Heterojunction cell photovoltaic module

Abstract

The utility model relates to the field of photovoltaic modules, and provides a heterojunction cell photovoltaic module, which comprises a heterojunction cell layer and a packaging adhesive film arranged on at least one side of the heterojunction cell layer, and the packaging adhesive film comprises a light conversion layer. And the PVA layer is tightly combined with the light conversion layer, so that a good oxygen barrier function is provided for the light conversion layer through the PVA layer, the light conversion layer is prevented from losing the light conversion function due to the action of oxygen, and the photoelectric conversion efficiency and the attractive appearance of the photovoltaic module are ensured.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic modules, and in particular to a heterojunction battery photovoltaic module. Background Technique

[0002] The heterojunction battery is fully called a crystalline silicon heterojunction solar cell, which is a new type of solar cell technology that combines the advantages of crystalline silicon cells and thin-film cells. The core of the heterojunction technology lies in utilizing the interfacial characteristics of two different semiconductor materials to form a heterojunction with a high built-in electric field, thereby effectively reducing the recombination rate of electrons and holes and improving the photoelectric conversion efficiency of the solar cell. Compared with traditional homojunction solar cells, the heterojunction technology has a lower surface recombination rate, a higher open-circuit voltage, and better temperature stability.

[0003] The heterojunction battery generally uses an N-type silicon wafer as the substrate. Taking the substrate as the boundary, on the front side of the battery are a transparent conductive oxide film (abbreviated as TCO), a P-type amorphous silicon thin film, and an intrinsic hydrogen-rich amorphous silicon thin film in sequence; on the back side of the battery are a TCO transparent conductive oxide film, an N-type amorphous silicon thin film, and an intrinsic amorphous silicon film in sequence. Research shows that the hydrogen bonds in the intrinsic hydrogen-rich amorphous silicon thin film exist in the form of dangling bonds, and these hydrogen bonds are easily broken by high-energy ultraviolet rays, thereby reducing the surface passivation effect on crystalline silicon.

[0004] Solutions to the above problems: 1. Use an ultraviolet high-cutoff film to intercept ultraviolet rays, but the cost is to abandon the photoelectric conversion power in the ultraviolet band, which is not conducive to improving the photoelectric conversion efficiency. 2. Use a light conversion film to convert ultraviolet light into visible light, which can not only intercept ultraviolet rays but also ensure the photoelectric conversion efficiency. Therefore, the light conversion film has become the preferred solution to protect the heterojunction battery from the influence of ultraviolet rays.

[0005] However, there are various types of light conversion films, mainly depending on the type of light conversion powder used in the light conversion film. The light conversion powder is divided into quantum dot light conversion powder, inorganic rare earth light conversion powder, organic coordination inorganic rare earth light conversion powder, and organic fluorescent pigment. Among them, the organic fluorescent pigment is the most widely used type of light conversion powder due to its excellent comprehensive properties such as good dispersion in the film, better light conversion efficiency, and longer lifespan. However, the organic fluorescent pigment is prone to oxidation and failure, and it will oxidize and fail even when applied in a double-glass photovoltaic module with the best oxygen barrier effect. Especially for the light conversion film at the position where the component junction box is installed, the phenomenon of losing the light conversion function is particularly obvious, resulting in inconsistent appearance colors of the components. Content of the Utility Model

[0006] In order to solve the above problems, the utility model provides a heterojunction battery photovoltaic module, which has the function of preventing the light conversion film from losing its light conversion function, and ensures the photoelectric conversion efficiency and the appearance beauty of the photovoltaic module.

[0007] A heterojunction battery photovoltaic module provided by the present utility model has the following specific technical solutions:

[0008] It includes a heterojunction battery layer, and an encapsulation adhesive film disposed on at least one side of the heterojunction battery layer. The encapsulation adhesive film includes a light conversion layer; and a PVA layer tightly combined with the light conversion layer. In this way, the PVA layer provides a good oxygen barrier function for the light conversion layer.

[0009] The light conversion layer includes organic fluorescent pigments, thus protecting the heterojunction battery and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0010] In some embodiments, the light conversion layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer, or an EMMA layer.

[0011] In some embodiments, the light conversion layer is composed of two adhesive film layers, and the two adhesive film layers are independently one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer, or an EMMA layer.

[0012] In some embodiments, the light conversion layer is composed of three adhesive film layers, and the three adhesive film layers are independently one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer, or an EMMA layer.

[0013] Preferably, the encapsulation adhesive film further includes an adhesive layer tightly attached to the PVA layer.

[0014] Preferably, the bonding strength between the adhesive layer and the heterojunction battery layer is greater than the bonding strength between the PVA layer and the heterojunction battery layer.

[0015] The adhesive layer can improve the bonding strength of the photovoltaic adhesive film to the heterojunction battery layer and ensure the long-term stability of the photovoltaic module.

[0016] In some embodiments, the adhesive layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer, or an EMMA layer.

[0017] Preferably, the encapsulation adhesive film further includes an ultraviolet cutoff layer tightly attached to the PVA layer.

[0018] The ultraviolet cutoff layer includes an ultraviolet cutoff agent, thus intercepting ultraviolet rays and further protecting the heterojunction battery from damage by ultraviolet rays.

[0019] In some embodiments, the ultraviolet cutoff layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer, or an EMMA layer.

[0020] Compared with the prior art, the utility model has the following beneficial effects:

[0021] 1. Through the combination of the light conversion layer and the PVA layer, the PVA layer can effectively block oxygen, prevent oxygen from contacting the organic fluorescent pigment in the light conversion layer 11, avoid the oxidation and failure of the organic fluorescent pigment, thereby further protecting the heterojunction battery and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0022] 2. The addition of the adhesive layer can further improve the bonding strength of the encapsulation film to the heterojunction battery layer, and the bonding strength of the adhesive layer to the heterojunction battery layer is greater than that of the PVA layer to the heterojunction battery layer, further improving the long-term stability of the photovoltaic module.

[0023] 3. The addition of the ultraviolet cut-off layer can not only intercept the ultraviolet rays that the light conversion layer fails to convert, but also ensure that the ultraviolet rays will not reach the heterojunction battery layer once the organic fluorescent pigment in the light conversion layer fails, further protecting the heterojunction battery from damage by ultraviolet rays. Description of the Drawings

[0024] Figure 1 : Schematic diagram of the partial layer structure of the photovoltaic module in an embodiment of the utility model;

[0025] Figure 2 : Schematic diagram of the partial layer structure of the encapsulation film in an embodiment of the utility model;

[0026] Figure 3 : Schematic diagram of the partial layer structure of the encapsulation film in another embodiment of the utility model;

[0027] Figure 4 : Schematic diagram of the partial layer structure of the encapsulation film in still another embodiment of the utility model.

[0028] Marking description in the drawings: 10 - encapsulation film; 11 - light conversion layer; 12 - PVA layer; 13 - adhesive layer; 14 - ultraviolet cut-off layer; 20 - heterojunction battery layer; 30 - front cover plate; 40 - rear cover plate. Detailed Embodiment

[0029] It should be particularly noted that:

[0030] EVA: Abbreviation for ethylene-vinyl acetate copolymer;

[0031] POE: Abbreviation for ethylene-butene copolymer or ethylene-octene copolymer;

[0032] POP: Abbreviation for vinyl polymer grafted polyether polyol;

[0033] PVB: Abbreviation for polyvinyl butyral;

[0034] PP: Abbreviation for polypropylene;

[0035] EAA: Abbreviation for ethylene - acrylic acid copolymer;

[0036] SEBS: Abbreviation for linear triblock copolymer with polystyrene as the end segment and ethylene - butene copolymer obtained by hydrogenating polybutadiene as the middle elastic block;

[0037] PE: Abbreviation for polyethylene;

[0038] EMA: Abbreviation for ethylene - methacrylic acid copolymer;

[0039] EMMA: Abbreviation for ethylene - methyl methacrylate copolymer.

[0040] The technical solutions of the present utility model will be elaborated one by one below in conjunction with the attached drawings and text description.

[0041] As Figure 1 shown, the present utility model provides a heterojunction battery photovoltaic module, which includes a heterojunction battery layer 20, and an encapsulation adhesive film 10 disposed on at least one side of the heterojunction battery layer 20. It also includes a front cover plate 30 disposed on the front surface of the heterojunction battery layer 20 and a rear cover plate 40 disposed on the back surface of the heterojunction battery layer 20. As Figure 2 shown, the encapsulation adhesive film 10 disposed on at least one side of the heterojunction battery layer 20 includes a light conversion layer 11 and a PVA layer 12 tightly combined with the light conversion layer 11.

[0042] By adopting the above - mentioned technical solution, the light conversion layer 11 includes an organic fluorescent pigment, which has the function of converting ultraviolet light into visible light. This visible light can be absorbed by the heterojunction battery and converted into electrical energy without damaging the heterojunction battery pair, thereby protecting the heterojunction battery and ensuring the photoelectric conversion efficiency of the photovoltaic module. However, the organic fluorescent pigment is easily oxidized and decomposed, thus losing the light conversion function. Since it is impossible to achieve absolute oxygen isolation in the photovoltaic module, oxygen will still slowly penetrate into the interior of the photovoltaic module. These oxygen will accelerate the oxidation of the organic fluorescent pigment and cause it to fail. Specifically, after the organic fluorescent pigment fails, it will no longer emit fluorescence, resulting in non - uniform color on the surface of the photovoltaic module. The non - fluorescent areas are darker, and the darker areas are mainly distributed around the perimeter of the module and the area corresponding to the installation position of the junction box, especially the area corresponding to the installation position of the junction box is particularly obvious. Therefore, by setting the PVA layer 12, oxygen can be effectively blocked, preventing oxygen from contacting the organic fluorescent pigment in the light conversion layer 11, avoiding the oxidation and failure of the organic fluorescent pigment, further protecting the heterojunction battery, and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0043] In addition to the light conversion function, the light conversion layer 11 also needs to have adhesive properties, which are mainly imparted by the matrix resin of the light conversion layer 11. Preferably, the light conversion layer 11 is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer or an EMMA layer. The above light conversion layers 11 all have adhesive properties.

[0044] As Figure 3 shown, the encapsulation adhesive film 10 disposed on at least one side of the heterojunction cell layer 20 includes a light conversion layer 11, a PVA layer 12 tightly combined with the light conversion layer 11, and an adhesive layer 13 tightly attached to the PVA layer 12.

[0045] Although the PVA layer 12 has adhesiveness, in order to ensure the long-term stability of the photovoltaic module, adopting the above technical solution can further improve the adhesive strength of the encapsulation adhesive film 10 to the heterojunction cell layer 20, and the adhesive strength of the adhesive layer 13 to the heterojunction cell layer 20 is greater than that of the PVA layer 12 to the heterojunction cell layer 20, further improving the long-term stability of the photovoltaic module.

[0046] Preferably, the adhesive layer 13 is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer or an EMMA layer.

[0047] As Figure 4 shown, the encapsulation adhesive film 10 disposed on at least one side of the heterojunction cell layer 20 includes a light conversion layer 11, a PVA layer 12 tightly combined with the light conversion layer 11, and an ultraviolet cut-off layer 14 tightly attached to the PVA layer 12.

[0048] By adopting the above technical solution, the ultraviolet cut-off layer 14 includes an ultraviolet cut-off agent, and the ultraviolet cut-off agent can absorb ultraviolet rays and play a role in intercepting ultraviolet rays. Setting the ultraviolet cut-off layer 14 can not only intercept the ultraviolet rays that the light conversion layer 11 fails to convert, but also ensure that ultraviolet rays will not reach the heterojunction cell layer 20 once the organic fluorescent pigment in the light conversion layer 11 fails, further protecting the heterojunction cell from damage by ultraviolet rays.

[0049] In addition to the ultraviolet cut-off function, the ultraviolet cut-off layer 14 also needs to have adhesive properties. Preferably, the ultraviolet cut-off layer 14 is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, an SEBS layer, a PE layer, an EMA layer or an EMMA layer.

[0050] The beneficial effects of the technical solution of the present invention are further described below through specific test examples.

[0051] Sample preparation method:

[0052] Lay the front glass, front encapsulation adhesive film, heterojunction battery, back encapsulation adhesive film, and back perforated glass in sequence, and laminate them according to the conventional lamination process. Seal the four sides of the specimen with butyl rubber in a way that does not block the heterojunction battery.

[0053] Test method:

[0054] a) Face the front glass of the specimen towards the light source and place it in the effective irradiation area of the ultraviolet aging test chamber. The test conditions are as follows:

[0055] 1) Ultraviolet spectral distribution: The irradiation intensity between wavelengths of 280 nm and 400 nm is 50 W / m2 to 150 W / m2, and the light uniformity on the surface of the tested specimen is within 15%. The irradiation dose in the 280 nm - 320 nm band accounts for 3% - 10% of the total irradiation dose;

[0056] 2) While irradiating with ultraviolet light, the surface temperature of the specimen in the test chamber is maintained at 60°C ± 5°C;

[0057] 3) Irradiation power accumulation: Accumulate according to the actual irradiation dose received on the surface of the specimen.

[0058] b) Test time: Using the dose meter of the accumulated irradiation power, 120 kWh / m2.

[0059] c) After the test, take out the specimen and restore it for 2 - 4 h in an open environment at 23°C ± 5°C and a relative humidity of less than 75%. Then, use an ultraviolet lamp for visual inspection to observe whether there is a color difference caused by different fluorescence brightness.

[0060] Specimen 1

[0061] In the above sample preparation, the front encapsulation adhesive film includes a light conversion layer and a PVA layer tightly combined with the light conversion layer. The light conversion layer is an EVA layer containing organic fluorescent pigments. The back encapsulation adhesive film is a conventional EVA adhesive film.

[0062] Specimen 2

[0063] In the above sample preparation, the front encapsulation adhesive film includes a light conversion layer, a PVA layer tightly combined with the light conversion layer, and an adhesive layer tightly combined with the PVA layer. The light conversion layer is a POE layer containing organic fluorescent pigments, and the adhesive layer is an EVA layer. The back encapsulation adhesive film is a conventional EVA adhesive film.

[0064] Specimen 3

[0065] In the above sample preparation, the front encapsulation film includes a light conversion layer, a PVA layer tightly bonded to the light conversion layer, and an ultraviolet cut-off layer tightly bonded to the PVA layer. The light conversion layer is an EAA layer containing organic fluorescent pigments; the ultraviolet cut-off layer is an EMA layer containing ultraviolet cut-off agents. The back encapsulation film is a conventional EVA film.

[0066] Specimen 4

[0067] In the above sample preparation, the front encapsulation film includes a light conversion layer, a PVA layer tightly bonded to the light conversion layer, and an ultraviolet cut-off layer tightly bonded to the PVA layer. The light conversion layer is composed of an EVA layer / POE layer / EVA layer, where the EVA layer contains organic fluorescent pigments; the ultraviolet cut-off layer is an EMA layer containing ultraviolet cut-off agents. The back encapsulation film is a conventional EVA film.

[0068] Specimen 5

[0069] In the above sample preparation, the front encapsulation film includes a light conversion layer, a PVA layer tightly bonded to the light conversion layer, and an adhesive layer tightly bonded to the PVA layer. The light conversion layer is composed of an EVA layer / POE layer, where the EVA layer contains organic fluorescent pigments, and the adhesive layer is an EVA layer. The back encapsulation film is a conventional EVA film.

[0070] Comparative sample 1

[0071] The difference from Specimen 3 is that the front encapsulation film does not include a PVA layer.

[0072] Test results

[0073] Item Specimen 1 Specimen 2 Specimen 3 Specimen 4 Specimen 5 Control Specimen 1 Appearance No color difference No color difference No color difference No color difference No color difference Color difference

[0074] The above test results show that the addition of the PVA layer can effectively prevent oxygen from contacting the light conversion layer, avoid the oxidation and failure of the organic fluorescent pigments in the light conversion layer, ensure the lifespan of the light conversion film to continuously provide the light conversion function, thereby continuously protecting the heterojunction battery and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0075] The above are all preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A heterojunction cell photovoltaic module, comprising a heterojunction cell layer, and a packaging film disposed on at least one side of the heterojunction cell layer, characterized in that: The packaging film includes a light conversion layer; and a PVA layer tightly combined with the light conversion layer, so that the PVA layer provides an oxygen barrier function for the light conversion layer.

2. The heterojunction cell photovoltaic module according to claim 1, characterized in that: The light conversion layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, a SEBS layer, a PE layer, an EMA layer or an EMMA layer.

3. The heterojunction cell photovoltaic module according to claim 1, characterized in that: The light conversion layer is composed of two adhesive film layers, and the two adhesive film layers are independently one of EVA layers, POE layers, POP layers, PVB layers, PP layers, EAA layers, SEBS layers, PE layers, EMA layers or EMMA layers.

4. The heterojunction cell photovoltaic module according to claim 1, characterized in that: The light conversion layer is composed of three adhesive film layers, and the three adhesive film layers are independently one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, a SEBS layer, a PE layer, an EMA layer or an EMMA layer.

5. The heterojunction cell photovoltaic module according to any one of claims 1 to 4, characterized in that: The packaging film also includes an adhesive layer that is tightly attached to the PVA layer.

6. The heterojunction cell photovoltaic module according to claim 5, characterized in that: The bonding layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, a SEBS layer, a PE layer, an EMA layer or an EMMA layer.

7. The heterojunction cell photovoltaic module according to claim 6, characterized in that: The bonding strength between the bonding layer and the heterojunction battery layer is greater than the bonding strength between the PVA layer and the heterojunction battery layer.

8. The heterojunction cell photovoltaic module according to any one of claims 1 to 4, characterized in that: The packaging film also includes an ultraviolet cut-off layer which is tightly attached to the PVA layer.

9. The heterojunction cell photovoltaic module according to claim 8, characterized in that: The ultraviolet cut-off layer is one of an EVA layer, a POE layer, a POP layer, a PVB layer, a PP layer, an EAA layer, a SEBS layer, a PE layer, an EMA layer or an EMMA layer.

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