Solar cell module and manufacturing method for solar cell module

Abstract

To provide a solar cell module with excellent sealing performance, capable of sufficiently suppressing inflow of steam and oxygen into a module.SOLUTION: A solar cell module 1 according to an example of an embodiment includes a base material 2, a first electrode layer 11 provided on the base material 2, a photoelectric conversion layer 10 provided on the first electrode layer 11, a second electrode layer 12 provided on the photoelectric conversion layer 10, an extraction electrode layer 20, and a sealing layer 30. The sealing layer 30 includes an opening 30A in a region corresponding to the extraction electrode layer 20. When the base material 2 is viewed in a plan view from a surface side where the photoelectric conversion layer 10 is provided, the extraction electrode layer 20 is exposed from the opening 30A and a peripheral part of the extraction electrode layer 20 is covered with the sealing layer 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a solar cell module and a manufacturing method thereof, and more particularly to a solar cell module in which a photoelectric conversion layer is formed on an insulating substrate such as a glass substrate, and a manufacturing method thereof. [Background technology]

[0002] Conventionally, solar cell modules are known in which a photoelectric conversion layer is formed on an insulating base material such as a glass base material. Patent Document 1 discloses a solar cell module including a substrate, a plurality of solar cells formed on the substrate, an extraction electrode formed on the substrate for extracting electric charge from the plurality of solar cells, an extraction wiring member for collecting electric charge from the extraction electrode, a covering material for covering the extraction wiring member, and a sealing material.

[0003] Patent Document 2 discloses a solar cell having a cathode, an anode, a photoelectric conversion layer disposed between the cathode and the anode, and a resin layer disposed on either the cathode or the anode. Patent Document 2 describes that the photoelectric conversion layer contains an organic-inorganic perovskite compound represented by the general formula RM-X3 (wherein R is an organic molecule, M is a metal atom, and X is a halogen atom or a chalcogen atom). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-188211 A [Patent Document 2] JP 2016-174151 A Summary of the Invention [Problem to be solved by the invention]

[0005] The photoelectric conversion layer of a solar cell is greatly degraded in output performance by the presence of water vapor, oxygen, and light, so as described in Patent Documents 1 and 2, the photoelectric conversion layer is sealed to prevent water vapor and oxygen from acting on the photoelectric conversion layer. In particular, when the photoelectric conversion layer is a perovskite element, the output reduction due to the influence of water vapor and oxygen is significant. In addition, as described in Patent Document 1, the solar cell module is provided with an electrode for extracting the power generated by the solar cell to the outside, but since the sealing performance around the electrode is more likely to deteriorate than other parts, it is expected that water vapor and oxygen will flow in from around the electrode.

[0006] An object of the present disclosure is to provide a solar cell module that can sufficiently suppress the inflow of water vapor and oxygen into the module and has excellent sealing performance. [Means for solving the problem]

[0007] The solar cell module according to the present disclosure comprises a substrate, a first electrode layer provided on the substrate, a photoelectric conversion layer provided on the first electrode layer, a second electrode layer provided on the photoelectric conversion layer, an extraction electrode layer provided on the substrate in a region that does not overlap with the photoelectric conversion layer when the substrate is viewed in a plane, and a sealing layer provided to cover the first electrode layer, the photoelectric conversion layer, the second electrode layer, and the extraction electrode layer and having an opening in a region corresponding to the extraction electrode layer, and when the substrate is viewed in a plane from the side on which the photoelectric conversion layer is provided, the extraction electrode layer is exposed from the opening, and the sealing layer covers the peripheral portion of the extraction electrode layer. Effect of the Invention

[0008] The solar cell module according to the present disclosure can sufficiently suppress the inflow of water vapor and oxygen into the module. The solar cell module according to the present disclosure has excellent sealing performance, and therefore can maintain good output performance for a long period of time, for example. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a solar cell module according to a first embodiment. [Diagram 2] FIG. 4 is a cross-sectional view of a solar cell module according to a second embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of a solar cell module according to a third embodiment. [Figure 4] FIG. 2 is a diagram for explaining an example of a method for manufacturing the solar cell module according to the first embodiment. [Diagram 5] 6A to 6C are diagrams illustrating an example of a method for manufacturing a solar cell module according to a second embodiment. [Figure 6] 13A to 13C are diagrams illustrating an example of a method for manufacturing a solar cell module according to a third embodiment. [Figure 7] FIG. 11 is a cross-sectional view of a solar cell module according to a fourth embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a solar cell module according to a fifth embodiment. [Figure 9] FIG. 13 is a cross-sectional view of a solar cell module according to a sixth embodiment. [Figure 10] FIG. 13 is a cross-sectional view of a solar cell module according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an example of an embodiment of a solar cell module according to the present disclosure will be described in detail with reference to the drawings. Note that the scope of the present disclosure includes configurations that selectively combine the respective components of the multiple embodiments and modifications described below.

[0011] FIG. 1 shows a schematic cross-sectional structure of a solar cell module 1 according to a first embodiment, cut in the X direction. A first direction along the surface of a substrate 2 is defined as the "X direction (shown in FIG. 1)", and a second direction along the surface of the substrate 2 and perpendicular to the X direction is defined as the "Y direction (direction perpendicular to the paper surface of FIG. 1)". As shown in FIG. 1, the solar cell module 1 includes a substrate 2 and a cell 3 provided on the substrate 2. The cell 3 is composed of a plurality of unit cells 4 connected in series. Each unit cell 4 includes a photoelectric conversion layer 10, a first electrode layer 11, and a second electrode layer 12.

[0012] The solar cell module 1 further includes an extraction electrode layer 20 and a sealing layer 30. The extraction electrode layer 20 is an electrode for extracting electric energy from the cell 3 to the outside of the module, and is provided in a region that does not overlap with the photoelectric conversion layer 10 when the base material 2 is viewed in plan. The sealing layer 30 is a layer that sandwiches the cell 3 together with the base material 2 and suppresses the inflow of water vapor and oxygen into the module. The sealing layer 30 is provided so as to cover the cell 3 (the photoelectric conversion layer 10, the first electrode layer 11, the second electrode layer 12) and the extraction electrode layer 20, and has an opening 30A in a region corresponding to the extraction electrode layer 20.

[0013] The solar cell module 1 may include an inorganic film 40 provided on the base material 2. The inorganic film 40 is interposed between the base material 2 and the first electrode layer 11. For example, the inorganic film 40 may be the same type of inorganic film as the barrier layer of the second layer 32 described later.

[0014] Although details will be described later, in the solar cell module 1, when the base material 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided, the extraction electrode layer 20 is exposed from the opening 30A of the sealing layer 30, and the peripheral portion of the extraction electrode layer 20 is covered by the sealing layer 30. That is, a part of the surface 21 of the extraction electrode layer 20 facing the side opposite the base material 2 is exposed from the opening 30A of the sealing layer 30, and the periphery of the exposed portion is covered by the sealing layer 30. In this case, water vapor and oxygen are effectively prevented from flowing into the module from the periphery of the extraction electrode layer 20.

[0015] The substrate 2 may be a conductive substrate having an insulating layer formed on its surface, but is preferably an insulating substrate. The substrate 2 is made of a material that is transparent to sunlight having a wavelength of 400 nm or more and 1000 nm or less and has a low water vapor transmission rate. The substrate 2 may be a resin substrate or a glass substrate. The thickness of the substrate 2 is, for example, 0.02 mm or more and 3 mm or less. Since the solar cell module 1 includes the support 5, it is also possible to use a resin film similar to a barrier film described later as the substrate 2.

[0016] As described above, the solar cell module 1 includes a plurality of unit cells 4 connected in series. A plurality of unit cells 4 are arranged in the X direction and are continuous in the Y direction perpendicular to the X direction. The unit cells 4 of this embodiment are perovskite type cells, and include a first electrode layer 11 provided on the substrate 2, a photoelectric conversion layer 10 provided on the first electrode layer 11, and a second electrode layer 12 provided on the photoelectric conversion layer 10. At least one of the substrate 2 and the sealing layer 30 covering the surface of the cell 3 (each unit cell 4) has optical transparency. In this case, light enters the module from the substrate 2 side, the sealing layer 30 side, or both sides and is absorbed by the photoelectric conversion layer 10 of each unit cell 4, but in this embodiment, the sealing layer 30 is opaque, and the surface of the substrate 2 becomes the light receiving surface of the module.

[0017] The photoelectric conversion layer 10 includes a light absorbing layer 13, an electron transport layer 14, and a hole transport layer 15, and has a laminated structure in which the electron transport layer 14 and the hole transport layer 15 are arranged to sandwich the light absorbing layer 13 from both sides. In the photoelectric conversion layer 10 of this embodiment, the electron transport layer 14, the light absorbing layer 13, and the hole transport layer 15 are arranged in this order from the substrate 2 side, except for a portion in which a groove described later is formed. The light absorbing layer 22 includes, for example, a perovskite compound represented by a composition formula ABX3 (wherein A is a monovalent cation, B is a divalent cation, and X is a halogen anion).

[0018] The electron transport layer 14 is made of an n-type semiconductor and is also called an n-layer. Examples of electron transport materials constituting the electron transport layer 14 include anatase-type titanium oxide and tin oxide. The hole transport layer 15 is made of a p-type semiconductor and is also called a p-layer. The hole transport layer 15 includes a hole transport material having an oxidation-reduction site. Examples of hole transport materials constituting the hole transport layer 15 include 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD).

[0019] An example of A in the above perovskite compound (ABX3) is a monovalent cation represented by R1R2R3-NH. When R1 and R2 are H and R3 is CH3, A is methylammonium (CH3NH3). The functional groups R1, R2, and R3 contain at least one element selected from carbon, hydrogen, nitrogen, and oxygen, for example. When the functional groups R1, R2, and R3 contain carbon atoms, the total number of carbon atoms in the functional groups R1, R2, and R3 is preferably 4 or less. The functional groups R1, R2, and R3 may contain a Group 1 element such as Rb or Cs.

[0020] As described above, B in ABX3 is a divalent cation. B is, for example, a divalent cation of a transition metal or a group 13 element, a group 14 element, or a group 15 element. Specific examples of B include Pb 2+ , Ge 2+ , Sn 2+ B is Pb 2+ and Sn 2+ and Pb 2+ , Sn 2+ may be partially substituted with other elements. Examples of the substituting element include Bi, Sb, In, Ge, Ni, etc. X in ABX3 is at least one selected from Cl, Br, and I.

[0021] Each of the A, M, and X sites may be occupied by multiple types of ions. Specific examples of the perovskite compound (ABX3) include CH3NH3PbI3, CH3CH2NH3PbI3, NH2CHNH2PbI3, CH3NH3PbBr3, CH3NH3PbCl3, CsPbI3, and CsPbBr3. The light absorbing layer 13 made of CH3NH3PbI3 is also called a PVSK element.

[0022] The first electrode layer 11 and the second electrode layer 12 are preferably light-transmitting and do not block the entry of light into the photoelectric conversion layer 10. The light transmittance of each electrode layer is, for example, 85% or more in a wavelength range of 450 nm or more and 900 nm or less. The sheet resistance of each electrode layer is preferably 200 Ω / □ or less, and may be 50 Ω / □ or less. An example of a suitable electrode layer is a transparent conductive layer composed of a transparent conductive oxide such as indium tin oxide (ITO) in which a metal oxide such as indium oxide or zinc oxide is doped with tungsten, tin, antimony, or the like. The thickness of the transparent conductive layer is, for example, 30 nm or more and 300 nm or less. Each electrode layer can be formed by a conventionally known method such as sputtering.

[0023] In FIG. 1, two unit cells 4 adjacent to each other in the X direction are illustrated, with the left unit cell 4 being referred to as "unit cell 4A" and the right unit cell 4 being referred to as "unit cell 4B". The number of unit cells 4 included in the solar cell module 1 is not particularly limited, and may be three or more. In the example shown in FIG. 1, the second electrode layer 12 of the unit cell 4A is electrically connected to the first electrode layer 11 of the unit cell 4B. When three or more unit cells 4 are included, for example, the second electrode layer 12 of the unit cell 4B is electrically connected to the first electrode layer 11 of a third unit cell 4 adjacent to each other in the X direction. In this manner, a plurality of unit cells 4 are connected in series along the X direction.

[0024] Grooves 16, 17, and 18 are formed in the cell 3. The grooves 16, 17, and 18 are formed by removing a portion of the layers constituting the cell 3, and are formed to extend in the Y direction and be approximately parallel to each other. Each groove can be formed by a conventionally known scribing method or the like. Each groove has a width of, for example, 30 μm or more and 300 μm or less. The groove 17 is filled with a resin constituting the sealing layer 30 so that no voids are formed in the groove.

[0025] The grooves 16 are grooves that divide the first electrode layer 11 of each unit cell 4. The grooves 17 divide the light absorbing layer 13, the hole transport layer 15, and the second electrode layer 12 of each unit cell 4. Note that the grooves 17 only need to divide the second electrode layer 12 of each unit cell 4, and the light absorbing layer 13 and the hole transport layer 15 do not have to be divided by the grooves 17. In this embodiment, the unit cells 4 are partitioned by the grooves 16 and 17.

[0026] The groove 18 is formed to penetrate the hole transport layer 15, the light absorption layer 13, and the electron transport layer 14, and to expose the first electrode layer 11 of the unit cell 4B. The second electrode layer 12 of the unit cell 4A is formed in the groove 18. This electrically connects the first electrode layer 11 of the unit cell 4B to the second electrode layer 12 of the unit cell 4A. That is, the groove 18 functions as a conductive path that connects the multiple unit cells 4 in series.

[0027] The cell 3 is produced, for example, by the following method. (1) On the substrate 2, a first electrode layer 11 and an electron transport layer 14 are formed in this order. (2) A portion of the first electrode layer 11 is laser scribed to form a groove 16 . (3) On the electron transport layer 14, a light absorbing layer 13 and a hole transport layer 15 are formed in this order. (4) The hole transport layer 15, the light absorption layer 13, and a portion of the electron transport layer 14 are subjected to a mechanical scribing process to form grooves 18. (5) The second electrode layer 12 is formed on the hole transport layer 15. At this time, the second electrode layer 12 is formed in the groove 18, and the conductive path is formed. (6) The second electrode layer 12, the hole transport layer 15, and a portion of the light absorbing layer 13 are subjected to a mechanical scribing process to form a groove 17.

[0028] The light absorbing layer 13, the electron transport layer 14, and the hole transport layer 15 can be formed, for example, by applying a solution in which the constituent materials of each layer are dissolved onto the surface of the substrate 2. These layers may be formed by a meniscus coating method, a spin coating method, or a dispenser. The thickness of each layer is not particularly limited, but is, for example, 10 nm or more and 500 nm or less.

[0029] The configurations of the extraction electrode layer 20 and the sealing layer 30 will be described in detail below.

[0030] The extraction electrode layer 20 has a structure in which metal layers are laminated, and is provided on the base material 2 in a region that does not overlap with the photoelectric conversion layer 10 when the base material 2 is viewed in a plan view. In other words, the extraction electrode layer 20 is provided in a region that does not overlap with the photoelectric conversion layer 10 in the thickness direction of the solar cell module 1. The extraction electrode layer 20 includes an extraction electrode layer 20A electrically connected to the first electrode layer 11 of the unit cell 4A, and an extraction electrode layer 20B electrically connected to the second electrode layer 12 of the unit cell 4B. The extraction electrode layer 20A is disposed at a first end in the X direction of the base material 2, and the extraction electrode layer 20B is disposed at a second end in the X direction opposite to the first end.

[0031] The metal layer constituting the extraction electrode layer 20 is composed of, for example, a metal such as aluminum, nickel, copper, or silver, or an alloy thereof. Among them, it is preferable to use silver. The metal layer may have a single-layer structure or a multi-layer structure including a heterogeneous metal layer. An example of the thickness of the extraction electrode layer 20 is 10 μm or more and 100 μm or less. The extraction electrode layer 20 may be formed by printing, sputtering, vapor deposition, or the like, or may be formed by a plating method.

[0032] The sealing layer 30 is a layer that covers the entire cell 3 and prevents water vapor and oxygen from flowing into the module. The sealing layer 30 may also have a function of capturing water vapor and the like. The sealing layer 30 covers the side surface of the extraction electrode layer 20 along the thickness direction. On the other hand, since the extraction electrode layer 20 is an electrode for extracting the power generated in the cell 3 to the outside of the module, a part of the surface 21 of the extraction electrode layer 20 facing the opposite side to the base material 2 is not covered by the sealing layer 30 and is exposed. The sealing layer 30 has an opening 30A that exposes a part of the surface 21 of the extraction electrode layer 20.

[0033] The sealing layer 30 covers the peripheral portion of the surface 21 of the extraction electrode layer 20 when the substrate 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided. The shape of the opening 30A of the sealing layer 30 is not particularly limited, but as an example, it is a circular shape when viewed in plan. The opening 30A of the sealing layer 30 is arranged so as to overlap with the surface 21 of the extraction electrode layer 20 in the thickness direction of the module, and the portion where the opening area is smallest is smaller than the surface 21. In this embodiment, the area of ​​the opening 30A is smallest at the portion in contact with the surface 21.

[0034] The sealing layer 30 may have a single-layer structure or a multi-layer structure having three or more layers, but in this embodiment, it has a two-layer structure including a first layer 31 and a second layer 32. The first layer 31 has a first opening 31A in a region corresponding to the extraction electrode layer 20. The second layer 32 is provided so as to cover the first layer 31, and has a second opening 32A in a region corresponding to the extraction electrode layer 20. As will be described in detail later, the first opening 31A and the second opening 32A are arranged to overlap in the thickness direction of the module, forming an opening 30A of the sealing layer 30.

[0035] The first layer 31 is filled in the groove 17 formed in the cell 3, between the cell 3 and the extraction electrode layer 20, etc., and is in close contact with the cell 3 and the extraction electrode layer 20. The first layer 31 is preferably in close contact with the cell 3 without any gaps so that no gaps are formed between the cell 3 and the first layer 31. In this case, the inflow of water vapor and oxygen into the module is suppressed. The first layer 31 is preferably made of a resin with low water vapor and oxygen permeability. The first layer 31 may contain a moisture absorbing filler. The first layer 31, which has the function of capturing moisture, is also called a getter layer.

[0036] The resin constituting the first layer 31 may be any resin that has low water vapor and oxygen permeability and good adhesion to the cell 3, and an example of a suitable resin is an olefin-based polymer. An olefin-based polymer is a polymer whose main constituent unit is an olefin-derived unit. The first layer 31 is, for example, a layer in which a moisture-absorbing filler is dispersed in an olefin-based polymer. The first layer 31 may contain other components other than the olefin-based polymer and the moisture-absorbing filler. Examples of the other components include a tackifier, a curing accelerator, an antioxidant, a plasticizer, and a rubber component.

[0037] The olefin-based polymer is preferably a copolymer of two or more kinds of olefins, or a copolymer of an olefin and a monomer other than an olefin, such as a non-conjugated diene, styrene, etc. Examples of the copolymer include an ethylene-non-conjugated diene copolymer, an ethylene-propylene copolymer, an ethylene-propylene-non-conjugated diene copolymer, an ethylene-butene copolymer, a propylene-butene copolymer, a propylene-butene-non-conjugated diene copolymer, a styrene-isobutene copolymer, a styrene-isobutene-styrene copolymer, and an isobutene-isoprene copolymer.

[0038] The olefin polymer preferably has a crosslinked structure, and is obtained by reacting a copolymer containing a first reactive functional group with a copolymer containing a second reactive functional group. The reactive functional group can be selected from the group consisting of an epoxy group, a carboxy group, an acid anhydride group, an amino group, a hydroxyl group, and an isocyanate group, and is used in a combination that reacts with each other. Specific examples of combinations of reactive functional groups include an epoxy group and a carboxy group, an epoxy group and an acid anhydride group, and a carboxy group and an acid anhydride group.

[0039] Examples of the moisture absorbing filler include uncalcined hydrotalcite, semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, magnesium oxide, calcined dolomite, calcium hydride, strontium oxide, aluminum oxide, barium oxide, molecular sieves, and silica.

[0040] The thickness of the first layer 31 is, for example, 10 μm to 100 μm, and preferably 30 μm to 70 μm. If the thickness of the first layer 31 is within this range, good sealing performance and performance of capturing water vapor and the like can be ensured. The material constituting the first layer 31 is supplied in the form of a film in the manufacturing process of the solar cell module 1, and flows when heated, pressurized, or pressurized while being heated, to adhere closely to the cells 3 without any gaps, and also fills the grooves of the cells 3.

[0041] The second layer 32 is a layer with low water vapor and oxygen permeability, and is provided so as to cover the entire first layer 31, suppressing the inflow of water vapor and oxygen into the module. The second layer 32 is preferably made of a resin film having a barrier layer. The resin film is mainly composed of, for example, olefin-based polymers such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonate, and polyimide. The barrier layer is preferably formed on the inner surface of the resin film, that is, the surface facing the first layer 31. Examples of the barrier layer include inorganic films such as a silica vapor deposition film, a silicon nitride film, and a silicon oxide film.

[0042] The thickness of the second layer 32 is, for example, 20 μm or more and 150 μm or less, and preferably 50 μm or more and 100 μm or less. Since the thickness of the barrier layer is thinner than that of the resin film, the thickness of the second layer 32 is substantially the same as the thickness of the resin film constituting the second layer 32. The relationship between the thicknesses of the first layer 31 and the second layer 32 is not particularly limited.

[0043] As described above, the first layer 31 and the second layer 32 are laminated in this order from the substrate 2 side, and are arranged so that the first opening 31A and the second opening 32A overlap. The extraction electrode layer 20 has a part of its surface 21 exposed from the opening 30A (the first opening 31A and the second opening 32A) of the sealing layer 30, but the surface 21 is located closer to the substrate 2 than the surface of the sealing layer 30 and is embedded in the sealing layer 30. In this embodiment, the surface 21 of the extraction electrode layer 20 is located closer to the substrate 2 than the interface between the first layer 31 and the second layer 32.

[0044] The first layer 31 preferably covers the periphery of the surface 21 of the extraction electrode layer 20 and adheres to the side surface along the thickness direction of the extraction electrode layer 20. In this case, the inflow of water vapor and oxygen into the module is more effectively suppressed. In this embodiment, the first opening 31A of the first layer 31 is formed smaller than the second opening 32A of the second layer 32. The opening 30A of the sealing layer 30 formed by the first opening 31A and the second opening 32A may be gradually smaller as it approaches the surface 21 of the extraction electrode layer 20. In the example shown in FIG. 1, the first opening 31A is gradually reduced in diameter toward the surface 21.

[0045] The first layer 31 preferably covers the entire peripheral area of ​​the surface 21. That is, the first layer 31 is in close contact with the surface 21 over the entire peripheral area of ​​the surface 21 so as to surround the portion of the surface 21 exposed through the first opening 31A. In this case, the effect of suppressing the inflow of water vapor and oxygen becomes more pronounced. The first layer 31 may be disposed over the entire circumference with a substantially constant width from the peripheral area of ​​the surface 21. The first layer 31 covers, for example, an area of ​​10% to 50% of the area of ​​the surface 21. In this embodiment, the second opening 32A of the second layer 32 is formed to be larger than the surface 21.

[0046] FIG. 2 is a cross-sectional view of a solar cell module 1X according to a second embodiment, and FIG. 3 is a cross-sectional view of a solar cell module 1Y according to a third embodiment.

[0047] 2 and 3, the solar cell modules 1X and 1Y are common to the solar cell module 1 in that the sealing layer 30 has a two-layer structure including a first layer 31 and a second layer 32, and the surface 21 of the extraction electrode layer 20 is located closer to the base material 2 than the interface between the first layer 31 and the second layer 32. That is, the extraction electrode layer 20 is embedded in the first layer 31. In this case as well, when the base material 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided, a part of the surface 21 of the extraction electrode layer 20 is exposed from the first opening 31A and the second opening 32A.

[0048] On the other hand, the solar cell modules 1X and 1Y differ from the solar cell module 1 in that the second opening 32A of the second layer 32 is formed smaller than the first opening 31A of the first layer 31. In other words, the first opening 31A is wider than the second opening 32A. In this case, the opening area on the outermost surface of the solar cell module 1 is smaller, so that the amount of water vapor and oxygen flowing into the opening can be reduced.

[0049] In the solar cell module 1X shown in FIG. 2, the second opening 32A of the second layer 32 is formed smaller than the area of ​​the surface 21 of the extraction electrode layer 20. The second layer 32 is disposed on the peripheral portion so as to cover the entire peripheral portion of the surface 21. Since the first layer 31 is interposed between the extraction electrode layer 20 and the second layer 32, the second layer 32 is not in contact with the surface 21. The opening area of ​​the second opening 32A is preferably small to the extent that it does not interfere with the extraction of power from the extraction electrode layer 20, and is, for example, 90% or less of the area of ​​the surface 21. In the solar cell module 1X, the first opening 31A of the first layer 31 is formed to be larger than the surface 21, and the peripheral portion of the surface 21 is not covered by the first layer 31.

[0050] As with the solar cell module 1X, the solar cell module 1Y shown in FIG. 3 has the second opening 32A of the second layer 32 formed smaller than the area of ​​the surface 21 of the extraction electrode layer 20, and the second layer 32 disposed on the peripheral portion of the surface 21. On the other hand, the solar cell module 1Y differs from the solar cell module 1X in that the first opening 31A of the first layer 31 is formed smaller than the area of ​​the surface 21, and the peripheral portion of the surface 21 is covered by the first layer 31. That is, the order is surface 21>first opening 31A>second opening 32A, and the peripheral portion of the surface 21 is covered by the first layer 31 and the second layer 32. In this case, the effect of suppressing the inflow of water vapor and oxygen becomes more pronounced.

[0051] An example of a method for manufacturing the solar cell modules 1, 1X, 1Y having the above configuration will be described in detail below with reference to Figures 4 to 6. Figures 4 to 6 show a cross-sectional structure of a solar cell module in the manufacturing process, cut in the X direction.

[0052] The manufacturing process of the solar cell modules 1, 1X, 1Y includes, for example, the following steps. (1) A step of providing a first electrode layer 11, a photoelectric conversion layer 10, and a second electrode layer 12 in this order on a substrate 2 (2) A step of providing an extraction electrode layer 20 on the substrate 2 in a region that does not overlap with the photoelectric conversion layer 10 when the substrate 2 is viewed in plan. (3) A step of providing a sealing layer 30 on the second electrode layer 12 and the extraction electrode layer 20 As described above, the photoelectric conversion layer 10, the first electrode layer 11, the second electrode layer 12, and the extraction electrode layer 20 can be provided on the substrate 2 by a conventionally known method.

[0053] 4 to 6 are diagrams showing the process of providing the sealing layer 30, each illustrating a different formation method. In the example shown in Figs. 4 to 6, a support 5 is used to support the base material 2. The support 5 is made of a material that is thicker and more rigid than the base material 2. The solar cell module is, for example, transported while being placed on the support 5, and each layer is formed on the base material 2. The use of the support 5 enables stable mass production of the solar cell module. An adhesive layer for adhesion may be provided between the support 5 and the base material 2.

[0054] Fig. 4 shows a manufacturing process of the solar cell module 1. In the example shown in Fig. 4, after the sealing layer 30 is disposed on the second electrode layer 12 and the extraction electrode layer 20, a part of the sealing layer 30 is removed to form an opening 30A. The opening 30A is formed in a region of the sealing layer 30 corresponding to the extraction electrode layer 20, i.e., at a position overlapping with the extraction electrode layer 20 in the thickness direction of the module, by a conventionally known scribing method or the like. The opening 30A is formed so that when the base material 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided, the extraction electrode layer 20 is exposed through the opening 30A and the peripheral portion of the extraction electrode layer 20 is covered by the sealing layer 30.

[0055] 4, a film 31F constituting the first layer 31 is disposed so as to cover the second electrode layer 12 and the extraction electrode layer 20, and a film 32F constituting the second layer 32 is disposed further thereon. The films 31F, 32F may be integrated in advance and then supplied onto the substrate 2. The film 31F disposed on the substrate 2 is heated, pressurized, or heated and pressurized, thereby adhering the film 31F to the cells 3 and the like. At this time, the material constituting the first layer 31 is also filled into the grooves 17.

[0056] 4, the opening 30A (first opening 31A of the first layer 31) of the sealing layer 30 is formed so that the opening area gradually decreases toward the surface 21 of the extraction electrode layer 20. The first layer 31 covers the entire periphery of the surface 21, but openings may be formed in each of the films 31F, 32F so that both the first layer 31 and the second layer 32 cover the periphery of the surface 21. That is, each opening may be formed so that both the first opening 31A and the second opening 32A are smaller than the area of ​​the surface 21.

[0057] FIG. 5 shows a manufacturing process of the solar cell module 1X. In the example shown in FIG. 5, a sealing layer 30 having an opening 30A is disposed on the second electrode layer 12 and the extraction electrode layer 20. In this case, when the base material 2 is viewed in plan from the surface side on which the photoelectric conversion layer 10 is provided, the sealing layer 30 is disposed so that the extraction electrode layer 20 is exposed through the opening 30A and the peripheral portion of the extraction electrode layer 20 is covered. That is, in this manufacturing process, films 31F and 32F in which openings are formed in advance are disposed on the base material 2. More specifically, the films 31F and 32F are disposed so that the extraction electrode layer 20, the first opening 31A, and the second opening 32A overlap in the thickness direction of the module.

[0058] Fig. 5 shows the manufacturing process of the solar cell module 1X, but the solar cell modules 1 and 1Y can be manufactured in a similar manner. In the example shown in Fig. 5, the second opening 32A of the second layer 32 is formed smaller than the first opening 31A of the first layer 31, and the surface 21 of the extraction electrode layer 20 ≧ the first opening 31A > the second opening 32A is satisfied, but the solar cell modules 1 and 1Y can be manufactured by changing the size of each opening.

[0059] Fig. 6 shows the manufacturing process of the solar cell module 1Y, but the solar cell module 1X can be manufactured by a similar method. In the example shown in Fig. 6, a first layer 31 having a first opening 31A formed therein in advance is provided on the second electrode layer 12 and the extraction electrode layer 20, a second layer 32 is provided on the first layer 31, and then a second opening 32A is formed. That is, this manufacturing process includes a step of providing the first layer 31 having the first opening 31A in a region corresponding to the extraction electrode layer 20, a step of providing the second layer 32 on the first layer 31, and a step of removing a part of the second layer 32 to form the second opening 32A.

[0060] 6, when the substrate 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided, the first layer 31 and the second layer 32 are provided and the second opening 32A is formed so that the extraction electrode layer 20 is exposed through the first opening 31A and the second opening 32A and the peripheral portion of the extraction electrode layer 20 is covered by at least one of the first layer 31 and the second layer 32. In this manufacturing process, the film 31F is disposed so that the extraction electrode layer 20 and the first opening 31A overlap in the thickness direction of the module, and after the film 32F is laminated on the film 31F, the second opening 32A is formed at a position overlapping the first opening 31A.

[0061] Another embodiment of the solar cell module will now be described with reference to Figures 7 to 10. The differences from the above embodiment will be described below.

[0062] In the fourth to sixth embodiments illustrated in Figs. 7 to 9, similarly to the above-mentioned embodiments, the surface 21 of the extraction electrode layer 20 is located closer to the base material 2 than the surface of the sealing layer 30, and is embedded in the sealing layer 30. The surface 21 of the extraction electrode layer 20 is exposed from the opening 30A of the sealing layer 30. Meanwhile, the surface 21 of the extraction electrode layer 20 is not covered by the first layer 31 and the second layer 32. However, the configurations of the first to third embodiments can be selectively applied to the fourth to sixth embodiments. In this case, the effect of suppressing the inflow of water vapor and oxygen becomes more remarkable.

[0063] 7, in the solar cell module 50 of the fourth embodiment, the grooves 17 filled with the first layer 31 of the sealing layer 30 are formed so as to gradually widen as they move away from the base material 2. The grooves 17 are formed, for example, by removing parts (parts overlapping in the thickness direction of the module) of the photoelectric conversion layer 10, the hole transport layer 15, and the second electrode layer 12, and the opening formed in the hole transport layer 15 is larger than the opening formed in the photoelectric conversion layer 10. Furthermore, the opening in the second electrode layer 12 is larger than the opening in the hole transport layer 15.

[0064] As described above, the solar cell module 50 has a groove 17 that gradually widens with increasing distance from the base material 2, and the first layer 31 is formed in the groove 17. The groove 17 may have a width that changes stepwise at the interface between the layers as shown in FIG. 7, or may have a width that increases continuously from the photoelectric conversion layer 10 toward the second electrode layer 12. By having such a groove 17, the constituent material of the first layer 31 is easily filled in the groove, and voids are less likely to form in the groove. As a result, the inflow of water vapor and oxygen into the module is effectively suppressed.

[0065] As shown in FIG. 8, in the solar cell module 51 according to the fifth embodiment, fine irregularities are formed on the surface of the second electrode layer 12 that contacts the first layer 31 of the sealing layer 30. In this case, the contact area between the first layer 31 and the second electrode layer 12 is increased, and the adhesion between the first layer 31 and the second electrode layer 12 is improved. As a result, a gap is unlikely to occur between the first layer 31 and the second electrode layer 12, and the inflow of water vapor and oxygen into the module is effectively suppressed. Although the irregularities may be formed only on the surface of the second electrode layer 12, in the example shown in FIG. 8, the irregularities are formed on the surface of the photoelectric conversion layer 10, and the hole transport layer 15 and the second electrode layer 12 are formed along the irregularities of the photoelectric conversion layer 10, thereby forming the irregularities on the surface of the second electrode layer 12.

[0066] The arithmetic mean roughness Ra of the surface of the second electrode layer 12 is, for example, 1 nm or more and 100 nm or less. When the arithmetic mean roughness Ra is within this range, the effect of improving the adhesion between the first layer 31 and the second electrode layer 12 becomes more significant. The arithmetic mean roughness Ra of the surface of the second electrode layer 12 can be measured by cross-sectional TEM. The method of forming the irregularities on the surface of the photoelectric conversion layer 10 is not particularly limited, but one example is a spin coating method.

[0067] As shown in Fig. 9, a solar cell module 52 according to the sixth embodiment includes a spring electrode 60 as a wiring member electrically connected to the extraction electrode layer 20. The spring electrode 60 is disposed in an opening 30A of the sealing layer 30, and one axial end of the spring electrode 60 is in contact with the surface 21 of the extraction electrode layer 20. The other axial end of the spring electrode 60 protrudes from the opening 30A and is connected to an external device (not shown). The opening 30A may be filled with a sealant 61 that fills the gap between the sealing layer 30 and the spring electrode 60. For example, the sealant 61 may be made of the same material as that of the first layer 31.

[0068] As shown in FIG. 10, in the solar cell module 53 according to the seventh embodiment, the thickness of the first layer 31 constituting the sealing layer 30 is reduced around the extraction electrode layer 20. The extraction electrode layer 20 is formed thicker than the sealing layer 30, and the opening of the film constituting the first layer 31 is made large enough to create a gap between the extraction electrode layer 20 and the film, so that the film fills the gap and sinks into the base material 2. Around the extraction electrode layer 20, the second layer 32 follows the first layer 31, and the surface of the second layer 32 is recessed. Therefore, the surface 21 of the extraction electrode layer 20 and its vicinity protrude from the sealing layer 30.

[0069] In the solar cell module 53, the sealing layer 30 is tightly adhered to the side surface of the extraction electrode layer 20, making it difficult for a gap to form between the extraction electrode layer 20 and the sealing layer 30. As a result, the inflow of water vapor and oxygen into the module is effectively suppressed.

[0070] As described above, the solar cell modules of the above embodiments can sufficiently suppress the inflow of water vapor and oxygen into the module. The solar cell modules of the above embodiments have excellent sealing performance, and therefore can maintain good output performance for a long period of time. In particular, as in the solar cell modules 1, 1X, and 1Y of the first to third embodiments, when the peripheral portion of the extraction electrode layer 20 is covered with the sealing layer 30 when the base material 2 is viewed in plan from the side on which the photoelectric conversion layer 10 is provided, the inflow of water vapor and oxygen from around the extraction electrode layer 20 into the module is effectively suppressed.

[0071] The above-mentioned embodiments can be appropriately modified in design without impairing the object of the present disclosure. As described above, the configurations of the first to third embodiments can be selectively applied to the fourth to sixth embodiments, and in this case, the effect of suppressing the inflow of water vapor and oxygen becomes more pronounced. In other words, at least one configuration selected from the group consisting of the widened shape of the groove 17 of the fourth embodiment, the surface irregularities of the second electrode layer 12 of the fifth embodiment, and the spring electrode 60 of the sixth embodiment may be applied to the solar cell modules 1, 1X, and 1Y.

[0072] The encapsulating layer may be supplied to the manufacturing process of the solar cell module in the form of a single film including the barrier layer as an intermediate layer. The barrier layer is sandwiched between, for example, two resin films. The resin film disposed on the substrate 2 may be a film having the same function as the film constituting the first layer 31, and the resin film disposed on the outer side of the barrier layer may be a film having the same function as the film constituting the second layer 32. [Explanation of symbols]

[0073] 1,1X,1Y,50,51,52,53 solar cell module, 2 substrate, 3 cell, 4,4A,4B unit cell, 5 support, 10 photoelectric conversion layer, 11 first electrode layer, 12 second electrode layer, 13 light absorption layer, 14 electron transport layer, 15 hole transport layer, 16,17,18 groove, 20,21,20B extraction electrode layer, 21 surface, 30 sealing layer, 30A opening, 31 first layer, 31A first opening, 32 second layer, 32A second opening, 40 inorganic film, 60 spring electrode, 61 sealing material

Claims

1. A substrate; a first electrode layer provided on the substrate; a photoelectric conversion layer provided on the substrate; a second electrode layer provided on the substrate; an extraction electrode layer provided on the base material in a region that does not overlap with the photoelectric conversion layer when the base material is viewed from above; a sealing layer; and Equipped with a layer containing at least the same material as the second electrode layer is provided between the substrate and the extraction electrode layer; The solar cell module, wherein the sealing layer covers a side surface of the extraction electrode layer along the thickness direction.

2. the photoelectric conversion layer includes a light absorbing layer, an electron transport layer, and a hole transport layer; The solar cell module according to claim 1 , wherein the light absorbing layer comprises a perovskite compound.

3. A semiconductor device having a plurality of unit cells connected in series, Each unit cell includes the photoelectric conversion layer, the first electrode layer, and the second electrode layer. The solar cell module according to claim 1 or 2.

4. The first electrode layer is optically transparent. The solar cell module according to any one of claims 1 to 3.

5. The extraction electrode layer is a metal layer. The solar cell module according to any one of claims 1 to 4.

6. The extraction electrode layer includes a first extraction electrode layer and a second extraction electrode layer, the first extraction electrode layer is electrically connected to the first electrode layer; the second extraction electrode layer is electrically connected to the second electrode layer; The solar cell module according to any one of claims 1 to 5.

7. The first electrode layer, the second electrode layer, and the extraction electrode layer are stacked in this order on the substrate. The solar cell module according to any one of claims 1 to 6.

8. A first scribe groove dividing the first electrode layer of the unit cell. The solar cell module according to claim 3 .

9. A second scribe groove dividing the photoelectric conversion layer of the unit cell. The solar cell module according to claim 3 or 8.

10. A third scribe groove dividing the photoelectric conversion layer and the second electrode layer of the unit cell, the third scribed groove is filled with a conductive material; The solar cell module according to claim 3, 8 or 9.

11. The sealing layer covers a surface of the extraction electrode layer. The solar cell module according to any one of claims 1 to 10.

Images