JP2012129391A - Solar cell module and backside protective sheet for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell module and a backside protective sheet for the same which have effects of increasing the power generation amount due to wavelength conversion.SOLUTION: The solar cell module having such a structure that a backside sealing material and the backside protective sheet are laminated on a surface opposite to a light-receiving surface of a solar battery cell, is characterized in that a wavelength conversion layer and a light-reflecting layer are independently provided in the backside protective sheet sequentially from the cell side.

Description

  The present invention relates to a solar cell module having a power generation improvement effect by wavelength conversion and a back surface protection sheet for solar cell module.

Solar cell modules that convert solar light energy into electrical energy are attracting attention as a clean energy source that can generate electricity without emitting carbon dioxide in response to environmental problems such as air pollution and global warming.
Generally, a solar cell module includes a photovoltaic cell that performs photoelectric conversion, a sealing material that is laminated on both surfaces of the solar cell, a surface protection sheet that is laminated on the surface side of the sealing material, and a back surface of the sealing material. It is schematically configured from a back surface protective sheet laminated on the side.

Conventionally, in a solar cell module, in order to improve the utilization efficiency of irradiated light energy, the back surface protection sheet has been required to have a high reflectance. (For example, refer to Patent Document 1).
In Patent Document 1, a polybutylene terephthalate film containing titanium oxide produced by a chlorine method or a solar cell back surface sealing film comprising a laminate of the polybutylene terephthalate film is oxidized to obtain a high reflectance. In addition to titanium, it has been proposed to use fluorescent whitening agents such as thiophenediyl.
The fluorescent whitening agent converts short-wavelength light that is not used for photoelectric conversion into long-wavelength light that is used for photoelectric conversion.

JP 2007-129204 A

  However, when both titanium oxide and fluorescent brightening agent are contained in the same layer, short wavelength light may be reflected by the titanium oxide before reaching the fluorescent brightening agent. Inefficient.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the solar cell module which can fully acquire the power generation amount improvement effect by wavelength conversion, and the back surface protection sheet for solar cell modules.

  In order to achieve the above object, the present invention provides a solar cell having a structure in which a back surface sealing material and a back surface protection sheet are laminated in order from the cell side on the surface (back surface) opposite to the light receiving surface of the solar battery cell. In the battery module, a solar cell module is provided in which a wavelength conversion layer and a light reflection layer are independently provided on the back surface sealing material in this order from the cell side.

  Further, in the solar cell module having a structure in which a back surface sealing material and a back surface protection sheet are laminated in order from the cell side on the surface opposite to the light receiving surface of the solar battery cell, wavelength conversion to the back surface sealing material Provided is a solar cell module in which a layer is provided and the back surface protection sheet is provided with a light reflection layer.

  Further, in a solar cell module having a structure in which a back surface sealing material and a back surface protection sheet are laminated in this order from the cell side on the surface opposite to the light receiving surface of the solar cell, the back surface protection sheet includes the cell. Provided is a solar cell module in which a wavelength conversion layer and a light reflection layer are independently provided in order from the side.

  In the solar cell module of the present invention, the wavelength conversion layer is a thermoplastic resin containing a wavelength conversion agent that absorbs irradiated light, converts the light into light having a wavelength longer than the wavelength of the light, and emits the light. Is preferred.

  In the solar cell module of the present invention, the light reflecting layer is preferably a thermoplastic resin layer containing a white pigment or bubbles.

  Moreover, this invention provides the back surface protection sheet for solar cell modules in which the light reflection layer and the wavelength conversion layer were laminated | stacked independently in order on one surface of the base material sheet.

  In the back surface protective sheet of the present invention, the wavelength conversion layer is a thermoplastic resin containing a wavelength conversion agent that absorbs irradiated light, converts the light into light having a wavelength longer than the wavelength of the light, and emits the light. Is preferred.

  The back surface protection sheet of this invention WHEREIN: It is preferable that the said light reflection layer is a thermoplastic resin layer containing a white pigment or a bubble, or a metal layer.

  Moreover, it is preferable that the fluororesin layer was laminated | stacked on the surface on the opposite side to the said light reflection layer of the said base material sheet.

  Since the solar cell module of the present invention has a configuration in which the wavelength conversion layer and the light reflection layer are independently provided in order from the cell side on the surface opposite to the light receiving surface of the solar cell, By converting the short wavelength light leaked to the back surface sealing material without being used into the long wavelength light used for power generation in the wavelength conversion layer and reflecting it toward the cell by the light reflection layer, the solar cell module The amount of power generation can be increased.

  Since the back surface protection sheet for solar cell modules of the present invention has a structure in which the light reflection layer and the wavelength conversion layer are sequentially and independently laminated on one surface of the base material sheet, the wavelength conversion layer of the back surface protection sheet is used. In solar cell modules stacked so as to be in contact with the back surface sealing material, short wavelength light leaked to the back surface protection sheet without being used for power generation in the cell is converted into long wavelength light used for power generation in the wavelength conversion layer. And the amount of electric power generation of a solar cell module can be increased by reflecting toward a cell with a light reflection layer.

It is a schematic sectional drawing of a solar cell module. It is a schematic sectional drawing which shows 1st Embodiment of the solar cell module of this invention. It is a schematic sectional drawing which shows 2nd Embodiment of the solar cell module of this invention. It is a schematic sectional drawing which shows 3rd Embodiment of the solar cell module of this invention, and 1st Embodiment of a back surface protection sheet.

  Hereinafter, with reference to drawings, embodiment of the solar cell module of this invention and the back surface protection sheet for solar cell modules is described.

(Configuration of solar cell module)
FIG. 1 is a schematic cross-sectional view of a solar cell module. The solar cell 11 has a light receiving surface sealed with a surface sealing material 14 and a surface opposite to the light receiving surface sealed with a back surface sealing material 12, and the surface sealing material 14 is covered with a surface protective sheet 15 or a glass plate. The back surface sealing material 12 is protected by a back surface protection sheet 13.

  The type and structure of the solar battery cell 11 (hereinafter abbreviated as “cell”) are not particularly limited, and a-Si (amorphous silicon), c-Si (crystalline silicon), μc-Si (microcrystalline silicon), GaAs ( Compound semiconductor type such as gallium arsenide), dye sensitized type, and the like.

  These cells can convert long-wavelength light (approximately 400 nm or more, sensitivity varies depending on the cell type) out of light contained in sunlight (approximately 300 to 2500 nm). Light (approximately less than 400 nm, depending on cell type) cannot be converted to electricity.

The back surface sealing material 12 and the front surface sealing material 14 are made of a thermoplastic resin, and are preferably polyolefin resins.
Examples of polyolefin resins include low density polyethylene (density: 0.910 g / cm ³ or more and less than 0.930 g / cm ³ ), medium density polyethylene (density: 0.930 g / cm ³ or more, less than 0.942 g / cm ^3). ), Polyethylene such as high density polyethylene (density: 0.942 g / cm ³ or more), polypropylene, olefin elastomer, cycloolefin resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl acetate-maleic anhydride A copolymer, an ethylene- (meth) acrylic acid copolymer and its ionomer, an ethylene- (meth) acrylic acid ester copolymer, and the like are used, and among these, EVA is particularly preferable.

  The back surface protection sheet has a function of protecting the cells 11 from moisture, and a conventional back surface protection sheet or a back surface protection sheet of the present invention described later can be used.

(First Embodiment of Solar Cell Module)
FIG. 2 is a schematic cross-sectional view showing a first embodiment of the solar cell module of the present invention. In the solar cell module of FIG. 1, the back surface sealing material 12 is changed to the back surface sealing material 22, and the cell 11, the surface sealing material 14, and the surface protection sheet 15 are omitted in FIG. 2.

  In this embodiment, the wavelength conversion layer 16 and the light reflection layer 17 are independently formed in the back surface sealing material 22 in order from the cell 11 side.

  The back surface protection sheet 13 is laminated so as to be in contact with the light reflecting layer 17 of the back surface sealing material 22.

  In the present embodiment, the wavelength conversion layer 16 absorbs light having a short wavelength that has leaked without being converted into electricity by the cell 11, converts it into light having a long wavelength (hereinafter sometimes referred to as fluorescence), and emits it. To do.

  The light reflection layer 17 reflects the fluorescence emitted from the wavelength conversion layer 16 toward the cell 11.

  The wavelength conversion layer 16 is preferably a thermoplastic resin layer containing a wavelength conversion agent. As a thermoplastic resin, the thing similar to what is used for the said back surface sealing material 12 can be used. When EVA is used, the vinyl acetate content is preferably 10 to 40% by mass. If it is less than 10% by mass, the sealing performance is insufficient.

The conversion agent is preferably an organic fluorescent agent or an inorganic fluorescent agent.
Examples of the organic fluorescent agent include cyanine dyes, phthalocyanine dyes, xanthine dyes, oxazine dyes, anthracene dyes, oligophenylene dyes, stilbene dyes, coumarin dyes, quinoline dyes, oxazole dyes, and oxazines. Examples thereof include fluorescent dyes such as azole dyes, phthalimide dyes, and pyrium dyes; and organic rare earth complexes containing rare earth elements such as Er ³⁺ , Yb ³⁺ , Tm ³⁺ , Ho ³⁺ , Pr ³⁺ , and Eu ³⁺ . One kind of the organic fluorescent agent may be used, or two or more kinds thereof may be used in combination.

Examples of the inorganic fluorescent agent include zinc oxide (ZnO), zinc sulfide (ZnS), zinc selenide (ZnSe), cadmium sulfide (CdS); Er ³⁺ , Yb ³⁺ , Tm ³⁺ , Ho ³⁺ , Pr ³⁺ , Eu ³⁺ Inorganic fluorescent agents such as rare earth-containing YAG (yttrium, aluminum, garnet) containing rare earth elements such as One kind of inorganic fluorescent agent may be used, or two or more kinds may be used in combination. Further, the organic fluorescent agent and the inorganic fluorescent agent may be used in combination.

  In a preferred embodiment of the present invention, an oxazole dye is particularly suitable as the conversion agent. For example, “TINOPAL OB” (trade name) 2,5-thiophenediylbis- (5-tert-butyl-1,3-benzoxazole) manufactured by BASF may be mentioned.

  When the organic fluorescent agent is used, the addition amount of the conversion agent in the wavelength conversion layer 16 is preferably in the range of 0.01 to 2% by mass, and more preferably in the range of 0.1 to 1% by mass. Moreover, when using an inorganic fluorescent agent, the range of 0.1-20 mass% is preferable, and the range of 1-10 mass% is more preferable. If the addition amount of the conversion agent is less than the above range, the ratio that the light incident on the wavelength conversion layer 16 is transmitted without being wavelength-converted increases. When the addition amount of the conversion agent exceeds the above range, concentration quenching occurs, so that the fluorescence emitted from the wavelength conversion layer 16 is reduced and the effect of increasing the power generation amount cannot be obtained. The concentration quenching refers to a phenomenon in which an adjacent fluorescent agent absorbs energy emitted by the fluorescent agent.

  The wavelength conversion layer 16 can be formed using an extrusion method (a method in which a thermoplastic resin is melted and extruded from a die). The thickness is preferably 10 to 500 μm.

  The light reflection layer 17 has a function of reflecting the fluorescence emitted from the wavelength conversion layer 16 to reach the cell 11.

  Examples of the light reflecting layer 17 suitable for the present invention include a thermoplastic resin layer containing a white pigment. As this thermoplastic resin, the thing similar to what is used for the back surface sealing material 12 can be used. When EVA is used, the content of vinyl acetate is preferably 10 to 40% by mass. If it is less than 10% by mass, the sealing performance is insufficient.

  The white pigment is not particularly limited as long as it is a white pigment, and a commonly used white pigment is selected. For example, titanium dioxide, zinc oxide (zinc white), zinc sulfide, barium sulfate, calcium carbonate, antimony trioxide, lead white, basic carbonate, basic silicate, lithopone and the like can be mentioned. Of these, titanium dioxide is preferable because of its high refractive index and excellent light reflectivity.

  The content of the white pigment in the light reflecting layer 17 is preferably in the range of 0.1 to 20% by mass, and more preferably in the range of 1 to 10% by mass. When the content of the white pigment is less than the above range, sufficient reflectance cannot be obtained. When the content of the white pigment exceeds the above range, the flexibility is lowered and the cell 11 cannot be sealed.

  The light reflection layer 17 can be formed using an extrusion method, similarly to the wavelength conversion layer 16. The thickness is preferably 10 to 500 μm.

  The back surface sealing material 22 provided with the wavelength conversion layer 16 and the light reflection layer 17 may be laminated by forming each of them by an extrusion method and then thermocompression-bonding, or may be laminated simultaneously with the formation by a coextrusion lamination method. You may do it.

  It does not specifically limit as the back surface protection sheet 13, A conventionally well-known back surface protection sheet can be applied.

  The solar cell module according to the present embodiment independently includes the wavelength conversion layer 16 and the light reflection layer 17 in order from the cell side on the back surface sealing material 22 laminated on the surface opposite to the light receiving surface of the cell 11. Since it is configured, the short wavelength light leaked to the back surface sealing material 22 without being used for power generation by the cell 11 is converted into long wavelength light (fluorescence) by the wavelength conversion layer 16, and the light reflection layer 17 The amount of power generation can be increased by being reflected toward 11.

(Second Embodiment of Solar Cell Module)
FIG. 3 shows a second embodiment of the solar cell module of the present invention. In the solar cell module of FIG. 1, the back surface sealing material 12 is changed to the back surface sealing material 32, and the back surface protection sheet 13 is changed to the back surface protection sheet 33. In FIG. The surface protection sheet 15 is omitted.

  In the present embodiment, the back surface sealing material 32 includes the wavelength conversion layer 16. The wavelength conversion layer 16 may be the same as that used in the first embodiment.

The back surface protective sheet 33 includes the light reflecting layer 17 on the surface of the base material sheet 18 on the cell 11 side.
The light reflecting layer 17 is preferably a white pigment, a thermoplastic resin containing bubbles, or a metal layer.

  As the thermoplastic resin used for the light reflecting layer 17 provided in the back surface protective sheet 33, it is preferable to use the same resin as that used for the back surface sealing material 12. When EVA is used, the vinyl acetate content is preferably 3 to 10% by mass. When it exceeds 10 mass%, when the back surface protection sheet 33 is wound in a roll shape, the light reflection layer 17 adheres to the base sheet 18, which is not preferable.

  In order to contain bubbles in the thermoplastic resin, there is a method in which a foaming agent is contained in the thermoplastic resin and heated.

As a means for forming the light reflection layer 17 made of a thermoplastic resin, an extrusion method can be mentioned.
As a means for laminating the light reflecting layer 17 made of a thermoplastic resin on one surface of the base sheet 18, a method of laminating the light reflecting layer 17 formed by an extrusion method and the base sheet 18 through an adhesive layer. Alternatively, a method (extrusion coating) of extruding a melted light reflecting layer on one surface of the base sheet 18 can be mentioned.

  Examples of the metal layer used for the light reflecting layer 17 include a metal foil and a metal vapor deposition layer. As the metal foil, aluminum foil is preferable, and is laminated on the base sheet 18 through an adhesive. The thickness of the metal foil is preferably 1 to 50 μm.

Silver or aluminum is preferable as the metal for forming the metal deposition layer.
Examples of the vapor deposition method include chemical vapor deposition such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition, or physical vapor deposition such as vacuum vapor deposition, sputtering, and ion plating. A phase method is used. Among these methods, the vacuum deposition method is preferable in consideration of operability and controllability of the layer thickness.
The thickness of the said metal vapor deposition layer should just have sufficient light reflectivity, and is not specifically limited.

  Examples of the resin used for the base sheet 18 include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate, styrene resins such as syndiotactic polystyrene, polyphenylene ether resins, Examples include polyphenylene sulfide resin.

  The thickness of the base sheet 18 is appropriately set based on the electrical insulation required for the solar cell module, and the thickness is preferably in the range of 10 μm to 300 μm. More specifically, when the base sheet 18 is PET, the thickness is preferably in the range of 10 μm to 300 μm, more preferably in the range of 20 μm to 250 μm, from the viewpoint of lightness and electrical insulation. A range of 30 μm to 200 μm is particularly preferable.

  Moreover, when the base material sheet 18 contains a white pigment or air bubbles and has light reflectivity, the light reflection layer and the base material sheet may not be independent.

(3rd Embodiment of a solar cell module and 1st Embodiment of a back surface protection sheet)
FIG. 4 is a schematic cross-sectional view showing a third embodiment of the solar cell module of the present invention and a first embodiment of a back surface protective sheet used therefor.

  In the solar cell module according to the present embodiment, the back surface protection sheet 13 in FIG. 1 is changed to a back surface protection sheet 43, and the cells 11, the surface sealing material 14, and the surface protection sheet 15 are omitted in FIG. 4.

In the present embodiment, the back surface protection sheet 43 is formed by sequentially laminating the light reflection layer 17 and the wavelength conversion layer 16 on one surface of the base material sheet 18.
The back surface protection sheet 43 is laminated so that the wavelength conversion layer 16 is in contact with the back surface sealing material 12.

  As the wavelength conversion layer 16, the same solar cell module as that of the first embodiment can be used. However, when EVA is used as the thermoplastic resin, the vinyl acetate content is preferably 3 to 10% by mass.

  The light reflection layer 17 can be the same as that of the second embodiment of the solar cell module.

  As the base material sheet 18, the same thing as what was used for 2nd Embodiment of the solar cell module can be used.

  As a method of laminating the light reflection layer 17 and the wavelength conversion layer 16 on one surface of the base material sheet 18, a method of laminating through the adhesive layer, or one of the base material sheets 18 without using the adhesive layer. A method of coextruding the melted light reflecting layer 17 and the wavelength conversion layer 16 (coextrusion coating) can be mentioned.

(2nd Embodiment of the back surface protection sheet for solar cell modules)
The back surface protective sheet of the present invention can be provided with a fluororesin layer on the surface of the base sheet 18 opposite to the light reflecting layer 17.

  The fluororesin layer is not particularly limited as long as it is a layer containing fluorine. As what forms this fluororesin layer, the coating film formed by apply | coating the sheet | seat which consists of fluorine-containing resin, the coating material which consists of fluorine-containing resin, etc. are mentioned, for example.

  When the fluororesin layer is a sheet made of a fluorine-containing resin, the fluororesin layer is laminated on the base film 18 via the adhesive layer. The adhesive layer is composed of an adhesive having adhesiveness to the base film 18.

  As the adhesive constituting the adhesive layer, polyacrylic adhesives, polyurethane adhesives, epoxy adhesives, polyester adhesives, polyester polyurethane adhesives, and the like are used. These adhesives may be used individually by 1 type, and may be used in combination of 2 or more type.

As the sheet made of a fluorine-containing resin, for example, a sheet in which a resin mainly composed of polyvinyl fluoride (PVF), ethylene chlorotrifluoroethylene (ECTFE), or ethylene tetrafluoroethylene (ETFE) is used is used. .
As the resin mainly composed of PVF, for example, “Tedlar (trade name, manufactured by DuPont)” is used.
For example, “Halar (trade name, manufactured by Solvay Solexis)” is used as the resin mainly composed of ECTFE.
As the resin mainly composed of ETFE, for example, “Fluon (trade name, manufactured by Asahi Glass Co., Ltd.)” is used.

  On the other hand, when the fluororesin layer is a coating film formed by applying a paint comprising a fluorine-containing resin, it is usually formed by directly applying the paint comprising a fluorine-containing resin to the base film 18 without using an adhesive layer. Is done.

  As the fluorine-containing resin contained in the paint, it is preferable to use a fluoroolefin resin having a curable functional group. Examples of the curable functional group include a hydroxyl group, a carboxyl group, an amino group, and a glycidyl group.

  Specifically, as the fluoroolefin resin, “LUMIFLON (trade name, manufactured by Asahi Glass Co., Ltd.)”, “CEFRAL COAT (trade name, manufactured by Central Glass Co., Ltd.)”, “FLUONATE (trade name, manufactured by DIC Corporation)”, etc. Examples thereof include polymers mainly composed of chlorotrifluoroethylene (CTFE) and polymers mainly composed of tetrafluoroethylene (TFE) such as “ZEFFLE (trade name, manufactured by Daikin Industries, Ltd.)”.

  The coating film is preferably cured with a crosslinking agent in order to improve weather resistance and scratch resistance.

  The crosslinking agent is not particularly limited as long as the effects of the present invention are not impaired, and metal chelates, silanes, isocyanates, or melamines are preferably used. Assuming that the back protection sheet is used outdoors for a long period of time, from the viewpoint of weather resistance, aliphatic isocyanates are preferable as the crosslinking agent.

  Since the back surface protection sheet of this embodiment has a fluororesin layer, weather resistance can be improved compared with 1st Embodiment.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

[Example 1]
As shown in FIG. 2, an evaluation sheet in which the back surface sealing material 22 including the wavelength conversion layer 16 and the light reflection layer 17 and the back surface protection sheet 13 were laminated was produced.
As the wavelength conversion layer 16, EVA (vinyl acetate content 28% by mass, manufactured by Sumitomo Chemical Co., Ltd., trade name “Evaate KA30”), organic fluorescent agent (manufactured by BASF, trade name “TINOPAL OB”, maximum absorption wavelength 375 nm, A wavelength conversion sheet having a thickness of 100 μm and made of a resin containing 0.3% by mass of the maximum radiation wavelength (435 nm) was produced.
Further, as the light reflecting layer 17, 5 masses of EVA (vinyl acetate content 28%, manufactured by Sumitomo Chemical Co., Ltd., trade name “Evaate KA30”) and titanium dioxide (made by Ishihara Sangyo Co., Ltd., trade name “Typaque CR-50”) are used. A light-reflecting sheet having a thickness of 100 μm made of a resin containing 1% was prepared.
A 125 μm thick PET sheet (manufactured by Teijin DuPont Films, trade name “Melinex S”) was used as the back surface protective sheet 13.
The light reflection sheet and the wavelength conversion sheet were sequentially laminated on one surface of the PET sheet, and put into a vacuum chamber under the conditions of a pressure of 1 atm, a temperature of 150 ° C., and 15 minutes, thereby producing an evaluation sheet.

[Example 2]
As shown in FIG. 3, an evaluation sheet in which a back surface sealing material 32 including the wavelength conversion layer 16 and a back surface protection sheet 33 including the light reflecting layer 17 on one surface of the base material sheet 18 were laminated.
As the back surface sealing material 32 including the wavelength conversion layer 16, a wavelength conversion sheet was produced in the same manner as in Example 1.
On the base material sheet 18, the 100-micrometer-thick light reflection layer 17 was laminated | stacked by extrusion coating, and the back surface protection sheet 33 was produced.
As the base material sheet 18, a PET sheet having a thickness of 125 μm (manufactured by Teijin DuPont Films, trade name “Melinex S”) was used.
As the light reflection layer 17, 5% by mass of EVA (vinyl acetate content 6 mass%, manufactured by Tosoh Corporation, trade name “Ultrasen 515F”) and titanium dioxide (made by Ishihara Sangyo Co., Ltd., trade name “Typaque CR-50”) The containing resin was used.
A wavelength conversion sheet was laminated on the light reflection layer 17 of the back surface protection sheet 33 and was put into a vacuum chamber under conditions of a pressure of 1 atm, a temperature of 150 ° C., and 15 minutes, thereby producing an evaluation sheet.

[Example 3]
The back surface protection sheet 43 provided with the wavelength conversion layer 16 and the light reflection layer 17 shown in FIG. 4 was produced.
On the base material sheet | seat 18, the 100-micrometer-thick light reflection layer 17 and the 100-micrometer-thick wavelength conversion layer 16 were laminated | stacked by coextrusion coating, and the sheet | seat for evaluation was produced.
As the light reflecting layer 17, EVA (vinyl acetate content: 6% by mass, manufactured by Tosoh Corporation, trade name: “Ultrasen 515F”) and titanium dioxide (made by Ishihara Sangyo Co., Ltd., trade name: “Typaque CR-50”) are contained by 5% by weight. Resin used was used.
As the wavelength conversion layer 16, EVA (vinyl acetate content 6 mass%, manufactured by Tosoh Corporation, trade name “Ultrasen 515F”) and organic fluorescent agent (trade name “TINOPAL OB” manufactured by BASF Corporation) are 0.3 mass. % Containing resin was used.

[Comparative Example 1]
A sheet for evaluation was produced in the same manner as in Example 1 except that the back surface sealing material 22 in Example 1 was changed to a single layer having a thickness of 200 μm and comprising a light reflecting layer containing a wavelength conversion agent. did.
As a single layer, EVA (vinyl acetate content 28% by mass, manufactured by Sumitomo Chemical Co., Ltd., trade name “Evaate KA30”) and organic fluorescent agent (BASF Corporation, trade name “TINOPAL OB”) 0.3 mass %, And a resin containing 5% by mass of titanium dioxide (trade name “Taipeke CR-50” manufactured by Ishihara Sangyo Co., Ltd.) was used.

[Comparative Example 2]
Evaluation was performed in the same manner as in Example 3 except that the wavelength conversion layer 16 and the light reflection layer 17 in Example 3 were changed to a single layer having a thickness of 200 μm and composed of a light reflection layer containing a wavelength conversion agent. A sheet was produced.
As a single layer, EVA (vinyl acetate content 6% by mass, manufactured by Tosoh Corporation, trade name “Ultrasen 515F”) and organic fluorescent agent (BASF Corporation, trade name “TINOPAL OB”) 0.3 mass %, And a resin containing 5% by mass of titanium dioxide (made by Ishihara Sangyo Co., Ltd., trade name “Taipeke CR-50”) was used.

  About each sheet | seat for evaluation produced in the said Examples 1-3 and Comparative Examples 1-2, the reflectance of wavelength 440nm was measured using the spectrocolorimeter (the Konica Minolta company make, CM-3600d) (light source xenon) lamp). The results are summarized in Table 1.

From the result of Table 1, Examples 1-3 which provided the wavelength conversion layer and the light reflection layer independently were compared with Comparative Examples 1-2 which provided the single layer which consists of the light reflection layer containing a wavelength conversion agent. Compared with it, it showed a high reflectance.
Therefore, the power generation amount of the solar cell module can be increased by applying the configuration of the present invention to the solar cell module.

  The present invention relates to a solar cell module having a power generation improvement effect by wavelength conversion and a back surface protection sheet for solar cell module.

DESCRIPTION OF SYMBOLS 10 Solar cell module 11 Solar cell 12,22,32 Back surface sealing material 13,33,43 Back surface protection sheet 14 Surface sealing material 15 Surface protection sheet 16 Wavelength conversion layer 17 Light reflection layer 18 Base material sheet

Claims (9)

In the solar cell module having a structure in which the back surface sealing material and the back surface protection sheet are laminated in order from the cell side on the surface opposite to the light receiving surface of the solar cell,
A solar cell module, wherein a wavelength conversion layer and a light reflection layer are independently provided on the back surface sealing material in this order from the cell side. In the solar cell module having a structure in which the back surface sealing material and the back surface protection sheet are laminated in order from the cell side on the surface opposite to the light receiving surface of the solar cell,
A wavelength conversion layer is provided on the back surface sealing material,
A solar cell module, wherein the back protective sheet is provided with a light reflecting layer. In the solar cell module having a structure in which the back surface sealing material and the back surface protection sheet are laminated in order from the cell side on the surface opposite to the light receiving surface of the solar cell,
The solar cell module, wherein a wavelength conversion layer and a light reflection layer are independently provided on the back surface protection sheet in order from the cell side.   The wavelength conversion layer is a thermoplastic resin containing a wavelength conversion agent that absorbs irradiated light, converts it into light having a wavelength longer than the wavelength of the light, and emits the light. 4. The solar cell module according to any one of 3 above.   The solar cell module according to any one of claims 1 to 4, wherein the light reflection layer is a thermoplastic resin layer containing a white pigment or air bubbles.   A back protective sheet for a solar cell module, wherein a light reflection layer and a wavelength conversion layer are sequentially and independently laminated on one surface of a substrate sheet.   The wavelength conversion layer is a thermoplastic resin containing a wavelength conversion agent that absorbs irradiated light, converts it into light having a wavelength longer than the wavelength of the light, and emits the light. The back surface protection sheet for solar cell modules of description.   The said light reflection layer is a thermoplastic resin layer containing a white pigment or a bubble, or a metal layer, The back surface protection sheet for solar cell modules of Claim 6 or 7 characterized by the above-mentioned.   The back protective sheet for a solar cell module according to any one of claims 6 to 8, wherein a fluororesin layer is laminated on a surface of the base sheet opposite to the light reflecting layer.

Images