Contact type grid line, preparation method thereof, solar cell and assembly

Abstract

The invention provides a contact type grid line, a preparation method thereof, a solar cell and a solar module, and relates to the technical field of solar cells, the contact type grid line comprises a silver seed layer and a non-metal material covering layer; wherein the silver seed layer is arranged to be in a cyclodextrin-like shape, and the cyclodextrin-like shape is in a vertical hollow circular truncated cone shape; the non-metal material covering layer covers the side surface of the silver seed layer and is higher than the silver seed layer; and the silver seed layer and the non-metal material covering layer jointly form a cyclodextrin-like shape. According to the invention, the reliability of the grid line can be improved while ultra-low silver consumption is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a contact-type grid line and a preparation method thereof, a solar cell and a component. Background Art

[0002] In recent years, with the growing demand for energy conservation, emission reduction, and renewable energy utilization, solar cells have attracted widespread attention as a clean and efficient new energy conversion technology. In the solar cell manufacturing process, silver paste screen printing is commonly used to create metal electrodes to achieve efficient current transmission.

[0003] However, silver is a precious metal, and the production of metal electrodes requires a large amount of silver paste, significantly increasing the cost of cell production. Furthermore, during operation, traditional silver grid electrodes are susceptible to deformation and corrosion from acetic acid, ultraviolet light, and other factors, which in turn affects cell efficiency and module power generation. Summary of the Invention

[0004] The present invention provides a contact-type grid line and a preparation method thereof, a solar cell and a component, which are used to achieve ultra-low silver consumption and improve the reliability of the grid line.

[0005] The present invention provides a contact-type gate line, comprising: a silver seed layer and a non-metallic material covering layer; wherein the silver seed layer is configured to be a cyclodextrin-like shape, and the cyclodextrin-like shape is a vertical hollow frustum; the non-metallic material covering layer covers the side surfaces of the silver seed layer and is higher than the silver seed layer; the silver seed layer and the non-metallic material covering layer together form the cyclodextrin-like shape.

[0006] According to the contact-type gate line provided by the present invention, the cyclodextrin-like hollow portion is cylindrical.

[0007] According to a contact-type grid line provided by the present invention, the material of the non-metallic material covering layer includes at least one of graphene, conductive ceramics and transparent conductive glass.

[0008] According to a contact-type gate line provided by the present invention, the bottom diameter of the silver seed layer is 5-15 μm, the top diameter is 3-5 μm, and the height is 1-3 μm; the bottom diameter of the non-metallic material covering layer is 10-20 μm, the top diameter is 5-8 μm, and the height is 3-6 μm.

[0009] The present invention also provides a solar cell comprising a plurality of contact grid lines as described above; wherein the plurality of contact grid lines are distributed in an array on the surface of the cell, and the contact grid lines are provided on both the front and back sides of the cell.

[0010] The present invention also provides a solar cell, comprising a plurality of contact-type grid lines as described above; wherein the plurality of contact-type grid lines are distributed in an array on the back of the cell, and the contact-type grid lines serving as positive electrode grid lines and the contact-type grid lines serving as negative electrode grid lines are distributed alternately in columns.

[0011] The present invention also provides a solar cell assembly, which comprises, from the front to the back of the assembly, front glass, front adhesive film, any one of the solar cells described above, back adhesive film and back glass.

[0012] The present invention also provides a method for preparing a contact-type gate line, comprising: Prepare silver seed layer by screen printing on qualified cells before metallization process; The silver seed layer is patterned by an ion etching process or a laser etching process to form a truncated cone structure; The silver seed layer of the truncated cone structure is sintered at high temperature to form a metal semiconductor contact; A precursor material for preparing a non-metallic material covering layer is prepared by a hydration method; Dispersing the precursor material in ethanol according to a first mass ratio, adding an adhesive, uniformly dispersing the precursor material by ultrasonication, and uniformly spraying the precursor material on the surface of the silver seed layer of the truncated cone structure to form a non-metallic material covering layer; Sintering and holding for the first preset time in an argon or nitrogen atmosphere; The non-metallic material covering layer is patterned by ion etching or laser etching to form a truncated cone structure; at the same time, the material at the center is removed to form a cyclodextrin-like contact grid line; the cyclodextrin-like shape is a vertical hollow truncated cone.

[0013] According to a method for preparing a contact-type gate line provided by the present invention, the precursor material of the non-metallic material covering layer is prepared by a hydration method, comprising: Mixing the 2-methylimidazole solution and the cobalt nitrate hexahydrate solution in a second mass ratio and stirring for a second preset time; The precursor material is washed with water and methanol for a preset number of times, centrifuged, and then dried in a vacuum drying oven for a third preset time to obtain the precursor material.

[0014] The present invention provides a contact-type grid line and a preparation method thereof, a solar cell and a component thereof, wherein the contact-type grid line includes: a silver seed layer and a non-metallic material covering layer; wherein the silver seed layer is configured to be a cyclodextrin-like shape, and the cyclodextrin-like shape is a vertical hollow truncated cone; the non-metallic material covering layer covers the side of the silver seed layer and is higher than the silver seed layer; the silver seed layer and the non-metallic material covering layer together form a cyclodextrin-like shape. Since the contact-type grid line only uses silver paste at the contact point, the consumption of silver paste can be reduced; since the contact-type grid line uses a silver seed layer, less silver paste is used than a traditional grid line, which can further reduce the consumption of silver paste; since the interior of the cyclodextrin-like shape is a hollow structure, the consumption of silver paste can be reduced again. Furthermore, since the non-metallic material covering layer is used to isolate ultraviolet rays and acetic acid from the inner silver seed layer, the ultraviolet stability and acetic acid stability can be improved, thereby improving the reliability of the grid line. Therefore, the present invention can achieve ultra-low silver consumption while improving the reliability of the grid line. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 Schematic diagram of the structure of the contact-type gate line provided by an embodiment of the present invention.

[0017] Figure 2 This is one of the distribution diagrams of the battery surface contact grid lines provided by an embodiment of the present invention.

[0018] Figure 3 This is the second schematic diagram of the distribution of the battery surface contact type grid lines provided by an embodiment of the present invention.

[0019] Figure 4 It is a schematic structural diagram of a solar cell assembly provided by an embodiment of the present invention.

[0020] Figure 5 It is a schematic flow chart of a method for preparing a contact-type gate line provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0022] The following combination Figure 1-Figure 5 The invention describes a contact-type grid line and a preparation method thereof, a solar cell and a component.

[0023] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of the contact type gate line provided by the embodiment of the present invention. Figure 1 As shown, the contact-type grid line includes: a silver seed layer 1 and a non-metallic material covering layer 2. The silver seed layer 1 is configured as a cyclodextrin-like shape, which is a vertical hollow truncated cone. The non-metallic material covering layer 2 covers the sides of the silver seed layer 1 and is higher than the silver seed layer 1. The silver seed layer 1 and the non-metallic material covering layer 2 together form a cyclodextrin-like shape.

[0024] This contact-type grid line adopts a triple silver consumption reduction technology: ① Since the contact-type grid line only uses silver paste at the contact point, the consumption of silver paste can be reduced; ② Since the contact-type grid line uses a silver seed layer 1, less silver paste is used than traditional grid lines, which can further reduce the consumption of silver paste; ③ Since the cyclodextrin-like interior is a hollow structure 3, the consumption of silver paste can be further reduced.

[0025] Furthermore, since the non-metallic material covering layer 2 is used to isolate ultraviolet rays and acetic acid from the inner silver seed layer 1, the ultraviolet stability and acetic acid stability can be improved, thereby improving the reliability of the gate line.

[0026] Preferably, the cyclodextrin-like hollow portion 3 is cylindrical, which is easy to prepare, but this embodiment is not limited thereto.

[0027] Optionally, the material of the silver seed layer 1 includes silver (Ag), lead dioxide (PbO2) and additives; the material of the non-metallic material covering layer 2 includes at least one of graphene, conductive ceramics and transparent conductive glass.

[0028] Optionally, the bottom diameter of the silver seed layer 1 is 5-15 μm, the top diameter is 3-5 μm, and the height is 1-3 μm; the bottom diameter of the non-metallic material covering layer 2 is 10-20 μm, the top diameter is 5-8 μm, and the height is 3-6 μm.

[0029] The contact-type gate line provided by the embodiment of the present invention includes: a silver seed layer and a non-metallic material covering layer; wherein the silver seed layer is configured to be a cyclodextrin-like shape, and the cyclodextrin-like shape is a vertical hollow frustum; the non-metallic material covering layer covers the side of the silver seed layer and is higher than the silver seed layer; the silver seed layer and the non-metallic material covering layer together form a cyclodextrin-like shape. Since the contact-type gate line only uses silver paste at the contact point, the consumption of silver paste can be reduced; since the contact-type gate line uses a silver seed layer, less silver paste is used than traditional gate lines, which can further reduce the consumption of silver paste; since the interior of the cyclodextrin-like shape is a hollow structure, the consumption of silver paste can be reduced again. Moreover, since the non-metallic material covering layer is used to isolate ultraviolet rays and acetic acid from the inner silver seed layer, the ultraviolet stability and acetic acid stability can be improved, thereby ensuring the reliability of the gate line. Therefore, the embodiment of the present invention can achieve ultra-low silver consumption while ensuring the reliability of the gate line.

[0030] Furthermore, the cyclodextrin-like contact grid lines can achieve the largest possible contact area while maintaining the same silver consumption, thereby better realizing carrier collection (i.e., current collection).

[0031] Furthermore, the material selected for the non-metallic material covering layer has ultra-high conductivity, which is conducive to carrier transmission (ie, current transmission).

[0032] The embodiment of the present invention improves the grid line structure of the existing TOPCon battery. Figure 2 As shown, an embodiment of the present invention further provides a solar cell, comprising a plurality of contact-type grid lines as described in any one of the above embodiments; wherein the plurality of contact-type grid lines are distributed in an array on the surface of the cell, and contact-type grid lines are provided on both the front and back sides of the cell.

[0033] Optionally, the same or equivalent number of contact grid lines are provided on the front and back of the battery, with the contact grid lines on the front of the battery serving as positive electrode grid lines and the contact grid lines on the back of the battery serving as negative electrode grid lines.

[0034] In this embodiment, the solar cell using contact-type grid lines achieves ultra-low silver consumption while effectively improving the battery's resistance to acetic acid and UV resistance, which can be improved by about 5%-10% compared to traditional batteries.

[0035] The embodiment of the present invention improves the grid line structure of the existing interdigitated back contact (IBC) battery. Figure 3 As shown, an embodiment of the present invention also provides another solar cell, comprising a plurality of contact-type grid lines as described in any one of the above embodiments; wherein the plurality of contact-type grid lines are distributed in an array on the back of the cell, and the contact-type grid lines serving as positive grid lines and the contact-type grid lines serving as negative grid lines are distributed alternately in columns.

[0036] In this embodiment, the solar cell using contact-type grid lines can achieve ultra-low silver consumption while effectively improving the battery's resistance to acetic acid and UV resistance, which can be improved by about 5%-10% compared to traditional batteries; at the same time, the bifaciality of the back contact battery (IBC battery) is greatly improved, which can be increased by 8%-10% compared to traditional battery cells.

[0037] It should be noted that, at the solar cell end, a finished battery can be made in the form of contact-type grid lines, or each column of contact-type grid lines can be interconnected by conductive glue to make a finished battery.

[0038] like Figure 4 As shown, an embodiment of the present invention further provides a solar cell assembly, which includes, from the front to the back of the assembly, a front glass 401, a front adhesive film 402, a solar cell 403 as described in any of the above embodiments, a back adhesive film 404 and a back glass 405.

[0039] If the solar cell is formed into a finished cell in the form of a contact grid line at the solar cell end, then at the module end, each column of the solar cell is interconnected with the contact grid line.

[0040] In one embodiment, at the module end, the outer non-metallic cover layer serves as the busbar. This means that each column of contact-type grid lines in the solar cell is interconnected using conductive adhesive, protecting the silver seed layer while also achieving current convergence. To address light shading issues, transparent conductive glass is the preferred material for the non-metallic cover layer.

[0041] In another embodiment, in order to better adapt to the traditional component end welding equipment, the transparent conductive glass is replaced with a silver-clad non-metallic material on the basis of the above embodiment, which can reduce the silver consumption to a certain extent, but the acetic acid resistance and UV resistance are not as good as the above embodiment.

[0042] Please refer to Figure 5 , Figure 5 FIG. 1 is a flow chart of a method for preparing a contact type gate line according to an embodiment of the present invention. Figure 5 As shown, the method may include steps 501-507.

[0043] Step 501: Prepare a silver seed layer on a qualified cell by screen printing before the metallization process.

[0044] For example, a silver seed layer is prepared by screen printing on a qualified solar cell before the metallization process prepared by conventional technology, and the gate line width is controlled to be 5-15 μm and the height is 3-6 μm, corresponding to a silver paste consumption of 4-10 mg / W.

[0045] Step 502: Pattern the silver seed layer using an ion etching process or a laser etching process to form a truncated cone structure.

[0046] For example, the silver seed layer is patterned by an ion etching process or a laser etching process to obtain a solid truncated cone-shaped structure, with the bottom diameter of the circle controlled at 5-15 μm and the top diameter controlled at 3-5 μm.

[0047] Step 503: Sinter the silver seed layer of the truncated cone structure at a high temperature to form a metal-semiconductor contact.

[0048] For example, the silver seed layer of the truncated cone structure is sintered at a high temperature to form a good metal-semiconductor contact, and the sintering temperature is controlled at 500-800°C.

[0049] Step 504: Prepare a precursor material for the non-metallic material covering layer by using a hydration method.

[0050] Specifically, for a Co-doped graphene material as the precursor material, a 2-methylimidazole solution and a cobalt nitrate hexahydrate solution are mixed in a second mass ratio and stirred for a second preset time; water and methanol are used to wash the mixture for a preset number of times, and after centrifugation, the mixture is dried in a vacuum drying oven for a third preset time to obtain the precursor material.

[0051] For example, the precursor material ZIF-67 of the non-metallic material covering layer is prepared by the hydration method. First, 2-methylimidazole solution and cobalt nitrate hexahydrate solution are mixed in a ratio of 1:1-1:3 and stirred for 30-180 minutes. The mixture is washed with water and methanol 3-5 times each. After centrifugation, the mixture is dried in a vacuum drying oven for 12-24 hours to obtain a clean precursor material ZIF-67.

[0052] Step 505: Disperse the precursor material in ethanol according to the first mass ratio, add an adhesive, uniformly disperse it by ultrasound, and evenly spray it on the surface of the silver seed layer of the truncated cone structure to form a non-metallic material covering layer.

[0053] For example, the precursor material is dispersed in ethanol at a mass ratio of 1:2-1:3, 10-20 μL of adhesive is added, and the material is evenly dispersed by ultrasonication for 30 minutes, and then precisely and evenly sprayed on the surface of the silver seed layer with a truncated cone structure to form a non-metallic material covering layer.

[0054] Step 506: Sintering and holding in an argon or nitrogen atmosphere for a first preset time.

[0055] For example, the sintering is carried out at 600-900° C. in an argon or nitrogen atmosphere for 2 hours (the precursor material is graphitized).

[0056] Step 507: Pattern the non-metallic material covering layer using an ion etching process or a laser etching process to form a truncated cone structure; simultaneously remove the material at the center to form a cyclodextrin-like contact grid line; the cyclodextrin-like shape is a vertical hollow truncated cone.

[0057] For example, the non-metallic material covering layer is patterned using an ion etching process or a laser etching process to form a truncated cone-shaped structure, with the bottom layer diameter controlled at 10-20μm and the upper layer diameter controlled at 5-8μm. Simultaneously, a cylinder with a diameter of 1-2μm at the center is removed (the silver paste can be recycled), forming a cyclodextrin-like contact grid line. The silver paste consumption of this contact grid line can be controlled at 1-3mg / W, while ensuring that the battery efficiency is controlled within 0.2%.

[0058] The present embodiment provides a method for preparing a contact-type grid line. First, a silver seed layer is prepared on a qualified battery cell by screen printing before a metallization process; the silver seed layer is patterned by an ion etching process or a laser etching process to form a truncated cone structure; the silver seed layer with the truncated cone structure is sintered at a high temperature to form a metal-semiconductor contact; then, a precursor material for a non-metallic material covering layer is prepared by a hydration method; the precursor material is dispersed in ethanol according to a first mass ratio, an adhesive is added, and the precursor material is uniformly dispersed by ultrasound and evenly sprayed on the surface of the silver seed layer with the truncated cone structure to form a non-metallic material covering layer; the precursor material is sintered and kept warm for a first preset time in an argon or nitrogen atmosphere; finally, the non-metallic material covering layer is patterned by an ion etching process or a laser etching process to form a truncated cone structure; and at the same time, the material at the center position is removed to form a cyclodextrin-like contact-type grid line; the cyclodextrin-like shape is a vertically hollow truncated cone. Because the contact-type grid lines only use silver paste at the contacts, silver paste consumption can be reduced; because the contact-type grid lines use a silver seed layer, less silver paste is used than traditional grid lines, which can further reduce silver paste consumption; and because the cyclodextrin-like structure has a hollow interior, silver paste consumption can be further reduced. Furthermore, because a non-metallic material covering layer is used to isolate ultraviolet light and acetic acid from the inner silver seed layer, ultraviolet stability and acetic acid stability can be enhanced, thereby improving the reliability of the grid lines. Therefore, the present invention can achieve ultra-low silver consumption while improving the reliability of the grid lines.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A contact type gate line, characterized in that: include: A silver seed layer and a non-metallic material covering layer; wherein the silver seed layer is configured to be a cyclodextrin-like shape, and the cyclodextrin-like shape is a vertical hollow frustum; the non-metallic material covering layer covers the side of the silver seed layer and is higher than the silver seed layer; the silver seed layer and the non-metallic material covering layer together form the cyclodextrin-like shape.

2. The contact gate line according to claim 1, wherein: The cyclodextrin-like hollow part is cylindrical.

3. The contact gate line according to claim 1, wherein: The material of the non-metallic material covering layer includes at least one of graphene, conductive ceramics and transparent conductive glass.

4. The contact gate line according to claim 1, wherein: The bottom diameter of the silver seed layer is 5-15 μm, the top diameter is 3-5 μm, and the height is 1-3 μm; the bottom diameter of the non-metallic material covering layer is 10-20 μm, the top diameter is 5-8 μm, and the height is 3-6 μm.

5. A solar cell, characterized in that: It comprises a plurality of contact-type grid lines according to any one of claims 1 to 4; wherein the plurality of contact-type grid lines are distributed in an array on the surface of the battery, and the contact-type grid lines are provided on both the front and back sides of the battery.

6. A solar cell, characterized in that: It comprises a plurality of contact-type grid lines according to any one of claims 1 to 4; wherein the plurality of contact-type grid lines are distributed in an array on the back of the battery, and the contact-type grid lines serving as positive electrode grid lines and the contact-type grid lines serving as negative electrode grid lines are distributed alternately in columns.

7. A solar cell module, characterized in that: From the front to the back of the component, it includes front glass, front adhesive film, the solar cell according to claim 5 or 6, back adhesive film and back glass.

8. The solar cell assembly according to claim 7, characterized in that Each column of contact-type grid lines in the solar cell is interconnected.

9. A method for preparing a contact type gate line, characterized in that: include: Prepare a silver seed layer by screen printing on qualified cells before metallization process; The silver seed layer is patterned by an ion etching process or a laser etching process to form a truncated cone structure; The silver seed layer of the truncated cone structure is sintered at high temperature to form a metal semiconductor contact; A precursor material for preparing a non-metallic material covering layer is prepared by a hydration method; Dispersing the precursor material in ethanol according to a first mass ratio, adding an adhesive, uniformly dispersing the precursor material by ultrasonication, and uniformly spraying the precursor material on the surface of the silver seed layer of the truncated cone structure to form a non-metallic material covering layer; Sintering and holding for the first preset time in an argon or nitrogen atmosphere; The non-metallic material covering layer is patterned by ion etching or laser etching to form a truncated cone structure; at the same time, the material at the center is removed to form a cyclodextrin-like contact grid line; the cyclodextrin-like shape is a vertical hollow truncated cone.

10. The method for preparing a contact type gate line according to claim 9, wherein: The precursor material for preparing the non-metallic material covering layer by the hydration method includes: Mixing the 2-methylimidazole solution and the cobalt nitrate hexahydrate solution in a second mass ratio and stirring for a second preset time; The precursor material is washed with water and methanol for a preset number of times, centrifuged, and then dried in a vacuum drying oven for a third preset time to obtain the precursor material.

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