solar cell element

Abstract

To provide a solar cell element in which the deterioration of a photoelectric conversion layer is suppressed without causing short-circuit due to etching.SOLUTION: A solar cell element includes a substrate 3, a first electrode 5a and a second electrode 5b formed apart from each other on the substrate 3, a photoelectric conversion layer formed in a region including the first electrode 5a and the second electrode 5b and including an electron transport layer 7a and an electron transport layer 7b, a perovskite layer 9a and a perovskite layer 9b, and a hole transport layer 11a and a hole transport layer 11b, a first back electrode 13a and a second back electrode 13b formed at positions respectively corresponding to the first electrode 5a and the second electrode 5b on the photoelectric conversion layer, and a connection electrode 15 connecting the first back electrode 13a and a part of the second electrode 5b, this part of the second electrode 5b and a part of the substrate 3 being exposed in a region where the photoelectric conversion layer does not exist and the first back electrode 13 and the second back electrode 13b do not exist.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing elements such as solar cells and organic EL devices. [Background technology]

[0002] Japanese Patent Publication No. 2018-163938 describes a solar cell.

[0003] For example, in order to obtain a solar cell module with a high voltage, it is desirable to connect cells in series on the same substrate to form a solar cell module with an integrated structure. When separating the power generation layer to obtain a module with an integrated structure, it was assumed that etching would be performed using a mask to remove part of the perovskite layer and hole transport layer. However, such etching would also remove the masked parts, causing a short circuit. In particular, when the power generation layer is separated by dry etching using plasma from carbon tetrafluoride gas or oxygen gas, there is a problem that the etching can get under the mask, causing damage to the masked area. Furthermore, there is a problem that the photoelectric conversion layer deteriorates during the production of solar cells. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-163938 Summary of the Invention [Problem to be solved by the invention]

[0005] The invention described in this specification aims to provide a method for manufacturing an element without causing short circuits due to etching.The invention described in this specification aims to provide a method for manufacturing an element while suppressing deterioration of the photoelectric conversion layer.

[0006] Another object of the invention described in this specification is to provide a method for manufacturing a solar cell module having an integrated structure. [Means for solving the problem]

[0007] One invention described in this specification is based on the finding that by etching an element material having a power generation layer using a separated electrode (e.g., a back electrode) as a mask, and then forming a connecting electrode, an element can be manufactured without causing a short circuit even when etching is performed.

[0008] An invention described in this specification relates to a method for manufacturing an element. This method for manufacturing an element includes preparing an element material, and then manufacturing the element through a process including a back electrode forming process, an etching process, and a connection electrode forming process. Examples of elements include solar cells and solar cell modules with an integrated structure.

[0009] The element material includes an electrode formed on a substrate, the electrode including a first electrode and a second electrode spaced apart, and a photoelectric conversion layer formed in a region including the first electrode and the second electrode.

[0010] This method is forming a first back surface electrode and a second back surface electrode on the photoelectric conversion layer at positions corresponding to the first electrode and the second electrode, respectively, wherein the first back surface electrode and the second back surface electrode are not connected; performing etching using the first rear surface electrode and the second rear surface electrode as a mask; and a connection electrode forming step of forming a connection electrode for connecting the first back surface electrode and the second back surface electrode.

[0011] A preferred example of this method is a process in which the connection electrode formation process forms the connection electrodes by screen printing. An example of a connection electrode formation process is a process in which the connection electrodes are formed by screen printing. Normally, the backside electrodes must be formed by vapor deposition using a mask. However, by using screen printing, the electrodes can be formed easily and without damaging each layer.

[0012] In a preferred embodiment of this method, the device material is forming a first electron transport layer and a second electron transport layer on the first electrode and the second electrode, respectively; forming a perovskite layer on the first electron transport layer and the second electron transport layer; forming a hole transport layer on the perovskite layer; It is manufactured by

[0013] A preferred example of this method is when the device material is: forming a first hole transport layer and a second hole transport layer on the first electrode and the second electrode, respectively; forming a perovskite layer on the first hole transport layer and the second hole transport layer; forming an electron transport layer on the perovskite layer. It is manufactured by [Effects of the Invention]

[0014] The invention described in this specification can provide a method for manufacturing an element without causing short circuits due to etching.The invention described in this specification can provide a method for manufacturing an element while suppressing deterioration of the photoelectric conversion layer.

[0015] An invention described in this specification can provide a method for manufacturing a solar cell module having an integrated structure. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a flowchart showing an example of a method for manufacturing an element. [Figure 2] FIG. 2 is a conceptual diagram showing an example of element materials. [Figure 3] FIG. 3 is a conceptual diagram showing an example of an electrode. [Figure 4] FIG. 4 is a conceptual diagram showing the device material in the process of being manufactured at a stage after the electron transport layer formation process. [Figure 5] FIG. 5 is a conceptual diagram showing the device material after the hole transport layer formation step. [Figure 6] FIG. 6 is a conceptual diagram showing the device in the middle of manufacture after the back electrode formation step. [Figure 7] FIG. 7 is a conceptual diagram showing the device in the process of being manufactured after the etching process. [Figure 8] FIG. 8 is a conceptual diagram showing the device in the middle of manufacture after the connection electrode formation step. [Figure 9] FIG. 9 is a conceptual diagram for explaining the solar cell in the first embodiment. [Figure 10] FIG. 10 is a conceptual diagram for explaining the solar cells in Examples 2 and 3. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] The following describes embodiments of the present invention with reference to the drawings. The present invention is not limited to the embodiments described below, and also includes appropriate modifications of the embodiments below within the scope obvious to those skilled in the art.

[0018] Examples of element 1 are solar cells and organic EL elements. An example of a solar cell is a perovskite solar cell. A perovskite solar cell has, for example, an electrode, an electron transport layer, a perovskite layer (light absorption layer), a hole transport layer, and a back electrode, in this order. A perovskite solar cell may be of a forward type in which an n-type semiconductor layer is provided on an electrode, or of an inverted type in which a p-type semiconductor layer is provided on an electrode (a substrate, an electrode, a hole transport layer, a perovskite layer, an electron transport layer, an electrode, and a connection electrode, formed in this order). Below, a perovskite solar cell will be described using as an example a perovskite solar cell that has, in this order, an electrode, an electron transport layer, a perovskite layer (light absorption layer), a hole transport layer, and a back electrode.

[0019] Fig. 1 is a flowchart showing an example of a method for manufacturing an element. As shown in Fig. 1, the method for manufacturing this element includes preparing an element material, followed by a back electrode forming step (S21), an etching step (S22), and a connection electrode forming step (S23).

[0020] Examples of the element include a solar cell, a solar cell module having an integrated structure, and an organic EL element. In addition to the respective configurations described below, these may also appropriately employ known elements that solar cells and organic EL elements have.

[0021] Fig. 2 is a conceptual diagram showing an example of an element material. As shown in Fig. 2, the element material has a substrate 3, an electrode 5 including a first electrode 5a and a second electrode 5b, a first electron transport layer 7a and a second electron transport layer 7b, a perovskite layer 9, and a hole transport layer 11. In this example, the first electron transport layer 7a, the second electron transport layer 7b, the perovskite layer 9, and the hole transport layer 11 function as a photoelectric conversion layer. The element material may have a photoelectric conversion layer including a first hole transport layer, a second hole transport layer, a perovskite layer, and an electron transport layer in this order.

[0022] Board 3 A known substrate for perovskite solar cells or organic EL elements can be used as the substrate 3. Examples of the substrate include a glass substrate, an insulating substrate, a semiconductor substrate, a metal substrate, and a conductive substrate (including a conductive film). In addition, a substrate having at least one film selected from a metal film, a semiconductor film, a conductive film, and an insulating film formed on part or all of the surface thereof can also be suitably used.

[0023] Examples of constituent metals of the metal film include one or more metals selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel, cobalt, zinc, magnesium, calcium, silicon, yttrium, strontium, and barium. Examples of constituent materials of the semiconductor film include elemental elements such as silicon and germanium, compounds containing elements from Groups 3 to 5 and Groups 13 to 15 of the periodic table, metal oxides, metal sulfides, metal selenides, and metal nitrides. Examples of constituent materials of the conductive film include tin-doped indium oxide (ITO), fluorine-doped indium oxide (FTO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), tin oxide (SnO2), indium oxide (In2O3), and tungsten oxide (WO3). Examples of materials constituting the insulating film include aluminum oxide (Al2O3), titanium oxide (TiO2), silicon oxide (SiO2), silicon nitride (Si3N4), and silicon oxynitride (Si4O5N3).

[0024] Examples of the shape of the substrate include a plate-like shape such as a flat plate or a disk, a fiber-like shape, a rod-like shape, a column-like shape, a rectangular column-like shape, a cylindrical shape, a spiral shape, a spherical shape, a ring-like shape, and a porous structure. Of these, a plate-like substrate is preferred. For example, the thickness of the substrate is preferably 0.1 μm to 100 mm, and more preferably 1 μm to 10 mm.

[0025] electrode 5 The electrodes are layers that support the electron transport layer and have the function of extracting electrons from the perovskite layer (light absorption layer). The electrodes are formed on the substrate 3 and include a first electrode 5a and a second electrode 5b that are spaced apart. Spaced apart means that they are not in physical contact and that the first electrode 5a and the second electrode 5b are not short-circuited. The electrodes are preferably transparent electrodes or metal electrodes.

[0026] Examples of transparent electrodes include tin-doped indium oxide (ITO) films, impurity-doped indium oxide (In2O3) films, impurity-doped zinc oxide (ZnO) films, fluorine-doped tin dioxide (FTO) films, and laminated films formed by laminating these. A metal electrode refers to an electrode containing a metal. Examples of metal electrodes include gold, silver, and copper. A metal electrode may not only be made of metal, but may also have a tin-doped indium oxide (ITO) film, impurity-doped indium oxide (In2O3) film, impurity-doped zinc oxide (ZnO) film, fluorine-doped tin dioxide (FTO) film, or a laminated film formed by laminating these on the surface of the metal. These films may function, for example, as a diffusion prevention layer. The thickness of these electrodes is not particularly limited, and it is usually preferable to adjust the sheet resistance to 5 to 15 Ω / □ (per unit area). Electrodes can be obtained by known film formation methods depending on the material to be formed.

[0027] Figure 3 is a conceptual diagram showing an example of electrodes. As shown in Figure 3, the electrodes 5 include a first electrode 5a and a second electrode 5b, which may be separated so as not to be connected. In the example of Figure 3, two electrodes are depicted, but there may be three or more electrodes.

[0028] Electron transport layer 7 The device material has an electron transport layer. The electron transport layer 7 is formed to increase the active surface area of ​​the perovskite layer (light absorption layer), improve photoelectric conversion efficiency, and facilitate electron collection. The electron transport layer may be a flat layer made of an organic semiconductor material such as a fullerene derivative. The electron transport layer may also be a layer containing a metal oxide such as titanium oxide (TiO2) (including mesoporous TiO2), tin oxide (SnO2), or zinc oxide (ZnO). The thickness of the electron transport layer is not particularly limited, and is preferably about 10 to 300 nm, more preferably about 10 to 250 nm, from the viewpoint of being able to collect more electrons from the perovskite layer (light absorption layer).

[0029] The electron transport layer has a first electron transport layer 7a and a second electron transport layer 7b formed on the first electrode 5a and the second electrode 5b, respectively. Usually, the electron transport layer is patterned so as to have the same shape as the electrode underneath. The first electron transport layer 7a and the second electron transport layer 7b have, for example, the same shapes as the first electrode 5a and the second electrode 5b, respectively. However, the same shape does not mean identical in the strict sense, and the same shape may be designed to be approximately the same shape.

[0030] Perovskite layer 9 The perovskite layer (light absorbing layer: photoactive layer) 9 in a perovskite solar cell is a layer that absorbs light and transfers excited electrons and holes to perform photoelectric conversion. The perovskite layer (light absorbing layer) contains a perovskite material or a perovskite complex. From the viewpoint of the balance between light absorption efficiency and the electron and hole diffusion lengths, and the absorption efficiency of light reflected by the electrode, the film thickness of the perovskite layer (light absorbing layer) is preferably, for example, 50 to 1000 nm, and more preferably 200 to 800 nm. The film thickness of the perovskite layer (light absorbing layer) of the present invention may be measured using a cross-sectional scanning electron microscope (cross-sectional SEM). Furthermore, the flatness of the perovskite layer (light absorption layer) of the present invention is preferably such that the difference in height within a horizontal area of ​​500 nm x 500 nm on the surface as measured by a scanning electron microscope is 50 nm or less (-25 nm to +25 nm), and more preferably 40 nm or less (-20 nm to +20 nm). This makes it easier to balance the light absorption efficiency and the exciton diffusion length, and further improves the absorption efficiency of light reflected by the electrode.

[0031] In the device material, the perovskite layer 9 is formed on the first electron transport layer 7a and the second electron transport layer 7b. In the example of Fig. 2, the perovskite layer is also formed in the portions (gap portions) on the substrate 3 where the first electrode 5a and the second electrode 5b are not present.

[0032] Hole transport layer 11 The hole transport layer 11 is a layer having the function of transporting charges. The hole transport layer 11 is a layer formed on the perovskite layer 9. For example, a conductor, a semiconductor, an organic hole transport material, etc. can be used for the hole transport layer. This material can function as a hole transport material that receives holes from the perovskite layer (light absorption layer) and transports the holes. The hole transport layer is formed on the perovskite layer (light absorption layer). Examples of the conductor and semiconductor include compound semiconductors containing monovalent copper, such as CuI, CuInSe2, and CuS; and compounds containing metals other than copper, such as GaP, NiO, CoO, FeO, Bi2O3, MoO2, and Cr2O3. Among these, semiconductors containing monovalent copper are preferred, and CuI is more preferred, from the viewpoint of more efficiently receiving only holes and achieving higher hole mobility. Examples of organic hole transport materials include polythiophene derivatives such as poly-3-hexylthiophene (P3HT) and polyethylenedioxythiophene (PEDOT); fluorene derivatives such as 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (Spiro-OMeTAD); carbazole derivatives such as polyvinylcarbazole; triphenylamine derivatives such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA); diphenylamine derivatives; polysilane derivatives; polyaniline derivatives, etc. Among these, triphenylamine derivatives and fluorene derivatives are preferred, with PTAA and Spiro-OMeTAD being more preferred, from the viewpoint of more efficiently receiving only holes and achieving higher hole mobility.

[0033] In order to further improve the hole transport properties, the hole transport layer may contain an oxidizing agent such as lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), silver bis(trifluoromethylsulfonyl)imide, trifluoromethylsulfonyloxysilver, NOSbF6, SbCl5, SbF5, or tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III) tri[bis(trifluoromethane)sulfonimide]. The hole transport layer may also contain a basic compound such as t-butylpyridine (TBP), 2-picoline, or 2,6-lutidine. The contents of the oxidizing agent and basic compound may be the amounts conventionally used. The thickness of the hole transport layer is preferably 50 to 500 nm, more preferably 100 to 300 nm, from the viewpoint of more efficiently receiving only holes and achieving higher hole mobility.

[0034] 1, the element material may be manufactured by a method including an electrode forming step (S11), an electron transport layer forming step (S12), a perovskite layer forming step (S13), and a hole transport layer forming step (S14). Alternatively, the element material may be manufactured by a process including a step of forming a first hole transport layer and a second hole transport layer on a first electrode and a second electrode, respectively, a step of forming a perovskite layer on the first hole transport layer and the second hole transport layer, and a step of forming an electron transport layer on the perovskite layer.

[0035] Electrode formation process (S11) The electrode formation step (S11) is a step of forming electrodes on a substrate. The electrodes include a first electrode and a second electrode that are spaced apart. Methods for forming electrodes on a substrate are well known. Examples of well-known methods include etching using a resist pattern and patterning using a laser.

[0036] Electron transport layer formation step (S12) The electron transport layer formation step is a step of forming an electron transport layer (first electron transport layer 7a and second electron transport layer 7b) on the electrode 3 (first electrode 5a and second electrode 5b). The electron transport layer can be obtained using a known film formation method depending on the material to be formed. For example, it can be produced by applying an aqueous dispersion of tin oxide microparticles at a concentration of 3 to 15% by mass (particularly 5 to 10% by mass) onto the electrode. Known or commercially available tin oxide microparticle aqueous dispersions can be used. The preferred application method is spin coating. The application can be carried out at a temperature of, for example, about 15 to 30°C. After the electrodes and electron transport layer are formed on the substrate, etching using a resist pattern or patterning using a laser may be performed.

[0037] Figure 4 is a conceptual diagram showing the device material in the middle of manufacturing at a stage after the electron transport layer formation process. As shown in Figure 4, an electron transport layer (first and second electron transport layers 7a, 7b) is formed on an electrode divided into multiple parts. In this example, an electrode divided into two parts is described. However, the electrode may be divided into three or more parts.

[0038] Perovskite layer formation step (S13) The perovskite layer forming step is a step of forming a perovskite layer 9 on the electron transport layer (first electron transport layer 7a and second electron transport layer 7b). The perovskite layer may be manufactured based on a known method.

[0039] An example of a perovskite layer formation process includes the steps of applying a solution containing a perovskite compound to a substrate, applying a poor solvent to the substrate, and annealing the substrate, in this order. Spin coating, dip coating, screen printing, roll coating, die coating, transfer printing, spraying, or slit coating may be used to apply the solution to the substrate. Among these, spin coating is preferred. Spin coating is a method in which the solution is applied to the substrate by rotating the substrate while dripping the solution. Alternatively, the substrate carrying the solution may be rotated, and the solution may be further applied to the substrate. The rotation speed may be set to a maximum speed of 1,000 to 10,000 rpm for 30 seconds to 5 minutes, 2 to 15 seconds to reach maximum speed, and 2 to 15 seconds to stop from maximum speed.

[0040] Next, the step of applying a poor solvent to the substrate will be described. A poor solvent is a solvent that can dissolve a solute but does not have a high solubility for the solute. Examples of poor solvents include substituted aliphatic hydrocarbons such as dichloromethane and chloroform; aromatic hydrocarbons such as toluene and benzene; substituted aromatic hydrocarbons such as chlorobenzene, orthodichlorobenzene, and nitrobenzene; ethers such as acetic acid, diethyl ether, and tetrahydrofuran (THF); alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; long-chain hydrocarbons (especially C4-10 hydrocarbons) such as hexane; and acetonitrile. These poor solvents can be used alone or in combination. Among these, chlorobenzene or toluene is preferred.

[0041] Next, the process of annealing the substrate will be described. Annealing refers to a process of heating the substrate, etc. The annealing process is preferably carried out promptly after the poor solvent has been dripped or after the substrate has stopped moving after spin coating has finished. As will be shown in the examples described later, the annealing process preferably includes a step of gradually heating the substrate in a closed system containing solvent vapor. In the closed system, it is preferable that vapor of the solvent contained in the solution containing the Sn-based perovskite compound is present, and it is preferable that the solvent in the closed system is at saturated vapor pressure or a partial pressure of 90% or more of the saturated vapor pressure.

[0042] Hole transport layer formation step (S14) The hole transport layer forming step is a step of forming a hole transport layer 11 on the perovskite layer 9. A known method may be appropriately adopted as the method for forming the hole transport layer. For example, it is preferable to form the hole transport layer 11 by applying (by spin coating, inkjet, die coater, etc.) a solution containing an organic hole transport material onto the perovskite layer (light absorption layer) in a dry atmosphere and heating it at 30 to 150°C (particularly 50 to 100°C). By forming the hole transport layer, the element material 21 can be obtained.

[0043] 5 is a conceptual diagram showing the device material after the hole transport layer forming step. As shown in FIG. 5, a hole transport layer 11 is formed so as to cover the entire perovskite layer 9.

[0044] Back electrode formation process (S21) The back surface electrode formation step is a step of forming a first back surface electrode 13a and a second back surface electrode 13b on the element material 21 at positions on the hole transport layer 11 corresponding to the first electrode 5a and the second electrode 5b, respectively.

[0045] When the back electrodes 13a-13b are made of metal, they are also called metal electrodes. The back electrodes are arranged opposite the electrodes and formed on the hole transport layer, allowing for the exchange of charges with the hole transport layer. Known materials used in the industry can be used for the back electrodes, such as platinum, titanium, stainless steel, aluminum, gold, silver, nickel, and other metals, or alloys of these. Of these, metal electrodes are preferably made of materials that can be formed by methods such as vapor deposition, since they can be formed in a dry atmosphere.

[0046] By appropriately combining the above method with a known method, it is also possible to manufacture perovskite solar cells having layer structures other than those described above.

[0047] FIG. 6 is a conceptual diagram showing a device in the middle of manufacture after the back electrode formation process. As shown in FIG. 6, the back electrode does not have to have the same shape as the electrode or electron transport layer. In the example of FIG. 6, first and second back electrodes 13a and 13b are formed. Some portions of the back electrodes do not have to cover the electrode or electron transport layer so that conductive connection can be made by the connection electrode. Some portions of the back electrodes may be located in areas where no electrode or electron transport layer is provided. For example, the first back electrode 13a has a main body portion and a protruding portion protruding from the main body portion. No electrode or electron transport layer is provided below the protruding portion (toward the substrate). On the other hand, the protruding portions near the centers of the first electrode 5a and the first electron transport layer 7a are not covered by the first back electrode 13a.

[0048] Etching process (S22) The etching process is a process in which etching is performed using the first back surface electrode 13a and the second back surface electrode 13b as a mask. Since the etching process is well known, a well-known etching method can be appropriately adopted. An example of etching is dry etching.

[0049] FIG. 7 is a conceptual diagram showing the device in the middle of manufacture after the etching step. As shown in FIG. 7, etching removes the perovskite layer 9 and hole transport layer 11 in the areas where the back electrode is not formed. This exposes parts of the electron transport layers 7a-7b and parts of the electrodes 5a-5b in the areas where the back electrode is not present. The photoelectric conversion layers on the first electrode 5a and second electrode 5b are also referred to as the first photoelectric conversion layer 6a and second photoelectric conversion layer 6b. The first photoelectric conversion layer 6a includes a first electron transport layer 7a, a first perovskite layer 9a, and a first hole transport layer 11a, and the second photoelectric conversion layer 6b includes a second electron transport layer 7b, a second perovskite layer 9b, and a second hole transport layer 11b.

[0050] Connection electrode formation process (S23) The connection electrode formation process is a process for forming connection electrodes 15 for connecting the first back surface electrode 13a and the second back surface electrode 13b. An example of the connection electrode formation process is a process for forming connection electrodes by screen printing. Normally, the back surface electrodes must be formed by vapor deposition using a mask. However, by using screen printing, the electrodes can be formed easily and without damaging each layer.

[0051] 8 is a conceptual diagram showing the element during manufacture after the connection electrode forming step. In this example, for example, first back surface electrode 13a and second electrode 5b are connected by first connection electrode 15a. Second connection electrode 15b is provided on second back surface electrode 13b.

[0052] After the connection electrode forming step, excess portions may be removed using, for example, a laser, and a sealing material layer (protective film) may also be formed.

[0053] Encapsulant layer The sealing material layer 23 is provided to protect the photoelectric conversion unit. Examples of materials that can be used to form the sealing material layer include thermoplastic resins such as ethylene-vinyl acetate copolymer (EVA), polyvinyl butyral (PVB), polyethylene terephthalate (PET), polyolefin (PO), and polyimide (PI), thermosetting resins such as epoxy, urethane, and polyimide, and inorganic materials such as glass, with EVA, PO, and glass being preferred.

[0054] The sealing material layer preferably has a thickness of 0.1 to 10 mm and a tensile modulus of elasticity of 0.005 to 0.05 GPa, for example. These parameters are explained below.

[0055] The thickness of the encapsulant layer is, for example, preferably 0.1 to 10 mm, and more preferably 0.2 to 1.0 mm. When the encapsulant layer has such a thickness, the photoelectric conversion section can be sufficiently encapsulated and protected.

[0056] The tensile modulus of the sealing material layer is preferably, for example, 0.005 to 0.05 GPa, and more preferably 0.01 to 0.05 GPa. When the tensile modulus of the sealing material layer is in this range, stress due to expansion and contraction of the surface protection substrate can be sufficiently alleviated.

[0057] Organic EL elements are known elements, and their manufacturing methods are also known, as described in, for example, Japanese Patent Application Laid-Open Nos. 2017-123352 and 2015-071619. An example of an organic EL element has a substrate, an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer is configured by stacking, in this order from the anode side, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, and an electron injection layer. [Example]

[0058] The following examples will specifically explain examples of the invention described in this specification. The invention described in this specification is not limited to the following examples, and includes those to which publicly known elements are appropriately added.

[0059] FIG. 9 is a conceptual diagram for explaining the solar cell in the first embodiment. A glass substrate 3 has an ITO (indium tin oxide) electrode 5 patterned in advance into a predetermined shape, and an electron transport layer 7, a perovskite layer 9, and a hole transport layer 11 are sequentially coated on it. The electron transport layer 7 can be formed by spin-coating a colloidal SnO2 aqueous solution and drying it. A high-quality perovskite layer 9 can be obtained by applying a predetermined material by the aforementioned spin-coating method, followed by further coating with a poor solvent. The hole transport layer 11 can be obtained by spin-coating a solution containing Spiro-MeOTAD and drying it. The above layers are basically formed by spin coating and are deposited over the entire surface of the substrate.

[0060] In conventional technology, a patterning process for stacked layers is often carried out before forming the back electrode, but this is not done in this embodiment because a high-precision pattern requires high positional precision for the subsequent back electrode as well, making this unsuitable.

[0061] First, the back electrode 13 is formed. To form the back electrode, a metal mask is used to create a pattern in advance, and the desired material is used as a target in a sputtering device. The metal mask is formed by adhering it to the laminated substrate 3. The target materials used were molybdenum oxide (MoO3), copper (Cu), and indium tin oxide (ITO).

[0062] Next, dry etching using CF4 and O2 is performed to remove the laminated film in the area where there is no back electrode 13. At this time, the back electrode acts as a mask and parts of the hole transport layer 11 and perovskite layer 9 are removed. This makes it possible to expose part of the electrode 5 in the area where there is no back electrode 13. A pulsed laser may also be used to remove the laminated film. Next, the connection electrode 15 is formed. It is formed using a sputtering device that uses a metal mask in the same way as the back electrode. Alternatively, it can be formed by screen printing a conductive paste. In this way, a solar cell module with an integrated structure can be obtained.

[0063] In the example of Fig. 9, photoelectric conversion layers (6a, 6b) including photoactive layers are formed on three surface electrodes, and back electrodes are formed on the photoactive layers. The back electrodes are connected to each other in the upper region of Fig. 9, with the leftmost electrode connected to the positive electrode and the rightmost electrode connected to the negative electrode.

[0064] FIG. 10 is a conceptual diagram for explaining the solar cells in Examples 2 and 3. In FIG. In Example 2 shown in Fig. 10(a), connection regions of the back electrodes are provided in the adjacent central regions of each front electrode, and they are connected to each other. In Example 3 shown in Fig. 10(b), connection regions of the back electrodes are provided in the adjacent regions of each front electrode, and they are connected to each other. [Industrial Applicability]

[0065] This invention can be used in technical fields related to solar cells and organic EL elements. [Explanation of symbols]

[0066] 1 element 3. Circuit Board 5 electrodes 6a First photoelectric conversion layer 6b Second photoelectric conversion layer 7a First electron transport layer 7b Second electron transport layer 9 Perovskite Layer 11 Hole transport layer 13a 1st back electrode 13b 2nd back electrode 15 Connecting electrode 21 Device materials 23 Encapsulant layer

Claims

[Claim 1] A substrate; a first electrode and a second electrode formed on the substrate and spaced apart from each other; a photoelectric conversion layer formed in a region including the first electrode and the second electrode, the photoelectric conversion layer including an electron transport layer, a perovskite layer, and a hole transport layer; a first back surface electrode and a second back surface electrode formed on the photoelectric conversion layer at positions corresponding to the first electrode and the second electrode, respectively; The photoelectric conversion layer is not present in the region where the first back surface electrode and the second back surface electrode are not present, a connection electrode located between the first electrode and the second electrode, the connection electrode connecting a part of the second electrode to a part of an area of ​​an upper surface of the first back surface electrode, and contacting and covering an inter-electrode substrate area, which is an area of ​​the front surface of the substrate facing the gap between the first electrode and the second electrode; A solar cell element comprising:

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