Light trapping film

Abstract

The utility model discloses a light trapping film, which effectively reduces the manufacturing procedures of a photovoltaic cell, enables the manufacturing of the photovoltaic cell to be fast and efficient, and reduces the energy consumption and pollution problems of the manufacturing of the photovoltaic cell. The film comprises a film body which continuously expands in four directions, a plurality of convex shapes are continuously arranged on the surface of the film body, and the film body comprises a first connecting layer, a base material layer, a structural layer and a second connecting layer which are sequentially compounded from top to bottom in the thickness direction. The upper convex model is of a microscopic pyramid structure or crater structure, the base material layer is made of a transparent high polymer material with the refractive index of 1.5-1.9, and the structural layer is a curing adhesive layer; the first connecting layer and the second connecting layer are polyolefin elastomer layers.

Description

Technical Field

[0001] This utility model relates to the technical field of photovoltaic cell materials, specifically a light-trapping film. Background Technology

[0002] The manufacturing process of photovoltaic cells generally includes multiple steps such as texturing, diffusion, SE laser doping, etching, oxidation, coating, laser, screen printing, and sintering. Among them, texturing is a process that uses alkaline etching to create light-trapping structures on the surface of silicon wafers, thereby increasing the absorption rate of sunlight by the silicon wafers and thus improving the efficiency of the cells.

[0003] The texturing process for photovoltaic cells is relatively complex, involving steps such as rough polishing, pre-cleaning, pure water washing, alkaline texturing, pure water washing, acid washing, pure water washing, and drying. This process is cumbersome and costly. It also requires the use of strong alkalis and acids such as sodium hydroxide, hydrochloric acid, nitric acid, and hydrofluoric acid, generating waste gases such as hydrogen chloride, hydrogen fluoride, and hydrogen, as well as wastewater such as alkaline washing wastewater and acid washing waste acid. This is a high-energy-consuming and highly polluting manufacturing process.

[0004] Therefore, there is an urgent need for a light-trapping film that can be obtained directly without the need for a texturing process, thereby reducing energy consumption and pollution problems. Utility Model Content

[0005] To address the aforementioned problems, this invention provides a light-trapping film that effectively reduces the manufacturing process of photovoltaic cells, making the production of photovoltaic cells faster and more efficient, while also reducing energy consumption and pollution issues in the production of photovoltaic cells.

[0006] A light-trapping film, characterized in that: it comprises a four-dimensionally continuously extended film body, and a plurality of upwardly convex shapes are disposed on the surface of the film body, the upwardly convex shapes being continuously disposed on the surface of the film body; the film body comprises a first connecting layer, a substrate layer, a structural layer, and a second connecting layer sequentially compounded from top to bottom in the thickness direction; the upwardly convex shapes are microscopic pyramid structures or crater structures; the substrate layer is a transparent polymer material with a refractive index of 1.5 to 1.9; the structural layer is a cured adhesive layer; the first connecting layer and the second connecting layer are both polyolefin elastomer layers.

[0007] Its further features are:

[0008] The transparent polymer material is one or a mixture of polycarbonate, polystyrene, and transparent nylon with a refractive index of 1.5 to 1.9, wherein the refractive index of the mixture is 1.5 to 1.9.

[0009] The cured adhesive layer is one or a mixture of epoxy resin, acrylic resin, polyurethane resin, and phenolic resin.

[0010] The polyolefin elastomer layer is one or a mixture of ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer.

[0011] The convex shapes are arranged in a continuous manner;

[0012] Alternatively, the convex shapes can be spaced apart by a flat membrane portion;

[0013] When the upward convex shape is a pyramid shape, the pyramid shape includes a base edge and several triangular surface regions connected from the base plate to the vertex. The base edge is the bottom mechanism of the membrane body, and the base edge encloses and forms a regular polygon.

[0014] The regular polygon has 3 to 8 sides;

[0015] The base side length of the regular polygon is 0.05-50 μm;

[0016] When the convex shape is a crater structure, the crater structure includes a regular polygonal base that is close to the membrane, a regular polygonal top that is away from the membrane, and several trapezoids that connect the regular polygonal base to the regular polygonal top. The regular polygonal base and the regular polygonal top have the same number of sides and the corresponding sides are arranged one-to-one. The upper surface of the regular polygonal top is a flat top or a concave top.

[0017] The number of sides of the regular polygon base is 3-8; the side length of the regular polygon base is 0.05-50um; the number of sides of the regular polygon vertices is 3-8; the side length of the regular polygon vertices is 0.05-25um.

[0018] Additives are added to the materials of the first connecting layer, the substrate layer, the structural layer, and the second connecting layer. The additives are one or more of the following: ultraviolet absorbers, light stabilizers, dispersants, and leveling agents.

[0019] The thickness of the substrate layer is 1-100um, the thickness of the structural layer is 1-20um, and the thickness of the first connecting layer and the second connecting layer is the same, both being 1-100um.

[0020] With the structure of this utility model, a number of convex shapes are directly formed on the surface of the light-trapping film, and the convex shapes are continuously arranged on the surface of the film. This allows the surface of the film to be prefabricated with various light-trapping structures, eliminating the need for texturing processes and enabling subsequent processing. This effectively reduces the manufacturing process of photovoltaic cells, making the manufacturing of photovoltaic cells faster and more efficient, and reducing energy consumption and pollution problems in the production of photovoltaic cells. Attached Figure Description

[0021] Figure 1 This is a cross-sectional schematic diagram of the membrane of this utility model;

[0022] Figure 2 This is a perspective view of a specific embodiment of the present utility model;

[0023] Figure 3 This is a schematic diagram of the convex shape of a specific embodiment of the present utility model;

[0024] Figure 4 This is a perspective view of a specific embodiment two of the present utility model;

[0025] Figure 5 This is a schematic diagram of the convex shape in a specific embodiment two of this utility model;

[0026] The names corresponding to the serial numbers in the diagram are as follows:

[0027] Membrane 10, convex shape 20, base edge 201, vertex 202, triangular region 203, regular polygon base 204, regular polygon apex 205, trapezoid 206, first connecting layer 30, substrate layer 40, structural layer 50, second connecting layer 60. Detailed Implementation

[0028] A light-trapping film, see Figures 1-5 It includes a four-dimensionally continuously extended membrane 10, with a plurality of upwardly protruding shapes 20 disposed on the surface of the membrane 10. The upwardly protruding shapes 20 are continuously disposed on the surface of the membrane 10. The membrane 10 includes a first connecting layer 30, a substrate layer 40, a structural layer 50, and a second connecting layer 60 sequentially composited from top to bottom in the thickness direction. The upwardly protruding shapes 20 are microscopic pyramid structures or crater structures. The substrate layer 40 is a transparent polymer material with a refractive index of 1.5 to 1.9. The structural layer 50 is a cured adhesive layer. The first connecting layer 30 and the second connecting layer 60 are both polyolefin elastomer layers.

[0029] In specific implementation, the transparent polymer material is one or a mixture of polycarbonate, polystyrene, and transparent nylon with a refractive index of 1.5 to 1.9, and the refractive index of the mixture is 1.5 to 1.9.

[0030] The cured adhesive layer is one or a mixture of epoxy resin, acrylic resin, polyurethane resin, and phenolic resin.

[0031] The polyolefin elastomer layer is one or a mixture of ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer.

[0032] Additives are added to the materials of the first connecting layer 30, the substrate layer 40, the structural layer 50, and the second connecting layer 60. The additives are one or more of the following: ultraviolet absorbers, light stabilizers, dispersants, and leveling agents.

[0033] The thickness of the substrate layer 40 is 1-100um, the thickness of the structural layer 50 is 1-20um, and the thickness of the first connecting layer 30 and the second connecting layer 60 is the same, both being 1-100um.

[0034] In a specific embodiment, the convex shapes 20 are arranged in a continuous manner. The convex shapes are pyramid shapes. The pyramid shapes include a base edge 201 and several triangular surfaces 203 connected from the base plate to the apex 202. The base edge 201 is the bottom mechanism of the membrane 10. The base edge 201 encloses and forms a regular polygon. The number of sides of the regular polygon is 4. The side length of the base edge of the regular polygon is 0.05-50um.

[0035] In a specific embodiment 2, the convex shapes 20 are spaced apart by flat membrane bodies 10; the convex shapes 20 are crater structures, which include a regular polygonal base 204 closely attached to the membrane body, a regular polygonal top 205 away from the membrane body, and a number of trapezoids 206 connected from the regular polygonal base to the regular polygonal top. The regular polygonal base 204 and the regular polygonal top 205 have the same number of sides and the corresponding sides are arranged one-to-one. The upper surface of the regular polygonal top 204 is a flat top or a concave top.

[0036] The base of the regular polygon 204 has 4 sides and the side length of the base of the regular polygon 204 is 0.05-50um. The top of the regular polygon 205 has 4 sides and the side length of the top of the regular polygon 205 is 0.05-25um.

[0037] Its beneficial effects are as follows: Several convex shapes are directly formed on the surface of the light-trapping film, and the convex shapes are continuously set on the surface of the film. This allows the surface of the film to be prefabricated with various light-trapping structures, eliminating the need for texturing processes and enabling subsequent processing. This effectively reduces the manufacturing process of photovoltaic cells, making the manufacturing of photovoltaic cells faster and more efficient, and reducing energy consumption and pollution problems in the production of photovoltaic cells.

[0038] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A light-trapping film, characterized in that: It includes a four-dimensionally continuously extended membrane body, on which a plurality of upwardly convex shapes are provided. The upwardly convex shapes are continuously disposed on the surface of the membrane body. The membrane body includes a first connecting layer, a substrate layer, a structural layer, and a second connecting layer sequentially compounded from top to bottom in the thickness direction. The upwardly convex shapes are microscopic pyramid structures or crater structures. The substrate layer is a transparent polymer material with a refractive index of 1.5 to 1.

9. The structural layer is a cured adhesive layer. The first connecting layer and the second connecting layer are both polyolefin elastomer layers.

2. The light-trapping film according to claim 1, characterized in that: The convex shapes are arranged in a continuous pattern.

3. The light-trapping film according to claim 1, characterized in that: The convex shapes are spaced apart by flat film sections.

4. A light-trapping film according to claim 2 or 3, characterized in that: When the upward convex shape is a pyramid shape, the pyramid shape includes a base edge and several triangular surface regions connected from the base plate to the vertex. The base edge is the bottom structure of the membrane body, and the base edge encloses and forms a regular polygon.

5. A light-trapping film according to claim 2 or 3, characterized in that: When the convex shape is a crater structure, the crater structure includes a regular polygonal base that is close to the membrane, a regular polygonal top that is away from the membrane, and several trapezoids that connect the regular polygonal base to the regular polygonal top. The regular polygonal base and the regular polygonal top have the same number of sides and the corresponding sides are arranged one-to-one. The upper surface of the regular polygonal top is a flat top or a concave top.

6. The light-trapping film according to claim 1, characterized in that: The thickness of the substrate layer is 1-100um, the thickness of the structural layer is 1-20um, and the thickness of the first connecting layer and the second connecting layer is the same, both being 1-100um.

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