FIG. 2B, unevenness 81 may occur due to bending of the photovoltaic sheet 1 caused by thermal expansion and contraction. When the unevenness 81 occurs in the photovoltaic sheet 1, dirt accumulates in the unevenness 81, and this dirt suppresses the incidence of sunlight on the photovoltaic sheet 1. In contrast, when the direction perpendicular to the direction in which the first regions 7 are adjacent to each other coincides with the inclination direction of the inclined surface in the second region 8 of the photovoltaic sheet 1, the unevenness 81 generated in the second region 8 extends along the inclination direction of the installation surface 12. Therefore, when water flows down the photovoltaic sheet 1 along the inclination of the installation surface 12 due to rain or the like, the dirt accumulated in the unevenness 81 also flows down the photovoltaic sheet 1 along the inclination of the installation surface 12. This makes it possible to suppress the accumulation of dirt in the unevenness 81 of the photovoltaic sheet 1, thereby suppressing the decrease in the power generation efficiency of the photovoltaic sheet 1 caused by the dirt suppressing the incidence of sunlight on the photovoltaic sheet 1.

[0117] In addition to being adhered to the installation surface 12 by the adhesive layer 13, the photovoltaic sheet 1 may be fixed to the installation surface 12 using a fastener. For example, at least a part of the third region 9 of the photovoltaic sheet 1 can be fixed to the installation surface 12 with a fastener. This allows the photovoltaic sheet 1 to be fixed to the installation surface 12 more strongly.

[0118] Examples of the fastener include a screw member having a flange such as a bolt, a screw, or a rivet, a staple, or other member capable of pressing the photovoltaic sheet 1 against the installation surface 12 from above to fix it to the installation surface 12. There are no particular limitations on the method of fastener for fixing the photovoltaic sheet 1 to the installation surface 12, and various other tools can be used as long as they can fix the photovoltaic sheet 1 to the installation surface 12.

[0119] (effect) As described above, according to this embodiment, on one main surface of the photovoltaic sheet 1, the first region 7 including the power generation section 3 is adhered to the installation surface 12 by the adhesive layer 13, and the second region 8 between two adjacent first regions 7 is not adhered to the installation surface 12. Therefore, even if the photovoltaic sheet 1 is thermally expanded or contracted due to a change in environmental temperature after being placed on the installation surface 12, the expansion and contraction of the first region 7 including the power generation section 3 can be absorbed by the second region 8. As a result, the second region 8 of the photovoltaic sheet 1 actively bends, and it is possible to prevent the first region 7 from bending and peeling off from the installation surface 12. Therefore, damage to the power generation section 3 due to bending of the first region 7 can be prevented.

[0120] Furthermore, according to this embodiment, on one main surface of the photovoltaic sheet 1, the second region 8 between two adjacent first regions 7 is not bonded to the installation surface 12 over the entire length in the direction perpendicular to the direction in which the first regions 7 are adjacent to each other. Therefore, when the photovoltaic sheet 1 thermally expands or contracts, the expansion and contraction of the first region 7 including the power generation section 3 can be effectively absorbed by the second region 8.

[0121] Furthermore, according to this embodiment, since the adhesive layer 13 has elasticity, the adhesive layer 13 is prone to deformation in the shear direction. Therefore, when the photovoltaic sheet 1 undergoes thermal expansion and contraction, the second region 8 adjacent to the first region 7 where the adhesive layer 13 is provided is prone to bending.

[0122] (Modification) Although one embodiment of the present invention has been described above, the above embodiment is merely one of various embodiments of the present invention. The embodiment can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved. Modifications of the embodiment are listed below. The modifications described below can be applied in appropriate combination.

[0123] In the above embodiment, in the second region 8 of the photovoltaic sheet 1, the non-adhesive portions 80 extend continuously in the width direction of the photovoltaic sheet 1 (a direction perpendicular to the direction in which the first regions 7 are adjacent), as shown in Fig. 4. As a modification, the non-adhesive portions 80 may be present intermittently in the width direction of the photovoltaic sheet 1 in the second region 8 of the photovoltaic sheet 1, as shown in Fig. 8. Alternatively, the non-adhesive portions 80 may be present only in a middle portion of the width direction of the photovoltaic sheet 1 in the second region 8 of the photovoltaic sheet 1, as shown in Fig. 9, or an adhesive layer 13 may be present in the middle portion of the width direction of the photovoltaic sheet 1, with non-adhesive portions 80 present on both sides of the adhesive layer 13, as shown in Fig. 10.

[0124] In the above embodiment, as shown in Fig. 2(A), at least a part of the second region 8 of the photovoltaic sheet 1 has a non-adhesive space 14 between it and the installation surface 12, and is a non-adhesive portion 80 that is not adhered to the installation surface 12. As a modified example, as shown in Figs. 11(A) and (B), instead of leaving a non-adhesive space 14 between at least a part of the second region 8 of the photovoltaic sheet 1 and the installation surface 12, a weak adhesive layer 15 having an adhesive strength weaker than the adhesive layer 13 may be interposed between the second region 8 and the installation surface 12, and the photovoltaic sheet 1 may be adhered to the installation surface 12 by the weak adhesive layer 15.

[0125] The weak adhesive layer 15 can be composed of an adhesive, a pressure sensitive adhesive, an adhesive sheet, or a double-sided tape. The adhesive strength of the weak adhesive layer 15 is preferably less than 70% of the adhesive strength of the adhesive layer 13, more preferably less than 60%, more preferably less than 50%, more preferably less than 25%, more preferably less than 15%, and more preferably less than 10%.

[0126] In the present disclosure, the adhesive strength of the adhesive layer 13 and the weak adhesive layer 15 mainly refers to the peeling force from the installation surface 12, and is preferably measured by a 90-degree peel test (JIS Z0237). The measurement method and peeling speed should be measured under the same conditions when making the above relative comparison.

[0127] In this modification, the weakly adhered portions 82 in the second region 8 of the photovoltaic sheet 1 exert an effect similar to that exerted by the non-fixed portions 80 in the above embodiment, making it possible to prevent damage to the power generation section 3 due to thermal contraction of the photovoltaic sheet 1. Furthermore, because the photovoltaic sheet 1 is adhered to the adhesive surface 12 over a wide area, it is possible to prevent the photovoltaic sheet 1 from vibrating due to the influence of wind, etc.

[0128] In the above embodiment, an adhesive layer 13 is provided on the main surface (rear surface) of the photovoltaic sheet 1 on the back sheet 2 side, and is adhered to the installation surface 12. As a modification, for a light-transmitting, preferably transparent, installation surface 12, an adhesive layer 13 may be provided on the main surface (front surface) of the photovoltaic sheet 1 on the barrier sheet 4 side, and adhered to the installation surface 12. In this modification, the adhesive layer 13 is light-transmitting.

[0129] In the above embodiment, the adhesive layer 13 has elasticity. As a modified example, the adhesive layer 13 may include an elastic body. For example, the adhesive layer 13 may have a three-layer structure of a first adhesive layer, an elastic body, and a second adhesive layer. The elastic body is, for example, a sheet formed of an elastic material. The thickness of the elastic body is preferably 0.1 mm or more, more preferably 1 mm or more, and more preferably 5 mm or more. On the other hand, the thickness of the elastic body is preferably 100 mm or less, more preferably 50 mm or less, and more preferably 10 mm or less. The numerical ranges obtained by combining the above-mentioned lower and upper limits in various ways are all preferred ranges for the thickness of the elastic body. When the thickness of the elastic body is within the range of 0.1 mm or more and 100 mm or less, it becomes easier to follow deformation due to thermal expansion and contraction, and the distance between the installation surface 12 and the photovoltaic sheet 1 can be made closer, so that vibrations due to wind blowing can be suppressed, and damage to the photovoltaic sheet 1 and the internal wiring can be suppressed. Examples of the elastic material include resin compositions containing at least one selected from vinyl acetate resin, ethylene vinyl acetate resin, epoxy resin, cyanoacrylate resin, acrylic resin, chloroprene rubber, styrene, butadiene rubber, polyurethane resin, silicone resin, and modified silicone resin.

[0130] The transverse elastic modulus of the elastic body is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, more preferably 1 MPa or more, and more preferably 10 MPa or more. On the other hand, the transverse elastic modulus of the elastic body is preferably 10000 MPa or less, more preferably 1000 MPa or less, more preferably 100 MPa or less, more preferably 50 MPa or less, and more preferably 10 MPa or less. The numerical ranges obtained by combining the above-mentioned lower and upper limits are all preferred ranges of the transverse elastic modulus of the elastic body. Since the transverse elastic modulus of the elastic body is within the range of 0.1 MPa or more and 10000 MPa or less, the photovoltaic sheet 1 can be applied to the installation surface 12 along the shape of the installation surface 12, so that the area can be effectively utilized. In addition, since the adhesive layer 13 including the elastic body is easily deformed in the shear direction, it is possible to easily cause deflection in the second region 8 adjacent to the first region 7 where the adhesive layer 13 is provided when the photovoltaic sheet 1 is thermally expanded or contracted.

[0131] In the above embodiment, the multiple power generation sections 7 are aligned in a row along the longitudinal direction of the photovoltaic sheet 1. As a variation, the power generation sections 3 may be aligned in multiple rows in the width direction of the photovoltaic sheet 1.

[0132] In the above embodiment, a solar power generation sheet 1 having a photoelectric conversion layer 331 containing a perovskite compound has been described as one form of the solar power generation sheet 1, but any flexible solar power generation sheet 1 can achieve the same effect. The solar power generation sheet 1 is not limited to a sheet that generates power using light, but may be a sheet that converts light energy into another form of energy (light energy conversion sheet). An example of a light energy conversion sheet is a light-generating sheet that converts light energy into thermal energy (a solar-powered thermoelectric conversion device). [Explanation of symbols]

[0133] 1. Photovoltaic sheet 3. Power Generation Division 7 First area 8 Second area 11 Setting surface 13 Adhesive layer 15 Weak adhesive layer

Claims

1. A photovoltaic sheet including a plurality of power generation units that generate electricity by receiving sunlight; An installation surface on which the solar power generation sheet is installed; an adhesive layer interposed between one main surface of the photovoltaic sheet and the installation surface to adhere a portion of the photovoltaic sheet to the installation surface; Equipped with the main surface of the photovoltaic sheet includes a plurality of first regions which are regions onto which the plurality of power generating portions are projected, and at least one second region which is a region between two adjacent first regions, The adhesive layer is interposed between the main surface and the installation surface so as to adhere at least the first region to the installation surface, An installation structure for a solar power generation sheet, wherein a non-adhesive space exists between the main surface and the installation surface, in which at least a portion of the second region is not adhered to the installation surface, or a weak adhesive layer is interposed, which adheres at least a portion of the second region to the installation surface with an adhesive force weaker than the adhesive force of the adhesive layer.

2. The solar power generation sheet installation structure according to claim 1 , wherein the non-adhesive space or the weakly adhesive layer extends over an entire length of the second region in a direction perpendicular to a direction in which the first regions are adjacent to each other.

3. The photovoltaic sheet installation structure according to claim 1 , wherein the adhesive layer has elasticity.

4. The solar power generation sheet installation structure according to claim 3 , wherein the adhesive layer has a modulus of transverse elasticity of 0.1 MPa or more and 10,000 MPa or less.

5. The photovoltaic sheet installation structure according to claim 1 , wherein the adhesive layer comprises an elastic material.

6. The solar power generation sheet installation structure according to claim 5 , wherein the elastic layer has a transverse elastic modulus of 0.1 MPa or more and 10,000 MPa or less.

7. The installation surface is an inclined surface that intersects with a horizontal plane at an angle, The plurality of power generating sections of the photovoltaic sheet are aligned in one direction, The solar power generation sheet installation structure according to claim 2 , wherein the solar power generation sheet is installed on the installation surface such that a direction perpendicular to a direction in which the plurality of power generation sections are arranged coincides with a tilt direction of the inclined surface.

8. A photovoltaic sheet including a plurality of power generating units that generate electricity by receiving sunlight, one main surface of the photovoltaic sheet that faces an installation surface when the photovoltaic sheet is installed on the installation surface includes a plurality of first regions that are regions onto which the plurality of power generating units are projected, and at least one second region that is a region between two adjacent first regions, A photovoltaic sheet having an adhesive area mark on the main surface, in a portion that includes at least the first region and does not include at least a portion of the second region, indicating a location where an adhesive layer is to be provided for adhering a portion of the photovoltaic sheet to the installation surface.

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