JP2015188041A - Solar cell module, vehicle member, and vehicle - Google Patents

Abstract

Provided is a solar cell module that is biaxially curved and in which a decrease in power generation efficiency is suppressed.
A biaxially curved solar cell module having a photoelectric conversion layer sandwiched between a front surface protective layer and a back surface protective layer via a sealing material, the photoelectric conversion layer portion of the solar cell module (TM-TP) / TM is 0.12 or more, where TM is the thickness of TM, and TP is the thickness of the peripheral edge where no photoelectric conversion layer is present.
[Selection] Figure 1

Description

  The present invention relates to a solar cell module. The present invention also relates to a vehicle member including the solar cell module and a vehicle equipped with the vehicle member.

  2. Description of the Related Art In recent years, solar cells that generate electricity by receiving sunlight have been spreading in response to improvements in energy saving and awareness of environmental issues. Along with this, many solar battery modules have been developed that generate power by sandwiching solar cells between plates such as resin and glass.

  Recently, attempts have been made to reduce the weight of solar cell modules and to use them for building materials or vehicle mounting applications. For example, a solar cell module that employs a lightweight and easily processable resin for the front and back protective layers has been proposed (for example, Patent Documents 1 and 2). By using a resin, it can be attached to a structure having a curved shape without impairing the appearance, and mounting in automobiles and the like has been developed in recent years.

  Moreover, as a solar cell module having a curvature with a resin layer, the solar cell or module is not stressed even when molded into a curved shape, and the solar cell and module are excellent in manufacturing yield and durability, and are easy to match the shape of the surrounding structure. A method for manufacturing a battery panel is described (for example, Patent Document 3).

Further, it has radii of curvature R ₁ , R ₂ , lengths l ₁ and l ₂ in the respective vertical directions d ₁ and d ₂ , and the total thickness of the layer with the polymer and the direction towards the sun It is described that when the polymer material covering the side surface of the combined photovoltaic cell has a specific relationship with the minimum thickness, it can be easily incorporated into a structure (for example, Patent Document 4).

Japanese Patent Laid-Open No. 10-070300 Japanese Patent Laid-Open No. 10-284745 JP 2002-217441 A Special table 2013-513248 gazette

The inventors of the solar cell module manufactured when manufacturing a biaxially curved solar cell module having a photoelectric conversion layer (solar cell) sandwiched between the front surface protective layer and the back surface protective layer. It has been found that the power generation efficiency decreases depending on the shape.
This invention solves the said problem, and makes it a subject to provide the solar cell module which was biaxially curved, Comprising: The fall of power generation efficiency was suppressed.

  When mounted on the roof of an automobile or the like, a solar cell module processed to have a curvature in two axes is required. As a result of intensive studies to solve the above problems, the inventors of the present invention have a biaxially curved solar cell module in which a photoelectric conversion layer is sandwiched between a front surface protective layer and a back surface protective layer. The present invention has been completed by finding that the above-mentioned problems can be solved when TM which is the thickness of TP and TP which is the thickness of the peripheral edge where no photoelectric conversion layer is present have a specific relationship.

That is, the gist of the present invention resides in the following [1] to [6].
[1] A solar cell module curved biaxially formed by sandwiching a photoelectric conversion layer through a sealing material between a front surface protective layer and a back surface protective layer,
A solar cell module in which (TM-TP) / TM is 0.12 or more, where TM is the thickness of the photoelectric conversion layer portion of the solar cell module and TP is the thickness of the peripheral portion where no photoelectric conversion layer is present.
[2] The solar cell module according to [1], wherein the TP is 1.2 mm or less.
[3] The solar cell module according to [1] or [2], wherein a minimum curvature radius of the biaxially curved solar cell module is 1 mm or more and 10,000 mm or less.
[4] The solar cell module according to any one of [1] to [3], wherein at least one of the surface protective layer and the back surface protective layer is a stretched polyester resin sheet.
[5] A vehicle member obtained by integrating the solar cell module according to any one of [1] to [4] and another vehicle member.
[6] A vehicle equipped with the vehicle member according to [5].

  ADVANTAGE OF THE INVENTION According to this invention, it is a solar cell module curved to biaxial, Comprising: The solar cell module by which the fall of power generation efficiency was suppressed can be provided.

It is a schematic diagram of one embodiment of the solar cell module of the present invention. It is a schematic diagram of one embodiment of the solar cell module of the present invention.

Embodiments of the solar cell module of the present invention will be specifically described below.
<1. Surface protective layer>
The surface protective layer in the solar cell module of the present invention will be described.
The surface protective layer of the present invention is a layer for imparting mechanical strength, weather resistance, scratch resistance, chemical resistance, gas barrier properties and the like to the solar cell module. Since the surface protective layer is located on the light receiving surface side, the total light transmittance is preferably 80% or more, more preferably 90% or more, from the viewpoint of not hindering light absorption of the photoelectric conversion layer. The measuring method of a total light transmittance can be measured by JISK7361-1, for example.

  Examples of the material for the surface protective layer of the present invention include polycarbonate (PC), polymethyl methacrylate (PMMA), cyclic polyolefin, polystyrene, polyethylene terephthalate (PET), ethylene-tetrafluoroethylene copolymer (ETFE), polytetra Fluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), stretched polyethylene terephthalate (stretched PET), stretched polyethylene naphthalate (stretched PEN), polyimide, polyphenylene sulfide, phenol resin, or their glass or carbon fiber reinforced products Etc. are mentioned. Among these, since the linear expansion coefficient is small and highly transparent, it is preferable that at least one of the surface protective layer and the back surface protective layer described later is a stretched polyester resin, and since the surface has high heat resistance, When a stretched polyester resin is used for the protective layer, a stretched polyester resin sheet such as stretched polyethylene terephthalate (stretched PET) is more preferable.

  The thickness of the surface protective layer is not particularly limited, but is preferably 0.02 to 1.0 mm, more preferably 0.05 to 0.5 mm, and still more preferably 0.1 to 0.2 mm. If it is less than 0.02 mm, it tends to be damaged, and if it exceeds 1.0 mm, the weight increases, which is not preferable.

  For the surface protective layer, if necessary, in order to improve adhesion with other layers, cleaning treatment with alcohol, corona treatment, plasma treatment, or urethane resin, low melting point PET resin, acrylic resin, A surface treatment such as chlorinated polyolefin may be performed.

<2. Back surface protective layer>
The back surface protective layer in the solar cell module of the present invention will be described.
Examples of the material for the back surface protective layer of the present invention include polycarbonate (PC), polymethyl methacrylate (PMMA), cyclic polyolefin, polystyrene, polyethylene terephthalate (PET), ethylene-tetrafluoroethylene copolymer (ETFE), and polytetra Fluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), stretched polyethylene terephthalate (stretched PET), stretched polyethylene naphthalate (stretched PEN), polyimide, polyphenylene sulfide, phenol resin, or their glass or carbon fiber reinforced products Etc. are mentioned. Among these, since the linear expansion coefficient is small and highly transparent, it is preferable that at least one of the surface protective layer and the back surface protective layer described later is a stretched polyester resin, and since the surface has high heat resistance, When a stretched polyester resin is used for the protective layer, a stretched polyester resin sheet such as stretched polyethylene terephthalate (stretched PET) is more preferable.

  Although there is no restriction | limiting in particular in the thickness of a back surface protective layer, 0.02-1.0 mm is preferable, 0.05-0.5 mm is more preferable, 0.1-0.2 mm is further more preferable. If it is less than 0.02 mm, it tends to be damaged, and if it exceeds 1.0 mm, the weight increases, which is not preferable.

<3. Sealing material>
The sealing material used for the solar cell module of the present invention will be described.
The encapsulant is a component for reinforcing the photoelectric conversion layer while being used to integrate the constituent layers (surface protective layer, photoelectric conversion layer, back surface protective layer, etc.) of the solar cell module of the present invention. . Since the photoelectric conversion layer is thin, the strength is usually weak, and thus the strength of the solar cell module tends to be weak. However, the strength can be maintained high by the sealing material.

Moreover, it is preferable that a sealing material has high intensity | strength from a viewpoint of the intensity | strength maintenance of a solar cell module.
The specific strength is related to the strength of the surface protective layer and back surface protective layer other than the sealing material, and it is difficult to define it in general, but the entire solar cell module has good durability and is used for a long time. However, it is desirable to have a strength that does not cause internal peeling.

  Further, the sealing material is preferably one that transmits visible light from the viewpoint of not hindering light absorption of the photoelectric conversion layer. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 85% or more. Preferably it is 90% or more, Especially preferably, it is 95% or more, Especially preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

  Furthermore, since the solar cell module is often heated by receiving light, it is preferable that the sealing material also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably It is 300 degrees C or less. By increasing the melting point, it is possible to reduce the possibility of the sealing material melting and deteriorating when the solar cell module is used.

It is not particularly limited as long as it is a synthetic resin material that transmits sunlight, and a known and commonly used material can be used. For example, polyolefin resin such as polyethylene or polypropylene, ethylene-vinyl acetate copolymer (EVA) resin, polyvinyl butyral (PVB) resin, modified polyethylene resin modified with maleic acid or silane, modified polypropylene resin, and epoxy adhesive An agent, a urethane-based adhesive, or the like can be used. Among these, polyolefin resins such as polyethylene or polypropylene are preferable because the plasticity under curved surface molding conditions of the solar cell module and the rigidity under normal temperature conditions are good.

  Although there is no restriction | limiting in the position which provides a sealing material, Usually, it provides so that a photoelectric converting layer may be pinched | interposed. This is for reliably protecting the photoelectric conversion layer. In the present invention, a layer formed by sealing the photoelectric conversion layer with a sealing material is used as a sealing material layer, and the sealing material layer may be composed of one layer or a plurality of layers.

The thickness of the sealing material layer is usually 0.1 mm or more, preferably 0.15 mm or more, more preferably 0.2 mm or more, and usually 2 mm or less, preferably 1.5 mm, including the photoelectric conversion layer. Below, more preferably, it is 1.0 mm or less.
By increasing the thickness, mechanical strength tends to increase, and insulation between the photoelectric conversion layer and the substrate can be secured. Thinning tends to increase flexibility and increase light transmittance.

<4-1. Photoelectric conversion layer>
The photoelectric conversion layer in the solar cell module of the present invention will be described.
The photoelectric conversion layer is an element that generates power based on sunlight incident from the sunlight receiving surface side. This photoelectric conversion layer only needs to be able to convert light energy into electric energy and extract the electric energy obtained by the conversion to the outside.
Therefore, as a photoelectric conversion layer, a pair of electrodes sandwiches a power generation layer (photoelectric conversion layer, light absorption layer), and a pair of electrodes sandwiches a stack of a power generation layer and another layer (buffer layer, etc.). It is possible to use a plurality of such devices connected in series and / or in parallel.

Various things can be adopted as a power generation layer of the photoelectric conversion layer. However, the power generation layer is composed of thin film single crystal silicon, thin film polycrystalline silicon, amorphous silicon, microcrystalline silicon, inorganic semiconductor materials such as CdTe and Cu-In- (Ge) -Se, organic dye materials such as black die, A layer made of an organic semiconductor material such as molecule / fullerene is preferably used, but thin film single crystal silicon or thin film polycrystalline silicon is more preferable from the viewpoint of power generation efficiency.
For example, silicon-based solar cells may be commercially available, such as Q-Cells, First Solar, Suntech, Sharp, Shinsung, Sunpower, Gintech, Taiwan Solar Energy Corporation, etc. The solar battery cell is mentioned.
Further, a multi-junction photoelectric conversion layer, a HIT photoelectric conversion layer, or the like may be employed.
In order to realize higher power generation efficiency, it is preferable to provide a sufficient light confinement structure, such as forming an uneven structure on the surface of the power generation layer or the photoelectric conversion layer substrate.

  If the power generation layer is an amorphous silicon layer, a photoelectric conversion layer that has a large optical absorption coefficient in the visible region and can sufficiently absorb sunlight even with a thin film having a thickness of about 1 μm can be realized. In addition, amorphous silicon, microcrystalline silicon, inorganic semiconductor materials, organic dye materials, and organic semiconductor materials are non-crystalline materials or materials with low crystallinity, and thus have resistance to deformation. Therefore, if the photoelectric conversion layer is provided with an amorphous silicon layer as a power generation layer, a particularly light-weight solar cell module having a certain degree of resistance to deformation can be realized.

If the power generation layer is an inorganic semiconductor material (compound semiconductor) layer, a photoelectric conversion layer with high power generation efficiency can be realized. From the viewpoint of power generation efficiency (photoelectric conversion efficiency), the power generation layer is defined as S
It is preferable to use a chalcogenide-based power generation layer containing a chalcogen element such as Se, Te, more preferably a I-III-VI group 2 semiconductor-based (chalcopyrite-based) power generation layer, and Cu using Cu as the group I element. -III-VI2 group semiconductor based power generation layer, in particular, CIS-based semiconductor _{[CuIn (Se 1-y S y} ) 2; 0 ≦ y ≦ 1 ] layer and a CIGS semiconductor _{[Cu (In 1-x Ga x} ) (Se _1-y S _y ) ₂ ; 0 <x <1, 0 ≦ y ≦ 1] It is desirable to have a layer.

Even when a dye-sensitized power generation layer composed of a titanium oxide layer, an electrolyte layer, or the like is employed as the power generation layer, a photoelectric conversion layer with high power generation efficiency can be realized.
As the power generation layer, an organic semiconductor layer (a layer including a p-type semiconductor and an n-type semiconductor) can be employed. In addition, as a p-type semiconductor which can comprise an organic-semiconductor layer, a purophylline compound such as tetrabenzoporphyrin, tetrabenzocopper porphyrin, tetrabenzozinc porphyrin; a phthalocyanine compound such as phthalocyanine, copper phthalocyanine, zinc phthalocyanine; a polycene of tetracene or pentacene; Examples include oligothiophenes such as sexithiophene and derivatives containing these compounds as a skeleton. In addition, examples of p-type semiconductors that can form the organic semiconductor layer include polymers such as polythiophene including poly (3-alkylthiophene), polyfluorene, polyphenylene vinylene, polytriallylamine, polyacetylene, polyaniline, polypyrrole, and the like. .

In addition, n-type semiconductors that can constitute the organic semiconductor layer include fullerenes (C ₆₀ , C ₇₀ , C ₇₆ ); octaapophylline; perfluoro compounds of the above p-type semiconductors; naphthalene tetracarboxylic acid anhydrides, nafra Examples thereof include aromatic carboxylic acid anhydrides such as lentetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, and perylenetetracarboxylic acid diimide, and imide compounds thereof; and derivatives containing these compounds as a skeleton.

  Further, as a specific configuration example of the organic semiconductor layer, a bulk heterojunction type having a layer (i layer) in which a p-type semiconductor and an n-type semiconductor are phase-separated in the layer, and a layer (p layer) each including a p-type semiconductor. And a layered type (hetero pn junction type) in which a layer containing an n-type semiconductor (n layer) is stacked, a Schottky type, and a combination thereof.

Each electrode of the photoelectric conversion layer can be formed using one or more arbitrary materials having conductivity. Examples of the electrode material (electrode constituent material) include metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, and alloys thereof; indium oxide and tin oxide Metal oxides such as, or alloys thereof (ITO: indium tin oxide); conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene; acids such as hydrochloric acid, sulfuric acid, sulfonic acid, A material containing a dopant such as a Lewis acid such as FeCl ₃ , a halogen atom such as iodine, or a metal atom such as sodium or potassium; a matrix such as a metal binder, conductive particles such as carbon black, fullerene, or carbon nanotube. For example, a conductive composite material dispersed in the film.

The electrode material is preferably a material suitable for collecting holes or electrons. Examples of electrode materials suitable for collecting holes (that is, materials having a high work function) include Au, Ag, Cu, Al, ITO, IZO, and ZnO ₂ . Moreover, Al can be illustrated as an electrode material suitable for electron collection (that is, a material having a low work function).

  There is no restriction | limiting in particular also in the formation method of an electrode. Therefore, the electrodes can be formed by a dry process such as vacuum deposition or sputtering, or can be formed by a wet process using a conductive ink or the like. As the conductive ink, an arbitrary one (conductive polymer, metal particle dispersion, etc.) can be used.

  Each electrode of the photoelectric conversion layer may be substantially the same size as the power generation layer or may be smaller than the power generation layer. However, in the case where the electrode on the light receiving surface side of the photoelectric conversion layer is relatively large (the area is not sufficiently smaller than the area of the power generation layer), the electrode is transparent ( The transmissivity of the light having a wavelength (for example, 300 to 1200 nm, preferably 500 to 800 nm) at which the electrode, particularly the power generation layer can be efficiently converted into electric energy, is relatively high (for example, 50% or more). ) Electrode. Examples of transparent electrode materials include oxides such as ITO and IZO (indium oxide-zinc oxide); metal thin films, and the like.

  Further, the thickness of each electrode of the photoelectric conversion layer and the thickness of the power generation layer can be determined based on the required output, etc., but if it is too thick, the electrical resistance increases, and if it is too thin, the durability is high. May fall.

<4-2. Photoelectric conversion layer substrate>
A photoelectric conversion layer base material is used as needed for the photoelectric conversion layer of the solar cell module of the present invention, and is a member on which one surface of the photoelectric conversion layer is formed. Therefore, it is desired that the photoelectric conversion layer base material has a relatively high mechanical strength, is excellent in weather resistance, heat resistance, water resistance, and the like, and is lightweight. It is also desirable that the photoelectric conversion layer base material has a certain degree of resistance to deformation. On the other hand, if the physical properties of the photoelectric conversion layer to be formed and the material properties (for example, linear expansion coefficient, melting point, etc.) are significantly different, distortion or peeling may occur at the interface after formation.

  Therefore, as the photoelectric conversion layer substrate, it is preferable to employ a metal foil, a resin film having a melting point of 85 ° C. or higher or no melting point, and several metal foil / resin film laminates. Examples of the metal foil that can be used as the photoelectric conversion layer substrate (or a component thereof) include foils made of aluminum, stainless steel, gold, silver, copper, titanium, nickel, iron, and alloys thereof.

  Examples of the resin film having a melting point of 85 ° C. or higher or no melting point include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polycarbonate, polyacetal, acrylic resin, polyamide resin, ABS resin, ACS resin, AES resin, ASA resin, copolymers thereof, fluorine resin, silicone resin, cellulose, nitrile resin, phenol resin, polyurethane, ionomer, polybutadiene, polybutylene, polymethylpentene, polyvinyl alcohol, polyarylate, polyether ether Examples thereof include films made of ketone, polyetherketone, polyethersulfone, polyimide and the like. Among these, polyimide resin, stretched polyethylene terephthalate, and stretched polyethylene naphthalate are preferable because they are resistant to the power generation layer forming process and have high heat resistance and low linear expansion.

  From the viewpoint of productivity of the metal resin composite substrate, the resin is preferably a thermoplastic resin. The resin film used as the power generation element substrate is a film in which inorganic substances such as antimony oxide, antimony hydroxide, barium borate, glass fiber, organic fibers, carbon fibers, etc. are dispersed in the resin as described above. There may be.

  The reason why the melting point of the resin film used as the photoelectric conversion layer substrate (or its constituent elements) is preferably 85 ° C. or higher is that when the melting point is excessively low, the photoelectric conversion is performed under the normal use environment of the solar cell module. This is because the layer base material is deformed and may damage the photoelectric conversion layer.

  Accordingly, the melting point of the resin film used as the photoelectric conversion layer substrate (or its constituent elements) is more preferably 100 ° C. or higher, further preferably 120 ° C. or higher, and more preferably 150 ° C. or higher. Particularly preferred is 180 ° C. or higher.

  The thermal expansion coefficient of the photoelectric conversion layer of the solar cell module of the present invention is not particularly limited, but is preferably 40 ppm / K or less, more preferably 35 ppm / K or less, and particularly preferably 30 ppm / K or less. . The measuring method of the thermal expansion coefficient is, for example, according to ASTM D696. When the thermal expansion coefficient exceeds 40 ppm / K, deformation due to temperature change is large, and therefore, it tends to be liable to fail under heating / cooling processes or actual use conditions. On the other hand, the lower limit is not particularly limited, but is usually −5 ppm / K or more, preferably 0 ppm / K or more.

<5. Other layers>
In addition to these layers, a known functional layer such as a contamination prevention layer, an insulating layer, a gas barrier layer, an ultraviolet cut layer, or a decorative layer may be laminated.
From the viewpoint of preventing dirt from being deposited on the surface protective layer, it is preferable that the contamination preventive layer is further laminated on the surface of the surface protective layer on the solar light receiving surface side. Preferred examples of the contamination prevention layer include fluorine resins such as ETFE and PTFE, silicon oxide, silicon resin, and (meth) acrylic resin. Among them, it is preferable to use an ETFE film excellent in heat resistance and stretchability.
In addition to these layers, a known functional layer such as a gas barrier layer or an ultraviolet cut layer may be laminated.
In addition, for the purpose of protecting the end portions and reinforcing the module, it is possible to perform sealing treatment, taping, or the like, such as aluminum fumes, butyl rubber, or the like.

<6. Solar cell module>
The solar cell module of this invention has said layer structure. Moreover, it has the electric power generation part in which a photoelectric converting layer exists, and the peripheral part in which a photoelectric converting layer does not exist, and is distorted convexly to the light-receiving surface side in the biaxial direction as a whole. By convexly curving toward the light receiving surface, rainwater, dust, earth and sand, leaves, etc. are not easily deposited or deposited even when the solar cell module faces the light receiving surface directly above (antifouling effect). In addition, when a part or all of the periphery of the solar cell module is fixed with a rail or the like, and fixed to a vehicle or the like so that the part other than the periphery is suspended in the air, the solar cell module is damaged because the rigidity against vertical movement increases. Hard to do (seismic effect). Furthermore, it also has the effect of suppressing the creep phenomenon that gradually deforms under its own weight at high temperatures (shape retention effect).

The solar cell module of the present invention will be described with reference to FIGS. 1 and 2, but the present invention is not limited to such an embodiment.
FIG. 1 is a perspective view of a solar cell module 10 according to an embodiment of the present invention. The solar cell module 10 according to one embodiment of the present invention is curved in two axes with the center as an intersection. In FIG. 1, only the surface of the surface protective layer 1 that is the outermost surface on the light receiving surface side and the photoelectric conversion layer 3 existing inside the solar cell module 10 are illustrated. The two axes are indicated by broken lines so that the two axes are curved.

FIG. 2 is a diagram showing a cut surface in the aa ′ direction of the solar cell module 10 shown in FIG. 1. As shown in FIG. 2, in the solar cell module 10 which is one embodiment of this invention, between the surface protective layer 1 and the back surface protective layer 2, the sealing material layer 4 and the photoelectric converting layer are provided from the surface protective layer 1 side. 3. The sealing material layer 5 is laminated.
As shown in FIG. 2, TM is the thickness of the thickest portion in the photoelectric conversion layer portion where the photoelectric conversion layer 3 is present, and TP is the thickness of the thinnest portion in the peripheral portion where the photoelectric conversion layer 3 is not present. At this time, the solar cell module of the present invention has (TM-TP) / TM of 0.12 or more. It can be set as the solar cell module by which the fall of power generation efficiency was suppressed because (TM-TP) / TM exists in the said value. Further, from the viewpoint of preventing the generation of wrinkles in the light receiving surface side layer, (TM-TP) / TM is preferably 0.15 or more. If wrinkles occur in the layer on the light-receiving surface side, not only the aesthetic appearance of the solar cell module is impaired, but the module may be damaged due to stress on the wrinkled part when continuously used.
In this specification, the thickness of the thickest portion in the photoelectric conversion layer portion where the photoelectric conversion layer exists is referred to as “the thickness of the photoelectric conversion layer portion”, and the thickness of the thinnest portion in the peripheral portion where the photoelectric conversion layer does not exist. May be referred to as “the thickness of the peripheral edge where no photoelectric conversion layer is present” or “the thickness of the peripheral edge”.

  In addition, the solar cell module of the present invention is preferable because the thickness TP of the peripheral portion where the photoelectric conversion layer is not present is 1.2 mm or less, so that the step between the object to be installed is eliminated and the design is improved. 1.1 mm or less, more preferably 1.0 mm or less.

The solar cell module of the present invention is biaxially curved means that the solar cell module is curved biaxially on the light receiving surface side in an environment of 25 ° C., atmospheric pressure, and relative humidity of 20 to 80%. It means that
At this time, the minimum radius of curvature of the outermost surface of the light receiving surface is not particularly limited, but is preferably 1 mm or more, more preferably from the viewpoint of preventing damage to the photoelectric conversion layer and preventing local abrasion of the surface protective layer. Is 10 mm or more, more preferably 100 mm or more. On the other hand, from the viewpoint of improving the designability and rigidity of the solar cell module, it is preferably 10,000 mm or less, more preferably 5,000 mm or less, and further preferably 3,000 mm or less.

  The method for producing the solar cell module of the present invention is not particularly limited. For example, a method of bending a solar cell module formed in a flat plate shape on a flat hot plate by post-processing or a curved hot plate A method of forming a curved surface, and further, a multilayer sheet including front and back protective layers, a sealing material layer, a photoelectric conversion layer, and the like is placed in a vacuum lamination apparatus, heated after evacuation, and cooled after a predetermined time, vacuum Lamination method etc. are mentioned.

In the solar cell module of the present invention, in order for the value of (TM-TP) / TM to satisfy the above condition, it is preferable that TM is as large as possible and TP is as small as possible. However, if the TP is too small, the thickness of the sealing material layer joining the surface protective layer and the back surface protective layer becomes too thin, which increases the risk of edge peeling, which is not preferable.
As a method for increasing TM, for example, a resin layer may be further provided on the photoelectric conversion layer. Examples of the resin layer include polyethylene, polypropylene, crosslinkable EVA, and polyvinyl butyral. Among these, polyolefin resins such as polyethylene and polypropylene are preferable because the plasticity under curved surface molding conditions of the solar cell module and the rigidity under normal temperature conditions are good.

Although it does not specifically limit as a method to make TP small, For example, manufacturing the solar cell module of this invention by the vacuum lamination method mentioned above is mentioned. The vacuum lamination includes vacuum forming (tensile mode) and vacuum pack forming (compression mode).
In vacuum forming (tensile mode), the four corners of the multilayer sheet including the front and back protective layers, the sealing material layer, the photoelectric conversion layer, etc. are fixed, and the mold is applied to the center of the heated multilayer sheet without being compressed all the time. While evacuating. Therefore, the central portion of the multilayer sheet to which the mold is addressed is not substantially stretched, and on the other hand, the portion other than the center is stretched, and as a result, TP can be reduced.
On the other hand, in vacuum pack molding (compression mode), a TP that is reduced in size is applied to the heated multilayer sheet, and TP can be reduced by compression molding.

  In addition, although the molding method by the vacuum lamination can suppress a decrease in the power generation effect by using any method, when vacuum pack molding (compression mode) is used, wrinkles are formed on the layer on the light receiving surface side. Since it may occur, it is preferable to use vacuum forming (tensile mode) from the viewpoint of preventing this. If wrinkles occur in the layer on the light-receiving surface side, not only the aesthetic appearance of the solar cell module is impaired, but the module may be damaged due to stress on the wrinkled part when continuously used.

Thermal lamination conditions are not particularly limited, and thermal lamination is possible under normal conditions.
It is preferably carried out under vacuum conditions, and usually the degree of vacuum is 0.01 Pa or more, preferably 0.05 Pa or more, more preferably 0.1 Pa or more. On the other hand, the upper limit is usually 200 Pa or less, preferably 150 Pa or less, more preferably 100 Pa or less. By setting it as the said range, since generation | occurrence | production of a bubble can be suppressed in each layer in a module and productivity is also improved, it is preferable.

  The vacuum time is usually 1 minute or longer, preferably 2 minutes or longer, more preferably 3 minutes or longer. On the other hand, the upper limit is usually 20 minutes or less, preferably 15 minutes or less, more preferably 10 minutes or less. Setting the vacuum time in the above range is preferable because the appearance of the solar cell module after heat lamination becomes good and the generation of bubbles in each layer in the module can be suppressed.

  The temperature condition of the thermal laminate is usually 120 ° C. or higher, preferably 125 ° C. or higher, more preferably 130 ° C. or higher. On the other hand, the upper limit is usually 180 ° C. or lower, preferably 160 ° C. or lower, more preferably 150 ° C. or lower. By setting the temperature range, sufficient adhesive strength can be obtained.

  Moreover, the heating time of the said temperature is 5 minutes or more normally, Preferably it is 10 minutes or more, More preferably, it is 15 minutes or more. On the other hand, the upper limit is 60 minutes or less, preferably 45 minutes or less, more preferably 30 minutes or less. By setting it as the said heat time, since a sealing material is bridge | crosslinked moderately, durability performance improves and it can have moderate softness | flexibility, and is preferable.

  Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.

Table 1 summarizes the evaluation results of the solar cell modules obtained in the examples and comparative examples. In addition, the evaluation method of the solar cell module of Table 1 is as follows.
[Surface difference]
The layer on the light-receiving surface side of the manufactured solar cell module was visually observed, and no step was recognized in the boundary region between the portion with and without the photoelectric conversion layer or wiring material. The result was judged as x.
[Wrinkle]
The layer on the light-receiving surface side of the manufactured solar cell module was visually observed, and the case where no wrinkle was observed was judged as ○, and the case where wrinkle was found was judged as ×.
[Output retention rate]
Using a solar simulator manufactured by PASAN, the maximum power generation amount before and after curved surface molding (unit: W, when irradiated with 1000 W / m ² pseudo sunlight according to JIS C8991) was measured, and after the curved surface molding with respect to the maximum power generation amount before curved surface molding. The ratio (%) of maximum power generation was calculated.

<Example 1>
The solar cell module according to Example 1 is manufactured by the following configuration / procedure.
Surface protective layer: 0.225 mm thick composite sheet view barrier FDK-3AA (hereinafter referred to as VB) consisting of an ETFE layer (thickness 20 μm), a UV absorbing layer, a gas barrier layer, and a stretched PET layer (thickness 125 μm) (Mitsubishi Resin Co., Ltd.)
Sealing material: 0.4 mm thick polyolefin film (Z74, manufactured by Dai Nippon Printing Co., Ltd.) Photoelectric conversion layer: 0.15 mm thick polyolefin film (Z74, manufactured by Dai Nippon Printing Co., Ltd.), and thickness 0.05mm amorphous silicon cell (Fuji Electric Co., Ltd.)
Sealing material: 0.4 mm thick polyolefin film (Z74, manufactured by Dai Nippon Printing Co., Ltd.) Back surface protective layer: PET layer (thickness 19 μm), decorative layer, stretched PET layer (thickness 25 μm) PET composite sheet with a thickness of 0.08mm (manufactured by Sealex Corporation)

These are laminated to form a laminate, and molded by heat lamination (vacuum degree: 40 to 60 Pa, vacuum time: 5 minutes, pressure: 100 kPa, heating and holding time: 30 minutes) using a vacuum laminator manufactured by NPC. Then, after producing a flat solar cell module, a solar cell module was produced by vacuum forming using a convex shape made of aluminum in order to form a curved surface. The surface temperature of the solar cell module during vacuum forming was 160 to 220 ° C.
When the solar cell module according to Example 1 was left standing on a horizontal plane with the light receiving surface facing upward, the thickness TM of the photoelectric conversion layer portion was 1.23 mm, the thickness TP of the peripheral portion was 1.04 mm, and (TM -TP) / TM was 0.15, the minimum curvature radius was 3,000 mm, and the shape was curved convexly toward the light receiving surface.

<Example 2>
A solar cell module was produced in the same manner as in Example 1 except that the shape of the aluminum convex shape used to shape the curved surface was changed.
When the solar cell module according to Example 2 was left standing on the horizontal surface with the light receiving surface facing upward, the thickness TM of the photoelectric conversion layer portion was 1.25 mm, the thickness TP of the peripheral portion was 0.95 mm, and (TM -TP) / TM was 0.24, the minimum curvature radius was 5 mm, and the shape was curved convexly toward the light receiving surface.

<Example 3>
A solar cell module was produced in the same manner as in Example 1 except that vacuum pack thermoforming (heating temperature: 120 to 150 ° C.) was applied to the glass fiber reinforced epoxy resin mold in order to form a curved surface. did.
When the solar cell module according to Example 3 was allowed to stand on a horizontal plane with the light receiving surface facing upward, the thickness TM of the photoelectric conversion layer portion was 1.23 mm, the thickness TP of the peripheral portion was 1.07 mm, and (TM -TP) / TM was 0.13, the minimum curvature radius was 3,000 mm, and the shape was convexly curved toward the light receiving surface.

<Comparative Example 1>
The solar cell module according to Comparative Example 1 is manufactured by the following configuration / procedure.
Surface protective layer and sealing material: 0.1 mm thick polyethylene terephthalate (PET) composite sheet (hot laminate film / GOLI film, 0.5 mm thick EVA resin, 0.5 mm thick EVA resin) (Made by Lamy Corporation)
Photoelectric conversion layer: 0.05 mm thick amorphous silicon cell (Fuji Electric Co., Ltd.)
Sealing material: EVA film with a thickness of 0.03 mm (super fast curing type, manufactured by CI Kasei Co., Ltd.)
Back surface protective layer: PET composite sheet (manufactured by Sealex Co., Ltd.) having a PET layer (thickness 25 μm), decorative layer, stretched PET layer (thickness 100 μm) and PET having a thickness of 0.5 mm Resin, 0.1 mm thick polyethylene terephthalate (PET) composite sheet (hot laminate film / GOLI film, manufactured by Ramie Corporation) made of 0.5 mm thick EVA resin is used for adhesion of EVA layer of GOLI film Polyethylene terephthalate (PET) composite sheet with a thickness of 0.24 mm

These are laminated and laminated using a vacuum laminator manufactured by NPC, and heat laminated at 130 ° C. (vacuum degree: 40 to 60 Pa, vacuum time: 5 minutes, pressure: 100 kPa, heating and holding time: 30 minutes) The solar cell module was manufactured by vacuum pack thermoforming in the same manner as in Example 3 except that the shape of the glass fiber reinforced epoxy resin mold was different.
When the solar cell module according to Comparative Example 1 was left standing on a horizontal plane with the light receiving surface facing upward, the thickness TM of the photoelectric conversion layer portion was 0.69 mm, and the thickness TP of the peripheral portion was 0.62 mm. -TP) / TM was 0.10, the minimum curvature radius was 5 mm, and the shape was curved convexly toward the light receiving surface.

It turns out that the solar cell module which concerns on Example 1 and 2 is excellent in output holding | maintenance rate (decrease in luminous efficiency fall), and a wrinkle does not generate | occur | produce. Moreover, although the wrinkle will generate | occur | produce the solar cell module which concerns on Example 3, it turns out that it is excellent in output holding | maintenance rate (decrease in luminous efficiency reduction).

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell module which can be used as components, such as building materials for exterior walls, exterior back panels, and roofs, vehicles (automobiles, railroads), ships, airplanes, spacecrafts, etc. can be obtained. Since the solar cell module according to the present invention is highly rigid, resistant to vibration, and lightweight, it is particularly suitable for vehicle applications.

DESCRIPTION OF SYMBOLS 10 Solar cell module 1 Surface protective layer 2 Back surface protective layer 3 Photoelectric conversion layer 4, 5 Sealing material layer

Claims (6)

Between the surface protective layer and the back surface protective layer, a solar cell module that is biaxially curved by sandwiching a photoelectric conversion layer through a sealing material,
A solar cell module in which (TM-TP) / TM is 0.12 or more, where TM is the thickness of the photoelectric conversion layer portion of the solar cell module and TP is the thickness of the peripheral portion where no photoelectric conversion layer is present.   The solar cell module according to claim 1, wherein the TP is 1.2 mm or less.   3. The solar cell module according to claim 1, wherein a minimum curvature radius of the biaxially curved solar cell module is 1 mm or more and 10,000 mm or less.   The solar cell module according to any one of claims 1 to 3, wherein at least one of the surface protective layer and the back surface protective layer is a stretched polyester resin sheet.   The member for vehicles formed by integrating the solar cell module of any one of Claims 1-4, and the other member for vehicles.   A vehicle equipped with the vehicle member according to claim 5.

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