WO2023037885A1

WO2023037885A1 - Solar battery device and solar battery module

Info

Publication number: WO2023037885A1
Application number: PCT/JP2022/032049
Authority: WO
Inventors: 広平小島
Original assignee: 株式会社カネカ
Priority date: 2021-09-13
Filing date: 2022-08-25
Publication date: 2023-03-16

Abstract

Provided is a solar battery device in which warping of the solar battery device attributable to warping of solar battery cells is reduced. The solar battery device (1) comprises double-sided electrode-type solar battery cells (2), a connection member (6) that is for electrically connecting the solar battery cells (2), and a light-reception-side adhesion member (7) and a rear-side adhesion member (8) that are for adhering together the connection member (6) and the solar battery cells (2). The solar battery cells (2) are tandem solar battery cells each containing a first photoelectric conversion portion (10) that includes a crystal silicon substrate and a second photoelectric conversion portion (20) that is disposed further on the light reception surface side than the first photoelectric conversion portion (10) and includes a perovskite thin film. The light-reception-side adhesion member (7) is a sheet-shaped or film-shaped resin member that covers the connection member (6) on the light reception surface side of each solar battery cell (2), the rear-side adhesion member (8) is a sheet-shaped or film-shaped resin member that covers the connection member (6) on the rear surface side of each solar battery cell (2), and the volume of the rear-side adhesion member (8) is larger than the volume of the light-reception-side adhesion member (7).

Description

Solar cell device and solar cell module

The present invention relates to solar cell devices and solar cell modules.

Solar cell devices in which a plurality of solar cells are connected by connecting members such as tabs, and solar cell modules in which the solar cell devices are sealed with a protective member such as glass or transparent resin and a sealing material are known. . As solar cells, crystalline silicon solar cells using a crystalline silicon substrate as a photoelectric conversion layer and thin film solar cells using an inorganic thin film such as an amorphous silicon thin film as a photoelectric conversion layer are known. As a thin-film solar cell, a perovskite thin-film solar cell using a perovskite thin film that is an organic thin film (more specifically, an organic/inorganic hybrid thin film) as a photoelectric conversion layer is known.

In recent years, multi-junction (tandem) solar cells, in which two photoelectric conversion units including photoelectric conversion layers with different bandgaps are stacked, have been developed for the purpose of effectively utilizing light in a wide wavelength range to increase the conversion efficiency of solar cells. Battery cells are known. For example, Patent Document 1 discloses a tandem solar cell including a bottom cell (first photoelectric conversion unit) including a crystalline silicon substrate as a photoelectric conversion layer and a top cell (second photoelectric conversion unit) including a perovskite thin film as a photoelectric conversion layer. A battery cell is disclosed.

Such tandem solar cells include a two-terminal type in which a top cell and a bottom cell are connected in series, and a four-terminal type in which electricity is extracted separately from the top and bottom cells. In addition, a three-terminal tandem solar cell has been devised that can utilize the advantages of these two-terminal and four-terminal types and has the possibility of further improving the photoelectric conversion efficiency (see, for example, Patent Document 2). ).

Japanese Unexamined Patent Application Publication No. 2018-11058 WO2020/196288

In a thin-film solar cell, an amorphous silicon thin film as a photoelectric conversion layer and a conductive amorphous silicon thin film are formed on relatively hard glass or transparent resin. On the other hand, in a crystalline silicon solar cell, a conductive amorphous silicon thin film is formed on a crystalline silicon substrate as a photoelectric conversion layer without using glass or transparent resin. Therefore, in a tandem solar cell in which a relatively thick perovskite thin film is formed on the light-receiving surface side of a crystalline silicon substrate, the thickness of the layers stacked on the light-receiving surface side of the crystalline silicon substrate and the thickness of the layers stacked on the back surface side of the crystalline silicon substrate are different. Due to the difference in the thickness of the layers, a relatively large amount of warping of the solar cell occurs in the manufacturing process of the solar cell device. As a result, a relatively large amount of warpage occurs in the solar cell device.

Therefore, in the manufacturing process of the solar cell module that seals the solar cell device, connection failure such as peeling of connection members such as tabs, cracking of the solar cell, and the like occur, resulting in a decrease in yield.

An object of the present invention is to provide a solar cell device and a solar cell module that reduce the warpage of the solar cell device caused by the warpage of the solar cells.

A solar cell device according to the present invention includes: a plurality of double-sided electrode type solar cells; a plurality of connection members electrically connecting the adjacent solar cells; a plurality of light-receiving side adhesive members for bonding the solar cells and the connecting members; and a plurality of back side adhesive members arranged on the back side of the solar cells for bonding the solar cells and the connecting members. , provided. The solar cell is of a tandem type including a first photoelectric conversion section including a crystalline silicon substrate and a second photoelectric conversion section disposed closer to the light receiving surface than the first photoelectric conversion section and including a perovskite thin film. A solar cell. The light-receiving-side adhesive member is a sheet-like or film-like resin member that covers the connection member on the light-receiving surface side of the solar cell, and the back-side adhesive member is a resin member that covers the connection member on the back surface side of the solar cell. It is a sheet-like or film-like resin member that covers the member, and the volume of the back side adhesive member is larger than the volume of the light receiving side adhesive member.

A solar cell module according to the present invention comprises one or more of the above solar cell devices, a light-receiving side protective member that protects the light-receiving surface side of the solar cell device, and a back side protective member that protects the back side of the solar cell device. and a sealing material disposed between the solar cell device and the light-receiving side protective member and between the solar cell device and the back side protective member to seal the solar cell device.

According to the present invention, in a solar cell device and a solar cell module, it is possible to reduce the warpage of the solar cell device caused by the warpage of the solar cells.

It is a sectional view showing typically a solar cell concerning this embodiment. 1 is a cross-sectional view of a solar cell device according to this embodiment; FIG. FIG. 3 is a view of a portion of the solar cell device shown in FIG. 2 as viewed from the light receiving surface side; FIG. 3 is a view of part of the solar cell device shown in FIG. 2 as seen from the back side; 1 is a cross-sectional view of a solar cell module according to this embodiment; FIG. It is a cross-sectional view of a solar cell device according to a modification of the present embodiment. It is a cross-sectional view of a solar cell device according to a modification of the present embodiment.

An example of an embodiment of the present invention will be described below with reference to the accompanying drawings. In each drawing, the same reference numerals are given to the same or corresponding parts. Also, for convenience, hatching, member numbers, etc. may be omitted, but in such cases, other drawings shall be referred to.

(solar battery cell)
FIG. 1 is a cross-sectional view schematically showing a solar cell according to this embodiment. An XY orthogonal coordinate system is shown in FIG. 1 and the drawings described later. The XY plane is a plane along the light-receiving surface and back surface of the solar cell and the solar cell device and solar cell module described later.

The solar cell 2 shown in FIG. 1 includes a first photoelectric conversion unit 10 (also referred to as a bottom cell B) and a second photoelectric conversion unit 20 (also referred to as a top cell T) stacked on the light receiving surface side of the first photoelectric conversion unit 10. ) and is a tandem type (multi-junction type) two-terminal type solar cell.

The first photoelectric conversion section 10 (bottom cell B) includes a first semiconductor layer as the photoelectric conversion layer 11 . The first semiconductor layer absorbs light and generates photocarriers. The first semiconductor layer as the photoelectric conversion layer 11 is a crystalline silicon substrate such as monocrystalline silicon or polycrystalline silicon.

When the first semiconductor layer as the photoelectric conversion layer 11 is a single crystal silicon substrate, as the first photoelectric conversion section 10, a diffusion layer of the second conductivity type is provided on the light receiving surface side of the single crystal silicon substrate of the first conductivity type. and a heterojunction cell in which silicon-based thin films are provided on both sides of a first-conductivity-type single-crystal silicon substrate.

In the case of a heterojunction cell in which the first semiconductor layer as the photoelectric conversion layer 11 is a single crystal silicon substrate and silicon-based thin films are provided on the front and back sides of the single crystal silicon substrate, the first photoelectric conversion unit 10 receives light from the photoelectric conversion layer 11. It has a conductive silicon-based thin film 14 formed on the surface side and a conductive silicon-based thin film 15 formed on the back surface side of the photoelectric conversion layer 11 .

The single crystal silicon substrate may be either p-type or n-type. When electrons are compared with holes, since electrons have higher mobility, conversion characteristics are particularly excellent when an n-type single crystal silicon substrate is used. Conductive silicon

thin films

14 and 15 are p-type silicon thin films or n-type silicon thin films.

It is preferable that intrinsic silicon

thin films

12 and 13 are provided between the single crystal silicon substrate as the photoelectric conversion layer 11 and the conductive silicon

thin films

14 and 15 . By providing the intrinsic silicon-based thin film on the surface of the single-crystal silicon substrate, it is possible to effectively perform surface passivation while suppressing diffusion of impurities into the single-crystal silicon substrate. By providing the intrinsic amorphous silicon thin film as the intrinsic silicon

thin films

12 and 13 on the surface of the single crystal silicon substrate, a high passivation effect for the surface of the single crystal silicon substrate can be obtained.

The second photoelectric conversion unit 20 (top cell T) includes a thin second semiconductor layer as the photoelectric conversion layer 21 . The second semiconductor layer absorbs light and generates photocarriers. The second semiconductor layer has a bandgap different from that of the first semiconductor layer described above. Therefore, the first semiconductor layer and the second semiconductor layer described above have spectral sensitivity characteristics in different wavelength ranges. Therefore, in the stacked photoelectric conversion unit in which the first photoelectric conversion unit 10 including the first semiconductor layer as the photoelectric conversion layer 11 and the second photoelectric conversion unit 20 including the second semiconductor layer as the photoelectric conversion layer 21 are stacked, the Light with a wide wavelength can contribute to photoelectric conversion.

Specifically, the thin film that constitutes the second semiconductor layer includes an organic semiconductor thin film, more specifically an organic-inorganic hybrid semiconductor thin film. The organic-inorganic hybrid semiconductor thin film includes a perovskite thin film containing a photosensitive material having a perovskite crystal structure.

A compound constituting a perovskite crystal material is represented by the general formula R ¹ NH ₃ M ¹ X ₃ or HC(NH ₂ ) ₂ M ¹ X ₃ . In the formula, R ¹ is an alkyl group, preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group. ^M1 is a divalent metal ion, preferably Pb or Sn. X is halogen and includes F, Cl, Br, and I; The three X's may all be the same halogen element, or a plurality of halogens may be mixed.

A preferred example of the compound constituting the perovskite crystal material is a compound represented by the formula CH ₃ NH ₃ Pb(I _1-x Br _x ) ₃ (where 0≦x≦1). The perovskite material can change the spectral sensitivity characteristics by changing the type and ratio of halogen. The perovskite semiconductor thin film can be formed by various dry processes or solution film formation such as spin coating.

When the photoelectric conversion layer 21 contains a perovskite semiconductor thin film, the second photoelectric conversion section 20 has charge transport layers 24 and 25 . One of the charge transport layers 24 and 25 is a hole transport layer and the other is an electron transport layer.

Materials for the hole transport layer include, for example, poly-3-hexylthiophene (P3HT), polythiophene derivatives such as poly(3,4-ethylenedioxythiophene) (PEDOT), 2,2′,7,7′- Fluorene derivatives such as tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD), carbazole derivatives such as polyvinylcarbazole, triphenylamine derivatives, diphenylamine derivatives, polysilanes derivatives, polyaniline derivatives and the like.

Materials for the electron transport layer include, for example, metal oxides such as titanium oxide, zinc oxide, niobium oxide, zirconium oxide, and aluminum oxide.

The first photoelectric conversion unit 10 and the second photoelectric conversion unit 20 described above are connected in series. The combination of the charge transport layer 24/charge transport layer 25/conductivity-type semiconductor layer 14/conductivity-type semiconductor layer 15 of the second photoelectric conversion unit 20 (top cell T) and the first photoelectric conversion unit 10 (bottom cell B) is as follows. A combination such as
・Hole transport layer (HTM) / electron transport layer (ETM) / n-type amorphous silicon semiconductor layer (na-Si) / p-type amorphous silicon semiconductor layer (pa-Si): pn-np junction type ・Electron transport layer (ETM) / hole transport layer (HTM) / n-type amorphous silicon semiconductor layer (na-Si) / p-type amorphous silicon semiconductor layer (pa-Si): np-np junction type, positive Hole transport layer (HTM)/electron transport layer (ETM)/p-type amorphous silicon semiconductor layer (pa-Si)/n-type amorphous silicon semiconductor layer (na-Si): pn-pn junction type/electron transport Layer (ETM)/hole transport layer (HTM)/p-type amorphous silicon semiconductor layer (pa-Si)/n-type amorphous silicon semiconductor layer (na-Si): np-pn junction type

An intermediate layer (not shown) may be provided between the first photoelectric conversion section 10 and the second photoelectric conversion section 20 . The intermediate layer is provided for purposes such as bandgap adjustment between two stacked photoelectric conversion units, selective movement of carriers, formation of a tunnel junction, wavelength selective reflection, and the like. The configuration of the intermediate layer is selected according to the type and combination of

photoelectric conversion units

10 and 20 . The intermediate layer can be omitted by providing the conductive semiconductor layer 14 and the charge transport layer 25 provided at the interface between the first photoelectric conversion section 10 and the second photoelectric conversion section 20 with a function as an intermediate layer. .

An electrode 31 for extracting photogenerated carriers is formed on the main surface of the second photoelectric conversion unit 20 opposite to the first photoelectric conversion unit 10, that is, on the light-receiving surface side of the solar cell 2. An electrode 32 for extracting photogenerated carriers is formed on the main surface of the first photoelectric conversion unit 10 opposite to the second photoelectric conversion unit 20 , that is, on the back surface side of the solar cell 2 .

The electrode 31 may include a transparent electrode 311 and a metal electrode 312. Similarly, electrode 32 may include transparent electrode 321 and metal electrode 322 . Metal oxides such as ITO, zinc oxide, and tin oxide are preferably used as materials for the

transparent electrodes

311 and 321 . Silver, copper, aluminum, or the like is preferably used as the material of the

metal electrodes

312 and 322 .

The metal electrode 312 on the light receiving surface side is a grid-like or slit-like electrode. Also, the metal electrode 322 on the back side is preferably a grid-like or slit-like electrode. As a result, not only light from the light-receiving surface side but also light from the back surface side can be made incident, and the photoelectric conversion efficiency can be improved.

(solar cell device)
2 is a cross-sectional view of the solar cell device according to the present embodiment, FIG. 3 is a view of part of the solar cell device shown in FIG. 2 as seen from the light receiving surface side, and FIG. 4 is shown in FIG. It is the figure which looked at a part of solar cell device from the back surface side. As shown in FIGS. 2 to 4, the solar cell device 1 includes a plurality of solar cells 2, a plurality of connecting members 6, a plurality of light receiving side adhesive members 7, and a plurality of back side adhesive members 8. FIG.

A plurality of solar cells 2 are arranged in the Y direction, for example. The connection member 6 electrically connects adjacent solar cells 2 . Specifically, one end of connection member 6 is connected to electrode 31 on the light receiving surface side of one solar cell 2 , and the other end of connection member 6 is connected to the back surface side of the other solar cell 2 . It is connected to the electrode 32 . A plurality of solar cells 2 connected in a string like this is referred to as a solar cell string (solar cell device).

As the connection member 6, a known interconnector such as a tab is used. For example, the connection member 6 may be a ribbon wire made of a copper core coated with a low-melting-point metal or solder, a conductive film made of a thermosetting resin film containing low-melting-point metal particles or metal fine particles, or a plurality of films. A member formed of a knitted or woven fabric knitted from conductive strands (for example, see Japanese Patent Application Laid-Open No. 2016-219799 or Japanese Patent Application Laid-Open No. 2014-3161).

The connection member 6 and the

electrodes

31 and 32 of the solar cell 2 may be connected via a conductive adhesive member. The conductive adhesive member includes a conductive film formed of a thermosetting resin film containing low-melting metal particles or metal fine particles, a conductive adhesive formed of low-melting metal fine particles or metal fine particles and a binder, or , a solder paste containing solder particles, or the like is used.

Also, the connection member 6 and the electrode 31 of the solar cell 2 are covered and connected with the light receiving side adhesive member 7 . Moreover, the connection member 6 and the electrode 32 of the solar cell 2 are covered and connected with the back side adhesive member 8 .

The light-receiving-side adhesive member 7 is arranged on the light-receiving surface side of the solar cell 2 and bonds the electrode 31 of the solar cell 2 and the connection member 6 . Specifically, the light-receiving side adhesive member 7 is a sheet-like or film-like resin member, and covers the connection member 6 on the light-receiving side of the solar cell 2 so that the electrode 31 of the solar cell 2 and the connection member 6 are bonded together. and glue.

The back side adhesive member 8 is arranged on the back side of the solar cell 2 and bonds the electrode 32 of the solar cell 2 and the connection member 6 . Specifically, the back-side adhesive member 8 is a sheet-like or film-like resin member, and covers the connection member 6 on the back side of the solar cell 2 so that the electrode 32 of the solar cell 2 and the connection member 6 are bonded together. to glue.

The volume of the back side adhesive member 8 is larger than the volume of the light receiving side adhesive member 7 . More specifically, the attachment volume of the back side adhesive member 8 attached to the back surface of the solar cell 2 and the connection member 6 is equal to the attachment volume of the light receiving side adhesive member 7 attached to the light receiving surface of the solar cell 2 and the connection member 6. bigger than

For example, as shown in FIGS. 3 and 4, the back side adhesive member 8 may be thicker than the light receiving side adhesive member 7 . More specifically, the adhesion thickness of the back side adhesive member 8 adhering to the back surface of the solar cell 2 and the connecting member 6 is the adhesion thickness of the light receiving side adhesive member 7 adhering to the light receiving surface of the photovoltaic cell 2 and the connecting member 6. It may be thicker than the thickness.

Also, as shown in FIGS. 3 and 4, the area of the back side adhesive member 8 may be larger than the area of the light receiving side adhesive member 7 . More specifically, the attachment area of the back side adhesive member 8 attached to the back surface of the solar cell 2 and the connection member 6 is equal to the attachment area of the light receiving side adhesive member 7 attached to the light receiving surface of the solar cell 2 and the connection member 6. may be greater than

Here, FIGS. 6 and 7 are cross-sectional views of solar cell devices according to modifications of the present embodiment. As shown in FIG. 6, the area of the back side adhesive member 8 is the same as the area of the light receiving side adhesive member 7, but the thickness of the back side adhesive member 8 may be thicker than the thickness of the light receiving side adhesive member 7. . Alternatively, as shown in FIG. 7, the thickness of the back side adhesive member 8 is the same as the thickness of the light receiving side adhesive member 7, but the area of the back side adhesive member 8 is larger than the area of the light receiving side adhesive member 7. good too.

The adhesion thickness described above is the thickness of the light-receiving side adhesive member 7 or the back side adhesive member 8 at the adhesion portion, and the adhesion area is the area of the light reception side adhesive member 7 or the back side adhesion member 8 at the adhesion portion. Also, the deposition volume is the product of the deposition thickness and the deposition area.

Materials for the light-receiving side adhesive member 7 and/or the back side adhesive member 8 include, for example, ethylene/vinyl acetate copolymer (EVA), ethylene/α-olefin copolymer, ethylene/vinyl acetate/triallyl isocyanurate (EVAT ), polyvinyl butyrate (PVB), acrylic resin, urethane resin, epoxy resin, or translucent resin such as silicone resin. The light-receiving side adhesive member 7 and the back side adhesive member 8 may be made of the same material or may be made of different materials.

According to the material of the light-receiving side adhesive member 7 described above, the light-receiving side adhesive member 7 has optical transparency. Moreover, it is preferable that the material of the back side adhesive member 8 is also the above-described material, since the back side adhesive member 8 also has light transmission properties. As a result, not only light from the light-receiving surface side but also light from the back surface side can be made incident, and the photoelectric conversion efficiency can be improved.

Also, the difference between the refractive index of the light-receiving side adhesive member 7 and the refractive index of the sealing material 5 described later is preferably 0.05 or less. Also, the difference between the refractive index of the back adhesive member 8 and the refractive index of the sealing material 5 described later is preferably 0.05 or less. For example, the material of the light-receiving side adhesive member 7 and/or the back side adhesive member 8 is ethylene/vinyl acetate copolymer (EVA) or ethylene/α-olefin copolymer, and the material of the sealing material 5 described later is ethylene/ Vinyl acetate copolymer (EVA) or ethylene/α-olefin copolymer may be used as long as the copolymer ratio is the same as or different from the material of the light-receiving side adhesive member 7 and/or the back side adhesive member 8 .

The softening temperature of the light-receiving side adhesive member 7 is preferably higher than the softening temperature of the sealing material 5 described later, and the softening temperature of the back side adhesive member 8 is preferably higher than the softening temperature of the sealing material 5 described later. . For example, the material of the light-receiving side adhesive member 7 and the back side adhesive member 8 is ethylene/vinyl acetate copolymer (EVA) or ethylene/α-olefin copolymer, and the material of the sealing material 5 described later is ethylene/vinyl acetate. A copolymer (EVA) or an ethylene/α-olefin copolymer may be used as long as the copolymer ratio is different from the material of the light-receiving side adhesive member 7 and/or the back side adhesive member 8 .

(solar cell module)
FIG. 5 is a cross-sectional view of the solar cell module according to this embodiment. As shown in FIG. 1 , a solar cell module 100 includes one or more solar cell devices 1 .

The solar cell device 1 is sandwiched between the light receiving side protective member 3 and the back side protective member 4 . A liquid or solid sealing material 5 is filled between the light-receiving-side protective member 3 and the back-side protective member 4 , thereby sealing the solar cell device 1 .

The sealing material 5 seals and protects the solar battery device 1, that is, the solar battery cell 2, between the light-receiving-side surface of the solar battery cell 2 and the light-receiving-side protective member 3, and between the solar battery cell. 2 and the back side protection member 4. The shape of the sealing material 5 is not particularly limited, and may be, for example, a sheet shape. This is because the sheet shape facilitates covering the front and back surfaces of the planar solar battery cell 2 .

Although the material of the sealing material 5 is not particularly limited, it is preferable that the material has the property of transmitting light (translucency). Moreover, it is preferable that the material of the encapsulant 5 has adhesiveness to bond the photovoltaic cell 2 , the light-receiving side protective member 3 , and the back side protective member 4 . Examples of such materials include ethylene/vinyl acetate copolymer (EVA), ethylene/α-olefin copolymer, ethylene/vinyl acetate/triallyl isocyanurate (EVAT), polyvinyl butyrate (PVB), acrylic Translucent resins such as resins, urethane resins, and silicone resins can be used.

The light-receiving-side protective member 3 covers the surface (light-receiving surface) of the solar battery device 1 , that is, the solar battery cell 2 via the sealing material 5 to protect the solar battery cell 2 . The shape of the light-receiving-side protective member 3 is not particularly limited, but a plate-like or sheet-like shape is preferable from the point of indirectly covering the planar light-receiving surface.

Although the material of the light-receiving side protective member 3 is not particularly limited, it is preferable to use a material that has translucency and is resistant to ultraviolet light, similar to the sealing material 5. For example, glass, or Transparent resins such as acrylic resins and polycarbonate resins can be used. Further, the surface of the light-receiving-side protective member 3 may be processed into an uneven shape, or may be coated with an antireflection coating layer. This is because the light-receiving-side protective member 3 having such a configuration makes it difficult to reflect the received light, and guides more light to the solar cell device 1 .

The back side protection member 4 covers the back side of the solar cell device 1 , that is, the solar cell 2 through the encapsulant 5 to protect the solar cell 2 . The shape of the back side protection member 4 is not particularly limited, but like the light receiving side protection member 3, it is preferably plate-like or sheet-like in that it indirectly covers the planar back side.

The material for the back side protection member 4 is not particularly limited, but a material that prevents the infiltration of water or the like (has high water impermeability) is preferable. For example, a resin film such as polyethylene terephthalate (PET), polyethylene (PE), olefin-based resin, fluorine-containing resin, or silicone-containing resin, or a translucent plate-shaped resin member such as glass, polycarbonate, or acrylic, A laminate with a metal foil such as an aluminum foil may be mentioned.

According to the material of the light-receiving side protective member 3 and the material of the sealing material 5 described above, the light-receiving side protective member 3 and the sealing material 5 have optical transparency. Moreover, it is preferable that the material of the back side protection member 4 is also the above-mentioned material, since the back side protection member 4 also has light transmittance. As a result, not only light from the light-receiving surface side but also light from the back surface side can be made incident, and the photoelectric conversion efficiency can be improved.

(Method for manufacturing solar cell device)
Next, a method for manufacturing a solar cell device according to this embodiment will be described.
(1) First, the solar cells 2 are arranged.
(2) Next, a conductive adhesive is placed on the

electrodes

31 and 32 of the solar cell 2 .
(3) Next, the connection member 6 is arranged on the

electrodes

31 and 32 of the solar cell 2 .
(4) Next, the light-receiving side adhesive member 7 is placed on the light-receiving surface side of the solar cell 2 so as to cover the connecting member 6 , and the back side adhesive member 8 is placed on the back side of the solar cell 2 so as to cover the connecting member 6 . to place.
Note that the procedures (1) to (4) may be interchanged.

(5) Next, the light-receiving-side adhesive member 7 and the connecting member 6 are adhered to the light-receiving surface side of the solar cell 2 by heat treatment, and the back-side adhesive member 8 and the connecting member 6 are bonded together by heat treatment. 2 on the back side.

(Manufacturing method of solar cell module)
Next, a method for manufacturing a solar cell device according to this embodiment will be described.
(6) Solar cell devices, transition wires, and lead wires are arranged to connect solar cell strings.
(7) Next, a light-receiving side protective member, a sealing material, a solar cell device, a sealing material, and a back side protective member are arranged in this order.
(8) Next, a known heating and pressurizing treatment is performed. As a result, a solar cell module 100 in which the solar cell device 1 is sealed with the light-receiving side protective member 3, the back side protective member 4, and the sealing material 5 is obtained.

In the procedure (5) in the manufacturing process of the solar cell device 1 described above, the heat treatment for bonding the connection member 6 to the solar cell 2 may cause the solar cell 2 to warp. Specifically, in the tandem solar cell 2 in which a relatively thick perovskite thin film is formed on the light-receiving surface side of the crystalline silicon substrate, the thickness of the layers stacked on the light-receiving surface side of the crystalline silicon substrate and the back surface of the crystalline silicon substrate Warpage of the solar cell 2 may occur due to the difference in thickness of the layer laminated on the side. As a result, the solar cell device 1 may warp.

Therefore, in the procedure (8) in the manufacturing process of the solar cell module 100 described above, in the heating and pressurizing process at the time of sealing the solar cell device 1, connection failure such as peeling of the connecting member 6 and crack failure of the solar cell 2 occur. Sometimes.

Regarding this point, in this embodiment, not only the conductive adhesive of procedure (2) but also the light-receiving side adhesive member 7 and the back side adhesive member 8 of procedure (4) are used.

That is, according to the solar cell device 1 and the solar cell module 100 of this embodiment, the light receiving side adhesive member 7 covers the connection member 6 on the light receiving surface side of the solar cell 2, and the back side adhesive member 8 covers the solar cell. 2 covers the connecting member 6 on the back side thereof. As a result, the connection members 6 can be fixed, and in the step (8) in the manufacturing process of the solar cell module 100 , the heating and pressurization process during the sealing of the solar cell device 1 , connection failure (peeling) of the connection members 6 can be prevented. can be reduced. In addition, due to the cushioning action of the light-receiving side adhesive member 7 and the back side adhesive member 8, crack defects in the solar battery cell 2 can be reduced.

Further, according to the solar cell device 1 and the solar cell module 100 of the present embodiment, the volume (ie, thickness and/or area) of the back side adhesive member 8 is equal to the volume (ie, thickness and area) of the light receiving side adhesive member 7. / or area). As a result, in the tandem solar cell 2 in which a relatively thick perovskite thin film is formed on the light-receiving surface side of the crystalline silicon substrate, the thickness of the layers stacked on the light-receiving surface side of the crystalline silicon substrate and the thickness of the back surface side of the crystalline silicon substrate Differences in thickness between laminated layers can be reduced. Therefore, in the step (5) in the manufacturing process of the solar cell device 1, the heat treatment for bonding the connection member 6 to the solar cell 2, the warping of the solar cell 2 can be reduced, and the warping of the solar cell 2 can be caused by It is possible to reduce the warpage of the solar cell device 1 to be used. As a result, it is possible to reduce poor connection (peel-off) of the connection members 6 caused by the warping of the solar cell 2, in other words, the warping of the solar cell device 1. FIG. In addition, in the procedure (8) in the manufacturing process of the solar cell module 100, the heating and pressurizing process at the time of sealing the solar cell device 1, it is possible to reduce connection failure such as peeling of the connecting member 6 and crack failure of the solar cell. can. In this way, defects in the manufacturing process of the solar cell device 1 and the solar cell module 100 can be reduced, and the yield can be improved.

By the way, in recent years, the size of solar cells has been increasing. As the size of the solar cell increases, the warping of the solar cell and the warping of the solar cell device tend to increase. The features of the present embodiment are more effective in solar cell devices and solar cell modules that include such large tandem solar cells.

Also, in recent years, there is a double-sided photovoltaic cell. In such a double-sided light-receiving type solar cell, if the metal electrode on the back side is made into a grid or a slit, the warpage of the solar cell and the warpage of the solar cell device tend to increase. The solar cell device and solar cell module having such double-sided electrode type, ie, grid-like or slit-like, tandem-type solar cells having backside metal electrodes are effective.

Further, in the present embodiment, the difference between the refractive index of the light receiving side adhesive member 7 and the refractive index of the sealing material 5 and the difference between the refractive index of the back side adhesive member 8 and the refractive index of the sealing material 5 are 0. 0.05 or less. Thereby, the reflection between the light-receiving side adhesive member 7 and the sealing material 5 and/or the reflection between the back side adhesive member 8 and the sealing material 5 can be reduced, thereby improving the photoelectric conversion efficiency. be able to. In addition, it is possible to improve designability.

Also, in this embodiment, the softening temperature of the light receiving side adhesive member 7 and the back side adhesive member 8 is higher than the softening temperature of the sealing material 5 . Thus, after the procedure (5) in the manufacturing process of the solar cell device 1, the heat treatment for bonding the connection members 6 to the solar cells 2, the procedure (8) in the manufacturing process of the solar cell module 100, and the sealing of the solar cell device 1 In the heating and pressurizing process, the light-receiving side adhesive member 7 and the back side adhesive member 8 are not softened, and connection failure (peeling) of the connection member 6 can be reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and variations are possible. For example, in the above-described embodiments and modifications, a solar cell device and a solar cell module including two-terminal tandem solar cells have been exemplified. However, the features of the present invention are also applicable to solar devices and modules with four-terminal tandem solar cells, and also to solar devices and modules with three-terminal tandem solar cells. It is also applicable to solar cell modules.

REFERENCE SIGNS LIST 1 solar cell device 2 solar cell 3 light-receiving-side protective member 4 back-side protective member 5 sealing material 6 connecting member 7 light-receiving-side adhesive member 8 back-side adhesive member 10, B first photoelectric conversion part (bottom cell)
11 photoelectric conversion layer (first semiconductor layer)
12, 13 intrinsic semiconductor layer (intrinsic silicon-based thin film)
14, 15 conductive semiconductor layer (conductive silicon thin film)
20, T Second photoelectric conversion unit (top cell)
21 photoelectric conversion layer (second semiconductor layer)
24, 25

charge transport layer

31, 32

electrode

311, 321

transparent electrode

312, 322 metal electrode 100 solar cell module

Claims

a plurality of double-sided electrode solar cells;
a plurality of connecting members for electrically connecting the adjacent solar cells;
a plurality of light-receiving-side adhesive members arranged on the light-receiving surface side of the solar cell and bonding the solar cell and the connecting member;
a plurality of back side adhesive members disposed on the back side of the solar cell and bonding the solar cell and the connection member;
with
The solar cell is
a first photoelectric conversion unit including a crystalline silicon substrate;
a second photoelectric conversion unit disposed closer to the light receiving surface than the first photoelectric conversion unit and including a perovskite thin film;
A tandem solar cell comprising
The light-receiving-side adhesive member is a sheet-like or film-like resin member that covers the connection member on the light-receiving surface side of the solar cell,
The back side adhesive member is a sheet-like or film-like resin member that covers the connection member on the back side of the solar cell,
The volume of the back side adhesive member is larger than the volume of the light receiving side adhesive member,
solar device.
The solar cell device according to claim 1, wherein the thickness of the back side adhesive member is thicker than the thickness of the light receiving side adhesive member.
The solar cell device according to claim 1 or 2, wherein the area of the back side adhesive member is larger than the area of the light receiving side adhesive member.
The light-receiving side adhesive member and the back side adhesive member have optical transparency,
The solar cell device according to any one of claims 1 to 3, wherein the electrodes on the light-receiving surface side and the electrodes on the back surface side of the solar cell have grid-like or slit-like metal electrodes.
one or more solar cell devices according to any one of claims 1 to 4;
a light-receiving side protection member that protects the light-receiving surface side of the solar cell device;
a back side protection member that protects the back side of the solar cell device;
a sealing material disposed between the solar cell device and the light-receiving side protective member and between the solar cell device and the back side protective member to seal the solar cell device;
A solar module, comprising:
The solar cell module according to claim 5, wherein the softening temperature of said light receiving side adhesive member and said back side adhesive member is higher than the softening temperature of said encapsulant.
The light-receiving side protective member, the sealing material, the light-receiving side adhesive member, the back side protective member, and the back side adhesive member have optical transparency,
The electrodes on the light-receiving surface side and the electrodes on the back surface side of the solar cell have grid-shaped or slit-shaped metal electrodes,
The solar cell module according to claim 5 or 6.
The difference between the refractive index of the light receiving side adhesive member and the refractive index of the sealing material and the difference between the refractive index of the back side adhesive member and the refractive index of the sealing material are 0.05 or less. Item 8. The solar cell module according to item 7.