Reflecting film and photovoltaic module

Abstract

The utility model provides a reflecting film for a photovoltaic module. The reflecting film comprises a reflecting layer, a first microstructure layer, a base film layer, a second microstructure layer and an adhesive film layer, wherein the first microstructure layer is arranged on the surface of one side of the base film layer, the reflecting layer is plated on the surface, away from the base film layer, of the first microstructure layer, the second microstructure layer is arranged on the surface of the other side of the base film layer, and the adhesive film layer is arranged on the surface, away from the base film layer, of the second microstructure layer. The utility model also provides a photovoltaic module using the reflecting film. A plurality of prism and / or pyramid structures are formed on the reflecting film, the light utilization rate of a photovoltaic cell can be increased, meanwhile, the second microstructure layer has high reflectivity and diffuse reflection, the angle application range of incident sunlight is wider, sunlight entering the backboard glass can be more effectively reflected to a backboard cell piece, and the photovoltaic cell piece can be more effectively protected. And the back photovoltaic power generation efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic components, in particular to a reflective film used for a photovoltaic component and a photovoltaic component with the reflective film. Background Art

[0002] In most current photovoltaic modules, the reflective film has a prism structure with aluminum coating on the surface. However, due to the limitation of optical performance, this structure can usually only efficiently reflect incident sunlight with an incident angle of 0-10° to the cell, and the utilization rate is lower for sunlight with a larger incident angle. In particular, the sunlight entering from the back of the module is the reflected light from the ground and other objects, and its incident angle is different from that of the sunlight entering from the front. The incident angle of the reflected light is wider, so the reflective film with an aluminum coating on the surface has a lower utilization rate. Therefore, the back photovoltaic power generation efficiency of the reflective film using the prism aluminum coating solution is not ideal. Utility Model Content

[0003] In view of this, the purpose of the present invention is to provide a reflective film and a photovoltaic module, which can fully utilize the light source in the gap area between the battery cells and improve the back photovoltaic power generation efficiency.

[0004] The utility model adopts the following technical scheme, and provides a reflective film for a photovoltaic module, characterized in that it includes a reflective layer, a first microstructure layer, a base film layer, a second microstructure layer and an adhesive film layer; the first microstructure layer is arranged on one side surface of the base film layer, the reflective layer is plated on the surface of the first microstructure layer away from the base film layer, the second microstructure layer is arranged on the other side surface of the base film layer, and the adhesive film layer is arranged on the surface of the second microstructure layer away from the base film layer.

[0005] Furthermore, the microstructures of the first microstructure layer and the second microstructure layer are arranged in back-to-back orientation.

[0006] Further, the first microstructure layer includes a plurality of first prism and / or pyramid structures, and the second microstructure layer includes a plurality of second prism and / or pyramid structures.

[0007] Furthermore, the first microstructure layer and the second microstructure layer include triangular prisms with a vertex angle of 110°-130°, the arrangement direction of the triangular prisms in the first microstructure layer is parallel to the triangular prisms in the second microstructure layer, and the arrangement direction of the triangular prisms forms an angle of 30°-60° with the X-axis direction of the plane.

[0008] Furthermore, particles are uniformly dispersed in the second microstructure layer, the particle size of the particles is 500 nm-2 μm, and the mass ratio of the second microstructure layer to the particles is 2:1-5:8.

[0009] Furthermore, the particles are inorganic particles, and the material of the inorganic particles includes any one or a combination of aluminum oxide, barium sulfate, calcium carbonate, and titanium dioxide.

[0010] Furthermore, the thickness of the first microstructure layer and the second microstructure layer is 10 μm-20 μm.

[0011] Furthermore, the thickness of the reflective layer is 30nm-500nm, the thickness of the base film layer is 18μm-100μm, and the thickness of the adhesive film layer is 60μm-80μm.

[0012] Furthermore, the total thickness of the reflective layer, the first microstructure layer, the base film layer, the second microstructure layer and the adhesive film layer is 100 μm-150 μm.

[0013] The utility model also provides a photovoltaic module, on which the above-mentioned reflective film is pasted.

[0014] The reflective film provided by the utility model has a double-layer microstructure layer structure, and the second microstructure layer is a microstructure layer made of a mixture of light-curing glue and inorganic particles, wherein the light-curing glue has better reflective performance than the surface aluminum-plated prism structure in the reflective film of the prior art after curing, and the inorganic particles mixed in the light-curing glue can form a uniform rough surface outside the second microstructure layer, so that the incident light within a larger angle range can be reflected by the undulating structure of the rough surface to the back panel solar cell. Therefore, compared with the prior art, the reflective film provided by the utility model can improve the reflectivity of the reflective film and further improve the back photovoltaic power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic cross-sectional view of a reflective film provided in the first embodiment of the utility model.

[0017] Figure 2 A schematic cross-sectional view of a reflective film provided in accordance with a second embodiment of the present invention.

[0018] In the figure: 1, reflective layer; 2, first microstructure layer; 3, base film layer; 4, second microstructure layer; 41, inorganic particles; 5, adhesive film layer; 6, reflective film. DETAILED DESCRIPTION

[0019] The specific embodiments of the utility model will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the description of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] First embodiment

[0021] like Figure 1 As shown, the first preferred embodiment of the utility model provides a reflective film 6A for a photovoltaic module, which is used to be attached to a cell to form a photovoltaic module. It includes a reflective layer 1, a first microstructure layer 2, a base film layer 3, a second microstructure layer 4A and an adhesive film layer 5; the first microstructure layer 2 is arranged on one side surface of the base film layer 3, the reflective layer 3 is plated on the surface of the first microstructure layer 2 away from the base film layer, the second microstructure layer 4A is arranged on the other side surface of the base film layer 3, and the adhesive film layer 5 is arranged on the surface of the second microstructure layer 4A away from the base film layer.

[0022] The reflective layer 1 can be made of metal materials such as aluminum, silver, and indium. The processing method can be evaporation and magnetron sputtering. The thickness can be 30nm-500nm, preferably 50nm. The first microstructure layer 2 includes a plurality of first prisms and / or pyramid structures, and the first prisms and / or pyramid structures are pressed by a embossing roller with a photocuring glue, including a triangular prism with a vertex angle of 110°-130°, wherein the vertex angle is preferably 120°, and the angle is preferably 45°. The thickness of the first microstructure layer 2 is 10μm-20μm. The base film layer 3 is a PET chemical film, and the thickness can be 18μm-100μm, preferably 23μm. The second microstructure layer 4A includes a plurality of second prisms and / or pyramid structures, and the second prisms and / or pyramid structures are pressed by a embossing roller after mixing the photocuring glue with the inorganic particles 41, including a triangular prism with a vertex angle of 110°-130°, wherein the vertex angle is preferably 120°. The microstructures of the first microstructure layer 2 and the second microstructure layer 4A are arranged in reverse, the microstructure protrusions of the first microstructure layer 2 are upward, and the microstructure protrusions of the second microstructure layer 4A are downward. The triangular prisms of the first microstructure layer 2 and the triangular prisms of the second microstructure layer 4A are arranged in the same direction, and the two are parallel to each other in the upper and lower spaces, and the arrangement directions of the two are both at an angle of 30°-60° with the X-axis direction of the plane, and the angle is preferably 45°. The oblique triangular prism-shaped microstructure arrangement can make light enter the silicon wafer better, increase the total amount of reflected light entering the photovoltaic silicon wafer, and thus improve the power generation efficiency. The second microstructure layer 4A is a microstructure layer made of a mixture of photocurable adhesive and inorganic particles 41, the inorganic particles 41 include any one or combination of aluminum oxide, barium sulfate, calcium carbonate, and titanium dioxide, and the particle size is 500nm-2μm. The mass ratio of the second microstructure layer to the inorganic particles is 2:1-5:8. Specifically, the mass content ratio of the second microstructure layer 4A to the inorganic particles 41 is shown in the following table. The thickness of the second microstructure layer 4A is 10 μm-20 μm. The material of the adhesive film layer 5 can be EVA or POE, with a crosslinking degree of 65%-80%, and a thickness of 60 μm-80 μm, preferably 70 μm. The total thickness of the reflective layer 1, the first microstructure layer 2, the base film layer 3, the second microstructure layer 4A and the adhesive film layer 5 can be 100 μm-150 μm, preferably 129 μm.

[0023] The reflective film of the first embodiment described above can be manufactured by the following specific method: First, a PET chemical film is used to make a base film layer 3. A transparent UV glue is coated on one side of the base film layer 3, and the transparent UV glue is embossed by a UV molding device to form a triangular prism-shaped microstructure, which is cured to form a first microstructure layer 2. Then, metal materials such as aluminum, silver, and indium are plated on the surface of the first microstructure layer 2 by evaporation or magnetron sputtering to form a reflective layer 1. The other side of the base film layer 3 is coated with UV glue to which inorganic particles 41 are added, wherein the content ratio of the inorganic particles 41 to the UV glue is shown in the following table, and the transparent UV glue is embossed by a UV molding device to form a triangular prism-shaped microstructure, which is cured to form a second microstructure layer 4A. EVA is sprayed on the surface of the second microstructure layer 2 to form a glue film layer 5, thereby forming a whole reflective film 6A. Finally, the reflective film is cut into narrow strips with a width of 5mm-7mm (preferably 6mm) by a slitting machine, which can be used to be attached to the battery cell.

[0024] First Example Glue and Inorganic Particle Content

[0025]

[0026] Second embodiment

[0027] like Figure 2 As shown, the first preferred embodiment of the utility model provides a reflective film 6B for a photovoltaic module, which is used to be attached to a cell to form a photovoltaic module. It includes a reflective layer 1, a first microstructure layer 2, a base film layer 3, a second microstructure layer 4B and an adhesive film layer 5; the first microstructure layer 2 is arranged on one side surface of the base film layer 3, the reflective layer 3 is plated on the surface of the first microstructure layer 2 away from the base film layer, the second microstructure layer 4B is arranged on the other side surface of the base film layer 3, and the adhesive film layer 5 is arranged on the surface of the second microstructure layer 4B away from the base film layer.

[0028] The specific features of the reflective layer 1, the first microstructure layer 2, the base film layer 3, and the adhesive film layer 5 are the same as the corresponding components in the reflective film described in the previous embodiment, and no further description is required here. The second microstructure layer 4B includes a plurality of second prisms and / or pyramid structures, and the second prisms and / or pyramid structures are formed by mixing the photocurable glue and the inorganic particles 41 and then being pressed by an embossing roller, including triangular prisms with a vertex angle of 110°-130°, wherein the vertex angle is preferably 120°. The microstructures of the first microstructure layer 2 and the second microstructure layer 4B are arranged back to back. The triangular prisms of the first microstructure layer 2 are parallel to the arrangement direction of the triangular prisms of the second microstructure layer 4B, and the arrangement direction of the triangular prism-shaped microstructure is at an angle of 30°-60° with the X-axis direction of the plane, and the angle is preferably 45°. The second microstructure layer 4B is a microstructure layer made of a mixture of a photocurable adhesive and inorganic particles 41. The inorganic particles 41 include any one or a combination of aluminum oxide, barium sulfate, calcium carbonate, and titanium dioxide, with a particle size of 500nm-2μm. The mass ratio of the second microstructure layer to the inorganic particles is 2:1-5:8. Specifically, the mass content ratio of the second microstructure layer 4B to the inorganic particles 41 is shown in the following table. The thickness of the second microstructure layer 4A is 10μm-20μm. The total thickness of the reflective layer 1, the first microstructure layer 2, the base film layer 3, the second microstructure layer 4A, and the adhesive film layer 5 can be 100μm-150μm, preferably 129μm.

[0029] The reflective film of the second embodiment described above can be manufactured by the following specific method: First, a PET chemical film is used to make a base film layer 3. A transparent UV glue is coated on one side of the base film layer 3, and the transparent UV glue is embossed by a UV molding device to form a triangular prism-shaped microstructure, which is cured to form a first microstructure layer 2. Then, metal materials such as aluminum, silver, and indium are plated on the surface of the first microstructure layer 2 by evaporation or magnetron sputtering to form a reflective layer 1. The other side of the base film layer 3 is coated with UV glue to which inorganic particles 41 are added, wherein the content ratio of the inorganic particles 41 to the UV glue is shown in the following table, and the transparent UV glue is embossed by a UV molding device to form a triangular prism-shaped microstructure, which is cured to form a second microstructure layer 4B. EVA is sprayed on the surface of the second microstructure layer 2 to form a glue film layer 5, thereby forming a whole reflective film 6B. Finally, the reflective film is cut into narrow strips with a width of 5mm-7mm (preferably 6mm) by a slitting machine, which can be used to be attached to the battery cell.

[0030] Second Example: Glue and Inorganic Particle Content

[0031] Element content UV glue 50％ Alumina 15％ Titanium Dioxide 30％ Additives 5％

[0032] Comparative Example

[0033] The applicant also provides a reflective film as a comparative example of the utility model scheme based on the prior art, including a reflective layer, a microstructure layer, a base film layer and an adhesive film layer; the microstructure layer is arranged on the two side surfaces of the base film layer, the reflective layer is plated on the surface of the microstructure layer away from the base film layer, and the adhesive film layer is arranged on the surface of the microstructure layer on the other side away from the base film layer.

[0034] The reflective layer material is a metal material such as aluminum, silver, and indium. The processing method can be evaporation and magnetron sputtering. The thickness can be 30nm-500nm, preferably 50nm. The microstructure layer includes a plurality of prisms and / or pyramid structures, and the prisms and / or pyramid structures are pressed by a photocuring glue through an embossing roller, including a triangular prism with a vertex angle of 110°-130°, wherein the vertex angle is preferably 120°, and the arrangement direction of the triangular prism-shaped microstructure is 30°-60° with the X-axis direction of the plane, and the angle is preferably 45°. The base film layer can be a PET chemical film, and the thickness can be 18μm-100μm, preferably 23μm. The adhesive film layer material can be EVA or POE, with a crosslinking degree of 65%-80%, and a thickness of 60μm-80μm, preferably 70μm. The total thickness of the reflective layer, microstructure layer, base film layer, microstructure layer, and adhesive film layer can be 100μm-150μm, preferably 129μm.

[0035] The reflective film of the above comparative example can be manufactured by the following specific method: first, a PET chemical film is used to make a base film layer. Transparent UV glue is applied to the surfaces of both sides of the base film layer, and the transparent UV glue is embossed by UV molding equipment to form a triangular prism-shaped microstructure, which is cured to form a microstructure layer. Then, metal materials such as aluminum, silver, and indium are plated on the surface of the microstructure layer by evaporation or magnetron sputtering to form a reflective layer. EVA is sprayed on the surface of the microstructure layer to form a film layer, thus forming a whole reflective film. Finally, the reflective film is cut into narrow strips with a width of 5mm-7mm (preferably 6mm) by a slitting machine, which can be used to be attached to the battery cell.

[0036] The applicant attached the three reflective films provided in the first embodiment, the second embodiment and the comparative example to the same solar cell respectively, and then performed performance tests on the back reflectivity and component gain of the three reflective films under the same front reflectivity conditions. The test results are shown in the following table.

[0037] Performance Test Results

[0038] performance Embodiment 1 Embodiment 2 Comparative Example thickness 129μm 129μm 129μm Front reflectivity 85％ 85％ 85％ Back reflectivity 85％ 88％ 85％ Component Gain 1.5％ 1.62％ 1.35％

[0039] As mentioned above, in the prior art of this industry, the reflective film has a prism structure with aluminum coating on the surface. However, due to the limitation of optical performance, this structure can usually only efficiently reflect incident sunlight with an incident angle of 0-10° to the solar cell, and the utilization rate of sunlight with a larger incident angle is lower. In particular, the sunlight entering from the back of the module is the reflected light from the ground and other objects, and its incident angle is different from that of the sunlight entering from the front. The incident angle of the reflected light is wider, so the reflective film with an aluminum coating on the surface has a lower utilization rate. Therefore, the back photovoltaic power generation efficiency of the reflective film using the prism aluminum coating solution is not ideal. In view of the above problems, the reflective film provided by the utility model is mixed with UV glue and inorganic particles to obtain a second prism and / or pyramid structure, and the second microstructure layer is a microstructure layer made of a mixture of photocurable glue and inorganic particles, wherein the photocurable glue has better reflective performance than the surface aluminum-plated prism structure in the reflective film of the prior art after curing, and the inorganic particles mixed in the photocurable glue can form a uniform rough surface outside the second microstructure layer, so that the incident light within a larger angle range can be reflected by the undulating structure of the rough surface to the back panel cell. Therefore, the reflective film provided by the utility model can improve the reflectivity of the reflective film compared with the prior art, and further improve the back photovoltaic power generation efficiency. In addition, through the test results, by comparing the first embodiment with the comparative example, it is found that when the inorganic particles have the same reflectivity, the gain of the photovoltaic module is improved; by comparing the first embodiment with the second embodiment, it is found that when the reflectivity is further improved, the gain of the photovoltaic module will continue to increase.

[0040] Third embodiment

[0041] Another embodiment of the utility model provides a photovoltaic module, which is cross-coated with the reflective film in the first embodiment. The reflective film used in this embodiment is obtained by mixing UV glue and inorganic particles to obtain a second prism and / or pyramid structure, and the second microstructure layer is a microstructure layer made by mixing photocuring glue and inorganic particles, wherein the photocuring glue has better reflective performance than the surface aluminum-plated prism structure in the reflective film of the prior art after curing, and the inorganic particles mixed in the photocuring glue can form a uniform rough surface outside the second microstructure layer, so that the incident light within a larger angle range can be reflected by the undulating structure of the rough surface to the back panel cell. Therefore, compared with the prior art, the reflective film provided by the utility model can improve the reflectivity of the reflective film and further improve the back photovoltaic power generation efficiency. The photovoltaic module in this embodiment has a higher power generation efficiency.

[0042] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A reflective film for a photovoltaic module, characterized in that: It includes a reflective layer, a first microstructure layer, a base film layer, a second microstructure layer and an adhesive film layer; the first microstructure layer is arranged on one side surface of the base film layer, the reflective layer is plated on the surface of the first microstructure layer away from the base film layer, the second microstructure layer is arranged on the other side surface of the base film layer, and the adhesive film layer is arranged on the surface of the second microstructure layer away from the base film layer.

2. The reflective film according to claim 1, characterized in that The microstructures of the first microstructure layer and the second microstructure layer are arranged in back-to-back orientation.

3. The reflective film according to claim 1, characterized in that The first microstructure layer includes a plurality of first prism and / or pyramid structures, and the second microstructure layer includes a plurality of second prism and / or pyramid structures.

4. The reflective film according to claim 3, characterized in that The first microstructure layer and the second microstructure layer include triangular prisms with a vertex angle of 110°-130°. The arrangement direction of the triangular prisms in the first microstructure layer is parallel to that of the second microstructure layer, and the arrangement direction of the triangular prisms forms an angle of 30°-60° with the X-axis direction of the plane.

5. The reflective film according to claim 1, characterized in that Particles are uniformly dispersed in the second microstructure layer, the particle size of the particles is 500nm-2μm, and the mass ratio of the second microstructure layer to the particles is 2:1-5:

8.

6. The reflective film according to claim 5, characterized in that The particles are inorganic particles, and the material of the inorganic particles includes any one or a combination of aluminum oxide, barium sulfate, calcium carbonate, and titanium dioxide.

7. The reflective film according to claim 1, characterized in that The thickness of the first microstructure layer and the second microstructure layer is 10 μm-20 μm.

8. The reflective film according to claim 1, characterized in that The thickness of the reflective layer is 30nm-500nm, the thickness of the base film layer is 18μm-100μm, and the thickness of the adhesive film layer is 60μm-80μm.

9. The reflective film according to claim 1, characterized in that The total thickness of the reflective layer, the first microstructure layer, the base film layer, the second microstructure layer and the adhesive film layer is 100 μm-150 μm.

10. A photovoltaic module, characterized in that: The photovoltaic module is covered with a reflective film as described in any one of claims 1 to 9.

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