Solar battery module and method for producing solar battery module

Abstract

A solar battery module according to the present disclosure comprises a first solar battery unit which is disposed on the light incident side and a second solar battery unit which is disposed on the opposite side from the light incident side and laminated on the first solar battery unit, wherein: the first solar battery unit has a plurality of first solar battery cells and a gap part which is disposed between adjacent first solar battery cells; the second solar battery unit has second solar battery cells which each have a first area and a third solar battery cell which has a second area that is smaller than the first area; and, as viewed from the direction in which the first solar battery unit and the second solar battery unit are laminated, the first solar battery cells overlap the second solar battery cells, and the gap part overlaps the third solar battery cell.

Description

Solar cell module and method for manufacturing a solar cell module

[0001] This disclosure relates to solar cell modules and methods for manufacturing the same.

[0002] In recent years, research and development of thin-film solar cells, such as perovskite solar cells, has been progressing.

[0003] Patent Document 1 discloses an integrated solar cell module formed by connecting perovskite solar cells in series as unit cells.

[0004] Patent document 2 discloses a solar cell module in which multiple integrated solar cell modules are stacked.

[0005] Japanese Patent Publication No. 7068934, Japanese Unexamined Patent Publication No. 2005-277113

[0006] However, the solar cell modules described in Patent Documents 1 and 2 still have room for improvement in terms of improving photoelectric conversion efficiency.

[0007] Therefore, the purpose of this disclosure is to provide a solar cell module with high photoelectric conversion efficiency.

[0008] A solar cell module according to one aspect of the present disclosure comprises a first solar cell unit arranged on the light incident side and a second solar cell unit arranged on the opposite side from the light incident side and stacked on the first solar cell unit, wherein the first solar cell unit has a plurality of first solar cells and gaps arranged between adjacent first solar cells, and the second solar cell unit has a second solar cell having a first area and a third solar cell having a second area smaller than the first area, wherein when viewed from the stacking direction of the first solar cell unit and the second solar cell unit, the first solar cells and the second solar cells overlap, and the gaps and the third solar cells overlap.

[0009] A method for manufacturing a solar cell module according to an aspect of the present disclosure includes partially removing a multilayer film formed on a first substrate to form a first solar cell unit having a plurality of first solar cell cells and a gap portion disposed between adjacent first solar cell cells; partially removing a multilayer film formed on a second substrate to form a second solar cell unit having a second solar cell cell having a first area and a third solar cell cell having a second area smaller than the first area; and aligning and laminating the first solar cell unit and the second solar cell unit such that the first solar cell cell and the second solar cell cell overlap and the gap portion and the third solar cell cell overlap.

[0010] A solar cell module according to an aspect of the present disclosure includes a light transmissive layer disposed on the light incident side and a solar cell unit disposed on the side opposite to the light incident side and laminated on the light transmissive layer. The light transmissive layer has a plurality of first transmissive portions having a first light transmittance and second transmissive portions disposed between adjacent first transmissive portions and having a second light transmittance higher than the first light transmittance. The solar cell unit has a second solar cell cell having a first area and a third solar cell cell having a second area smaller than the first area. When viewed from the lamination direction of the light transmissive layer and the solar cell unit, the first transmissive portion and the second solar cell cell overlap, and the second transmissive portion and the third solar cell cell overlap.

[0011] According to the present disclosure, a solar cell module having high photoelectric conversion efficiency can be provided.

[0012] Perspective view of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of the first unit of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of the second unit of the solar cell module according to Embodiment 1 of the present disclosure Perspective view of the second unit of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of the second unit of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of a modified example of the second unit of the solar cell module according to Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Modified Example 1 of Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Modified Example 2 of Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Modified Example 3 of Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Modified Example 4 of Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Modified Example 5 of Embodiment 1 of the present disclosure Perspective view of the solar cell module according to Modified Example 6 of Embodiment 1 of the present disclosure Perspective view of the second unit according to Modified Example 6 of Embodiment 1 of the present disclosure Cross-sectional view of the solar cell module according to Embodiment 2 of the present disclosure Cross-sectional view of the solar cell module according to Example 1 of the present disclosure Cross-sectional view of the solar cell module according to Comparative Example 1 Graph showing the I-V curve of the solar cell in Example 1 Cross-sectional view of the solar cell module according to Example 2 of the present disclosure Cross-sectional view of the solar cell module according to Example 3 of the present disclosure Cross-sectional view of the solar cell module according to Comparative Example 2

[0013] <Definition of terms> As used herein, the term "perovskite compound" means a perovskite crystal structure represented by the chemical formula ABX3 (where A is a monovalent cation, B is a divalent cation, and X is a halogen anion) and a structure having a crystal similar thereto.

[0014] As used herein, the term "perovskite solar cell" means a solar cell containing a perovskite compound as a photoelectric conversion material.

[0015] As used herein, the term "tandem solar cell" means a solar cell having a structure in which a plurality of solar cells using photoelectric conversion materials with different band gaps are stacked on each other.

[0016] As used herein, the term "thin-film solar cell" refers to a general term for solar cells manufactured by depositing a photoelectric conversion material onto a substrate.

[0017] As used herein, the term "solar cell module" means a structure having multiple solar cell units stacked on top of each other. The term "solar cell unit" means a structure having a substrate and multiple solar cell units formed on the substrate. The term "solar cell" means an element that includes a layer of photoelectric conversion material and functions as a solar cell. Multiple cell units are electrically connected in series to form a string, and in a single cell unit, multiple strings are electrically connected in parallel to each other via wiring.

[0018] <Knowledge on which this disclosure is based> Tandem solar cells generally have a structure in which a solar cell using a photoelectric conversion material with a wide bandgap (i.e., the top layer) and a solar cell using a photoelectric conversion material with a narrow bandgap (i.e., the bottom layer) are stacked. Tandem solar cells can absorb light over a wider band than solar cells using a single photoelectric conversion material, and can realize solar cells with high conversion efficiency.

[0019] When using thin-film solar cells, such as perovskite solar cells, as tandem solar cells, this can be achieved by separately fabricating an integrated unit for the top layer and an integrated unit for the bottom layer, and then stacking them.

[0020] In thin-film solar cells, laser processing is typically used to realize integrated units. By scanning the laser irradiation position, the thin film along the scanning path is removed, allowing for free setting of the number of series stages, parallel stages, and transmitted light intensity of the module. In this case, in the integrated module of the top layer, the amount of light transmitted differs between the laser-processed area and the area where the thin film remains unprocessed. Therefore, the light that passes through the top layer and irradiates the bottom layer will have an illuminance difference depending on its position on the bottom layer.

[0021] Since the amount of electrons generated in a solar cell, i.e., the amount of current, depends on the light intensity, when there is a difference in illuminance, the amount of electrons generated in each cell that makes up the bottom layer will differ, and therefore the amount of current generated will differ.

[0022] However, in integrated modules, since each cell is electrically connected in series, the total current value of the module is equal to the value of the cell with the smallest current. In other words, if there is a cell that is irradiated with weak light, the current value of that cell is limited. Electrons generated in cells irradiated with strong light are not extracted to the outside and are wasted, resulting in a problem where high power generation cannot be achieved.

[0023] In light of these findings, the inventors have diligently researched and found that, in the bottom layer unit, it is possible to improve the photoelectric conversion efficiency of the solar cell module by reducing the area of ​​cells that are hit by light that has passed through the laser-processed portion of the top layer compared to the area of ​​cells that are hit by light that has passed through the thin film of the top layer.

[0024] <Embodiments of the Disclosure> Embodiments of the Disclosure will be described below with reference to the drawings. However, the Disclosure is not limited by these embodiments. Furthermore, substantially identical components are denoted by the same reference numerals in the drawings. For illustrative purposes, the dimensions of elements in the drawings may be exaggerated and may not necessarily be to scale.

[0025] Furthermore, in the following, two mutually orthogonal directions will be referred to as the X direction and the Y direction, and the direction orthogonal to the XY plane will be referred to as the Z direction. For the sake of explanation, terms such as "up," "down," "right," "left," and "side" will be used to indicate directions, assuming the state of normal use, but this does not mean that the usage state of the solar cell module related to this disclosure is limited.

[0026] (Embodiment 1) Figure 1A is a schematic perspective view showing the solar cell module 100 in Embodiment 1. Figure 1B is a schematic cross-sectional view showing the solar cell module 100 in Embodiment 1. Figure 2A is a cross-sectional view of the first unit 101 of the solar cell module 100. Figure 2B is a cross-sectional view of the second unit 102 of the solar cell module 100. Figure 2C is a perspective view of the second unit 102 of the solar cell module 100.

[0027] As shown in Figures 1A and 1B, the solar cell module 100 in Embodiment 1 comprises a first unit 101 and a second unit 102 stacked on the first unit 101. In this case, the first unit 101 is installed on the side where light is incident, and the second unit 102 is installed on the opposite side. Therefore, the direction of incident light is the +Z direction, passing through units 101 and 102 in order. The first unit 101 may be referred to as the "top layer" and the second unit 102 as the "bottom layer".

[0028] In Embodiment 1, the first unit 101 and the second unit 102 are each solar cell units having multiple solar cells. The band gap of the solar cells in the first unit 101 is smaller than the band gap of the solar cells in the second unit 102. Therefore, the first unit 101 and the second unit 102 function together as a tandem solar cell module.

[0029] The first unit 101 and the second unit 102 are fixed to each other. A gap may be provided between the first unit 101 and the second unit 102, and the gap may be in a vacuum state or filled with a material such as resin. Alternatively, the first unit 101 and the second unit 102 may be fixed in contact with each other.

[0030] The outer periphery of the first unit 101 and the second unit 102 may be sealed to prevent air or moisture from entering between them.

[0031] The first unit 101 will now be described in more detail. The first unit 101 has the function of adjusting the intensity of light incident on the second unit 102. As shown in Figure 1A, the first unit 101 comprises a first substrate 5, a plurality of first transparent parts 1, and gaps 2. The plurality of first transparent parts 1 are arranged side by side in the X direction on the first substrate 5. The gaps 2 are arranged between adjacent first transparent parts 1 on the first substrate 5. In other words, the first transparent parts 1 and the gaps 2 are arranged alternately side by side in the X direction.

[0032] The first substrate 5 is a plate-shaped member that plays a role in holding each layer of the first unit 101. The first substrate 5 can be formed from a transparent material. As such a material, a glass substrate or a plastic substrate can be used. The plastic substrate may also be a plastic film.

[0033] The first transmissive portion 1 is an element that has the function of absorbing a portion of the irradiated light and transmitting the rest. In Embodiment 1, the first transmissive portion 1 is a thin-film solar cell, and in the following description, the first transmissive portion 1 will be described as the first solar cell 1. The first solar cell 1 may have the function of absorbing only specific wavelengths of the irradiated light, or it may have the function of reducing the amount of light transmitted across the entire spectrum of light.

[0034] The gap 2 is a portion of the first substrate 5 adjacent to the first solar cell 1 and having a higher light transmittance than the first solar cell 1. The gap 2 transmits most of the irradiated light. In Embodiment 1, the gap 2 corresponds to a processed area that includes the space where the multilayer film was removed to form the first solar cell 1 and the third electrode 10 (see Figure 2A) between the first solar cells 1. On the other hand, the space of the gap 2 may be filled with other materials or organic materials. Also, the gap 2 does not have to include the third electrode 10. In this case, the gap 2 may be referred to as the "gap".

[0035] The first solar cell 1 is electrically connected in series with the adjacent first solar cell 1. As shown in Figure 2A, the connection can be achieved by placing the third electrode 10 and the fourth electrode 11 on either side of each first solar cell 1, and connecting the fourth electrode 11 to the third electrode 10 of the adjacent cell. In this case, it is desirable that the third electrode 10 and the fourth electrode 11 have the function of transmitting light. Note that in some drawings, such as Figures 1A, 1B and 2C, the electrodes are omitted for convenience.

[0036] Returning to Figure 1A, the second unit 102 will be described in more detail. The second unit 102 comprises a second substrate 6, a plurality of second solar cells 3, and a third solar cell 4. The plurality of second solar cells 3 and the third solar cell 4 are arranged on the second substrate 6. In Embodiment 1, the plurality of second solar cells 3 are arranged in a line in the X direction, and the third solar cell 4 is arranged between adjacent second solar cells 3.

[0037] The second substrate 6 is a plate-shaped member that plays a role in holding each layer of the second unit 102. The second substrate 6 can be formed from a transparent material. As such a material, a glass substrate or a plastic substrate can be used. The plastic substrate may also be a plastic film.

[0038] The second solar cell 3 and the third solar cell 4 are thin-film solar cells having the same stacked structure. The second solar cell 3 and the third solar cell 4 have the function of absorbing some or all of the light that passes through the first unit 101.

[0039] When viewed from the stacking direction of units 101 and 102 (the direction of incident light, the Z direction), each second solar cell 3 has a first area S1, and the third solar cell 4 has a second area S2. The second area S2 is smaller than the first area S1 (S2 < S1). As shown in Figure 1B, the width d2 of the third solar cell 4 in the X direction is smaller than the width d1 of the second solar cell 3. In addition to, or instead of, the size relationship in the X direction, the dimension of the third solar cell 4 in the Y direction may be smaller than the dimension of the second solar cell 3 in the Y direction.

[0040] In Embodiment 1, the widths d1 and d2 of the solar cells 3 and 4 are constant in the Y direction. On the other hand, if the second area S2 of the third solar cell 4 is smaller than the first area S1 of the second solar cell 3, the widths d1 and d2 of the solar cells 3 and 4 may change along the Y direction.

[0041] After forming a thin-film solar cell on the second substrate 6, a second solar cell 3 and a third solar cell 4 can be formed by laser processing or the like. At this time, the area of ​​the second solar cell 3 and the third solar cell 4 can be easily controlled by controlling the laser processing position.

[0042] In the second unit 102, the second solar cell 3 and the third solar cell 4 are electrically connected in series. As shown in Figure 2B, the connection method involves placing a first electrode 8 and a second electrode 9 on either side of each cell, and connecting the first electrode 8 to the second electrode 9 of the adjacent cell. In this case, it is desirable that the first electrode 8 has the function of transmitting light.

[0043] As shown in Figure 2C, when the third solar cell 4 is placed between the second solar cells 3A and 3B, the third solar cell 4 is connected in series to each of the second solar cells 3A and 3B.

[0044] Returning to Figure 1B, when viewed from the stacking direction of units 101 and 102 (the direction of incident light, the Z direction), the second solar cell 3 is positioned at the location corresponding to the first solar cell 1 of the first unit 101, and the third solar cell 4 is positioned at the location corresponding to the gap 2. In other words, the first solar cell 1 and the second solar cell 3 overlap, and the gap 2 and the third solar cell 4 overlap. In this specification, "overlap" means that part or all of one component overlaps with another component.

[0045] In Embodiment 1, the entirety of the third solar cell 4 overlaps with the gap 2.

[0046] With the above configuration, the second solar cell 3 is irradiated with light that has passed through the first solar cell 1, and the third solar cell 4 is irradiated with light that has passed through the gap 2. The intensity of the light irradiated between the second solar cell 3 and the third solar cell 4 is different. Specifically, since the light that passes through the gap 2 is more intense than the light that passes through the first solar cell 1, the light irradiated onto the third solar cell 4 is more intense than the light irradiated onto the second solar cell 3.

[0047] Since the operating current density of a solar cell is determined by the intensity of light irradiated onto the cell, the operating current density J2 of the third solar cell 4 is greater than that of the second solar cell 3 (J2 > J1).

[0048] Generally, the operating current of a solar cell is determined by the product of the operating current density J, which is proportional to the irradiation intensity, and the area S of the solar cell, J × S.

[0049] Because multiple cells are connected in series, the total current value of the solar cell unit is determined by the current value of the cell with the lowest operating current value. The current from cells with higher operating current values ​​cannot be extracted externally and is therefore wasted.

[0050] In Embodiment 1, the difference in current values ​​between cells can be reduced by making the second area S2 of the third solar cell 4 smaller than the first area S1 of the second solar cell 3 (S2 < S1) in order to reduce the influence of the relative magnitudes of the operating current densities J2 and J1 (J2 > J1). As a result, the photoelectric conversion efficiency of the solar cell module 100 can be improved.

[0051] When the operating current density of the second solar cell 3 is J1 and its area is S1, and the operating current density of the third solar cell 4 is J2 and its area is S2, the relationship J1 × S1 ≈ J2 × S2 holds true, and the current values ​​of each cell become close to each other. Therefore, power can be generated efficiently, and the amount of power generated can be improved.

[0052] In Embodiment 1, the ratio of the current values ​​of solar cells 3 and 4, (J1 × S1) / (J2 × S2), satisfies 0.7 < (J1 × S1) / (J2 × S2) < 1.3, preferably 0.9 < (J1 × S1) / (J2 × S2) < 1.1, and more preferably (J1 × S1) / (J2 × S2) = 1.0.

[0053] The following describes the solar cells 3 and 4 in detail. Figure 3A is a cross-sectional view of the second unit 102 of the solar cell module 100 according to Embodiment 1. Figure 3B is a cross-sectional view of a modified example of the second unit 102.

[0054] As shown in Figure 3A, solar cells 3 and 4 have a photoelectric conversion layer 12. Solar cells 3 and 4 may further have a hole transport layer 13 and an electron transport layer 14 sandwiching the photoelectric conversion layer 12. By providing the hole transport layer 13 and the electron transport layer 14, the extraction efficiency of electrons and holes can be improved, and even higher efficiency can be obtained.

[0055] The hole transport layer 13 may be positioned between the second electrode 9 and the photoelectric conversion layer 12, as shown in Figure 3A, or between the first electrode 8 and the photoelectric conversion layer 12, as shown in Figure 3B.

[0056] The electron transport layer 14 may be positioned between the first electrode 8 and the photoelectric conversion layer 12, as shown in Figure 3A, or between the second electrode 9 and the photoelectric conversion layer 12, as shown in Figure 3B.

[0057] Similarly, the first solar cell 1 may also have a photoelectric conversion layer, and a hole transport layer and an electron transport layer sandwiching the photoelectric conversion layer.

[0058] The following provides a more detailed explanation of each layer that makes up solar cells 3 and 4.

[0059] [Photoelectric Conversion Layer 12] The photoelectric conversion layer 12 of the solar cells 3 and 4 contains a photoelectric conversion material. Examples of photoelectric conversion materials include silicon, perovskite compounds, chalcopyrite-type compounds such as CIGS, or III-V group compounds such as GaAs.

[0060] The photoelectric conversion layer 12 may contain a thin-film solar cell material. Examples of the thin-film solar cell material include perovskite compounds, chalcopyrite-type compounds such as CIGS, or amorphous silicon.

[0061] The photoelectric conversion layer 12 may contain a perovskite material. By using the perovskite material, high photoelectric conversion efficiency can be achieved. In this case, the second solar cell 3 and the third solar cell 4 are perovskite solar cells.

[0062] The perovskite material is represented by the composition formula ABX3. Here, A is a monovalent cation. Examples of the monovalent cation are alkali metal cations or organic cations. Examples of the alkali metal cation are potassium cation (K ３ ,

[0063] ), cesium cation (Cs ＋ ), or rubidium cation (Rb ＋ ). Examples of the organic cation are methylammonium cation (CH ３ NH ３ ＋ ), formamidinium cation (HC(NH ２ ) ２ ＋ ), ethylammonium cation (CH ３ CH ２ NH ３ ＋ ), or guanidinium cation (CH ６ N ３ ＋ ). B is a divalent cation. Examples of the divalent cation are Sn cation (Sn ２＋ ), Ge cation (Ge ２＋ ), or Pb cation (Pb ２＋ ). The divalent cation may contain at least one selected from the group consisting of Sn cation, Ge cation, and Pb cation. X is a monovalent anion. Examples of the monovalent anion are halogen anions. Each site of A, B, and X may be occupied by multiple types of ions.

[0063] Specific examples of the perovskite material include MAPbI ３ 、FAPbI３ MAPbBr ３ MAPbCl ３ , CsPbI ３ , or CsPbBr ３ And so on. Note that "FA" is "NH ２ CHNH ２ " represents " and "MA" is "CH ３ NH ３ This represents ".

[0064] The photoelectric conversion layer 12 may contain materials other than the photoelectric conversion material. The photoelectric conversion layer 12 may further contain, for example, a quenching material to reduce the defect density of the perovskite material. An example of a quenching material is a fluorine compound such as tin fluoride. The molar ratio of the quenching material to the photoelectric conversion material may be 5% or more and 20% or less.

[0065] The photoelectric conversion layer 12 may contain impurities. The photoelectric conversion layer 12 may further contain compounds other than the perovskite material described above.

[0066] The thickness of the photoelectric conversion layer 12 may be between 100 nm and 2000 nm, depending on the amount of light absorption of the photoelectric conversion layer 12.

[0067] The photoelectric conversion layer 12 can be formed using methods such as solution coating, printing, vapor deposition, or sputtering. The photoelectric conversion layer 12 may also be formed by cutting out a perovskite compound.

[0068] The photoelectric conversion material used in the first solar cell 1 has a smaller band gap than the photoelectric conversion material (e.g., perovskite compound) used in the photoelectric conversion layer 12 of solar cells 3 and 4. Examples of photoelectric conversion materials used in the first solar cell 1 include amorphous silicon, perovskite compounds, or III-V group compounds such as InGaAs and InGaP.

[0069] When both the photoelectric conversion material and the photoelectric conversion layer 12 of the first solar cell 1 are made of perovskite material, an example of the photoelectric conversion material of the first solar cell 1 is MAPbI ３ , FAPbi ３ MAPbIBr３ , FAPbIBr ３ CaPb IBr ３ Examples of photoelectric conversion layers 12 include MASnI ３ FASnI ３ , CsSnI ３ , FAMASbPbI ３ , CsSnPbI ３ These materials can be used. By using these materials in combination, the solar cell module 100 functions as a tandem solar cell module.

[0070] [First Electrode] The first electrode 8 is conductive. The first electrode 8 is translucent. The first electrode 8 transmits light from the visible region to the near-infrared region, for example. The first electrode 8 may be composed of a transparent and conductive metal oxide, for example. Examples of such metal oxides are indium-tin composite oxide, antimony-doped tin oxide, fluorine-doped tin oxide, zinc oxide doped with at least one of boron, aluminum, gallium, or indium, or composites thereof.

[0071] The first electrode 8 may be formed using an opaque material with a light-transmitting pattern. Examples of light-transmitting patterns include linear (e.g., stripes), wavy, grid-like (e.g., mesh), or perforated metal-like patterns with a large number of fine through-holes arranged regularly or irregularly. When the first electrode 8 has these patterns, light can pass through areas where the electrode material is not present. Examples of opaque materials include platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, iron, nickel, tin, zinc, or alloys containing any of these. Conductive carbon materials may be used as the opaque material.

[0072] The light transmittance of the first electrode 8 may be, for example, 50% or more, or 80% or more. The wavelength of light transmitted by the first electrode 8 depends on the absorption wavelength of the photoelectric conversion layer 12.

[0073] The first electrode 8 may have a thickness of, for example, 1 nm or more and 1000 nm or less.

[0074] The third electrode 10 and the fourth electrode 11 may have a configuration similar to that of the first electrode 8.

[0075] [Second Electrode] The second electrode 9 is a conductive layer similar to the first electrode 8, and the same materials and configuration can be used. The second electrode 9 does not need to be translucent, and opaque electrode materials can be used without processing.

[0076] [Electron Transport Layer] The electron transport layer 14 includes a semiconductor. Preferably, the electron transport layer 14 is formed from a semiconductor with a band gap of 3.0 eV or more. This allows visible light and infrared light to be transmitted to the photoelectric conversion layer. Examples of semiconductors are organic n-type semiconductors or inorganic n-type semiconductors. Examples of organic n-type semiconductors are imide compounds, quinone compounds, fullerenes, or fullerene derivatives. Examples of inorganic n-type semiconductors are metal oxides or perovskite oxides. Examples of metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Zr, Sr, Ga, Si, or Cr. Examples of metal oxides include TiO ２ or SnO ２ An example of a perovskite oxide is SrTiO ３ Or CaTiO ３ That is the case.

[0077] The electron transport layer 14 may contain a material with a band gap larger than 6 eV. Examples of materials with a band gap larger than 6 eV include: (i) alkali metal or alkaline earth metal halides such as lithium fluoride and calcium fluoride; (ii) alkaline earth metal oxides such as magnesium oxide; or (iii) silicon dioxide. In this case, the electron transport layer 14 may have a thickness of, for example, 10 nm or less to ensure electron transport.

[0078] The electron transport layer 14 may include multiple layers made of different materials.

[0079] [Hole Transport Layer] The hole transport layer 13 contains a hole transport material. The hole transport material is a material that has the ability to transport holes. The hole transport material is, for example, an organic or inorganic semiconductor. Examples of organic semiconductors are phenylamines, triphenylamine derivatives, or PEDOT:PSS containing a tertiary amine in their backbone. The molecular weight of the organic is not particularly limited, but it may be a polymer. Examples of inorganic semiconductors are CuO, Cu ２ It is O, CuSCN, or NiO.

[0080] The thickness of the hole transport layer 13 may be 1 nm or more and 1000 nm or less, or 10 nm or more and 50 nm or less. Within this range, sufficient hole transport performance can be achieved. Since low resistance can be maintained, photovoltaic power generation can be performed with high efficiency.

[0081] Examples of methods for forming the hole transport layer 13 include coating or printing. Examples of coating methods include doctor blade method, bar coating method, spray method, dip coating method, or spin coating method. An example of a printing method is screen printing.

[0082] The hole transport layer 13 may contain a supporting electrolyte and a solvent. The supporting electrolyte and solvent have the effect of stabilizing the holes in the hole transport layer. Examples of supporting electrolytes are ammonium salts or alkali metal salts. Examples of ammonium salts are tetrabutylammonium perchlorate, tetraethylammonium hexafluoride phosphate, imidazolium salt, or pyridinium salt. Examples of alkali metal salts are lithium perchlorate or potassium borotetrafluoride.

[0083] The solvent contained in the hole transport layer 13 may have high ionic conductivity. The solvent may be either an aqueous solvent or an organic solvent. To stabilize the solute, the solvent may be an organic solvent. Examples of organic solvents are heterocyclic compounds such as tert-butylpyridine, pyridine, and n-methylpyrrolidone.

[0084] Ionic liquids may be used as solvents, either alone or in mixture with other solvents. Ionic liquids have low volatility and high flame retardancy. Examples of ionic liquids include imidazolium compounds such as 1-ethyl-3-methylimidazolium tetracyanoborate, pyridine compounds, alicyclic amine compounds, aliphatic amine compounds, or azonium amine compounds.

[0085] [Method for Manufacturing Solar Cell Modules] Known methods for manufacturing solar cell modules can be used to manufacture the solar cell module 100. For example, the following steps may be used to manufacture the solar cell module 100.

[0086] First, a third electrode 10 is formed on the surface of the first substrate 5, and a first electrode 8 is formed on the surface of the second substrate 6. The third electrode 10 and the first electrode 8 can be formed, for example, by chemical vapor deposition or sputtering.

[0087] Next, dividing grooves are formed to divide the third electrode 10 and the first electrode 8 into multiple parts. Laser scribing, mechanical scribing, etc., can be used to form the dividing grooves.

[0088] Next, a multilayer film for forming the first solar cell 1 is formed on the first substrate 5, and the multilayer film is partially removed to form multiple first solar cells 1 and gaps 2. For example, laser processing is used to remove the multilayer film. The third electrode 10 is not removed during the removal of the multilayer film.

[0089] Next, a multilayer film including a hole transport layer 13, a photoelectric conversion layer 12, and an electron transport layer 14 is formed on the second substrate 6. The photoelectric conversion layer 12 can be formed, for example, by a solution coating method, a printing method, or a vapor deposition method. The hole transport layer 13 and the electron transport layer 14 can be formed, for example, by a solution coating method, a printing method, or a vapor deposition method.

[0090] Next, the multilayer film on the second substrate 6 is partially removed to form segmented grooves. Laser scribing, mechanical scribing, etc., can be used to form the segmented grooves. Multiple solar cells 3 and 4 are formed on the second substrate 6 by this method. In forming the segmented grooves, only the multilayer film is removed, and the first electrode 8 is not removed.

[0091] Next, a fourth electrode 11 is formed on the first solar cell 1, and second electrodes 9 are formed on solar cells 3 and 4. The second electrodes 9 connect adjacent solar cells 3 and 4 on the second substrate 6 in series. The fourth electrode 11 and second electrodes 9 can be formed, for example, by chemical vapor deposition or sputtering. The fourth electrode 11 and second electrodes 9 can also be formed by patterning the thin film into a predetermined shape. The patterning method is not particularly limited, and for example, patterning via a metal mask, or separation by laser scribing or mechanical scribing can be used.

[0092] The first unit 101 and the second unit 102 can be formed by the process described above.

[0093] Next, the first unit 101 and the second unit 102 are aligned and stacked on top of each other. Specifically, the first unit 101 and the second unit 102 are aligned so that the first solar cell 1 and the second solar cell 3 overlap, and the gap 2 and the third solar cell 4 overlap.

[0094] Next, the first unit 101 and the second unit 102 may be sealed to prevent air and moisture from entering between them.

[0095] Thus, a solar cell module 100 is obtained.

[0096] [Effects] The solar cell module 100 and its manufacturing method according to Embodiment 1 can provide the following effects.

[0097] The solar cell module 100 of Embodiment 1 comprises a first unit 101 (first solar cell unit) arranged on the light incident side, and a second unit 102 (second solar cell unit) arranged on the opposite side from the light incident side and stacked on the first unit 101. The first unit 101 has a plurality of first solar cells 1 and gaps 2 arranged between adjacent first solar cells 1. The second unit 102 has a second solar cell 3 having a first area S1 and a third solar cell 4 having a second area S2 smaller than the first area S1. When viewed from the stacking direction (Z direction) of units 101 and 102, the first solar cells 1 and the second solar cells 3 overlap, and the gaps 2 and the third solar cells 4 overlap.

[0098] With this configuration, the second solar cell 3 has a low operating current because the intensity of light incident through the first solar cell 1 is low. The third solar cell 4 has a high operating current because the intensity of light incident through the gap 2 is high. The area S2 of the third solar cell 4, which has a high operating current, is smaller than the area S1 of the second solar cell 3, which has a low operating current. Therefore, the current values ​​generated by solar cells 3 and 4 can be made closer to each other. As a result, when solar cells 3 and 4 are connected in series, power can be generated without waste, improving the amount of power generated and improving the photoelectric conversion efficiency of the solar cell module 100.

[0099] In the solar cell module 100 of Embodiment 1, the second solar cell 3 and the third solar cell 4 are electrically connected in series.

[0100] With this configuration, even when the total current value of the second unit 102 is determined to be the current value of the cell with the lowest current value, the photoelectric conversion efficiency of the solar cell module 100 can be improved by adjusting the areas S1 and S2.

[0101] In the solar cell module 100 of Embodiment 1, when the current density of the second solar cell 3 is J1 and its area is S1, and the current density of the third solar cell 4 is J2 and its area is S2, the relationship 0.9 < (J1 × S1) / (J2 × S2) < 1.1 is satisfied.

[0102] This configuration allows the current values ​​generated by each of the solar cells 3 and 4 to be brought even closer to each other.

[0103] In the solar cell module 100 of Embodiment 1, the second solar cell 3 and the third solar cell 4 are perovskite solar cells.

[0104] This configuration enables high photoelectric conversion efficiency.

[0105] In the solar cell module 100 of Embodiment 1, the band gap of the first solar cell 1 is smaller than the band gap of the second solar cell 3 and the band gap of the third solar cell 4.

[0106] With this configuration, the solar cell module 100 functions as a tandem solar cell module.

[0107] The manufacturing method for the solar cell module 100 of Embodiment 1 includes partially removing a multilayer film formed on a first substrate 5 to form a first unit 101 having a plurality of first solar cells 1 and gaps 2 arranged between adjacent first solar cells 1. The manufacturing method also includes partially removing a multilayer film formed on a second substrate 6 to form a second unit 102 having a second solar cell 3 having a first area S1 and a third solar cell 4 having a second area S2 smaller than the first area S1. The manufacturing method also includes aligning and stacking the first unit 101 and the second unit 102 such that the first solar cells 1 and the second solar cells 3 overlap and the gaps 2 and the third solar cells 4 overlap.

[0108] This configuration allows the current values ​​generated by solar cells 3 and 4 to be brought closer to each other. Therefore, when solar cells 3 and 4 are connected in series, power can be generated without waste, improving the amount of power generated and enabling the manufacture of a solar cell module 100 with improved photoelectric conversion efficiency.

[0109] In the manufacturing method of the solar cell module 100 of Embodiment 1, the gap portion 2 is formed by laser processing.

[0110] This configuration makes it easy to adjust the areas S1 and S2 of the solar cells 3 and 4.

[0111] In Embodiment 1, an example was described in which the first transmissive portion 1 is the first solar cell 1 and the solar cell module 100 is a tandem solar cell module, but the invention is not limited to this. Other configurations are also acceptable as long as the first transmissive portion 1 has the function of absorbing a portion of the irradiated light and transmitting the rest, and has a lower light transmittance than the gap portion 2, that is, as long as the gap portion 2 transmits more light. For example, the first transmissive portion 1 can be a color filter, optical filter, light shielding plate, mesh structure plate, colored glass, UV-cut glass, infrared-cut glass, etc. In this case, the first unit 101 may be called the "light-transmitting layer" and the gap portion 2 may be called the "second transmissive portion".

[0112] [Modified Versions] The following shows modified versions of the solar cell module 100 of Embodiment 1. In the modified versions, components that are the same as or equivalent to those in Embodiment 1 are denoted by the same reference numerals and described accordingly, and descriptions that are redundant with Embodiment 1 are omitted. Figures 4 to 9 are cross-sectional views of the solar cell module according to a modified version of Embodiment 1.

[0113] Figure 4 is a schematic cross-sectional view showing a solar cell module 110 in a modified example 1 of Embodiment 1. In the solar cell module 110 in Figure 4, the second solar cell 3 and the third solar cell 4 are positioned on the light incidence side of the second unit 102, and the second substrate 6 is positioned on the opposite side of the light incidence direction. As shown in Figure 4, the solar cell module 110 can perform its photoelectric conversion function even if the front and back sides of the second unit 102 are reversed. In the solar cell module 110 in Figure 4, it is desirable that the electrodes on the surface side (-Z side) of the second solar cell 3 and the third solar cell 4 be transparent electrodes.

[0114] Furthermore, the solar cell module 110 has a sealing member 117 that joins the periphery of the first unit 101 and the second unit 102. In a plan view, the sealing member 117 is provided on the outside of the solar cells 1, 3, and 4. The sealing member 117 fixes the first unit 101 and the second unit 102 to each other and seals the gap between the first unit 101 and the second unit 102. The sealing member 117 may be provided around the entire circumference of the units 101 and 102. The sealing member 117 may include, for example, a resin material such as an ultraviolet curing resin and a thermosetting resin, or a rubber material such as butyl rubber.

[0115] A filler 118 is filled between the first unit 101, the second unit 102, and the sealing member 117. The filler 118 may contain resins such as epoxy resin, silicone resin, and polyolefin resin.

[0116] The solar cell module 110 may also have a configuration in which the sealing member 117 and the filler 118 are omitted.

[0117] Figure 5 is a schematic cross-sectional view showing a solar cell module 120 in a modified example 2 of Embodiment 1. In the solar cell module 120 in Figure 5, the first solar cell 1 and the gap 2 are positioned on the light incidence side of the first unit 101, while the first substrate 5 is positioned on the opposite side of the light incidence direction. As shown in Figure 5, the solar cell module 120 can perform its photoelectric conversion function even if the front and back sides of the first unit 101 are reversed.

[0118] Figure 6 is a schematic cross-sectional view showing a solar cell module 130 in a modified example 3 of Embodiment 1. As shown in Figure 6, in the solar cell module 130, the second unit 102 has two third solar cells 4 arranged side by side in the X direction so as to overlap with one gap 2.

[0119] The second unit 102 may have three or more third solar cells 4 arranged in the X direction so as to overlap with one gap 2.

[0120] Figure 7A is a schematic cross-sectional view showing a solar cell module 140 in a modified example 4 of Embodiment 1. In the solar cell module 140 in Figure 7A, a portion of the third solar cell 4 overlaps with the gap 2 in the second unit 102. Even in this case, by making the area of ​​the third solar cell 4 smaller than the area of ​​the second solar cell 3, the current values ​​generated by the solar cells 3 and 4 can be made closer to each other. Therefore, the photoelectric conversion efficiency of the solar cell module 140 can be improved.

[0121] Figure 7B is a schematic cross-sectional view showing a solar cell module 150 in a modified example 5 of Embodiment 1. As shown in Figure 7B, when there are multiple gaps 2, the photoelectric conversion efficiency of the solar cell module 150 can be improved by arranging the third solar cell 4 at each position corresponding to the gaps 2.

[0122] Figure 8 is a perspective view showing a solar cell module 160 in modified example 6 of Embodiment 1. Figure 9 is a perspective view of the second unit 162 of the solar cell module 160 in modified example 6 of Embodiment 1. As shown in Figure 8, a plurality of divided third solar cells 164A, 164B may be arranged in the Y direction between adjacent second solar cells 3. In this case, the Y-direction dimension of each third solar cell 164A, 164B is smaller than the Y-direction dimension of the second solar cell 3.

[0123] As shown in Figure 9, when multiple third solar cells 164A and 164B are arranged in the Y direction between second solar cells 3A and 3B, one second solar cell 3A is electrically connected in series with an adjacent third solar cell 164A. The third solar cell 164A is electrically connected in series with an adjacent third solar cell 164B. The third solar cell 164B is electrically connected in series with the other second solar cell 3B. If other third solar cells are provided between third solar cells 164A and 164B, the third solar cells are connected in series sequentially in the Y direction.

[0124] (Embodiment 2) Next, a solar cell module 180 according to Embodiment 2 of the present disclosure will be described. In Embodiment 2, mainly the differences from Embodiment 1 will be described, and explanations that overlap with Embodiment 1 will be omitted. In Embodiment 2, components that are the same as or equivalent to those in Embodiment 1 will be denoted by the same reference numerals.

[0125] Figure 10 is a schematic cross-sectional view showing the solar cell module 180 in Embodiment 2.

[0126] As shown in Figure 10, the solar cell module 180 according to Embodiment 2 comprises a first unit 181 and a second unit 182 stacked on the first unit 181. In this case, the first unit 181 is installed on the side where light is incident, and the second unit 182 is installed on the opposite side. The first unit 181 and the second unit 182 are each solar cell units having multiple solar cells.

[0127] The first unit 181 comprises a first substrate 5, a plurality of first solar cells 1, and a gap 2, and may have a configuration common to the first unit 101 in Embodiment 1.

[0128] The second unit 182 comprises a second substrate 6, a plurality of second solar cells 3, a plurality of third solar cells 4, and a plurality of fourth solar cells 15. The fourth solar cells 15 are arranged on the second substrate 6 between the second solar cells 3 and the third solar cells 4, and the solar cells 3, 15, and 4 are arranged in order in the X direction.

[0129] When viewed from the stacking direction of units 181 and 182, similar to Embodiment 1, the first solar cell 1 and the second solar cell 3 overlap, and the gap 2 and the third solar cell 4 overlap. Specifically, the entire third solar cell 4 overlaps with the gap 2, and the third solar cell 4 is positioned away from the boundary K between the first solar cell 1 and the gap 2 in the X direction.

[0130] On the other hand, when viewed from the stacking direction of units 181 and 182, the fourth solar cell 15 is positioned to overlap with the boundary K. That is, a part of the fourth solar cell 15 overlaps with the first solar cell 1, and the other part of the fourth solar cell 15 overlaps with the gap 2.

[0131] Therefore, in the second unit 182, the intensity of light irradiated increases in the order of the third solar cell 4, the fourth solar cell 15, and the second solar cell 3. Consequently, the operating current density also increases in the order of the third solar cell 4, the fourth solar cell 15, and the second solar cell 3.

[0132] Furthermore, if the area of ​​each fourth solar cell 15 is defined as the third area S3, then the third area S3 is larger than the second area S2 and smaller than the first area S1 (S2 < S3 < S1). In the solar cell module 180 of the second embodiment, the influence of the relative magnitudes of the operating current densities can be reduced by adjusting the area of ​​the solar cells, thereby improving the conversion efficiency of the solar cell module 180.

[0133] When the operating current density of the second solar cell 3 is J1 and its area is S1, the operating current density of the third solar cell 4 is J2 and its area is S2, and the operating current density of the optimal area of ​​the fourth solar cell 15 is J3 and its area is S2, then J1 × S1 ≈ J2 × S2 ≈ J3 × S3 holds true, and the current values ​​of each cell become close to each other. Therefore, power can be generated without waste, and the amount of power generated can be improved.

[0134] [Effects] The solar cell module 180 according to Embodiment 2 can achieve the following effects.

[0135] In the solar cell module 180 of Embodiment 2, the second unit 182 (second solar cell unit) further includes a fourth solar cell 15 between the second solar cell 3 and the third solar cell 4. When viewed from the stacking direction, the third solar cell 4 is positioned away from the boundary K between the first solar cell 1 and the gap 2, while the fourth solar cell 15 overlaps with the boundary K.

[0136] This configuration also makes it possible to improve the photoelectric conversion efficiency of the solar cell module 180.

[0137] (Examples) The solar cell module relating to this disclosure will be described in more detail below with reference to examples and comparative examples. However, this disclosure is not limited to the following examples.

[0138] [Example 1 and Comparative Example 1] Below, the power generation of the solar cell modules of Example 1 and Comparative Example 1 were evaluated. Figure 11 is a schematic cross-sectional view showing the configuration of the solar cell module of Example 1. Figure 12 is a schematic cross-sectional view showing the configuration of the solar cell module of Comparative Example 1.

[0139] The solar cell module 200 in Example 1 has a first unit 201 and a second unit 202.

[0140] In the first unit 201, the first substrate 5 is a glass substrate (TEC-15) with a thickness of 1.3 mm, the third electrode 10 is a fluorine-doped tin oxide (FTO) electrode with a thickness of 300 nm, and the fourth electrode 11 is an indium tin oxide (ITO) electrode with a thickness of 150 nm (see Figure 2A). The electron transport layer is a 50 nm thick SnO layer. ２ The photoelectric conversion layer is a 300 nm thick CsPbI ２．８５ Br ０．１５ The layer is a PTAA layer with a thickness of 50 nm, and the hole transport layer is a PTAA layer.

[0141] As a method for fabricating the first unit 201, a third electrode 10 was formed on a glass substrate on which FTO had been deposited using a laser patterning apparatus.

[0142] Next, an electron transport layer was formed on the third electrode 10 by applying the electron transport layer raw material solution using a spin coating method. The electron transport layer raw material solution is SnO ２ A dispersion (manufactured by Taki Chemical Co., Ltd.) was used. Next, a photoelectric conversion layer was formed on the electron transport layer by applying the photoelectric conversion layer raw material solution using a spin coating method. The photoelectric conversion layer raw material solution was 0.48 mol / L PbI ２ (Manufactured by Tokyo Chemical Industry Co., Ltd.), 0.41 mol / L PbBr ２A solution was prepared by dissolving 0.89 mol / L of CsI (a rare metal), 0.68 mol / L of dimethylammonium iodide (manufactured by Tokyo Chemical Industry Co., Ltd.), and dimethyl sulfoxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in a mixed solution of dimethyl sulfoxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and N,N-dimethylformamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in the mixed solution. The mixing ratio of dimethyl sulfoxide and N,N-dimethylformamide in the mixed solution was 1:4 (by volume). Next, a hole transport layer was formed on the photoelectric conversion layer by coating the hole transport layer raw material solution using the spin coating method. The hole transport layer raw material solution was SnO ２ A dispersion (manufactured by Taki Chemical Co., Ltd.) was used. A 16 mg / mL solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]:PTAA (manufactured by Kyocera Document Solutions) was prepared and dissolved in toluene (manufactured by Fujifilm Wako Pure Chemical Industries).

[0143] Next, a first solar cell 1 and a gap 2 were formed by dividing the laminate of the hole transport layer, photoelectric conversion layer, and electron transport layer using a laser patterning apparatus. A fourth electrode 11 was formed on the laminate by forming an ITO layer using a sputtering method, which contacts the side wall of the photoelectric conversion layer from above the hole transport layer and contacts the third electrode 10.

[0144] Next, the laminate of the fourth electrode 11, hole transport layer, photoelectric conversion layer, and electron transport layer was separated using a laser patterning apparatus. The first unit 201 was fabricated using the above method.

[0145] The width w1 of the first solar cell 1 in the first unit 201 was set to 5.0 mm, and the width A1 of the gap 2 was set to 4.5 mm. The dimension d in the depth direction (Y direction in the drawing) of each cell was 10 mm.

[0146] In the second unit 202, the second substrate 6 is a glass substrate with a thickness of 0.7 mm, the first electrode 8 is an indium tin oxide (ITO) electrode with a thickness of 150 nm, and the second electrode 9 is a silver electrode with a thickness of 100 nm (see Figure 2B). The electron transport layer is a fullerene (C) layer with a thickness of 20 nm. ６０ ) and a 6 nm thick bathocproine layer, and the photoelectric conversion layer is a 900 nm thick FAMAPbSnI ３The layer is a PEDOT:PSS layer with a thickness of 50 nm.

[0147] As a method for fabricating the second unit 202, the first electrode 8 was formed on a glass substrate on which ITO had been deposited by sputtering using a laser patterning apparatus.

[0148] Next, a hole transport layer was formed on the first electrode 8 by applying a hole transport layer raw material solution using a spin coating method. The hole transport layer raw material solution used was a PEDOT:PSS dispersion (Hereaus). Next, a photoelectric conversion layer was formed on top of the hole transport layer by applying a photoelectric conversion layer raw material solution using a spin coating method. The photoelectric conversion layer raw material solution was 0.58 mol / L PbI ２ (Manufactured by Tokyo Chemical Industry Co., Ltd.), 0.87 mol / L SnI ２ (Sigma-Aldrich), 0.087 mol / L SnF ２ A 0.58 mol / L solution of formamidinium iodide (manufactured by GreatCell Solar, hereinafter referred to as "FAI") and a 0.87 mol / L solution of methylammonium iodide (manufactured by GreatCell Solar) were prepared and dissolved in a mixed solution of dimethyl sulfoxide (manufactured by Fujifilm Wako Pure Chemical Industries) and N,N-dimethylformamide (manufactured by Fujifilm Wako Pure Chemical Industries). The mixing ratio of dimethyl sulfoxide and N,N-dimethylformamide in the mixed solution was 1:4 (by volume). Next, an electron transport layer was formed on the photoelectric conversion layer by continuously depositing a fullerene layer and a bathocproine layer using vapor deposition.

[0149] Next, a second solar cell 3 and a third solar cell 4 were formed by dividing the laminate of the hole transport layer, photoelectric conversion layer, and electron transport layer using a laser patterning apparatus. The area of ​​the second solar cell 3 and the third solar cell 4 was determined by changing the scanning position of the laser. A second electrode 9, which contacts the first electrode 8, was formed on the electron transport layer via the side wall of the photoelectric conversion layer by forming a silver layer on the laminate using a vapor deposition method.

[0150] Next, the laminate of the second electrode 9, electron transport layer, photoelectric conversion layer, and electron transport layer was separated using a laser patterning apparatus. The second unit 202 was fabricated using the above method.

[0151] The width w2 of the second solar cell 3 in the second unit 202 was set to 4.5 mm, the width w3 of the third solar cell 4 was set to 2.0 mm, and the width A2 between cells in the second unit 202 was set to 0.5 mm. The depth dimension d of each cell was 10 mm.

[0152] Therefore, the solar cell module 200 of Example 1 was obtained by stacking and fixing the first unit 201 and the second unit 202 with a matching oil having a refractive index of 1.5 in between.

[0153] The solar cell module 300 in Comparative Example 1 has a first unit 301 and a second unit 302. The configuration of the first unit 301 is the same as that of the first unit 201 in Example 1. The configuration of the second unit 302 is similar to that of the second unit 202 in Example 1, and the film configuration is the same. However, in the second unit 302, there is no third solar cell 4, and only second solar cells 3 are present, which have the same area (width w2 of 4.5 mm) and are arranged at equal intervals in the X direction.

[0154] Furthermore, in the second units 202 and 302 of Example 1 and Comparative Example 1, the total area of ​​the module, including the openings, is the same.

[0155] Since the configuration of the first units 201 and 301 is the same in Example 1 and Comparative Example 1, the maximum output of the first units 201 and 301 is the same. Therefore, the maximum output of the entire solar cell modules 200 and 300 is determined by the maximum output of the second units 202 and 302.

[0156] Therefore, in order to evaluate the maximum output of the second units 202 and 302, lead electrode wires were connected to each cell, and the current-voltage characteristics (I-V characteristics) of each cell were evaluated when the solar cell modules 200 and 300 were irradiated with simulated sunlight. A solar simulator (manufactured by Spectrometer Co., Ltd.) and an electrochemical analyzer ALS (manufactured by BAS Corporation) were used to evaluate the characteristics. The second units 202 and 302 were irradiated with 1 sun of simulated sunlight. The output of the solar simulator was set to 100 mW / cm². ２ The settings were adjusted. The I-V characteristics of the solar cell modules 200 and 300 of Example 1 and Comparative Example 1 were measured by measuring the output current value while varying the applied voltage using an electrochemical analyzer.

[0157] Figure 13 is a graph showing the I-V characteristics of the second solar cell 3 and the third solar cell 4 in the solar cell module 200 of Example 1 under simulated sunlight irradiation. In Figure 13, the horizontal axis represents voltage and the vertical axis represents current density.

[0158] Table 1 shows the measurement results for Example 1. In the table, Voc represents the open-circuit voltage, Jsc represents the entangled current density, Vop represents the maximum operating voltage, Jop represents the maximum operating current density, FF represents the fill factor, and PCE represents the conversion efficiency.

[0159]

[0160] In Example 1, the area of ​​the second solar cell 3 is w² × d = 0.45 [cm²] ２ The maximum operating current is the product of the maximum operating current density Jop and the area, and the maximum operating current of the second solar cell 3 is 13.1 × 0.45 = 5.90 [mA]. ​​Also, the area of ​​the third solar cell 4 is w3 × d = 0.20 [cm²]. ２ The maximum operating current of the third solar cell 4 is 29.33 × 0.2 = 5.87 [mA].

[0161] Since all cells are connected in series, the maximum operating current of the entire unit is limited to the lower of the two. Therefore, the maximum operating current of the entire second unit 202 in Example 1 is 5.87 [mA].

[0162] In the second unit 202, the maximum operating voltage of both the second solar cell 3 and the third solar cell 4 is 0.72 [V], and the number of cells is 4 [cells]. Therefore, the maximum output of the second unit 202 in Example 1 is 0.72 × 4 × 5.87 = 16.89 [mW].

[0163] In Comparative Example 1, the area of ​​the second solar cell 3 is w² × d = 0.45 [cm²] ２ The maximum operating current of the second solar cell 3 overlapping with the first solar cell 1 is 13.1 × 0.45 = 5.90 [mA]. ​​Also, the maximum operating current density of the central second solar cell 3 overlapping with the gap 2 is 29.33 × 0.45 = 13.20 [mA]. ​​Therefore, the maximum operating current of the second unit 302 of Comparative Example 1 is 5.90 [mA].

[0164] In the second unit 302, the maximum operating voltage is 0.72 [V] and the number of cells is 3 [cells]. Therefore, the maximum output of the second unit 302 in Comparative Example 1 is 0.72 × 3 × 5.90 = 12.73 [mW].

[0165] Comparing the maximum outputs of the second units 202 and 302, the value for Example 1 was greater than the value for Comparative Example 1. Therefore, the solar cell module 200 of Example 1 was able to obtain a higher maximum output than Comparative Example 1.

[0166] In Example 1, the cell widths are designed so that the maximum operating currents of the second solar cell 3 and the third solar cell 4 are approximately the same. This configuration minimizes current loss due to series connection and allows for the highest maximum output power to be obtained for the same module area.

[0167] [Example 2] A solar cell module of Example 2 was fabricated, and the power generation amount of the solar cell module was evaluated. Figure 14 is a schematic cross-sectional view showing the configuration of the solar cell module of Example 2.

[0168] The solar cell module 400 in Example 2 has a first unit 401 and a second unit 402. The configuration of the first unit 401 is the same as that of the first unit 201 in Example 1. The configuration of the second unit 402 in Example 2 is similar to that of the second unit 202 in Example 1, and the film configuration is the same. However, in the second unit 402, the width of the third solar cell 4 is different from that in Example 1, and a fourth solar cell 15 is further provided between the solar cells 3 and 4.

[0169] In Example 2, the width w2 of the second solar cell 3 was 3.4 mm, the width w3 of the third solar cell 4 was 1.5 mm, the width w4 of the fourth solar cell 15 was 2.1 mm, and the width A2 between cells was 0.5 mm. The depth dimension d of each cell was 10 mm. The areas of solar cells 3, 4, and 15 were determined by changing the scanning position of the laser in a process using a laser patterning device.

[0170] Since the film structure of the solar cell module 400 in Example 2 is the same as in Example 1, the I-V characteristics of the cells are the same as those shown in Figure 13.

[0171] In Example 2, the area of ​​the second solar cell 3 is w² × d = 0.34 [cm²] ２ The maximum operating current of the second solar cell 3 is 13.1 × 0.34 = 4.45 [mA]. ​​Also, the area of ​​the third solar cell 4 in Example 2 is w3 × d = 0.15 [cm²]. ２ The maximum operating current of the third solar cell 4 is 29.33 × 0.15 = 4.40 [mA]. ​​In addition, in the fourth solar cell 15 of Example 2, it is considered that a cell with an area exposed to strong light (overlapping with the gap 2) and a cell with an area exposed to weak light (overlapping with the first solar cell 1) are connected in parallel. In the fourth solar cell 15, the area of ​​the part exposed to strong light is 0.11 [cm²]. ２ The area of ​​the weak part is 0.10 [cm²]. ２ The maximum operating current in the bright light area is 29.33 × 0.11 = 3.23 [mA], and the maximum operating current in the weak light area is 13.1 × 0.1 = 1.31 [mA]. ​​Due to the parallel connection, the total maximum operating current for the fourth solar cell 15 is 3.23 + 1.31 = 4.54 [mA].

[0172] Since all cells are connected in series, and the maximum operating current of the entire unit is governed by the lower of the two, the maximum operating current of the second unit 402 in Example 2 is 4.40 [mA]. ​​The maximum operating voltage is 0.72 [V], and the number of cells is 5, so the maximum output of the second unit 402 in Example 2 is 0.72 × 5 × 4.40 = 15.83 [mW].

[0173] Comparing the maximum outputs of the second units 302 and 402, the value for Example 2 was greater than the value for Comparative Example 1. Therefore, the solar cell module 400 of Example 2 was able to obtain a higher maximum output than Comparative Example 1.

[0174] [Example 3 and Comparative Example 2] Below, the power generation of the solar cell modules of Example 3 and Comparative Example 2 were evaluated. Figure 15 is a schematic cross-sectional view showing the configuration of the solar cell module of Example 3. Figure 16 is a schematic cross-sectional view showing the configuration of the solar cell module of Comparative Example 2.

[0175] The solar cell module 500 in Example 3 has a first unit 501 and a second unit 502. The configurations of units 501 and 502 are similar to those of units 201 and 202 in Example 1, and the film configuration is the same.

[0176] The solar cell module 600 in Comparative Example 2 has a first unit 601 and a second unit 602. The configurations of units 601 and 602 are similar to those of units 201 and 202 in Example 1, and the film configuration is common to both.

[0177] In Example 3 and Comparative Example 2, the widths of the solar cells 1, 3, and 4 and the gap 2 are different from those in Example 1.

[0178] In Example 3, the width w1 of the first solar cell 1 in the first unit 501 was 5.0 mm, and the width A1 of the gap 2 was 0.2 mm. The width w2 of the second solar cell 3 in the second unit 502 was 3.3 mm, the width w3 of the third solar cell 4 was 3.0 mm, and the width A2 between cells in the second unit 502 was 0.2 mm. The depth dimension d of each cell was 10 mm.

[0179] In Comparative Example 2, the width w1 of the first solar cell 1 in the first unit 601 was 5.0 mm, and the width A1 of the gap 2 was 0.2 mm. The width w2 of the second solar cell 3 in the second unit 602 was 3.2 mm, and the width A2 between cells in the second unit 602 was 0.2 mm. The depth dimension d of each cell was 10 mm.

[0180] The areas of solar cells 1, 3, and 4 were determined by changing the laser scanning position in a process using a laser patterning device.

[0181] Since the configuration of the first units 501 and 601 is the same in Example 3 and Comparative Example 2, the maximum output of the first units 501 and 601 is the same. Therefore, the maximum output of the entire solar cell modules 500 and 600 is determined by the maximum output of the second units 502 and 602.

[0182] Since the film configuration of the solar cell modules 500 and 600 in Example 3 and Comparative Example 2 is the same as in Example 1, the I-V characteristics of the cells are the same as those shown in Figure 13.

[0183] In Example 3, the area of ​​the second solar cell 3 is w² × d = 0.33 [cm²] ２ The maximum operating current of the second solar cell 3 is 13.1 × 0.33 = 4.32 [mA]. ​​In addition, in the third solar cell 4 of Example 3, it is considered that the cells are connected in parallel corresponding to the area exposed to light. In the third solar cell 4, the area of ​​the part with strong light is 0.02 [cm²]. ２ The area of ​​the weak part is 0.28 [cm²]. ２ Therefore, the maximum operating current in the bright light area is 29.33 × 0.02 = 0.59 [mA], and the maximum operating current in the weak light area is 13.1 × 0.28 = 3.67 [mA]. ​​Due to the parallel connection, the total maximum operating current of the third solar cell 4 is 0.59 + 3.67 = 4.25 [mA].

[0184] Since all cells are connected in series, and the maximum operating current of the entire unit is governed by the lower of the two, the maximum operating current of the second unit 502 in Example 3 is 4.25 [mA]. ​​The maximum operating voltage is 0.72 [V], and the number of cells is 3, so the maximum output of the second unit 502 in Example 3 is 0.72 × 3 × 4.25 = 9.19 [mW].

[0185] In Comparative Example 2, the area of ​​the second solar cell 3 is w² × d = 0.32 [cm²] ２ The maximum operating current of the outer second solar cell 3 is 13.1 × 0.32 = 4.19 [mA]. ​​In addition, in the central second solar cell 3 of Comparative Example 2, it is considered that the cells are connected in parallel corresponding to the area exposed to light. In the central second solar cell 3, the area of ​​the part with strong light is 0.02 [cm²]. ２ The area of ​​the weak part is 0.30 [cm²]. ２ Therefore, the maximum operating current in the areas with strong light is 29.33 × 0.02 = 0.59 [mA], and the maximum operating current in the areas with weak light is 13.1 × 0.30 = 3.93 [mA]. ​​Due to the parallel connection, the total maximum operating current of the central second solar cell 3 is 0.59 + 3.93 = 4.52 [mA].

[0186] Since all cells are connected in series, the maximum operating current of the entire unit is governed by the lower value, so the maximum operating current of the second unit 602 in Comparative Example 2 is 4.19 [mA]. ​​The maximum operating voltage is 0.72 [V], and the number of cells is 3, so the maximum output of the second unit 602 in Comparative Example 2 is 0.72 × 3 × 4.19 = 9.05 [mW].

[0187] Comparing the maximum outputs of the second units 502 and 602, the value for Example 3 was greater than the value for Comparative Example 2. Therefore, the solar cell module 500 of Example 3 was able to obtain a higher maximum output than Comparative Example 2.

[0188] The results of the maximum output of the second unit in the above examples and comparative examples are summarized in Table 2.

[0189]

[0190] Based on the above results, it was confirmed that the solar cell module described in this disclosure can improve photoelectric conversion efficiency.

[0191] The solar cell module in the first embodiment comprises a first solar cell unit arranged on the light incident side and a second solar cell unit arranged on the opposite side from the light incident side and stacked on the first solar cell unit, wherein the first solar cell unit has a plurality of first solar cells and gaps arranged between adjacent first solar cells, and the second solar cell unit has a second solar cell having a first area and a third solar cell having a second area smaller than the first area, wherein when viewed from the stacking direction of the first solar cell unit and the second solar cell unit, the first solar cells and the second solar cells overlap, and the gaps and the third solar cells overlap.

[0192] In the second embodiment of the solar cell module, the second solar cell and the third solar cell are electrically connected in series, as in the solar cell module of the first embodiment.

[0193] In a third embodiment, the solar cell module is such that, in the solar cell module of the first or second embodiment, the first solar cell and the gap are arranged in a first direction, and the second solar cell unit has a plurality of third solar cells arranged in a first direction so as to overlap with one gap.

[0194] As a solar cell module in a fourth embodiment, in a solar cell module in any of the first to third embodiments, the second solar cell unit further has a fourth solar cell between the second solar cell and the third solar cell, and when viewed from the stacking direction, the third solar cell is positioned away from the boundary between the first solar cell and the gap, and the fourth solar cell overlaps with the boundary.

[0195] As a solar cell module in the fifth embodiment, in a solar cell module in any of the first to fourth embodiments, when the current density of the second solar cell is J1 and its area is S1, and the current density of the third solar cell is J2 and its area is S2, the relationship 0.9 < (J1 × S1) / (J2 × S2) < 1.1 is satisfied.

[0196] As a solar cell module in the sixth embodiment, in a solar cell module in any of the first to fifth embodiments, the second solar cell and the third solar cell are perovskite solar cells.

[0197] As a solar cell module in the seventh embodiment, in a solar cell module in any of the first to sixth embodiments, the band gap of the first solar cell is smaller than the band gap of the second solar cell and the band gap of the third solar cell.

[0198] A method for manufacturing a solar cell module in the eighth aspect includes: partially removing a multilayer film formed on a first substrate to form a first solar cell unit having a plurality of first solar cells and gaps disposed between adjacent first solar cells; partially removing a multilayer film formed on a second substrate to form a second solar cell unit having a second solar cell having a first area and a third solar cell having a second area smaller than the first area; and aligning and stacking the first solar cell unit and the second solar cell unit such that the first solar cells and the second solar cells overlap and the gaps and the third solar cells overlap.

[0199] In the manufacturing method of the solar cell module according to the ninth embodiment, the gap portion is formed by laser processing in the manufacturing method of the solar cell module according to the eighth embodiment.

[0200] The solar cell module in the tenth embodiment comprises a light-transmitting layer disposed on the light incident side and a solar cell unit disposed on the opposite side from the light incident side and laminated on the light-transmitting layer, wherein the light-transmitting layer has a plurality of first transparent portions having a first light transmittance and a second transparent portion disposed between adjacent first transparent portions and having a second light transmittance higher than the first light transmittance, and the solar cell unit has a second solar cell having a first area and a third solar cell having a second area smaller than the first area, wherein when viewed from the lamination direction of the light-transmitting layer and the solar cell unit, the first transparent portions and the second solar cells overlap, and the second transparent portions and the third solar cells overlap.

[0201] While this disclosure is adequately described in relation to preferred embodiments with reference to the accompanying drawings, various modifications and alterations will be obvious to those skilled in the art. Such modifications and alterations should be understood to be included within the scope of the invention as defined by the appended claims.

[0202] The solar cell module described herein is useful as a solar cell module because it can realize solar cells with high conversion efficiency.

[0203] 1. First solar cell 2. Gap 3. Second solar cell 4. Third solar cell 5. First substrate 6. Second substrate 8. First electrode 9. Second electrode 10. Third electrode 11. Fourth electrode 12. Photoelectric conversion layer 13. Hole transport layer 14. Electron transport layer 15. Fourth solar cell 100, 160. Solar cell module 101, 161. First unit 102, 162. Second unit

Claims

1. A solar cell module comprising: a first solar cell unit positioned on the light incident side; and a second solar cell unit positioned on the opposite side from the light incident side and stacked on the first solar cell unit, wherein the first solar cell unit has a plurality of first solar cells and gaps positioned between adjacent first solar cells; and the second solar cell unit has a second solar cell having a first area and a third solar cell having a second area smaller than the first area, wherein when viewed from the stacking direction of the first solar cell unit and the second solar cell unit, the first solar cells and the second solar cells overlap, and the gaps and the third solar cells overlap.

2. The solar cell module according to claim 1, wherein the second solar cell and the third solar cell are electrically connected in series.

3. The solar cell module according to claim 1 or 2, wherein the first solar cell and the gap are arranged side by side in a first direction, and the second solar cell unit has a plurality of third solar cells arranged side by side in the first direction so as to overlap with one of the gaps.

4. The solar cell module according to claim 1 or 2, wherein the second solar cell unit further comprises a fourth solar cell between the second solar cell and the third solar cell, and when viewed from the stacking direction, the third solar cell is positioned away from the boundary between the first solar cell and the gap, and the fourth solar cell overlaps the boundary.

5. A solar cell module according to claim 1 or 2, wherein when the current density of the second solar cell is J1 and its area is S1, and the current density of the third solar cell is J2 and its area is S2, the relationship 0.9 < (J1 × S1) / (J2 × S2) < 1.1 is satisfied.

6. The solar cell module according to claim 1 or 2, wherein the second solar cell and the third solar cell are perovskite solar cells.

7. The solar cell module according to claim 1 or 2, wherein the band gap of the first solar cell is smaller than the band gap of the second solar cell and the band gap of the third solar cell.

8. A method for manufacturing a solar cell module, comprising: partially removing a multilayer film formed on a first substrate to form a first solar cell unit having a plurality of first solar cells and gaps disposed between adjacent first solar cells; partially removing a multilayer film formed on a second substrate to form a second solar cell unit having a second solar cell having a first area and a third solar cell having a second area smaller than the first area; and aligning and stacking the first solar cell unit and the second solar cell unit such that the first solar cells and the second solar cells overlap and the gaps and the third solar cells overlap.

9. The method for manufacturing a solar cell module according to claim 8, wherein the gap is formed by laser processing.

10. A solar cell module comprising: a light-transmitting layer disposed on the side where light is incident; and a solar cell unit disposed on the opposite side from the side where light is incident and laminated on the light-transmitting layer, wherein the light-transmitting layer has a plurality of first transparent portions having a first light transmittance and a second transparent portion disposed between adjacent first transparent portions and having a second light transmittance higher than the first light transmittance, wherein the solar cell unit has a second solar cell having a first area and a third solar cell having a second area smaller than the first area, and when viewed from the lamination direction of the light-transmitting layer and the solar cell unit, the first transparent portions and the second solar cells overlap, and the second transparent portions and the third solar cells overlap.

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