Solar cell module

Abstract

The present invention provides a solar cell module that can have high durability. The solar cell module (100) of the present invention includes: a substrate (1), a photoelectric conversion layer (5), a first sealing layer (4) located between the substrate (1) and the photoelectric conversion layer (5), a second sealing layer (3) located between the substrate (1) and the first sealing layer (4), and an end face sealing structure (7) that covers at least a part of the end of the substrate (1) and at least a part of the end of the second sealing layer (3). Here, the photoelectric conversion layer (5) contains an organic material and converts light into energy, the second sealing layer (3) has a lower water vapor transmittance than the first sealing layer (4), and at least a part of the first sealing layer (4) is isolated from the end face sealing structure (7).

Description

Technical Field

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

[0002] In recent years, research and development of perovskite solar cells have been carried out. Perovskite solar cells use a compound having a perovskite crystal structure or a crystal structure similar thereto represented by the compositional formula AMX3 (where A is a monovalent cation, M is a divalent cation, and X is a monovalent anion) (hereinafter referred to as a "perovskite compound") as a light absorption material. In addition, in this specification, a solar cell using a perovskite compound is referred to as a "perovskite solar cell".

[0003] Non-Patent Document 1 discloses the basic configuration of a perovskite solar cell. A perovskite solar cell having the basic configuration sequentially includes a transparent electrode, an electron transport layer, a light absorption layer using a perovskite crystal for light absorption and charge separation (hereinafter referred to as a "perovskite layer"), a hole transport layer, and a collector. That is, an electron transport layer (n), a perovskite layer (i), and a hole transport layer (p) are sequentially stacked from the transparent electrode side. Such a configuration is referred to as an n-i-p structure or a forward stacking structure.

[0004] Non-Patent Document 2 discloses a perovskite solar cell having a configuration in which a hole transport layer, a perovskite layer, and an electron transport layer are sequentially stacked from the transparent electrode side. Such a configuration is referred to as a p-i-n structure or a reverse stacking structure.

[0005] A solar cell is a device that generates electricity by receiving sunlight, that is, a device that uses sunlight as an energy source. Therefore, a solar cell module equipped with a solar cell is usually installed outdoors. As a result, moisture penetrates into the solar cell module through rainwater and humidity, causing deterioration of the characteristics of the solar cell. In order to prevent deterioration of characteristics caused by such penetration of moisture, for example, Patent Documents 1 to 3 propose various configurations for suppressing the penetration of moisture into the solar cell module.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-26455

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2004-79823

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2012-94608

[0011] Non-Patent Documents

[0012] Non-Patent Document 1: Julian Burchcka et al., 6 persons, "Nature" (UK), July 2013, Vol. 499, p. 316-319

[0013] Non-Patent Document 2: Wei Chen et al., 10 persons, "SCIENCE" (USA), November 2015, Vol. 350, No. 6263, p. 944-948 Summary of the Invention

[0014] Problems to be Solved by the Invention

[0015] An object of the present invention is to provide a solar cell module having high durability.

[0016] Means for Solving the Problems

[0017] The present invention relates to a solar cell module including:

[0018] a substrate,

[0019] a photoelectric conversion layer,

[0020] a first sealing layer located between the substrate and the photoelectric conversion layer,

[0021] a second sealing layer located between the substrate and the first sealing layer, and

[0022] an end face sealing structure covering at least a part of an end portion of the substrate and at least a part of an end portion of the second sealing layer;

[0023] Here,

[0024] the photoelectric conversion layer contains an organic material and converts light into energy,

[0025] the second sealing layer has a lower water vapor transmission rate than the first sealing layer, and

[0026] at least a part of the first sealing layer is isolated from the end face sealing structure.

[0027] Additional effects and advantages of the disclosed embodiments can be understood from the specification and the drawings. Effects and / or advantages can be provided respectively by various embodiments or features disclosed in the specification and the drawings, and it is not necessary to obtain all the embodiments or features in order to obtain one or more of them.

[0028] Advantages of the Invention

[0029] The present invention provides a solar cell module having high durability. Brief Description of the Drawings

[0030] Figure 1AIt is a cross-sectional view schematically showing a solar cell module according to an embodiment of the present invention.

[0031] Figure 1B is Figure 1A a top view of the solar cell module shown.

[0032] Figure 2 is a constituent Figure 1A cross-sectional view of the photoelectric conversion layer of the solar cell module shown.

[0033] Figure 3 It is a cross-sectional view of a solar cell module showing a modified example of an embodiment of the present invention.

[0034] Figure 4 It is a photograph of the solar cell module of Example 1 after the accelerated test.

[0035] Figure 5 It is a photograph of the solar cell module of Comparative Example 2 after the accelerated test. Detailed Description of the Invention

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037] <Insights Underlying the Present Invention>

[0038] The insights underlying the present invention are as follows.

[0039] The perovskite layer used in a perovskite solar cell deteriorates in characteristics due to deterioration caused by water. Therefore, if moisture penetrates into the solar cell module, the conversion efficiency of the solar cell decreases. In order to suppress the decrease in the conversion efficiency of the solar cell, it is necessary to provide a sealing structure for suppressing the penetration of moisture in the solar cell module.

[0040] As a sealing structure in a solar cell module, a structure in which ethylene-vinyl acetate copolymer (Ethylene Vinyl Acetate Copolymer: EVA) or a polyolefin resin is filled between a support and a thin film formed of a material having a relatively low water vapor transmission rate, and then the end is sealed with butyl rubber having a relatively low water permeability is mostly adopted. With this structure, the waterproofness and impact resistance of the solar cell module can be ensured. Here, the support is, for example, a glass substrate or the like to which a laminate film is attached in the case of a thin film solar cell. The laminate film includes the photoelectric conversion layer of the solar cell. In addition, an example of a material having a relatively low water vapor transmission rate is a metal.

[0041] The present inventors conducted research and found that when the above-described sealing structure is applied to a perovskite solar cell module, deterioration of the perovskite layer occurs and the conversion efficiency of the solar cell decreases. The reason is considered as follows.

[0042] Although the butyl rubber of the sealed end is a material with relatively low water permeability, it does not completely prevent water from passing through. Therefore, after a certain period of time, the water passing through the butyl rubber reaches the filling material composed of a polyolefin resin or the like. The water content rate of such a filling material is high. Therefore, water easily reaches the perovskite solar cell in contact with the filling material.

[0043] Based on the above insights, the present inventors repeatedly conducted research and found a solar cell module with a novel sealing structure that can suppress the deterioration of the solar cell in the solar cell module due to moisture. For example, in the case of a perovskite solar cell, it can suppress the deterioration of the perovskite layer due to moisture.

[0044] <Embodiments of the present invention>

[0045] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0046] Figure 1A is a cross-sectional view schematically showing the solar cell module 100 of the present embodiment. Figure 1B is Figure 1A a top view of the solar cell module 100 shown. Figure 1B The top view is a top view of the solar cell module 100 viewed from the side of the light-transmitting substrate 6 Figure 1A of.

[0047] As Figure 1A shown, the solar cell module 100 includes a substrate 1, a third sealing layer 2, a second sealing layer 3, a first sealing layer 4, a photoelectric conversion layer 5, a light-transmitting substrate 6, and an end surface sealing structure 7. The first sealing layer 4 is located between the substrate 1 and the photoelectric conversion layer 5. The second sealing layer 3 is located between the substrate 1 and the first sealing layer 4. The third sealing layer 2 is located between the substrate 1 and the second sealing layer 3. In addition, the third sealing layer 2 is an optional component and may not be provided. The end surface sealing structure 7 covers at least a part of the end of the substrate 1 and at least a part of the end of the second sealing layer 3. At least a part of the first sealing layer 4 is isolated from the end surface sealing structure 7.

[0048] First, the photoelectric conversion layer 5 provided to exhibit the function of the solar cell module 100 will be described.

[0049] The photoelectric conversion layer 5 contains an organic material and converts light into energy. The organic material contained in the photoelectric conversion layer 5 may also be a light absorption material that can convert light into charge, for example. Therefore, the photoelectric conversion layer 5 may also contain a perovskite-type compound, for example.

[0050] Figure 2 is a component of Figure 1ACross-sectional view of the photoelectric conversion layer 5 of the solar cell module 100 shown.

[0051] As Figure 2 shown, the photoelectric conversion layer 5 has, for example, a first electrode 16, an electron transport layer 15, a porous layer 14, a light absorption layer 13, a hole transport layer 12, and a second electrode 11. In the photoelectric conversion layer 5, the first electrode 16, the electron transport layer 15, the porous layer 14, the light absorption layer 13, the hole transport layer 12, and the second electrode 11 are stacked in sequence.

[0052] With respect to the photoelectric conversion layer 5, the light-transmissive substrate 6 can be located either on the side of the first electrode 16 or on the side of the second electrode 11. That is to say, the solar cell module 100 can also have a forward stacking structure in which the light-transmissive substrate 6, the first electrode 16, the electron transport layer 15, the porous layer 14, the light absorption layer 13, the hole transport layer 12, and the second electrode 11 are stacked in sequence. In addition, the solar cell module 100 can also have a reverse stacking structure in which the light-transmissive substrate 6, the second electrode 11, the hole transport layer 12, the light absorption layer 13, the electron transport layer 15, and the first electrode 16 are stacked in sequence.

[0053] When the solar cell module 100 has a forward stacking structure, the first electrode 16 has light transmissivity, and light is incident on the solar cell module 100 from the side of the light-transmissive substrate 6. Therefore, in this case, the electron transport layer 15 and the porous layer 14 are arranged on the light incident side with respect to the light absorption layer 13.

[0054] When the solar cell module 100 has a reverse stacking structure, the second electrode 11 has light transmissivity, and light is incident on the solar cell module 100 from the side of the light-transmissive substrate 6. Therefore, in this case, the hole transport layer 12 is arranged on the light incident side with respect to the light absorption layer 13.

[0055] The light absorption layer 13 converts light into charge. The light absorption layer 13 contains, for example, a perovskite-type compound represented by the compositional formula AMX3. Here, A is a monovalent cation, M is a divalent cation, and X is a monovalent anion.

[0056] Next, the basic effects of the solar cell module 100 of the present embodiment, especially the photoelectric conversion layer 5, will be described.

[0057] When light is irradiated onto the solar cell module 100, the light passes through the light-transmissive substrate 6 and enters the photoelectric conversion layer 5. The light absorption layer 13 absorbs the light and generates excited electrons and holes. The excited electrons move to the first electrode 16 via the porous layer 14 and the electron transport layer 15. On the other hand, the holes generated in the light absorption layer 13 move to the second electrode 11 via the hole transport layer 12. In the photoelectric conversion layer 5, current can be taken out with the first electrode 16 as the negative electrode and the second electrode 11 as the positive electrode.

[0058] Hereinafter, each component related to the photoelectric conversion layer 5 and the light-transmissive substrate 6 will be described.

[0059] [Light-transmissive substrate 6]

[0060] The light-transmissive substrate 6 physically holds each layer constituting the photoelectric conversion layer 5 in the form of a film. Examples of the light-transmissive substrate 6 include a glass substrate or a plastic substrate. The plastic substrate may also be a plastic film.

[0061] [First electrode 16 and second electrode 11]

[0062] The first electrode 16 and the second electrode 11 have conductivity. At least one of the first electrode 16 and the second electrode 11 has light-transmittance. When the solar cell module 100 has a forward stacking structure, at least the first electrode 16 has light-transmittance. When the solar cell module 100 has a reverse stacking structure, at least the second electrode 11 has light-transmittance. In this specification, the so-called "electrode has light-transmittance" means that more than 10% of the light with a wavelength of 200 nm or more and 2000 nm or less passes through the electrode at any wavelength.

[0063] The electrode having light-transmittance can transmit light, for example, from the visible region to the near-infrared region. The electrode having light-transmittance can be formed of at least one of a metal oxide and a metal nitride having transparency and conductivity.

[0064] Examples of the metal oxide are:

[0065] (Ⅰ) Titanium oxide doped with at least one selected from lithium, magnesium, niobium, and fluorine,

[0066] (Ⅱ) Gallium oxide doped with at least one selected from tin and silicon,

[0067] (Ⅲ) Indium-tin composite oxide,

[0068] (Ⅳ) Tin oxide doped with at least one selected from antimony and fluorine, or

[0069] (Ⅴ) Zinc oxide doped with at least one selected from boron, aluminum, gallium, and indium.

[0070] Two or more metal oxides can be used in combination as a composite.

[0071] Examples of metal nitrides are gallium nitride doped with at least one selected from silicon and oxygen. Two or more metal nitrides can be used in combination.

[0072] Metal oxides and metal nitrides can be used in combination.

[0073] A light-transmissive electrode can be formed by designing a light-transmitting pattern using an opaque material. As the light-transmitting pattern, for example, linear, wavy, lattice-shaped, and perforated metal-shaped patterns in which a plurality of fine through-holes are regularly or irregularly arranged can be cited. If the electrode has these patterns, light can pass through the portion where there is no electrode material. As the opaque material, for example, platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, iron, nickel, tin, zinc, and alloys containing any one of them can be cited. In addition, a conductive carbon material can also be used.

[0074] When the photoelectric conversion layer 5 does not have the electron transport layer 15, the first electrode 16 can be formed of a material having a hole-blocking property that blocks holes moving from the light absorption layer 13. In this case, the first electrode 16 does not make an ohmic contact with the light absorption layer 13. The hole-blocking property that blocks holes moving from the light absorption layer 13 means that only electrons generated in the light absorption layer 13 can pass through, and holes cannot pass through. The Fermi level of the material having a hole-blocking property can also be higher than the energy of the valence band top of the light absorption layer 13. As such a material, for example, aluminum can be cited. When the photoelectric conversion layer 5 has the electron transport layer 15 between the light absorption layer 13 and the first electrode 16, the first electrode 16 may not have the hole-blocking property that blocks holes moving from the light absorption layer 13. Therefore, the first electrode 16 can also be formed of a material that can make an ohmic contact with the light absorption layer 13.

[0075] When the photo-electric conversion layer 5 does not have the hole transport layer 12, the second electrode 11 can be formed of a material having an electron-blocking property that blocks electrons moving from the light absorption layer 13. In this case, the second electrode 11 does not make an ohmic contact with the light absorption layer 13. The so-called electron-blocking property that blocks electrons moving from the light absorption layer 13 means that only holes generated in the light absorption layer 13 can pass through, and electrons cannot pass through. The Fermi level of the material having an electron-blocking property is lower than the energy level at the bottom of the conduction band of the light absorption layer 13. The Fermi level of the material having an electron-blocking property can also be lower than the Fermi level of the light absorption layer 13. Specifically, the second electrode 11 can be formed of a carbon material such as platinum, gold, or graphene. These materials have an electron-blocking property but do not have light-transmitting property. Therefore, when forming the light-transmitting second electrode 11 using such a material, as described above, the second electrode 11 having a pattern through which light can pass can be formed. When the photo-electric conversion layer 5 has the hole transport layer 12 between the light absorption layer 13 and the second electrode 11, the second electrode 11 may not have an electron-blocking property that blocks electrons moving from the light absorption layer 13. Therefore, the second electrode 11 can also be formed of a material that can make an ohmic contact with the light absorption layer 13.

[0076] The light transmittance of the light-transmitting electrode can be 50% or more, or can be 80% or more. The wavelength of the light passing through the electrode depends on the absorption wavelength of the light absorption layer 13. The thickness of each of the first electrode 16 and the second electrode 11 is, for example, 1 nm or more and 1000 nm or less.

[0077] [Electron transport layer 15]

[0078] The electron transport layer 15 contains a semiconductor. The electron transport layer 15 can also be a semiconductor having a band gap of 3.0 eV or more. By forming the electron transport layer 15 of a semiconductor having a band gap of 3.0 eV or more, visible light and infrared light can pass through to the light absorption layer 13. Examples of such a semiconductor are an organic n-type semiconductor and an inorganic n-type semiconductor.

[0079] Examples of the organic n-type semiconductor are imide compounds, quinone compounds, fullerenes, or derivatives of fullerenes. Examples of the inorganic n-type semiconductor are metal oxides, metal nitrides, or perovskite-type oxides. Examples of the metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, or Cr. As a specific example, TiO2 can be cited. Examples of the perovskite-type oxides are SrTiO3 or CaTiO3.

[0080] The electron transport layer 15 may also contain a material having a band gap width greater than 6.0 eV. Examples of materials having a band gap width greater than 6.0 eV are (i) halides of alkali metals or alkaline earth metals such as lithium fluoride or calcium fluoride, (ii) alkali metal oxides such as magnesium oxide, or (iii) silicon dioxide. In this case, to ensure the electron transport property of the electron transport layer 15, the thickness of the electron transport layer 15 is, for example, 10 nm or less.

[0081] The electron transport layer 15 may also include a plurality of layers formed of different materials from each other.

[0082] [Porous layer 14]

[0083] The porous layer 14 serves as the basis for forming the light absorption layer 13. The porous layer 14 does not hinder the light absorption of the light absorption layer 13 and the movement of electrons from the light absorption layer 13 to the electron transport layer 15.

[0084] The porous layer 14 contains a porous body. Examples of the porous body are porous bodies formed by connecting insulating or semiconductor particles. Examples of the insulating particles are particles of alumina or silica. Examples of the semiconductor particles are particles of inorganic semiconductors. Examples of the inorganic semiconductors are metal oxides (including perovskite-type oxides), metal sulfides, or metal chalcogenides. Examples of the metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, or Cr. As a specific example, TiO2 can be cited. Examples of the perovskite-type oxides are SrTiO3 or CaTiO3. Examples of the metal sulfides are CdS, ZnS, In2S3, SnS, PbS, Mo2S, WS2, Sb2S3, Bi2S3, ZnCdS2, or Cu2S. Examples of the metal chalcogenides are CdSe, CsSe, In2Se3, WSe2, HgS, SnSe, PbSe, or CdTe. In addition, in this specification, the so-called "porous" refers to a material having pores inside.

[0085] The thickness of the porous layer 14 can be 0.01 μm or more and 10 μm or less, or can be 0.1 μm or more and 1 μm or less. The surface roughness of the porous layer 14 can also be large. Specifically, the surface roughness coefficient given by the value of the actual area / projected area can be 10 or more, or can be 100 or more. In addition, the so-called projected area is the area of the shadow formed behind when an object is irradiated with light from the front. The so-called actual area refers to the actual surface area of the object. The actual area can be calculated from the volume obtained from the projected area and thickness of the object, and the specific surface area and volume density of the material constituting the object. The specific surface area can be measured, for example, by the nitrogen adsorption method.

[0086] In addition, Figure 2 a certain form of the porous layer 14 is shown, but the photoelectric conversion layer 5 may also not contain the porous layer 14.

[0087] [Light absorption layer 13]

[0088] The light absorption layer 13 contains, for example, a compound having a perovskite structure represented by the composition formula AMX3 as a light absorption material. A is a monovalent cation. Examples of A include monovalent cations such as alkali metal cations or organic cations. Specifically, examples of A include methylammonium cation (CH3NH3 + ), formamidinium cation (NH2CHNH2 + ), cesium cation (Cs + ), or rubidium cation (Rb + ).

[0089] In the composition formula AMX3, M is a divalent cation. M is, for example, a divalent cation of a transition metal or an element of Group 13 to Group 15. More specifically, examples of M include Pb 2+ , Ge 2+ , or Sn 2+ . In the composition formula AMX3, X is a monovalent anion such as a halogen anion.

[0090] The sites of A, M, or X may each be occupied by a plurality of ions. Specific examples of the compound having a perovskite structure are CH3NH3PbI3, CH3CH2NH3PbI3, NH2CHNH2PbI3, CH3NH3PbBr3, CH3NH3PbCl3, CsPbI3, CsPbBr3, RbPbI3, or RbPbBr3, etc.

[0091] The thickness of the light absorption layer 13 is, for example, 100 nm or more and 1000 nm or less. The thickness of the light absorption layer 13 may depend on the magnitude of the light absorption of the light absorption layer 13. The light absorption layer 13 can be formed by a solution-based coating method or a co-evaporation method, etc. In addition, the light absorption layer 13 may also be in a form in which a part thereof is mixed with the second electron transport layer 14.

[0092] [Hole transport layer 12]

[0093] The hole transport layer 12 can be composed of an organic substance or an inorganic semiconductor. The hole transport layer 12 may also include a plurality of layers formed of different materials from each other.

[0094] As the organic substance, for example, aniline having a tertiary amine in the skeleton, a triphenylamine derivative, poly(triallylamine) (Poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine: PTAA), and a PEDOT (poly(3,4-ethylenedioxythiophene)) compound having a thiophene structure can be cited. The molecular weight is not particularly limited, and it may also be a polymer. When forming the hole transport layer 12 with the organic substance, the film thickness may be 1 nm or more and 1000 nm or less, or may be 100 nm or more and 500 nm or less. As long as the film thickness is within this range, sufficient hole transportability can be exhibited. In addition, as long as the film thickness is within this range, low resistance can be maintained, and thus photoelectric power generation can be performed with high efficiency.

[0095] As the inorganic semiconductor, a p-type semiconductor such as CuO, Cu2O, CuSCN, molybdenum oxide, or nickel oxide can be used. When forming the hole transport layer 12 with the inorganic semiconductor, the film thickness may be 1 nm or more and 1000 nm or less, or may be 10 nm or more and 50 nm or less. As long as the film thickness is within this range, sufficient hole transportability can be exhibited. In addition, as long as the film thickness is within this range, low resistance can be maintained, and thus photoelectric power generation can be performed with high efficiency.

[0096] As a method for forming the hole transport layer 12, a coating method or a printing method can be adopted. Examples of the coating method are a doctor blade method, a rod coating method, a spraying method, a dip coating method, or a spin coating method. Examples of the printing method are a screen printing method. In addition, various materials may be mixed as needed to form the hole transport layer 12, and then the hole transport layer 12 may be pressed or fired. When the material of the hole transport layer 12 is an organic low molecule or an inorganic semiconductor, the hole transport layer 12 can be formed by a vacuum evaporation method or the like.

[0097] The hole transport layer 12 may also contain a supporting electrolyte and a solvent. The supporting electrolyte and the solvent can stabilize the holes in the hole transport layer 12.

[0098] Examples of the supporting electrolyte are an ammonium salt or an alkali metal salt. Examples of the ammonium salt are tetrabutylammonium perchlorate, tetraethylammonium hexafluorophosphate, an imidazolium salt, or a pyridinium salt. Examples of the alkali metal salt are lithium perchlorate or potassium tetrafluoroborate.

[0099] The solvent contained in the hole transport layer 12 may also have high ionic conductivity. Either an aqueous solvent or an organic solvent can be used. To make the solute more stable, the solvent may also be an organic solvent. Examples of the organic solvent are heterocyclic compounds such as tert-butylpyridine, pyridine, or N-methylpyrrolidone.

[0100] The solvent contained in the hole transport layer 12 may also be an ionic liquid. The ionic liquid can be used alone or in combination with other solvents. The ionic liquid is preferred in terms of low volatility and high flame retardancy.

[0101] Examples of the ionic liquid include imidazolium compounds such as 1-ethyl-3-methylimidazolium tetracyanoborate, pyridine compounds, alicyclic amine compounds, aliphatic amine compounds, or azoamine compounds.

[0102] In this specification, the thickness of each layer may be the average value of the values measured at any number of points (for example, at 5 points). The thickness of each layer can be measured using an electron microscope image of the cross section.

[0103] Thus far, Figure 2 the components of the photoelectric conversion layer 5 have been described. Figure 2 The structure shown is intended to be easily understood and to illustrate the multilayer film structure of the photoelectric conversion layer 5. Hereinafter, specific examples of the more practical structure of the photoelectric conversion layer 5 will be described.

[0104] Figure 3 is a cross-sectional view schematically showing the integrated solar cell module 200. The integrated solar cell module 200 has a structure in which Figure 2 the shown photoelectric conversion layer 5 is divided into a plurality of unit cells 20 and the plurality of unit cells 20 are connected in series. In addition, Figure 3 although not shown in the figure, the integrated solar cell module 200 is also the same as Figure 1A the shown solar cell module 100 and further includes a substrate 1, a third sealing layer 2, a second sealing layer 3, a first sealing layer 4, and an end face sealing structure 7. In addition, the integrated solar cell module 200 may not include the third sealing layer 2.

[0105] As Figure 3 shown, the integrated solar cell module 200 has a light-transmissive substrate 6, a first electrode 16, an electron transport layer 15, a porous layer 14, a light absorption layer 13, a hole transport layer 12, and a second electrode 11.

[0106] The first electrode 16, the electron transport layer 15, and the porous layer 14 are respectively divided into a plurality of first electrodes 26, a plurality of electron transport layers 25, and a plurality of porous layers 24 by a first dividing groove 17. The light absorption layer 13 and the hole transport layer 12 are respectively divided into a plurality of light absorption layers 23 and a plurality of hole transport layers 22 by a second dividing groove 18. The second electrode 11 is divided into a plurality of second electrodes 21 by a third dividing groove 19. In addition, the third dividing groove 19 may also be formed on the light absorption layer 13 and the hole transport layer 12. The first dividing groove 17, the second dividing groove 18, and the third dividing groove 19 may, for example, extend in a stripe shape. These grooves may also be formed substantially parallel to each other.

[0107] The plurality of unit cells 20 each have a stacked structure in which a first electrode 26, an electron transport layer 25, a porous layer 24, a light absorption layer 23, a hole transport layer 22, and a second electrode 21 are stacked in this order. When viewed from the normal direction of the light-transmissive substrate 6, the second division groove 18 is arranged so as to overlap with the first electrode 26, the electron transport layer 25, and the porous layer 24. In the second division groove 18, the second electrodes 21 of the adjacent unit cells 20 are arranged. The first electrode 26 is electrically connected to the second electrode 21 of the adjacent unit cell 20 in the second division groove 18. That is to say, the second division groove 18 functions as a battery connection groove.

[0108] In this way, each unit cell 20 is an independent solar cell having an electron transport layer 25, a porous layer 24, a light absorption layer 23, and a hole transport layer 22 that form an n-i-p junction, and output terminals, namely, the first electrode 26 and the second electrode 21.

[0109] Here, a certain unit cell 20 (the first unit cell 20A), a second unit cell 20B adjacent to the first unit cell 20A, and a third unit cell 20C are used to illustrate the electrical connection of the plurality of unit cells 20.

[0110] The first electrode 26 of the first unit cell 20A is electrically connected to the second electrode 21 of the third unit cell 20C among the second unit cell 20B and the third unit cell 20C adjacent to both sides. The second electrode 21 of the first unit cell 20A is electrically connected to the first electrode 26 of the second unit cell 20B. In this way, the plurality of unit cells 20 are connected in series. In addition, in the integrated solar cell module 200 having such a plurality of unit cells 20, the light absorption layer 23 formed on the porous layer 24 abuts against the first electrode 26 and the electron transport layer 25, which are the lower layers of the porous layer 24, in the first division groove 17.

[0111] When the solar cell module 100 and the integrated solar cell module 200 are finally used outdoors, it is necessary to particularly prevent the deterioration of the photoelectric conversion layer 5 including the light absorption layer 13, which contains materials with relatively weak moisture resistance. Therefore, it is necessary to suppress the infiltration of moisture into the photoelectric conversion layer 5 by means of the weather-resistant solar cell module 100 having the structure shown. Figure 1A The infiltration of moisture into the photoelectric conversion layer 5 is suppressed by the weather-resistant solar cell module 100 having the structure shown.

[0112] The substrate 1 holds the photoelectric conversion layer 5. To ensure mechanical strength, the substrate 1 can have a thickness of, for example, 5 mm or more, or 10 mm or more. In addition, since the solar cell module is used outdoors, an outer wall material or a roof material of a building can also be used as the substrate 1. Examples of the outer wall material or the roof material are a metal plate, a ceramic plate, cement (such as mortar, concrete, or slate), bricks, tiles, or stucco. Among them, especially when mortar or slate, which is a cement-based material, is used as the substrate 1, the substrate 1 is formed of a material that can transmit and retain moisture. In this way, the substrate 1 is sometimes formed of a material that can transmit and retain moisture. For example, the moisture content of the substrate 1 can also be 0.3 mg / cm 3 or more under the conditions of a temperature of 60°C and an atmospheric pressure. In addition, the substrate 1 can also have a higher water vapor transmission rate than the first sealing layer 4. Even in such a case, since the second sealing layer 3 having a lower water vapor transmission rate than the first sealing layer 4 is disposed between the substrate 1 and the photoelectric conversion layer 5, the moisture passing through the substrate 1 hardly reaches the photoelectric conversion layer 5. In addition, the water vapor transmission rate can be measured, for example, by the isobaric method (MOCON method).

[0113] The second sealing layer 3 has a lower water vapor transmission rate than the first sealing layer 4. Examples of the second sealing layer 3 are a metal thin film, or a resin thin film having a metal film or an oxide film. Examples of the resin thin film having a metal film or an oxide film are thin films in which a metal film such as Al or an oxide film such as SiO2 is formed on a resin thin film such as polyethylene (PE) or polyethylene terephthalate (PET). The thickness of the formed Al film, SiO2 film, etc. can be determined, for example, so that the water vapor transmission rate of the thin film satisfies 0.1 g / m 2 / day or less under the conditions of a temperature of 40°C and a relative humidity of 90% RH. In the case of the Al film, the thickness is about 7 μm, for example.

[0114] To bond the substrate 1 and the second sealing layer 3, a third sealing layer 2 can also be disposed between the substrate 1 and the second sealing layer 3. To prevent cracks from occurring when the substrate 1 is subjected to an external impact, the third sealing layer 2 can also be in contact with at least a part of the end face sealing structure 7. In addition, to bond the second sealing layer 3 and the light-transmitting substrate 6 on which the photoelectric conversion layer 5 is formed, a first sealing layer 4 can be disposed between the second sealing layer 3 and the photoelectric conversion layer 5. Examples of the materials of the third sealing layer 2 and the first sealing layer 4 are resins such as ethylene-vinyl acetate copolymer resin (EVA), polyolefin (PO) resin, or polyvinyl fluoride resin (PVF).

[0115] In the solar cell module 100, an end face sealing structure 7 can be disposed at the peripheral portion of a laminate including a substrate 1, a third sealing layer 2, a second sealing layer 3, a first sealing layer 4, a photoelectric conversion layer 5, and a light-transmissive substrate 6. The end face sealing structure 7 covers at least a part of the end portion of the substrate 1 and at least a part of the end portion of the second sealing layer 3. With this configuration, the end face sealing structure 7 can suppress the infiltration of moisture from the end face of the solar cell module 100. The so-called end portion of the substrate 1 is the peripheral portion of the substrate 1. The so-called end portion of the second sealing layer 3 is the peripheral portion of the second sealing layer 3.

[0116] The end face sealing structure 7 can cover at least 95% or more of the entire end portion of the substrate 1, that is, the entire peripheral portion of the substrate 1, or can cover the entire peripheral portion of the substrate 1. With this configuration, the end face sealing structure 7 can more surely suppress the infiltration of moisture from the end face of the solar cell module 100.

[0117] The end face sealing structure 7 can cover at least 95% or more of the entire end portion of the second sealing layer 3, that is, the entire peripheral portion of the second sealing layer 3, or can cover the entire peripheral portion of the second sealing layer 3. With this configuration, the end face sealing structure 7 can more surely suppress the infiltration of moisture from the end face of the solar cell module 100. For example, when the substrate 1 and the third sealing layer 2 are formed of a material having a high water vapor transmission rate, it is necessary to suppress the infiltration of moisture into the photoelectric conversion layer 5 through the second sealing layer 3 and the end face sealing structure 7. Therefore, as Figure 1A shown, the peripheral portion of the second sealing layer 3 is completely covered by the end face sealing structure 7 or can be buried by the end face sealing structure 7. In addition, the structure in which the peripheral portion of the second sealing layer 3 is buried by the end face sealing structure 7, in other words, can be said to be a structure in which the end face sealing structure 7 intrudes into the peripheral portion of the second sealing layer 3. With this configuration, the end face sealing structure 7 can more surely suppress the infiltration of moisture from the end face of the solar cell module 100. Here, the so-called material having a high water vapor transmission rate is a material having a water vapor transmission rate of 1 g / m 2 / day or more under the conditions of a temperature of 40 °C and a relative humidity of 90% RH.

[0118] As Figure 1A shown, for example, the end face sealing structure 7 can also be provided so as to continuously surround the entire end face of the solar cell module 100 without gaps.

[0119] The end face sealing structure 7 can use, for example, a material having a low water vapor transmission rate. Examples of the material of the end face sealing structure 7 are, for example, butyl rubber. Here, the so-called material having a low water vapor transmission rate is a material having a water vapor transmission rate of 0.5 g / m 2 / day or less under the conditions of a temperature of 40 °C and a relative humidity of 90% RH.

[0120] By covering at least a part of the end portion of the substrate 1 and at least a part of the end portion of the second sealing layer 3 with the end face sealing structure 7 as described above, the infiltration of moisture into the solar cell module 100 can be suppressed. However, in the end face sealing structure 7, in addition to the boundary surfaces with the substrate 1 and the second sealing layer 3, there is also a boundary surface with the first sealing layer 4. Therefore, it can be considered that with only the structure of covering at least a part of the end portion of the substrate 1 and at least a part of the end portion of the second sealing layer 3 by the end face sealing structure 7, due to long-term exposure outdoors, moisture will slowly infiltrate into the solar cell module 100. Here, resins such as EVA used for the first sealing layer 4 are materials with a high moisture content rate. Therefore, if the moisture that penetrates through the end face sealing structure 7 reaches the first sealing layer 4, this moisture accumulates in the first sealing layer 4. Under the action of the moisture accumulated in the first sealing layer 4, the deterioration of the photoelectric conversion layer 5 is promoted. Thus, in order to suppress the moisture from reaching the first sealing layer 4, as Figure 1A shown, at least a part of the first sealing layer 4 is isolated from the end face sealing structure 7.

[0121] Here, a material with a high moisture content rate is a material that contains 0.3 mg / cm 3 or more of moisture under the conditions of a temperature of 60 °C and a pressure of one atmosphere in a space assumed to be filled with air without moisture (i.e., dry air).

[0122] The first sealing layer 4 can also be completely isolated from the end face sealing structure 7. With this configuration, since it is more difficult for the moisture that penetrates through the end face sealing structure 7 to reach the first sealing layer 4, the deterioration of the photoelectric conversion layer 5 caused by the moisture accumulated in the first sealing layer 4 can be more reliably suppressed.

[0123] The width of the isolation between the first sealing layer 4 and the end face sealing structure 7 (hereinafter referred to as "the isolation width between the first sealing layer and the end face sealing structure") is, for example, 1 mm or more, and can also be 5 mm or more. In addition, the "isolation width between the first sealing layer and the end face sealing structure" is the distance from the surface of the end face sealing structure 7 facing the first sealing layer 4 to the outer edge of the first sealing layer 4.

[0124] Similar to the first sealing layer 4, the photoelectric conversion layer 5 can also be isolated from the end face sealing structure 7. With this configuration, the moisture that penetrates through the end face sealing structure 7 can be suppressed from reaching the photoelectric conversion layer 5, so the deterioration of the photoelectric conversion layer 5 caused by moisture can be suppressed. The width of the isolation between the photoelectric conversion layer 5 and the end face sealing structure 7 (hereinafter referred to as "the isolation width between the photoelectric conversion layer and the end face sealing structure") can also be wider than the isolation width between the first sealing layer and the end face sealing structure. By increasing the isolation width between the photoelectric conversion layer and the end face sealing structure, it is possible to more reliably suppress the moisture that penetrates through the end face sealing structure 7 from reaching the photoelectric conversion layer 5, and thus the deterioration of the photoelectric conversion layer 5 caused by moisture can be further suppressed.

[0125] Further, when the space assumed to be isolated is filled with air without moisture (i.e., dry air), the amount of saturated water vapor that can exist in this space is 0.12 mg / cm under the conditions of a temperature of 60°C and an atmospheric pressure of 1 atm. 3 or so, which is less than the amount of moisture contained in the resin or cement (0.3 mg / cm under the same conditions). 3 or more). Therefore, the first sealing layer 4 can also be isolated from the end face sealing structure 7 through the space provided between them. The first sealing layer 4 is isolated from the end face sealing structure 7 through the space, thereby further suppressing the moisture from reaching the first sealing layer 4.

[0126] The first sealing layer 4 can also be isolated from the end face sealing structure 7 via a member having a lower water vapor transmission rate than that of the end face sealing structure 7. By isolating the first sealing layer 4 from the end face sealing structure 7 via a member having a lower water vapor transmission rate than that of the end face sealing structure 7, the moisture reaching the first sealing layer 4 can be further suppressed. The member having a lower water vapor transmission rate than that of the end face sealing structure 7 can also be made of a material capable of adsorbing moisture, for example.

[0127] The isolated space can also have the following structure: it not only blocks the flow of air without moisture but also blocks the flow of moisture infiltrating from the end face sealing structure 7 toward the first sealing layer 4.

[0128] (Example)

[0129] The present invention will be described in more detail with reference to the following examples.

[0130] Solar cell modules of Examples 1 to 5 and Comparative Examples 1 to 3 were fabricated, and the weather resistance of these solar cell modules was evaluated.

[0131] First, the configurations and fabrication methods of the solar cell modules of each example and comparative example will be described.

[0132] [Example 1]

[0133] The solar cell module of Example 1 has substantially the same structure as the solar cell module 100 shown in Figure 1A and Figure 1B and the photoelectric conversion layer 5 shown in Figure 2 . The materials, sizes, and thicknesses of the respective components in the solar cell module of Example 1 are shown below.

[0134] Substrate 1: Mortar board, size 100 mm square, thickness 6 mm, water vapor transmission rate 50 g / m 2 / day

[0135] Third sealing layer 2: Polyolefin resin sheet, size 90 mm square, thickness 0.5 mm

[0136] Second sealing layer 3: Al vapor-deposited film (PET / Al / PET), size 100 mm square, thickness PET(50 μm) / Al(7 μm) / PET(50 μm), water vapor transmission rate 0.1 g / m 2 / day

[0137] First sealing layer 4: Polyolefin resin sheet, size 86 mm square, thickness 0.5 mm, water vapor transmission rate 1.6 g / m 2 / day

[0138] Photoelectric conversion layer 5: Described later

[0139] Light-transmissive substrate 6: Glass substrate, size 100 mm square, thickness 1 mm

[0140] End-face sealing structure 7: Butyl rubber, sealing the peripheral part of the solar cell module with a width of 7 mm (burying a width of 5 mm from the ends of the substrate 1, the second sealing layer 3, and the light-transmissive substrate 6 to the inside), water vapor transmission rate 0.2 / m 2 / day

[0141] The materials and thicknesses of the respective components of the photoelectric conversion layer 5 are shown below.

[0142] First electrode 16: Fluorine-doped SnO2 layer (surface resistance: 10 Ω / sq.)

[0143] Electron transport layer 15: TiO2, thickness 30 nm

[0144] Porous layer 14: TiO2, thickness: 150 nm

[0145] Light absorption layer 13: (Rb 0.03 Cs 0.05 (CH3NH3) 0.16 (CH3(NH)2) 0.76 )Pb(I 0.95 Br 0.05 )3, thickness 350 nm

[0146] Hole transport layer 12: PTAA, thickness 40 nm

[0147] Second electrode 11: Au, thickness 200 nm

[0148] The manufacturing method of the solar cell module of Example 1 is as described below.

[0149] First, prepare a conductive substrate having a transparent conductive layer that functions as the first electrode 16 on its surface. The conductive substrate is a substrate in which the light-transmissive substrate 6 and the first electrode 16 are integrated. In the present embodiment, as the conductive substrate, a conductive glass substrate (manufactured by Nippon Sheet Glass) having a thickness of 1 mm and a fluorine-doped SnO2 layer on its surface is used.

[0150] Next, on the first electrode 16, i.e., the fluorine-doped SnO2 layer, a TiO2 layer with a thickness of approximately 30 nm is formed as the electron transport layer 15. The TiO2 layer is formed by spray coating using a 0.2 mol / L solution of diisopropyl bis(acetylacetonato)titanium(IV) obtained by diluting an isopropanol solution (75 wt%, manufactured by Sigma-Aldrich) of diisopropyl bis(acetylacetonato)titanium(IV) 10 times with isopropanol. The substrate temperature during the solution spraying is 400°C. Thus, the electron transport layer 15 is formed.

[0151] Subsequently, on the electron transport layer 15, i.e., the TiO2 layer, a porous TiO2 layer with a thickness of approximately 150 nm is formed as the porous layer 14. Prepare a 1.5 g TiO2 slurry (30NR-D, manufactured by Greatcell Solar) obtained by forming TiO2 nanoparticles with a particle size of approximately 30 nm into a slurry state, and suspend it in 10 mL of ethanol to obtain a solution. Coat this solution on the TiO2 layer by spin coating. In addition, set the rotation speed of the spin coating so that the thickness of the porous layer 14 reaches approximately 150 nm. Then, perform heat treatment on a hot plate at 85°C, and further perform heat treatment at 500°C in an electric furnace. Thus, the porous layer 14 is formed.

[0152] Next, on the porous layer 14, i.e., the porous TiO2 layer, a light absorption layer 13 is formed as (Rb 0.03 Cs 0.05 (CH3NH3) 0.16 (CH3(NH)2) 0.76 )Pb(I 0.95 Br 0.05)Three layers. Specifically, first, a perovskite solution is prepared. The perovskite solution contains a mixture of lead iodide (PbI2, manufactured by Tokyo Chemical Industry) and lead bromide (PbBr2, manufactured by Tokyo Chemical Industry) at 1.26 mol / L (PbI2∶PbBr2 = 95∶5 (molar ratio)), and contains a mixture of rubidium iodide (RbI, manufactured by Sigma-Aldrich), cesium iodide (CsI, manufactured by Sigma-Aldrich), methylammonium iodide (CH3NH3I, manufactured by Tokyo Chemical Industry), and formamidinium iodide (CH3(NH)2I, manufactured by Tokyo Chemical Industry) at 1.2 mol / L (RbI∶CsI∶CH3NH3I∶CH3(NH)2I = 3∶5∶16∶76 (molar ratio)). The solvent in the perovskite solution is a mixed solvent formed by mixing N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a volume ratio of 4∶1. Next, the perovskite solution is coated on the light-transmissive substrate 6 having a porous TiO2 layer by spin coating. Then, heat treatment is performed on a hot plate at 120 °C to obtain the light absorption layer 13. In addition, the rotation speed of spin coating is set so that the thickness of the light absorption layer 13 reaches approximately 350 nm. Furthermore, in order to promote the crystallization of the light absorption layer 13 during heat treatment, toluene is dropped onto the rotating light-transmissive substrate 6 approximately 40 seconds after the start of spin coating.

[0153] Next, on the light absorption layer 13, i.e., (Rb 0.03 Cs 0.05 (CH3NH3) 0.16 (CH3(NH)2) 0.76 )Pb(I 0.95 Br 0.05 )3 layer, a PTAA layer with a thickness of approximately 40 nm is formed as the hole transport layer 12. The PTAA layer is formed by spin coating from a solution prepared by dissolving 100 mg of PTAA (manufactured by Sigma-Aldrich) in 10 mL of toluene, adding 60 μL of 4-tert-butylpyridine (manufactured by Sigma-Aldrich) and 48 μL of a solution prepared by dissolving lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI, manufactured by Tokyo Chemical Industry) in acetonitrile at a concentration of 1.8 mol / L.

[0154] Next, on the hole transport layer, i.e., the PTAA layer, a Au layer with a thickness of approximately 200 nm is formed as the second electrode 11 by resistance heating evaporation.

[0155] The periphery of the photoelectric conversion layer 5 formed on the light-transmitting substrate 6 as described above is removed by cutting to a width of 7 mm, thereby forming a photoelectric conversion layer 5 with a size of 86 mm square on a light-transmitting substrate 6 with a size of 100 mm square. In addition, in order to evaluate the performance of the formed photoelectric conversion layer 5 as a solar cell, copper tapes with a width of 3 mm and a thickness of 0.1 mm are bonded to the first electrode 16 and the second electrode 11, so as to take out the electrodes outside the sealing part of the solar cell module 100.

[0156] Next, on the light-transmitting substrate 6 on which the photoelectric conversion layer 5 is formed, the first sealing layer 4, the second sealing layer 3, the third sealing layer 2 and the substrate 1 are sequentially laminated. The first sealing layer 4 is a polyolefin resin sheet with a size of 86 mm square and a thickness of 0.5 mm. The second sealing layer 3 is an Al-evaporated thin film (PET / Al / PET) with a size of 100 mm square and a total thickness of 107 μm. The third sealing layer 2 is a polyolefin resin sheet with a size of 90 mm square and a thickness of 0.5 mm. The substrate 1 is a mortar board with a size of 100 mm square and a thickness of 6 mm. In addition, between the light-transmitting substrate 6 and the second sealing layer 3 and between the second sealing layer 3 and the substrate 1, butyl rubber sheets with a width of 7 mm and a thickness of 0.5 mm are inserted into a width of 5 mm at their respective peripheral parts. At this time, butyl rubber sheets with a thickness of 0.2 mm are arranged above and below the copper tapes provided for taking out the electrodes to the outside, so that the total thickness with the copper tapes is the same as that of the surrounding butyl rubber sheets with a thickness of 0.5 mm. Then, using a vacuum lamination device, the polyolefin resin sheet is crosslinked and cured at 150 °C. Finally, the semi-molten butyl rubber heated to about 200 °C is coated on the peripheral parts of the light-transmitting substrate 6, the second sealing layer 3 and the substrate 1 in such a way as to be integrated with the bulging butyl rubber sheets, and is embedded in an aluminum mold, thereby obtaining the solar cell module of Example 1 with Figure 1A the shape shown.

[0157] In addition, all the processes for manufacturing the solar cell module of Example 1 are carried out in a drying room with a dew point of -40 °C or lower.

[0158] [Example 2]

[0159] The cutting width around the photoelectric conversion layer 5 is set to 6 mm wide, and a photoelectric conversion layer 5 with a size of 88 mm square is formed on a light-transmitting substrate 6 with a size of 100 mm square. Except for this, the solar cell module of Example 2 is manufactured in the same manner as in Example 1.

[0160] [Example 3]

[0161] The cutting width around the photoelectric conversion layer 5 was set to 5 mm wide, and a photoelectric conversion layer 5 with a size of 90 mm square was formed on a light-transmissive substrate 6 with a size of 100 mm square. Except for this, the solar cell module of Example 3 was produced in the same manner as in Example 1.

[0162] [Example 4]

[0163] The cutting width around the photoelectric conversion layer 5 was set to 4 mm wide, and a photoelectric conversion layer 5 with a size of 92 mm square was formed on a light-transmissive substrate 6 with a size of 100 mm square. Except for this, the solar cell module of Example 4 was produced in the same manner as in Example 1.

[0164] [Example 5]

[0165] The size of the first sealing layer 4 was set to 88 mm square. Except for this, the solar cell module of Example 5 was produced in the same manner as in Example 1.

[0166] [Comparative Example 1]

[0167] The size of the first sealing layer 4 was set to 90 mm square. Except for this, the solar cell module of Comparative Example 1 was produced in the same manner as in Example 1.

[0168] [Comparative Example 2]

[0169] The size of the first sealing layer 4 was set to 90 mm square and the cutting width around the photoelectric conversion layer 5 was set to 5 mm wide, and a photoelectric conversion layer 5 with a size of 90 mm square was formed on a light-transmissive substrate 6 with a size of 100 mm square. Except for this, the solar cell module of Comparative Example 2 was produced in the same manner as in Example 1.

[0170] [Comparative Example 3]

[0171] The size of the second sealing layer 3 was set to 90 mm square. Except for this, the solar cell module of Comparative Example 3 was produced in the same manner as in Example 1.

[0172] [Evaluation of Solar Cells]

[0173] For the solar cells of Examples 1 to 5 and Comparative Examples 1 to 3, first, the photoelectric conversion characteristics of the solar cell modules just after production were evaluated.

[0174] First, a solar simulator (manufactured by CERIC Co., Ltd.) was used to irradiate the solar cell module with light having an illuminance of 100 mW / cm 2 , and the current-voltage characteristics were measured. At this time, from the stabilized current-voltage characteristics, the open-circuit voltage (V), short-circuit current density (mA / cm2 ) Fill factor and conversion efficiency (%).

[0175] Then, the solar cell module was put into a thermo-hygrostat chamber at a temperature of 85°C and a relative humidity of 85% (85% RH) for an accelerated test. After 1000 hours, the solar cell module was taken out, and the photoelectric conversion characteristics after the accelerated test were evaluated by the above method.

[0176] In addition, the optical reflectance on the light-transmitting substrate 6 side from the solar cell module before and after the accelerated test was measured with a spectrophotometer. In addition, the presence or absence of deteriorated parts was visually observed simultaneously.

[0177] Table 1 shows the evaluation results of investigating the maintenance rate of the photoelectric conversion characteristics, the change rate of the optical reflectance, and the presence or absence of deteriorated parts for Examples 1 to 5 and Comparative Examples 1 to 3. The maintenance rate of the photoelectric conversion characteristics is the maintenance rate of the conversion efficiency after acceleration at 85°C, 85% RH, and 1000 hours with respect to the conversion efficiency of the photoelectric conversion characteristics of the solar cell module just after fabrication. In addition, the change rate of the optical reflectance is the change rate of the optical reflectance after acceleration at 85°C, 85% RH, and 1000 hours with respect to the optical reflectance of the solar cell module just after fabrication. In addition, in Table 1, the "intrusion depth of the end face sealing structure 7 based on the end of the second sealing layer 3" represents the degree to which the end face sealing structure 7 covers the second sealing layer 3 (i.e., the "coverage degree"). That is, in the second sealing layer 3, the distance from the end of the second sealing layer 3 into which the end face sealing structure 7 intrudes is used to represent the coverage degree.

[0178]

[0179] As shown in Table 1, in the weather-resistant solar cell modules of Examples 1 to 5 having a structure in which the end face sealing structure 7 and the first sealing layer 4 are isolated and the end of the second sealing layer 3 is covered by the end face sealing structure 7, the maintenance rate of the conversion efficiency after acceleration at 85°C, 85% RH, and 1000 hours is as high as 88% or more. In addition, in the weather-resistant solar cell modules of Examples 1 to 5, the change rate of the optical reflectance is also as small as 5% or less. On the other hand, in the solar cell modules of Comparative Examples 1 and 2 having a structure in which the end face sealing structure 7 and the first sealing layer 4 are not isolated, it was found that although the change in the optical reflectance is relatively small, the maintenance rate of the conversion efficiency is poor, less than 80%. In addition, in Comparative Example 3 having a structure in which the second sealing layer 3 is not covered by the end face sealing structure 7, it was found that the maintenance rate of the conversion efficiency is relatively poor, 50%, and the change in the optical reflectance is also 20% or more.

[0180] In addition, regarding the presence or absence of deteriorated portions, no deteriorated portions were visually observed in the solar cell modules of Examples 1 to 5. However, in the solar cell modules of Comparative Example 2 and Comparative Example 3, deteriorated portions were visually observed. In addition, when changing color from black to yellow visually, it was judged that a deteriorated portion was observed. Figure 4 It is a photograph showing the solar cell module of Example 1 after the accelerated test. Figure 5 It is a photograph showing the solar cell module of Comparative Example 2 after the accelerated test. The photoelectric conversion layer 5 in the solar cell module of Example 1 does not change color even after the accelerated test and remains the same black color as before the accelerated test. On the other hand, the peripheral portion of the photoelectric conversion layer 5 in the solar cell module of Comparative Example 2 changes color to yellow after the accelerated test. That is, in the solar cell module of Comparative Example 2, it is considered that since the first sealing layer 4 is not isolated from the end face sealing structure 7, moisture passing through the end face sealing structure 7 reaches the first sealing layer 4, and under the action of this moisture, the light absorption layer 13 of the photoelectric conversion layer 5 deteriorates.

[0181] From the above results, it is known that in a solar cell module, by forming a structure in which the end face sealing structure 7 is isolated from the first sealing layer 4 and at least a part of the end portion of the second sealing layer 3 is covered by the end face sealing structure 7, the weather resistance can be improved. In addition, it was also confirmed that by forming a structure in which the end face sealing structure 7 is isolated from the photoelectric conversion layer 5, the weather resistance can be further improved.

[0182] Industrial availability

[0183] The solar cell module of the present invention is particularly useful as a building material integrated solar cell module provided on, for example, the wall material and roof material of a building.

[0184] Symbol description:

[0185] 1 Substrate

[0186] 2 Third sealing layer

[0187] 3 Second sealing layer

[0188] 4 First sealing layer

[0189] 5 Photoelectric conversion layer

[0190] 6 Light-transmissive substrate

[0191] 7 End face sealing structure

[0192] 11, 21 Second electrode

[0193] 12, 22 Hole transport layer

[0194] 13, 23 Light absorption layer

[0195] 14, 24 Porous layer

[0196] 15, 25 Electron transport layer

[0197] 16, 26 First electrode

[0198] 17 First dividing groove

[0199] 18 Second dividing groove

[0200] 19 Third dividing groove

[0201] 20 Unit cell

[0202] 20A First unit cell

[0203] 20B Second unit cell

[0204] 20C Third unit cell

[0205] 100 Solar cell module

[0206] 200 Integrated solar cell module

Claims

1. A solar cell module, comprising: a substrate, a photoelectric conversion layer, a first sealing layer located between the substrate and the photoelectric conversion layer, a second sealing layer located between the substrate and the first sealing layer, and an end face sealing structure covering at least a part of an end of the substrate and an end of the second sealing layer; Here, the photoelectric conversion layer contains an organic material and converts light into energy, the second sealing layer has a lower water vapor transmission rate than the first sealing layer, at least a part of the first sealing layer is isolated from the end face sealing structure, and the end of the second sealing layer is buried in the end face sealing structure.

2. The solar cell module according to claim 1, wherein, At least a part of the first sealing layer is isolated from the end face sealing structure through a space provided between the end face sealing structures.

3. The solar cell module according to claim 1, wherein, At least a part of the first sealing layer is isolated from the end face sealing structure via a member having a lower water vapor transmission rate than the end face sealing structure.

4. The solar cell module according to any one of claims 1 to 3, further comprising a third sealing layer located between the substrate and the second sealing layer and in contact with at least a part of the end face sealing structure.

5. The solar cell module according to any one of claims 1 to 3, wherein, The photoelectric conversion layer is isolated from the end face sealing structure.

6. The solar cell module according to any one of claims 1 to 3, wherein, The substrate has a higher water vapor transmission rate than the first sealing layer.

7. The solar cell module according to any one of claims 1 to 3, wherein, The moisture content of the substrate is 0.3 mg / cm under the conditions of a temperature of 60 °C and an atmospheric pressure. 3 or more.

8. The solar cell module according to any one of claims 1 to 3, wherein, The photoelectric conversion layer contains a perovskite-type compound.

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