Electrode film, power generation substrate, organic solar cell, and photovoltaic power generation system

Abstract

[Problem] To improve the efficiency of converting light incident to an organic solar cell into electric power. [Solution] An electrode film 30 is used in the production of an organic solar cell 10. The electrode film 30 includes: a support 31; an electrode 40 supported by the support 31; and a stress relaxation layer 32 disposed between the support 31 and the electrode 40.

Description

Electrode film, power generation substrate, organic solar cell, solar power generation system

[0001] The present disclosure relates to an electrode film, a power generation substrate, an organic solar cell, and a solar power generation system.

[0002] Photovoltaic power generation systems are known as a power generation method that places little strain on the environment. Photovoltaic power generation systems use multiple solar cells. Solar cells convert light into electricity. Solar cells are classified into inorganic solar cells and organic solar cells. Organic solar cells have the advantage of low manufacturing costs.

[0003] Japanese Patent Application Laid-Open No. 2019-036598

[0004] Organic solar cells are required to efficiently convert incident light into electric power. Conventional organic solar cells have room for improvement in converting incident light into electric power near the electrode. The present disclosure aims to provide an electrode film that can improve the efficiency of converting incident light into electric power in organic solar cells.

[0005] The electrode film of the present disclosure is an electrode film used in the manufacture of an organic solar cell, and comprises: a support; an electrode supported by the support; and a stress relief layer disposed between the support and the electrode.

[0006] Effect of the Invention According to the present disclosure, it is possible to improve the efficiency of converting light incident on an organic solar cell into electric power.

[0007] Fig. 1 is a plan view showing a photovoltaic power generation system having an organic solar cell according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view of an example of an electrode film. Fig. 4A is a cross-sectional view of another example of an electrode film. Fig. 4B is a cross-sectional view of another example of an electrode film. Fig. 5 is a plan view of an example of an electrode. Fig. 6 is a cross-sectional view of an example of a power generation substrate. Fig. 7 is a cross-sectional view of another example of a power generation substrate. Fig. 8 is a cross-sectional view corresponding to Fig. 2, showing a modified example of the organic solar cell and the photovoltaic power generation system.

[0008] In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding. Components shown in some drawings may be omitted in other drawings.

[0009] In this specification, terms such as "parallel," "orthogonal," and "identical," which specify shapes and geometric conditions and their degrees, as well as values ​​of lengths and angles, are not limited to their strict meanings but are interpreted to include a range of degrees within which similar functions can be expected.

[0010] In this specification, terms such as "sheet," "film," and "plate" are not distinguished from one another solely on the basis of differences in name. For example, an "electrode film" cannot be distinguished from a member called an "electrode sheet" or an "electrode plate" solely on the basis of differences in name.

[0011] In this specification, the normal direction of a sheet-like member refers to the normal direction to the sheet surface of the target sheet-like member. Also, the "sheet surface" refers to the surface that coincides with the target sheet-like member when the target sheet-like member is viewed overall and in a global perspective. The same applies when "sheet" is read as "film" or "plate," etc.

[0012] In this specification, when multiple upper limit value candidates and multiple lower limit value candidates are listed for a parameter, the parameter may be a numerical range that combines any one upper limit value candidate and any one lower limit value candidate.

[0013] An embodiment of the present disclosure relates to the following [1] to

[23] .

[0014] [1] An electrode film used in the manufacture of organic solar cells, comprising: a support; an electrode supported by the support; and a stress relief layer disposed between the support and the electrode. [2] The electrode film according to [1], wherein the electrode is formed of a plurality of linear conductors extending to define an opening. [3] An electrode film used in the manufacture of organic solar cells, comprising: a support; and an electrode supported by the support, wherein the electrode is formed of a plurality of linear conductors extending to define an opening. [4] The electrode film according to [2] or [3], wherein the linear conductors have a line width that decreases with increasing distance from the support. [5] The electrode film according to any one of [2] to [4], wherein the material of the linear conductors is a conductive metal. [6] The electrode film according to [5], wherein the material of the linear conductors is copper or a copper alloy. [7] The electrode film according to any one of [2] to [6], further comprising a transparent conductive layer disposed at least in the opening and connected to the linear conductors. [8] The electrode film according to any one of [1] to [7], wherein the electrode comprises a binder resin and conductive nanowires that are held by the binder resin while some of the nanowires protrude from the binder resin. [9] An electrode film used in the manufacture of an organic solar cell, comprising: a support; and an electrode supported on the support, wherein the electrode comprises a binder resin and conductive nanowires that are held by the binder resin while some of the nanowires protrude from the binder resin.

[10] The electrode film according to [1], wherein the electrode comprises a binder resin and conductive nanowires that are held by the binder resin while some of the nanowires protrude from the binder resin, and the electrode is disposed over an entire area of ​​the electrode film.

[11] The electrode film according to any one of [1] to

[10] , further comprising seed crystals of crystals that form a photoelectric conversion layer of an organic solar cell, the seed crystals comprising an organic material, and the seed crystals being disposed on the side of the electrode opposite the support.

[12] The electrode film according to

[11] , wherein the electrode is formed of a plurality of linear conductors extending to define openings, and further comprising a transparent conductive layer disposed in at least the openings and connected to the linear conductors, the seed crystals being held by the transparent conductive layer.

[13] The electrode film according to

[11] or

[12] , further comprising a carrier transport layer disposed on the side of the electrode opposite the support, and the seed crystals being held by the carrier transport layer.

[14] The electrode film according to any one of

[11] to

[13] , wherein the seed crystals comprise a perovskite compound.

[15] The electrode film according to any one of

[11] to

[14] , wherein the average primary particle diameter of the seed crystals is 0.003 μm or more and 1 μm or less.

[16] The electrode film according to any one of [1] to

[15] , further comprising a carrier transport layer disposed on the side of the electrode opposite to the support.

[17] The electrode film according to any one of [1] to

[16] , further comprising a barrier layer disposed between the support and the electrode.

[18] The electrode film according to any one of [1] to

[17] , further comprising a hard coat layer disposed on the side of the support opposite to the electrode.

[19] A power generation substrate comprising: an electrode; a photoelectric conversion layer electrically connected to the electrode; and a stress relaxation layer disposed on the side of the electrode opposite to the photoelectric conversion layer, wherein the photoelectric conversion layer contains an organic material.

[20] A power generation substrate comprising: an electrode; and a photoelectric conversion layer electrically connected to the electrode, wherein the photoelectric conversion layer contains an organic material, and the electrode is formed by a plurality of linear conductors extending to define an opening.

[21] A power generating substrate comprising: an electrode; and a photoelectric conversion layer electrically connected to the electrode, wherein the photoelectric conversion layer contains an organic material; and the electrode contains conductive nanowires.

[22] An organic solar cell comprising: the power generation substrate according to any one of

[19] to

[21] ; and a second electrode arranged on the opposite side of the photoelectric conversion layer from the electrode.

[23] A solar power generation system comprising: a plurality of organic solar cells according to

[22] ; and a circuit connecting the plurality of organic solar cells.

[0015] An embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a plan view of a solar power generation system according to the embodiment. The solar power generation system 1 supplies electric power when irradiated with light. The solar power generation system 1 converts light energy into electrical energy. The solar power generation system 1 supplies electric power not only from sunlight but also from illumination light, image light, and the like. As shown in FIG. 1 , the solar power generation system 1 includes a substrate 3, a circuit 5, and a plurality of organic solar cells 10. The solar power generation system 1 supplies electric power generated when the organic solar cells 10 are irradiated with light via the circuit 5 to a power consuming device and a storage battery that stores the electric power, both of which are not shown.

[0016] The substrate 3 supports the circuit 5 and the organic solar cell 10. The substrate 3 is plate-shaped. The thickness of the substrate 3 may be 1 μm or more, 25 μm or more, 10 mm or less, or 500 μm or less. The substrate 3 is an insulator. The material of the substrate 3 may be an inorganic material such as glass, a plastic material such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cycloolefin polymer, or polyimide, or a composite material such as a nanocomposite.

[0017] The circuit 5 electrically connects multiple organic solar cells 10 together, and also connects the organic solar cells 10 to a power-consuming device (not shown) or a storage battery (not shown) for storing power. Between two organic solar cells 10, the circuit 5 includes a first connection portion 6 and a second connection portion 7. The first connection portion 6 and the second connection portion 7 are connected to each other. The first connection portion 6 is connected to an electrode 40 (described later) of the organic solar cell 10. The second connection portion 7 is connected to a second electrode 60 (described later) of the organic solar cell 10. The first connection portion 6 and the second connection portion 7 connect adjacent organic solar cells 10. Power generated in the organic solar cells 10 is transmitted via the circuit 5. The circuit 5 extends linearly. The circuit 5 is made of a conductive material such as copper. A diode may be disposed in the circuit 5. The diode bypasses an organic solar cell 10 that is unable to generate power due to shadowing, a malfunction, or the like.

[0018] The organic solar cell 10 generates power using incident light. The organic solar cell 10 can generate power not only using sunlight but also using illumination light, image light, etc. The organic solar cell 10 is in the form of a thin film. The organic solar cell 10 may be an organic thin-film solar cell. The organic solar cell 10 may be a perovskite solar cell. The thickness of the organic solar cell 10 may be 0.05 μm or more, 100 μm or less, or 0.5 μm or less. The organic solar cell 10 may be transparent. The visible light transmittance of the organic solar cell 10 may be 10% or more, or 30% or more.

[0019] In this specification, visible light transmittance is specified as the average value of the total light transmittance at each wavelength when measured in 1 nm increments within a wavelength range of 380 nm to 780 nm using a spectrophotometer (Shimadzu Corporation's "UV-3600i Plus," compliant with JIS K0115). The angle of incidence when measuring visible light transmittance is set to 0° unless a particular transmission direction is specified. The angle of incidence is the angle between the normal to the incident surface and the traveling direction of incident light, and is a value less than 90°.

[0020] In the example shown in FIG. 1, a plurality of organic solar cells 10 are regularly arranged in two dimensions. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 2 shows a cross-sectional view of the organic solar cell 10. As shown in FIG. 2, the organic solar cell 10 includes a first surface 10A and a second surface 10B opposite the first surface 10A. The first surface 10A and the second surface 10B form a pair of plate surfaces of the organic solar cell 10. The organic solar cell 10 contacts the substrate 3 at the first surface 10A. The organic solar cell 10 includes, in this order from the first surface 10A to the second surface 10B, a hard coat layer 37, a support 31, a barrier layer 36, a stress relaxation layer 32, an electrode 40, a transparent conductive layer 33, a carrier transport layer 34, a photoelectric conversion layer 25, a second carrier transport layer 54, and a second electrode 60. The second electrode 60 is disposed on the opposite side of the photoelectric conversion layer 25 to the electrode 40. The electrode 40 and the second electrode 60 are disposed opposite to each other. The photoelectric conversion layer 25 is disposed between the electrode 40 and the second electrode 60.

[0021] The photoelectric conversion layer 25 absorbs light to excite electrons and holes therein. The photoelectric conversion layer 25 is electrically connected to the electrode 40 and the second electrode 60. The excited electrons move toward the electrode 40. The excited holes move toward the second electrode 60. The movement of electrons and holes generates electricity. In this way, the photoelectric conversion layer 25 converts light into electricity. The photoelectric conversion layer 25 contains an organic material. The photoelectric conversion layer 25 may contain a perovskite compound. A perovskite compound refers to a semiconductor compound having a perovskite structure. A perovskite structure is usually formed by perovskite (CaTiO ３ AMX such as perovskite ３ The perovskite compound has a crystal structure represented by the following composition. The perovskite compound can have various compositions depending on the type of ligand and central metal. The photoelectric conversion layer 25 containing the perovskite compound contains lead to increase the photoelectric conversion efficiency. The perovskite compound is, for example, CH ３ NH ３ PbI ３ , CH(NH ２ ) ２ PbI３ , Cs ０．０５ (FA ０．８５ MA ０．１５ ) ０．９５ Pb(I ０．８９ Br ０．１１ ) ３ , Cs ０．１ FA ０．６ MA ０．３ Sn ０．５ Pb ０．５ I ３ , CsPbCl ３ The photoelectric conversion layer 25 may be made of a high-purity perovskite compound. Specifically, the photoelectric conversion layer 25 may contain 98% by mass or more, or 99% by mass or more, of the perovskite compound. The photoelectric conversion layer 25 containing an organic material can generate electricity by absorbing visible light, for example, with a wavelength of 410 nm or more and 700 nm or less. The photoelectric conversion layer 25 containing an organic material can also generate electricity using light with lower illuminance than sunlight, such as illumination light or image light. Compared to a photoelectric conversion layer containing an inorganic material such as silicon, the photoelectric conversion layer 25 containing an organic material is more likely to generate electricity using light from a direction oblique to the normal direction of the photoelectric conversion layer 25. The photoelectric conversion layer 25 may be transparent. Specifically, the visible light transmittance of the photoelectric conversion layer 25 may be 10% or more, or 30% or more. The thickness of the photoelectric conversion layer 25 may be 0.05 μm or more, 100 μm or less, or 0.5 μm or less.

[0022] The organic solar cell 10 is manufactured using an electrode film 30 as shown in Figures 3, 4A, and 4B. Figure 3 is a cross-sectional view of an example of the electrode film 30, and Figure 4A is a cross-sectional view of another example of the electrode film 30. Figure 4B is a cross-sectional view of another example of the electrode film 30. The electrode film 30 will be described below.

[0023] The electrode film 30 includes a third surface 30A and a fourth surface 30B opposite to the third surface 30A. The third surface 30A and the fourth surface 30B form a pair of film surfaces of the electrode film 30. In the example shown in FIG. 3 , the electrode film 30 includes, from the third surface 30A to the fourth surface 30B, a hard coat layer 37, a support 31, a barrier layer 36, a stress relief layer 32, an electrode 40, a transparent conductive layer 33, a carrier transport layer 34, and a plurality of seed crystals 35. In the example shown in FIGS. 4A and 4B , the transparent conductive layer 33 is omitted from the electrode film 30. The electrode film 30 of the example shown in FIGS. 4A and 4B may also include the transparent conductive layer 33.

[0024] The support 31 supports the hard coat layer 37, the barrier layer 36, the stress relaxation layer 32, the electrode 40, the transparent conductive layer 33, and the carrier transport layer 34 in the electrode film 30. The support 31 is in the form of a film. The thickness of the support 31 may be 1 μm or more, 25 μm or more, or 500 μm or less. The support 31 is an insulator. The material of the support 31 may be polyethylene terephthalate, polycarbonate, cyclic polyolefin, a thin glass sheet, or an organic-inorganic nanocomposite sheet.

[0025] The electrode 40 extracts electrons that have migrated from the photoelectric conversion layer 25. The electrode 40 may be transparent. Specifically, the visible light transmittance of the electrode 40 may be 75% or more, or 85% or more. The thickness of the electrode 40 may be 5 nm or more, 50 nm or more, 3000 nm or less, or 150 nm or less.

[0026] FIG. 5 shows an example of a plan view of the electrode 40 in the electrode film 30 shown in FIG. 3 . As shown in FIG. 5 , the electrode 40 may include a plurality of linear conductors 41. The linear conductors 41 extend to define openings 43. That is, the electrode 40 may be mesh-shaped. The line width of the linear conductors 41 may be 0.1 μm or more and 100 μm or less. The pitch P of the openings 43 may be 0.4 μm or more and 500 μm or less. The line width of the linear conductors 41 may decrease with increasing distance from the support 31. In other words, the linear conductors 41 may be tapered. The material of the electrode 40 and the linear conductors 41 may be a conductive metal. The metal may be any metal such as gold, silver, copper, iron, tin, aluminum, nickel, or chromium, or an alloy of these metals. Considering conductivity and cost, the material of the electrode 40 and the linear conductors 41 is preferably copper or a copper alloy. The electrodes 40 and the linear conductors 41 may be single-layered or multi-layered.

[0027] In the mesh-shaped electrode 40, the electrode 40 and the linear conductors 41 may contain a binder resin and conductive nanowires held by the binder resin. Portions of the conductive nanowires protrude from the binder resin. The electrode 40 and the linear conductors 41 are conductive from their surfaces to their interiors. The electrode 40 and the linear conductors 41 have conductive nanowires connected to each other inside. The electrode 40 and the linear conductors 41 are conductive as a whole. Even if the amount of conductive nanowires is small, the electrode 40 and the linear conductors 41 can efficiently have conductivity.

[0028] The binder resin protects the conductive nanowires while holding them and preventing them from detaching. The binder resin is flexible. The binder resin is stretchable. The thickness of the binder resin may be 10 nm or more, 50 nm or more, 90 nm or more, 300 nm or less, 200 nm or less, or 180 nm or less. When the thickness of the binder resin is not too thick, a portion of the conductive nanowires can easily protrude from the binder resin. When the thickness of the binder resin is not too thin, the binder resin can properly hold and protect the conductive nanowires.

[0029] The thickness of the binder resin is determined by the following method. Using a scanning electron microscope (SEM), a scanning transmission electron microscope (STEM), or a transmission electron microscope (TEM), an image of the cross section of the binder resin is obtained at a magnification of 1,000 to 500,000. The thickness of the binder resin is measured at 10 random locations on the obtained image. The average of the measured thicknesses is determined as the thickness of the binder resin. The thickness of the binder resin in the obtained image is measured using image processing software "ImageJ."

[0030] The binder resin material may be a polymer of a polymerizable compound or a solvent-drying resin. The polymerizable compound may be an ionizing radiation-polymerizable compound and / or a thermally polymerizable compound.

[0031] The ionizing radiation-polymerizable compound has at least one ionizing radiation-polymerizable functional group per molecule. In this specification, the term "ionizing radiation-polymerizable functional group" refers to a functional group that can undergo a polymerization reaction upon exposure to ionizing radiation. The ionizing radiation-polymerizable functional group may be, for example, an ethylenically unsaturated group such as a (meth)acryloyl group, a vinyl group, or an allyl group. The term "(meth)acryloyl group" encompasses both an "acryloyl group" and a "methacryloyl group." The ionizing radiation used to polymerize the ionizing radiation-polymerizable compound may be visible light, ultraviolet light, X-rays, an electron beam, α-rays, β-rays, or γ-rays.

[0032] The ionizing radiation-polymerizable compound may be an ionizing radiation-polymerizable monomer, an ionizing radiation-polymerizable oligomer, or an ionizing radiation-polymerizable prepolymer. The ionizing radiation-polymerizable compound is preferably a combination of an ionizing radiation-polymerizable monomer and an ionizing radiation-polymerizable oligomer or an ionizing radiation-polymerizable prepolymer.

[0033] The ionizing radiation-polymerizable monomer may be, for example, a monomer containing a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or 2-ethylhexyl (meth)acrylate, or a (meth)acrylic acid ester, such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, or glycerol (meth)acrylate.

[0034] The ionizing radiation-polymerizable oligomer is preferably a polyfunctional oligomer having two or more functional groups, and more preferably a polyfunctional oligomer having three or more (trifunctional) ionizing radiation-polymerizable functional groups. The polyfunctional oligomer may be, for example, polyester (meth)acrylate, urethane (meth)acrylate, polyester-urethane (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, isocyanurate (meth)acrylate, or epoxy (meth)acrylate.

[0035] The ionizing radiation polymerizable prepolymer has a weight-average molecular weight of more than 10,000, preferably from 10,000 to 80,000, and more preferably from 10,000 to 40,000. If the weight-average molecular weight exceeds 80,000, the viscosity will be high, which may reduce the coatability and deteriorate the appearance of the resulting cover resin. The multifunctional prepolymer may be urethane (meth)acrylate, isocyanurate (meth)acrylate, polyester-urethane (meth)acrylate, epoxy (meth)acrylate, etc.

[0036] A thermally polymerizable compound has at least one thermally polymerizable functional group per molecule. In this specification, a "thermally polymerizable functional group" refers to a functional group that can undergo a polymerization reaction with other functional groups or with other functional groups upon heating. The thermally polymerizable functional group may be a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, a cyclic ether group, a mercapto group, or the like.

[0037] The thermally polymerizable compound may be, for example, an epoxy compound, a polyol compound, an isocyanate compound, a melamine compound, a urea compound, a phenol compound, or the like.

[0038] The solvent-drying resin is a resin, such as a thermoplastic resin, that can be formed into a coating by simply drying the solvent added to adjust the solid content during coating. When a solvent-drying resin is added, coating defects on the surface to which the coating liquid is applied can be effectively prevented when forming a cover resin. The solvent-drying resin may be a thermoplastic resin.

[0039] The thermoplastic resin may be, for example, a styrene-based resin, a (meth)acrylic resin, a vinyl acetate-based resin, a vinyl ether-based resin, a halogen-containing resin, an alicyclic olefin-based resin, a polycarbonate-based resin, a polyester-based resin, a polyamide-based resin, a cellulose derivative, a silicone-based resin, a rubber, an elastomer, or the like. The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving multiple polymers and curable compounds). From the viewpoints of transparency and weather resistance, the thermoplastic resin is preferably a styrene-based resin, a (meth)acrylic resin, an alicyclic olefin-based resin, a polyester-based resin, a cellulose derivative (such as a cellulose ester), or the like.

[0040] The diameter of the conductive nanowire may be 10 nm or more, 15 nm or more, 200 nm or less, or 180 nm or less. When the diameter of the conductive nanowire is not too large, high haze in the electrode 40 can be suppressed. The length of the conductive nanowire may be 1 μm or more, 3 μm or more, 10 μm or more, 500 μm or less, 300 μm or less, or 30 μm or less. When the length of the conductive nanowire is not too short, the conductivity of the electrode 40 and the linear conductor 41 can be improved. When the length of the conductive nanowire is not too long, the electrode 40 can be easily made transparent. The conductive nanowire may be made of metals such as gold, silver, copper, iron, aluminum, nickel, and titanium, or alloys thereof. The conductive nanowire may be made by coating a synthetic fiber such as acrylic fiber with a metal such as gold, silver, copper, aluminum, nickel, and titanium, or alloys thereof. The conductive nanowire may contain a plurality of these materials.

[0041] The diameter and length of the conductive nanowires are determined by the following method: A transmission electron microscope (TEM) is used to obtain an image of the cross section of the electrode 40 observed at 1,000 to 500,000 magnifications. In the obtained image, the diameters and lengths of 50 conductive nanowires are measured. The average diameters and average lengths of the measured conductive nanowires are determined as the diameter and length of the conductive nanowires contained in the electrode. The diameter and thickness of the conductive nanowires in the obtained image are measured using the image processing software "ImageJ."

[0042] In the mesh electrode 40, the electrode 40 and the linear conductors 41 may contain a binder resin and conductive particles held in the binder resin. In other words, the electrode 40 and the linear conductors 41 may be made of a conductive paste. The binder resin may have the same structure as the binder resin that holds the conductive nanowires described above.

[0043] The material of the conductive particles may be metal particles such as gold, silver, platinum, copper, nickel, tin, or aluminum. The conductive particles may be particles in which the surface of core particles such as high-resistivity metal particles, resin particles, or inorganic particles is coated with a low-resistivity metal such as gold or silver, or may be graphite particles, conductive polymer particles, or conductive ceramic particles. The shape of the conductive particles may be various polyhedral shapes such as regular polyhedrons and truncated polyhedrons, or may be spherical, spheroidal, flaky, discoidal, dendritic, fibrous, or the like. The average particle diameter of the conductive particles may be 0.01 μm or more and 10 μm or less.

[0044] The average particle size of the conductive particles is determined by the following method. A transmission electron microscope (TEM) is used to obtain an image of the cross section of the electrode 40 observed at 1,000 to 500,000 magnifications. The particle sizes of 50 conductive particles are measured in the obtained image. The average of the measured particle sizes of the conductive particles is determined as the average particle size of the conductive particles contained in the electrode. The particle sizes of the conductive particles in the obtained image are measured using image processing software "ImageJ."

[0045] As shown in FIG. 4A , the electrode 40 may be disposed over the entirety of one region of the electrode film 30. In other words, the electrode 40 may be disposed solidly over a certain area of ​​the electrode film 30. The electrode 40 may be disposed over the entirety of the electrode film 30. In other words, the electrode 40 may be disposed solidly over the entirety of the electrode film 30. In an organic solar cell 10 manufactured using the electrode film 30, the electrode 40 may be disposed over the entirety of one region of the organic solar cell 10, or may be disposed over the entirety of the organic solar cell 10. The electrode 40 shown in FIG. 4A includes a binder resin 47 and a plurality of conductive nanowires 45 held in the binder resin 47. The binder resin 47 and the conductive nanowires 45 may have a structure similar to that of the binder resin and the conductive nanowires included in the mesh-shaped electrode 40 described above.

[0046] As shown in FIG. 4B , the electrode 40 of the electrode film 30 may include a first portion 48 including a plurality of linear conductors 41 and a second portion 49 disposed over an entire region of the electrode film 30. The description of the electrode 40 of the electrode film 30 shown in FIG. 3 may be applied to the first portion 48 unless inconsistent. The first portion 48 may be mesh-shaped. The first portion 48 may be mesh-shaped as shown in FIG. 5. The description of the electrode 40 of the electrode film 30 shown in FIG. 4A may be applied to the second portion 49 unless inconsistent. In the example shown in FIG. 4B , the second portion 49 includes a binder resin 47 and a plurality of conductive nanowires 45 held in the binder resin 47. In the example shown in FIG. 4B , some of the conductive nanowires 45 included in the second portion 49 protrude from the binder resin 47. In the example shown in FIG. 4B , the distance between the second portion 49 and the fourth surface 30B is smaller than the distance between the first portion 48 and the fourth surface 30B. In the example shown in FIG. 4B , the seed crystal 35 is held by the carrier transport layer 34. In particular, in the electrode film 30 shown in FIG. 4B , the second portion 49 and the carrier transport layer 34 are in contact with each other. A portion of the conductive nanowires 45 included in the second portion 49 protrudes from the binder resin 47 toward the carrier transport layer 34. In particular, a portion of the conductive nanowires 45 included in the second portion 49 protrudes from the binder resin 47 toward the carrier transport layer 34 so as to penetrate into the carrier transport layer 34. In particular, a portion of the conductive nanowires 45 included in the second portion 49 protrudes from the binder resin 47 toward the carrier transport layer 34 so as to slightly penetrate into the carrier transport layer 34. Although not shown, the electrode film 30 having the electrode 40 including the first portion 48 and the second portion 49 may further include a transparent conductive layer 33, and the seed crystal 35 may be held in the transparent conductive layer 33.

[0047] 4B includes a mesh-like first portion 48 and a second portion 49 including a binder resin 47 and a plurality of conductive nanowires 45. Some of the conductive nanowires 45 protrude from the binder resin 47 toward the carrier transport layer 34 so as to penetrate into the carrier transport layer 34. The effects of such an electrode film 30 will be described.

[0048] The mesh-like first portion 48 is more likely to have high conductivity than the second portion 49 including the binder resin 47 and the plurality of conductive nanowires 45. According to the electrode film 30 shown in Fig. 4B, the first portion 48, which is more likely to have high conductivity, can serve as the main conductive path.

[0049] On the other hand, the second portion 49, which includes the binder resin 47 and the plurality of conductive nanowires 45, is more likely to have a large aspect ratio of the conductive portion than the mesh-like first portion 48. In particular, the second portion 49, which includes the binder resin 47 and the plurality of conductive nanowires 45, can have a needle-like structure with a large aspect ratio. In the first portion 48, the "conductive portion" is the linear conductor 41. In the second portion 49, the "conductive portion" is the conductive nanowire 45. As described above, by allowing a portion of the conductive nanowire 45, which can have a large aspect ratio, to protrude so as to penetrate into the carrier transport layer 34, the second portion 49 can be used to efficiently collect current from the photoelectric conversion layer 25. According to the electrode film 30 shown in FIG. 4B , the second portion 49, which can efficiently collect current, can be assigned the role of collecting current from the photoelectric conversion layer 25.

[0050] That is, the electrode film 30 shown in FIG. 4B can take advantage of both the advantage of easily increasing the conductivity of the first portion 48 and the advantage of being able to collect current efficiently from the photoelectric conversion layer 25 of the second portion 49.

[0051] When the electrode 40 includes the binder resin 47 and the conductive nanowires 45, the proportion of the binder resin in the electrode 40 may be 20% by mass or more, 30% by mass or more, 80% by mass or less, or 70% by mass or less. The refractive index of the electrode 40 can be changed by adjusting the proportion of the binder resin in the electrode 40. The refractive index of the electrode 40 may be 1.40 or more, 1.44 or more, 1.60 or less, or 1.56 or less.

[0052] The electrode 40 is transparent as a whole because it is in a mesh shape or because it contains a binder resin 47 and a plurality of conductive nanowires 45 held in the binder resin 47 .

[0053] The electrode 40 has flexibility due to being in a mesh shape or due to including the binder resin 47 and the plurality of conductive nanowires 45 held by the binder resin 47. The flexibility prevents the film stress on the electrode 40 from becoming too high. The film stress on the electrode 40 is, for example, the stress that is applied between the electrode 40 and the photoelectric conversion layer 25 during the manufacture of the organic solar cell 10 or inside the manufactured organic solar cell 10.

[0054] The transparent conductive layer 33 improves the conductivity of the electrode 40 while maintaining the transparency of the electrode 40. When the electrode 40 is mesh-shaped, the transparent conductive layer 33 is disposed at least in the openings 43. The transparent conductive layer 33 is connected to the linear conductors 41. The transparent conductive layer 33 may cover the linear conductors 41. The transparent conductive layer 33 may be provided over the entire electrode 40. The transparent conductive layer 33 is in the form of a thin film. The thickness of the transparent conductive layer 33 may be 0.01 μm or more or 2 μm or less. The transparent conductive layer 33 may be a conductive polymer (PEDOT). The transparent conductive layer 33 may include a binder resin and conductive nanowires held in the binder resin. The binder resin and the conductive nanowires may have the same configuration as the binder resin and conductive nanowires contained in the mesh-shaped electrode 40 described above.

[0055] The seed crystals 35 are seed crystals for forming the photoelectric conversion layer 25. The crystal structure inside the seed crystals 35 is uniform. The crystal structure of the seed crystals 35 grows to form the photoelectric conversion layer 25. The seed crystals 35 are made of the same material as the photoelectric conversion layer 25. The seed crystals 35 contain an organic material. The seed crystals 35 may contain a perovskite compound. The seed crystals 35 are arranged on the side of the electrode 40 opposite the support 31. The seed crystals 35 are arranged along the electrode 40. The seed crystals 35 may be held by the transparent conductive layer 33 or the carrier transport layer 34. The seed crystals 35 are arranged on the fourth surface 30B of the electrode film 30. The average primary particle diameter of the seed crystals 35 may be 0.003 μm or more or 1 μm or less.

[0056] The average primary particle diameter of the seed crystals 35 is determined by observing a cross section of the electrode film 30 or a cross section of the organic solar cell 10 manufactured using the electrode film 30 with a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). Specifically, images of the cross section of the electrode film 30 or a cross section of the organic solar cell 10 manufactured using the electrode film 30 are acquired with a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). The acquired images are binarized. For example, the image density is divided into gradations of 0 to 255, and a gradation threshold is set for binarization so that the seed crystals 35 can be distinguished from other components. From the binarized image, 1,000 seed crystals 35 are randomly selected, and the primary particle diameter of each is measured. The average of the measured particle diameters is defined as the average primary particle diameter of the seed crystals 35. The acquired images are processed and the particle diameters in the binarized images are measured using the image processing software "ImageJ."

[0057] The stress relaxation layer 32 relieves stress applied between the electrode 40 and the photoelectric conversion layer 25, for example, during the manufacture of the organic solar cell 10 or inside the manufactured organic solar cell 10. The stress relaxation layer 32 is flexible. The stress relaxation layer 32 is easily stretchable. The stress relaxation layer 32 may be a laminate of multiple layers. The stress relaxation layer 32 is disposed between the support 31 and the electrode 40. The stress relaxation layer 32 may be an insulator. The stress relaxation layer 32 is in the form of a thin film. The thickness of the stress relaxation layer 32 may be 1 μm or more, 3 μm or more, 5 μm or more, 10 μm or more, 350 μm or less, 20 μm or less, 15 μm or less, or 10 μm or less. The material of the stress relaxation layer 32 may be any of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), ethylene vinyl acetate copolymer (EVA), acrylic resin (hard and soft), urethane resin (hard and gel), nanocomposite, polymer melt such as polyisoprene, various rubber materials, and physical gel. When the stress relaxation layer 32 is to be heat-resistant, the material of the stress relaxation layer 32 may be polyimide resin, epoxy resin, acrylic / urethane resin, novolac resin, or the like.

[0058] The carrier transport layer 34 is disposed on the opposite side of the electrode 40 from the support 31, between the photoelectric conversion layer 25 and the electrode 40. The carrier transport layer 34 efficiently transports electrons from the photoelectric conversion layer 25 to the electrode 40. The carrier transport layer 34 improves the photoelectric conversion efficiency of the organic solar cell 10. The carrier transport layer 34 may be transparent. Specifically, the visible light transmittance of the carrier transport layer 34 may be 95% or more, or 98% or more. The thickness of the carrier transport layer 34 may be 0.005 μm or more, or 0.120 μm or less. The material of the carrier transport layer 34 may be titanium oxide or tin oxide. The carrier transport layer 34 may be the same as the transparent conductive layer 33. The carrier transport layer 34 may also serve as the transparent conductive layer 33.

[0059] The barrier layer 36 blocks oxygen and water vapor, protecting the photoelectric conversion layer 25 in the organic solar cell 10 manufactured using the electrode film 30 from oxygen and water vapor. The barrier layer 36 is disposed between the support 31 and the electrode 40, and between the stress relaxation layer 32 and the support 31. The barrier layer 36 has water vapor barrier properties and oxygen barrier properties. Specifically, the water vapor permeability of the barrier layer 36 is 0.5 g / m ２ ・It may be 0.1 g / m or less. ２ The oxygen permeability of the barrier layer 36 may be 10 cc / m or less. ２ ・day・atm or less, 5cc / m ２ Water vapor permeability [g / m ２ ·day] is a value measured in accordance with JIS K7129B. The water vapor permeability is measured using a water vapor permeability measuring instrument (PERMATRAN manufactured by MOCON) under an environment of a temperature of 40°C and a humidity of 90% RH. Oxygen permeability [cc / m ２ ·day·atm] is a value measured in accordance with JIS K7126-1. The oxygen permeability is measured using an oxygen permeability measuring device (OXTRAN manufactured by MOCON) in an environment of a temperature of 23°C and a humidity of 90% RH. The barrier layer 36 may be transparent. Specifically, the visible light transmittance of the barrier layer 36 may be 85% or more, or 95% or more. The barrier layer 36 is in the form of a thin film. The thickness of the barrier layer 36 may be 5 nm or more, or 80 nm or less. The material of the barrier layer 36 may be silicon oxide, aluminum oxide, or silicon nitride.

[0060] The hard coat layer 37 protects the electrode film 30 and other components of the organic solar cell 10 manufactured using the electrode film 30. The hard coat layer 37 is weather resistant. The hard coat layer 37 is disposed on the side of the support 31 opposite the electrode 40. The hard coat layer 37 forms the third surface 30A of the electrode film 30. The hard coat layer 37 is transparent. Specifically, the visible light transmittance of the hard coat layer 37 may be 85% or more, or 95% or more. The hard coat layer 37 is thin-film shaped. The thickness of the hard coat layer 37 may be 0.5 μm or more, 1 μm or more, 3 μm or more, 50 μm or less, 40 μm or less, or 20 μm or less. The material of the hard coat layer 37 may be a composition such as a polyester resin, an epoxy resin, a polyurethane resin, an aminoalkyd resin, a melamine resin, a guanamine resin, a urea resin, a fluorine-based resin, a silicone-based resin, a thermosetting acrylic resin, or an electron beam curable resin, or a combination thereof. From the viewpoint of weather resistance and scratch resistance, the hard coat layer 37 is preferably made of a cured product of an electron beam curable resin composition.

[0061] The hard coat layer 37 may contain an ultraviolet absorber or a light stabilizer to provide sufficient weather resistance. The ultraviolet absorber may be a benzophenone-based, benzotriazole-based, salicylate-based, acrylonitrile-based, metal complex salt-based, or inorganic material such as ultrafine titanium oxide or ultrafine zinc oxide, or a combination thereof. The light stabilizer may be a hindered amine-based compound.

[0062] The hard coat layer 37 may further have flame retardancy. The hard coat layer 37 may contain a flame retardant to impart flame retardancy. The flame retardant may be one or a combination of a phosphorus-based, phosphorus + halogen-based, chlorine-based, bromine-based, ammonium hydroxide, magnesium hydroxide, antimony-based, guanidine-based, zirconium-based, zinc borate, silicone-based, nitrogen-based, low-melting-point glass-based, nanocomposite-based, and the like.

[0063] In the organic solar cell 10 manufactured using the electrode film 30 described above, as shown in FIG. 2, the stress relaxation layer 32 is disposed on the side of the electrode 40 opposite to the photoelectric conversion layer 25 .

[0064] The second electrode 60 extracts holes that have migrated from the photoelectric conversion layer 25. By extracting holes using the second electrode 60, and in addition to extracting electrons using the electrode 40, it is possible to transmit the power generated in the photoelectric conversion layer 25 to the outside. The second electrode 60 may be transparent. Specifically, the visible light transmittance of the second electrode 60 may be 75% or more, or 85% or more. The thickness of the second electrode 60 may be 5 nm or more, or 150 nm or less. The second electrode 60 may have a configuration similar to that of the electrode 40.

[0065] The second carrier transport layer 54 is disposed between the photoelectric conversion layer 25 and the second electrode 60. The second carrier transport layer 54 efficiently transports holes from the photoelectric conversion layer 25 to the second electrode 60. The second carrier transport layer 54 improves the photoelectric conversion efficiency of the organic solar cell 10. The second carrier transport layer 54 may be transparent. Specifically, the visible light transmittance of the second carrier transport layer 54 may be 95% or more, or 98% or more. The thickness of the second carrier transport layer 54 may be 0.050 μm or more, or 0.2 μm or less. The material of the second carrier transport layer 54 may be Spiro-OMeTAD or copper thiocyanate.

[0066] In the organic solar cell 10, the electrode 40 and the second electrode 60 may be interchanged. In other words, the electrode 40 and the second electrode 60 may be reversed. In this case, the carrier transport layer 34 and the second carrier transport layer 54 are also interchanged. In other words, the carrier transport layer 34 and the second carrier transport layer 54 are also reversed.

[0067] The organic solar cell 10 may further include other layers intended to perform specific functions. The organic solar cell 10 may include, for example, a filler layer, a strength support layer, an antifouling layer, a light-confining layer, and an adhesive layer. The organic solar cell 10 may further include a second transparent electrode layer, a second stress relief layer, a second barrier layer, and a second hard coat layer overlying the second electrode 60. In the organic solar cell 10, the support 31, the stress relief layer 32, the transparent conductive layer 33, the barrier layer 36, and the hard coat layer 37 may be omitted. In the electrode film 30, the stress relief layer 32, the transparent conductive layer 33, the seed crystal 35, the barrier layer 36, and the hard coat layer 37 may be omitted. The seed crystal 35 may be provided on the electrode film 30 immediately before manufacturing the organic solar cell 10 using the electrode film 30.

[0068] An example of a manufacturing method for the electrode film 30 will be described. For example, an ionizing radiation curable resin is applied to the support 31, and the ionizing radiation curable resin is irradiated with an electron beam to cure, thereby forming a hard coat layer 37. A barrier layer 36 is formed on the surface of the support 31 opposite to the surface on which the hard coat layer 37 is formed. The barrier layer 36 is formed, for example, by sputtering. A stress relief layer 32 is formed on the barrier layer 36, for example, by coating. An electrode 40 is formed on the stress relief layer 32. The electrode 40 is formed by a plurality of linear conductors 41 extending to define openings 43 as shown in FIGS. 3 and 5, for example, by providing a metal film and etching the metal film into a predetermined pattern. A transparent conductive layer 33 is formed, for example, by imprinting technology, so as to be positioned at least in the openings 43. The electrode 40, which includes conductive nanowires 45 held in a binder resin 47 with some portions protruding from the binder resin 47 as shown in FIG. 4A, is formed by, for example, slit coating, roll coating, dip coating, blade coating, wire bar coating, or screen printing. In these formation methods, the film thickness can be controlled by adjusting the feed rate, moving speed, lifting speed, rotation speed, and / or blade spacing. The carrier transport layer 34 is formed by applying the carrier transport layer 34 by, for example, spin coating so as to overlap the electrode 40 or the transparent conductive layer 33. Seed crystals 35 are dispersed so as to be held by the transparent conductive layer 33 or the carrier transport layer 34. Alternatively, the seed crystals 35 can be formed by vacuum deposition, such as sputtering, on the transparent conductive layer 33 or the carrier transport layer 34.

[0069] An example of a method for manufacturing an organic solar cell 10 using the electrode film 30 will be described. The method for manufacturing an organic solar cell 10 using the electrode film 30 includes a step of growing a seed crystal 35 in the photoelectric conversion layer 25, and a step of providing a second electrode 60 and a second carrier transport layer 54. The method for manufacturing an organic solar cell 10 using the electrode film 30 may further include a step of peeling off the support 31.

[0070] The support 31 is peeled off. For example, the support 31 may be peeled off by providing a peeling layer (not shown) between the support 31 and another member overlapping the support 31. Peeling off the support 31 makes the stress relaxation layer 32 more likely to expand and contract.

[0071] A coating liquid containing an organic material that will be the material for the photoelectric conversion layer 25 is applied to the seed crystal 35 to form a coating film that overlaps the seed crystal 35. The coating liquid contains, for example, a precursor compound with a perovskite structure and an organic solvent capable of dissolving the precursor compound. A crystalline structure grows around the seed crystal 35 as a nucleus. The growth of the crystalline structure forms the photoelectric conversion layer 25. The uniformity of the crystalline structure of the seed crystal 35 results in the formation of the photoelectric conversion layer 25 with a uniform crystalline structure. Stress generated during the growth of the seed crystal 35 is relieved by the stress relaxation layer 32. Thereafter, an annealing step is performed to remove the organic solvent. The organic solvent is dried in an environment at a predetermined annealing temperature. The annealing temperature may be 50°C or higher, 90°C or higher, 200°C or lower, or 150°C or lower. By selecting an appropriate annealing temperature, the organic solvent can be appropriately removed and a smooth photoelectric conversion layer 25 can be obtained.

[0072] By growing the seed crystal 35 into the photoelectric conversion layer 25, the electrode film 30 shown in FIG. 3 becomes the power generation substrate 20 shown in FIG. 6, and the electrode film 30 shown in FIG. 4A becomes the power generation substrate 20 shown in FIG. 7.

[0073] A second electrode 60 and a second carrier transport layer 54 are provided on the power generation substrate 20. The second electrode 60 and the second carrier transport layer 54 may be provided by an electrode film having substantially the same configuration as the electrode film 30 except that the seed crystal 35 is not included. The second carrier transport layer 54 may be provided so as to overlap the photoelectric conversion layer 25, and then the second electrode 60 may be provided so as to overlap the second carrier transport layer 54.

[0074] Through the above steps, the organic solar cell 10 is manufactured using the electrode film 30. The organic solar cell 10 is disposed on the substrate 3 and connected by the circuit 5, whereby the solar power generation system 1 is manufactured.

[0075] There is a demand for improving the efficiency of converting incident light into electric power in large-scale solar cells. The following are thought to be causes of a decrease in the efficiency of light-to-electric power conversion. First, when stress is applied to the photoelectric conversion layer of a solar cell during the formation of its crystalline structure, defects in the crystalline structure occur. Even when light excites electrons and holes in the photoelectric conversion layer, defects in the crystalline structure prevent the electrons and holes from migrating to the electrode. The electrons and holes whose migration is hindered do not generate electric power. If the electrodes and the supports supporting the electrodes are difficult to stretch, stress is likely to be applied during the formation of the crystalline structure of the photoelectric conversion layer. To relieve stress during the formation of the crystalline structure of the photoelectric conversion layer, solar cells such as those described in Patent Document 1 include a stress-relieving member inside the solar cell. However, conventional stress-relieving layers are insufficient to relieve stress. These layers do not contribute to stress relief during the formation of the crystalline structure of the photoelectric conversion layer, resulting in defects in the crystalline structure. Second, when a solar cell contains a perovskite-type compound, visible light is converted into electric power. The electrodes are transparent to allow visible light to pass through. Indium oxide has traditionally been used for such electrodes. As solar cells become larger, the electrodes also become larger. When extracting power from the electrodes, the movement of electricity in the electrodes becomes longer. As a result, the higher the resistance of the electrodes, the more power is consumed by the electrodes. Because indium oxide has high resistance, larger solar cells consume more power at the electrodes. Thirdly, inside the solar cell, the light path passing through the photoelectric conversion layer is short, so much light passes through the photoelectric conversion layer without being converted into power.

[0076] The electrode film 30 of this embodiment has a stress relaxation layer 32 disposed between the support 31 and the electrode 40. The stress relaxation layer 32 is stretchable. The stress relaxation layer 32 enables the electrode film 30 to relax the stress applied when forming the crystalline structure of the photoelectric conversion layer 25, i.e., the stress applied in the direction in which the crystalline structure stretches. Defects are less likely to occur in the crystalline structure of the photoelectric conversion layer 25. The movement of electrons and holes to the electrode is less likely to be hindered by defects in the crystalline structure. In an organic solar cell 10 manufactured using the electrode film 30, the efficiency of converting incident light into electricity can be improved.

[0077] In the power generation substrate 20 and organic solar cell 10 of this embodiment, the stress relaxation layer 32 makes it difficult for defects to occur in the crystal structure of the photoelectric conversion layer 25. The movement of electrons and holes to the electrodes is less likely to be hindered by defects in the crystal structure. This can improve the efficiency of converting light incident on the organic solar cell 10 into electric power.

[0078] In the electrode film 30 of this embodiment, the electrode 40 is formed by a plurality of linear conductors 41 that extend so as to define openings 43. The electrode 40 is mesh-shaped. The mesh-shaped structure allows the electrode 40 to relieve stress in the surface direction in which the electrode 40 is arranged. The crystalline structure of the photoelectric conversion layer 25 is formed so as to extend along the mesh-shaped structure. The mesh-shaped structure makes it less likely for defects to occur in the crystalline structure of the photoelectric conversion layer 25. Defects in the crystalline structure are less likely to hinder the movement of electrons and holes to the electrode. The efficiency of converting light incident on the organic solar cell 10 into electricity can be improved.

[0079] In the power generation substrate 20 and organic solar cell 10 of this embodiment, the electrode 40 is formed of a plurality of linear conductors 41 that extend so as to define an opening 43. Even if the material of the electrode 40 is a highly conductive metal, the electrode 40 can be made transparent. If the material of the electrode 40 is a light-reflecting material such as a metal, light that has not been converted into electricity in the photoelectric conversion layer 25 can be reflected by the electrode 40 and made to re-enter the photoelectric conversion layer 25. The light that has re-entered the photoelectric conversion layer 25 can be converted into electricity in the photoelectric conversion layer 25. This can improve the efficiency of converting light that has entered the organic solar cell 10 into electricity.

[0080] When the electrode 40 is formed of a plurality of linear conductors 41 extending to define the openings 43, it is believed that the efficiency of converting light incident on the organic solar cell 10 into electric power can be improved for the following presumed reason. The light transmitted through the mesh-shaped electrode 40 varies in intensity. For example, by appropriately setting the pitch P of the openings 43, the light transmitted through the mesh-shaped electrode 40 is more likely to vary in intensity. When strong light is absorbed by the photoelectric conversion layer 25, a high voltage difference is generated in the photoelectric conversion layer 25 due to excited electrons and holes. Electrons and holes excited by weak light absorbed by the photoelectric conversion layer 25 can move to the electrode due to this high voltage difference. Electrons and holes generated by weak light also easily move to the electrode. The presence of strong light allows electrons and holes generated by the incident light to move efficiently. The efficiency of converting light incident on the organic solar cell 10 into electric power can be improved. The reason for the improvement in the efficiency of converting light incident on the organic solar cell 10 into electric power in this embodiment is not limited to the presumption described above.

[0081] The transparent conductive layer 33 is disposed in the opening 43 and is connected to the linear conductor 41. Electrons and holes can be moved in the opening 43 as well. Electrons and holes generated by incident light can be efficiently moved. The efficiency of converting light incident on the organic solar cell 10 into electricity can be improved. The transparent conductive layer 33 easily holds the seed crystal 35. By disposing the transparent conductive layer 33, the effects of the seed crystal 35, which will be described later, can be effectively achieved.

[0082] In the electrode film 30 of this embodiment, the electrode 40 includes a binder resin 47 and conductive nanowires 45 that are held by the binder resin 47 while partially protruding from the binder resin 47. The binder resin 47 is stretchable. The binder resin 47 enables the electrode film 30 to relieve stress applied when forming the crystalline structure of the photoelectric conversion layer 25, i.e., stress applied in the direction in which the crystalline structure extends. Defects are less likely to occur in the crystalline structure of the photoelectric conversion layer 25. Defects in the crystalline structure are less likely to hinder the movement of electrons and holes to the electrode. In an organic solar cell 10 manufactured using the electrode film 30, the efficiency of converting incident light into electricity can be improved.

[0083] In the power generation substrate 20 and organic solar cell 10 of this embodiment, the electrode 40 includes a binder resin 47 and conductive nanowires 45 that are held by the binder resin 47 but partially protrude from the binder resin 47. The electrode 40 can be made transparent even if the conductive nanowires 45 are made of a highly conductive metal. When the electrode 40 is made of a light-reflecting material such as a metal, light that is not converted into electricity in the photoelectric conversion layer 25 can be reflected by the electrode 40 and re-enter the photoelectric conversion layer 25. Because the conductive nanowires 45 are sufficiently fine, they easily reflect light while scattering it. The light that re-enters the photoelectric conversion layer 25 can be converted into electricity in the photoelectric conversion layer 25. This improves the efficiency of converting light incident on the organic solar cell 10 into electricity.

[0084] The refractive index of the electrode 40 can be adjusted by adjusting the proportion of the binder resin 47 in the electrode 40. By appropriately setting the refractive index of the electrode 40, the reflectance at the interface between the electrode 40 and other members can be improved. Light that has not been converted into electricity in the photoelectric conversion layer 25 can be more easily reflected by the electrode 40. Light that is again incident on the photoelectric conversion layer 25 can be converted into electricity in the photoelectric conversion layer 25. The efficiency of converting light incident on the organic solar cell 10 into electricity can be improved.

[0085] The electrode film 30 of this embodiment has a seed crystal 35 of a crystal that forms the photoelectric conversion layer 25 of the organic solar cell 10. The seed crystal 35 is arranged on the side of the electrode 40 opposite the support 31. Since the electrode film 30 has the seed crystal 35, the crystal structure growing from the seed crystal 35 is aligned. Defects are less likely to occur in the crystal structure of the photoelectric conversion layer 25 formed by growing the seed crystal 35. Defects in the crystal structure are less likely to hinder the movement of electrons and holes to the electrode. The efficiency of converting light incident on the organic solar cell 10 into electricity can be improved.

[0086] The electrode film 30 of the present embodiment is used in manufacturing an organic solar cell 10 and includes a support 31 and an electrode 40 supported by the support 31. The electrode film 30 further includes a stress relief layer 32 disposed between the support 31 and the electrode 40, or the electrode 40 is formed by a plurality of linear conductors 41 extending to define openings 43, or the electrode 40 includes a binder resin 47 and conductive nanowires 45 that are held by the binder resin 47 and have portions protruding from the binder resin 47. The efficiency of converting light incident on the organic solar cell 10 manufactured using the electrode film 30 of the present embodiment into electric power can be improved.

[0087] The organic solar cell 10 manufactured using the electrode film 30 of this embodiment can be used by being attached to a transparent member such as a window.

[0088] The aspects of the present disclosure are not limited to the above-described embodiments, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the contents of the above-described embodiments. Various additions, modifications, and partial deletions can be made to the above-described embodiments without departing from the conceptual idea and intent of each disclosure derived from the contents defined in the claims and their equivalents.

[0089] For example, Fig. 8 shows a cross-sectional view of a modified example of the solar cell 1 and organic solar cell 10 according to the embodiment described above. In the modified example shown in Fig. 8, the support 31 of the organic solar cell 10 also serves as the substrate 3 of the solar cell 1. The hard coat layer 37 of the organic solar cell 10 is provided over the entire solar cell 1. The hard coat layer 37 can protect the entire solar cell 1. As shown in Fig. 8, the barrier layer 36 and stress relaxation layer 32 of the organic solar cell 10 may also be provided over the entire solar cell 1.

[0090] REFERENCE SIGNS LIST 1 Photovoltaic power generation system 3 Substrate 5 Circuit 6 First connection portion 7 Second connection portion 10 Organic solar cell 20 Power generation substrate 25 Photoelectric conversion layer 30 Electrode film 31 Support 32 Stress relaxation layer 33 Transparent conductive layer 34 Carrier transport layer 35 Seed crystal 36 Barrier layer 37 Hard coat layer 40 Electrode 41 Linear conductor 43 Opening 45 Conductive nanowire 47 Binder resin 54 Second carrier transport layer 60 Second electrode

Claims

1. An electrode film for use in the manufacture of an organic solar cell, comprising: a support; an electrode supported by the support; and a stress relief layer disposed between the support and the electrode.

2. The electrode film according to claim 1, wherein the electrodes are formed by a plurality of linear conductors extending to define an opening.

3. An electrode film for use in the manufacture of an organic solar cell, comprising: a support; and an electrode supported by the support, the electrode being formed by a plurality of linear conductors extending to define an opening.

4. The electrode film according to claim 2 or 3, wherein the linear conductor has a line width that decreases with increasing distance from the support.

5. The electrode film according to claim 2 or 3, wherein the material of the linear conductor is a metal having electrical conductivity.

6. The electrode film according to claim 5, wherein the material of the linear conductor is copper or a copper alloy.

7. The electrode film according to claim 2 or 3, further comprising a transparent conductive layer disposed in at least the opening and connected to the linear conductor.

8. The electrode film according to claim 1, wherein the electrode comprises a binder resin and a conductive nanowire that is held by the binder resin and has a portion protruding from the binder resin.

9. An electrode film used in the manufacture of an organic solar cell, comprising: a support; and an electrode supported by the support, the electrode including a binder resin and conductive nanowires that are held by the binder resin while portions of the conductive nanowires protrude from the binder resin.

10. The electrode film according to claim 8 or 9, wherein the electrodes are disposed over an entire area of ​​the electrode film.

11. The electrode film according to claim 1, 3 or 9, further comprising a seed crystal of a crystal that forms a photoelectric conversion layer of an organic solar cell, the seed crystal including an organic material, and the seed crystal is disposed on the opposite side of the electrode to the support.

12. The electrode film according to claim 11, wherein the electrode is formed by a plurality of linear conductors extending to define an opening, and further comprises a transparent conductive layer disposed in at least the opening and connected to the linear conductors, and the seed crystal is supported by the transparent conductive layer.

13. The electrode film according to claim 11, further comprising a carrier transport layer disposed on the opposite side of the electrode from the support, the seed crystal being supported by the carrier transport layer.

14. The electrode film of claim 11, wherein the seed crystal comprises a perovskite compound.

15. The electrode film according to claim 11, wherein the average primary particle size of the seed crystals is 0.003 μm or more and 1 μm or less.

16. The electrode film according to claim 1, 3 or 9, further comprising a carrier transport layer disposed on the opposite side of the electrode from the support.

17. The electrode film of claim 1, 3 or 9, further comprising a barrier layer disposed between the support and the electrode.

18. The electrode film according to claim 1, 3 or 9, further comprising a hard coat layer disposed on the opposite side of the support from the electrode.

19. A power generating substrate comprising: an electrode; a photoelectric conversion layer electrically connected to the electrode; and a stress relaxation layer arranged on the opposite side of the electrode to the photoelectric conversion layer, wherein the photoelectric conversion layer contains an organic material.

20. A power generation substrate comprising: an electrode; and a photoelectric conversion layer electrically connected to the electrode, wherein the photoelectric conversion layer includes an organic material; and the electrode is formed by a plurality of linear conductors extending to define an opening.

21. A power generating substrate comprising: an electrode; and a photoelectric conversion layer electrically connected to the electrode, wherein the photoelectric conversion layer contains an organic material; and the electrode contains conductive nanowires.

22. An organic solar cell comprising: a power generation substrate according to any one of claims 19 to 21; and a second electrode disposed on the opposite side of the photoelectric conversion layer to the electrode.

23. A solar power generation system comprising: a plurality of organic solar cells according to claim 22; and a circuit connecting the plurality of organic solar cells.

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