Solar cell and photovoltaic module

Abstract

The invention relates to a solar cell, a manufacturing method thereof and a photovoltaic module, at least one of a first grid line electrode on a first surface of the solar cell and a second grid line electrode on a second surface of the solar cell is set to comprise a silver-copper electrode, and the silver-copper electrode is further designed to comprise a silver contact layer and a silver-coated copper layer; on one hand, the silver-copper electrode is connected with the substrate through the silver contact layer, and the silver contact layer and the substrate have good conductivity, so that the silver-copper electrode and the substrate have low contact resistance, and it is ensured that the solar cell has good photoelectric conversion efficiency; and on the other hand, the silver-coated copper layer comprises the silver-coated copper particles and the second silver particles, so that the silver consumption of the first grid line electrode and the second grid line electrode is reduced, the production cost of the solar cell can be effectively reduced, and the competitive activity of the cell can be improved.

Description

[0001] This application is a divisional application of application number 2024111655299 (Solar cells and methods for manufacturing thereof, photovoltaic modules, application date: August 23, 2024). Technical Field

[0002] This disclosure relates to the field of photovoltaic technology, and in particular to a solar cell and its manufacturing method, and a photovoltaic module. Background Technology

[0003] In the field of photovoltaic power generation, TOPCON (Tunnel Oxide Passivated Contact) cells have become the mainstream in the photovoltaic market due to their superior photoelectric conversion performance.

[0004] However, with the rapid development of other solar cells, such as HJT cells and PERC cells, how to reduce the production cost of TOPCON cells and maintain their market competitiveness is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] Therefore, it is necessary to provide a solar cell, its manufacturing method, and a photovoltaic module to address the problem of high cost of existing solar cells.

[0006] In a first aspect, this disclosure provides a solar cell, comprising:

[0007] The substrate includes a first surface and a second surface disposed opposite to each other. The first surface is provided with a first passivation antireflection layer, and the second surface is provided with a second passivation antireflection layer.

[0008] The first gate electrode is disposed on the side of the first passivation antireflection layer away from the first surface, and the first gate electrode at least partially penetrates the first passivation antireflection layer and contacts the substrate;

[0009] The second gate electrode is disposed on the side of the second passivation antireflection layer away from the second surface, and the second gate electrode at least partially penetrates the second passivation antireflection layer and contacts the substrate;

[0010] At least one of the first grid electrode and the second grid electrode includes a silver-copper electrode;

[0011] The silver-copper electrode includes:

[0012] A silver contact layer is disposed on a substrate, and the silver contact layer includes first silver particles;

[0013] A silver-clad copper layer is disposed on a silver contact layer. The silver-clad copper layer is in contact with the substrate through the silver contact layer. The silver-clad copper layer includes silver-clad copper particles and second silver particles.

[0014] The copper component in the silver-copper electrode has a mass content greater than 30%.

[0015] In one embodiment, the diameter of the first silver particle is 5nm-30nm; the diameter of the silver-coated copper particle is 1μm-10μm; and the diameter of the second silver particle is 30nm-100nm.

[0016] In one embodiment, the first gate electrode includes a first main gate, the first main gate is connected to a plurality of first fine gates, the first fine gates penetrate the first passivation antireflection layer and contact the substrate, and at least one of the first main gate and the first fine gates is a silver-copper electrode.

[0017] The second gate electrode includes a second main gate, which is connected to a plurality of second fine gates. The second fine gates penetrate the second passivation antireflection layer and contact the substrate. At least one of the second main gate and the second fine gate is a silver-copper electrode.

[0018] In one embodiment, the number of first gate electrodes is greater than or equal to the number of second gate electrodes.

[0019] In one embodiment, the orthographic projection of the first gate electrode on the substrate overlaps with the orthographic projection of the second gate electrode on the substrate.

[0020] Alternatively, the orthographic projection of the first gate electrode on the substrate and the orthographic projection of the second gate electrode on the substrate are separated by a first distance, which is less than 30 μm.

[0021] Secondly, this disclosure provides a method for manufacturing a solar cell, comprising:

[0022] A substrate is provided, the substrate including a first surface and a second surface disposed opposite to each other, the first surface having a first passivation antireflection layer formed thereon, and the second surface having a second passivation antireflection layer formed thereon;

[0023] A first gate electrode is formed on the side of the first passivation antireflection layer away from the first surface, and the first gate electrode at least partially penetrates the first passivation antireflection layer and contacts the substrate; a second gate electrode is formed on the side of the second passivation antireflection layer away from the second surface, and the second gate electrode at least partially penetrates the second passivation antireflection layer and contacts the substrate.

[0024] At least one of the first grid electrode and the second grid electrode includes a silver-copper electrode;

[0025] The silver-copper electrode includes:

[0026] A silver contact layer is disposed on a substrate, and the silver contact layer includes first silver particles;

[0027] A silver-clad copper layer is disposed on a silver contact layer. The silver-clad copper layer is in contact with the substrate through the silver contact layer. The silver-clad copper layer includes silver-clad copper particles and second silver particles.

[0028] The copper component in the silver-copper electrode has a mass content greater than 30%.

[0029] In one embodiment, the manufacturing method includes:

[0030] Conductive paste for the first gate electrode is printed on the side of the first passivation antireflection layer away from the first surface;

[0031] Conductive paste for the second gate electrode is printed on the side of the second passivation antireflection layer away from the second surface. At least one of the conductive paste for the first gate electrode and the conductive paste for the second gate electrode includes silver-copper paste.

[0032] Dry the conductive paste of the first grid electrode and the conductive paste of the second grid electrode;

[0033] The conductive paste of the dried first gate electrode is subjected to laser sintering treatment, and a first reverse bias voltage is applied between the first gate electrode and the second gate electrode so that the first gate electrode at least partially penetrates the first passivation antireflection layer and contacts the substrate.

[0034] The conductive paste of the dried second gate electrode is subjected to laser sintering treatment, and a second reverse bias is applied between the first and second gate electrodes, so that the second gate electrode at least partially penetrates the second passivation antireflection layer and contacts the substrate.

[0035] In one embodiment, a conductive paste for the first gate electrode is printed on the side of the first passivation antireflection layer away from the first surface, including:

[0036] Conductive paste for the first main gate is printed on the first passivation antireflection layer to form the first main gate;

[0037] Conductive paste for printing a first fine grid on a first passivation antireflection layer to form a first fine grid, and a first main grid connecting multiple first fine grids;

[0038] Wherein, at least one of the conductive paste of the first main gate and the conductive paste of the first fine gate includes silver-copper paste, and at least one of the first main gate and the first fine gate is a silver-copper electrode;

[0039] The conductive paste for the second gate electrode is printed on the side of the second passivation antireflection layer away from the second surface, including:

[0040] The conductive paste of the second main gate is printed on the second passivation antireflection layer to form the first main gate;

[0041] Conductive paste for printing a second fine grid is printed on the second passivation antireflection layer to form the second fine grid, and the second main grid connects multiple second fine grids;

[0042] The conductive paste of the second main gate and the conductive paste of the second fine gate include at least one silver-copper paste, and at least one of the second main gate and the second fine gate is a silver-copper electrode.

[0043] In one embodiment, the silver-copper paste includes silver-coated copper particles, second silver particles, first silver particles, and a binder, wherein the silver-coated copper particles, second silver particles, and first silver particles are dispersed in the binder;

[0044] After drying and laser sintering, the silver-copper paste burns through the first or second passivation and antireflection layer and comes into contact with the substrate. The first silver particles in the silver-copper paste precipitate to the surface of the substrate, forming a silver contact layer in contact with the substrate. The remaining silver-copper paste forms a silver-copper layer on the silver contact layer.

[0045] The diameter of the first silver particle is 5nm-30nm; the diameter of the silver-coated copper particle is 1μm-10μm; and the diameter of the second silver particle is 30nm-100nm.

[0046] Thirdly, this disclosure provides a photovoltaic module, including a solar cell as described in the first aspect, or a solar cell manufactured by a method as described in the second aspect.

[0047] The solar cell and its manufacturing method disclosed herein, as well as the photovoltaic module, wherein at least one of the first grid electrode on the first side and the second grid electrode on the second side of the solar cell is configured to include a silver-copper electrode, and the silver-copper electrode is further designed to include a silver contact layer and a silver-clad copper layer. On the one hand, the silver-copper electrode is connected to the substrate through the silver contact layer, and the silver contact layer and the substrate have good conductivity, so that the silver-copper electrode and the substrate have low contact resistance, which is beneficial to ensuring that the solar cell has good photoelectric conversion efficiency. On the other hand, the silver-clad copper layer includes silver-clad copper particles and second silver particles, which reduces the silver consumption of the first grid electrode and the second grid electrode, effectively reducing the production cost of the solar cell and improving the competitiveness of the cell. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments or conventional technologies of this disclosure, the accompanying drawings used in the description of the embodiments or conventional technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the structure of a solar cell provided in one embodiment;

[0050] Figure 2 This is a schematic diagram of the structure of a silver-copper electrode provided in one embodiment;

[0051] Figure 3 This is a schematic diagram of the structure of a solar cell provided in another embodiment;

[0052] Figure 4 This is a schematic diagram of the structure of a solar cell provided in another embodiment;

[0053] Figure 5 This is a schematic diagram of the structure of a solar cell provided in another embodiment;

[0054] Figure 6 This is a schematic diagram of the structure of a solar cell provided in another embodiment;

[0055] Figure 7 This is a schematic diagram of the orthographic projection of the first gate electrode provided in one embodiment onto the substrate;

[0056] Figure 8 This is a schematic diagram of the orthographic projection of the second gate electrode provided in one embodiment onto the substrate;

[0057] Figure 9 This is a process flow diagram of a method for manufacturing a solar cell provided in one embodiment;

[0058] Figure 10 This is a schematic diagram illustrating the specific steps involved in forming the first gate electrode and the second gate electrode in one embodiment.

[0059] Explanation of reference numerals in the attached figures:

[0060] 10. Substrate; 10a. First surface; 10b. Second surface; 11. First passivation and antireflection layer; 12. Second passivation and antireflection layer; 13. Tunneling layer; 14. Semiconductor doped layer; 20. First gate electrode; 21. First main gate; 22. First fine gate; 30. Second gate electrode; 31. Second main gate; 32. Second fine gate; 50. Silver-copper electrode; 51. Silver contact layer; 52. Silver-coated copper layer; 53. Adhesive layer; 511. First silver particle; 512. Silver-coated copper particle; 513. Second silver particle; d1. First distance. Detailed Implementation

[0061] To facilitate understanding of this disclosure, a more complete description will now be given with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are shown. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0063] As described in the background section, reducing the production cost of TOPCON batteries and maintaining their market competitiveness are pressing issues that need to be addressed by those skilled in the art. In the fabrication of TOPCON batteries, a boron diffusion method is used to form an emitter structure on the first side of the battery. An oxide layer and a doped semiconductor are sequentially formed on the second side to create a composite contact structure. Then, metal electrodes are screen-printed on both the first and second sides of the TOPCON battery.

[0064] Currently, in order to reduce the contact resistance of metal electrodes and improve the conversion efficiency of TOPCON batteries, silver electrodes are usually formed by printing silver paste on the first and second sides of the TOPCON battery. However, the manufacturing cost of this design is difficult to reduce.

[0065] In order to reduce the cost of the metallization process of the first and second sides of the TOPCON battery, other metal pastes, such as aluminum paste, are used to form aluminum electrodes on the first and second sides of the TOPCON battery. However, this will increase the contact resistance of the metal electrodes and affect the conversion efficiency of the TOPCON battery.

[0066] In view of this, this application provides a solar cell and a method for manufacturing the same, as well as a photovoltaic module. At least one of the first grid electrode on the first side and the second grid electrode on the second side of the solar cell is configured to include a silver-copper electrode. Furthermore, the silver-copper electrode is designed to include a silver contact layer and a silver-clad copper layer. On one hand, the silver-copper electrode is connected to the substrate through the silver contact layer, and the silver contact layer has good conductivity with the substrate, resulting in low contact resistance between the silver-copper electrode and the substrate, which is beneficial for ensuring good photoelectric conversion efficiency of the solar cell. On the other hand, the silver-clad copper layer includes silver-clad copper particles and second silver particles, reducing the silver consumption of the first and second grid electrodes, effectively reducing the production cost of the solar cell, and improving the cell's competitiveness.

[0067] According to an exemplary embodiment, this embodiment provides a solar cell, referring to... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6As shown, the solar cell includes a substrate 10, a first grid electrode 20, and a second grid electrode 30; the substrate 10 includes a first surface 10a and a second surface 10b disposed opposite to each other, wherein the second surface 10b can be the back surface 10b.

[0068] The first surface 10a has a first passivation antireflection layer 11, which can be a single layer or multiple layers. For example, the first passivation antireflection layer 11 may include a silicon oxide layer, a nitride layer, or a stacked silicon oxide layer and a silicon nitride layer. The second surface 10b has a second passivation antireflection layer 12, which can be a single layer or multiple layers. For example, the second passivation antireflection layer 12 may include a silicon oxide layer, a nitride layer, or a stacked silicon oxide layer and a silicon nitride layer. A stacked tunneling layer 13 and a semiconductor doped layer 14 are also disposed between the second surface 10b of the substrate 10 and the second passivation antireflection layer 12. The tunneling layer 13 is disposed on the side closer to the substrate 10. The first gate electrode 20 is disposed on the side of the first passivation antireflection layer 11 away from the first surface 10a. On one side, the first gate electrode 20 is electrically connected to the substrate 10. For example, the first gate electrode 20 can at least partially penetrate the first passivation antireflection layer 11 and contact the substrate 10. The first gate electrode 20 is directly connected to the first surface 10a of the substrate 10. The second gate electrode 30 is disposed on the side of the second passivation antireflection layer 12 away from the second surface 10b. The second gate electrode 30 at least partially penetrates the second passivation antireflection layer 12 and contacts the substrate 10. The second gate electrode 30 is electrically connected to the substrate 10. For example, the second gate electrode 30 can penetrate the second passivation antireflection layer 12 and directly contact the semiconductor doped layer 14 of the second surface 10b. The second gate electrode 30 contacts the second surface 10b of the substrate 10 through the semiconductor doped layer 14.

[0069] At least one of the first grid electrode 20 and the second grid electrode 30 includes a silver-copper electrode 50; wherein, reference Figure 2 The silver-copper electrode 50 includes a silver contact layer 51 and a silver-clad copper layer 52. The silver contact layer 51 is disposed on the substrate 10 and includes first silver particles 511. The silver-clad copper layer 52 is disposed on the silver contact layer 51 and contacts the substrate 10 through the silver contact layer 51. The silver-clad copper layer 52 includes silver-clad copper particles 512 and second silver particles 513. The silver-clad copper particles 512 are copper particles inside and coated with second silver particles 513 on the outside. The mass content of copper component in the silver-copper electrode 50 is greater than 30%.

[0070] The statement that the mass content of copper component in silver-copper electrode 50 is greater than 30% means that the mass of copper component in silver-copper electrode 50 is greater than 30% of the total mass of copper component and silver component. For example, the mass content of copper component in silver-copper electrode 50 can be 30%, 35%, 40%, 45%, 50%, or 55%.

[0071] It should be noted that, in this application, "electrical connection" refers to a state in which, as far as the art is concerned, current or electrical signals are allowed to pass between two conductive components when the device is generating or supplying power, since the connection material is a conductive material.

[0072] In this embodiment of the solar cell, at least one of the first grid electrode 20 and the second grid electrode 30 is configured to include a silver-copper electrode 50, wherein the copper component in the silver-copper electrode 50 has a mass content greater than 30%, thereby reducing the total amount of silver metal consumed in the first grid electrode 20 and the second grid electrode 30 and reducing the manufacturing cost of the solar cell; at the same time, by designing the structure of the silver-copper electrode 50, the silver contact layer 51 of the silver-copper electrode 50 is made to contact the substrate 10, ensuring that the silver-copper electrode 50 and the substrate 10 have low contact resistance, which is beneficial to ensuring that the solar cell has good photoelectric conversion efficiency.

[0073] In one embodiment, the copper component in the silver-copper electrode 50 has a mass content of 30%-50%. This not only reduces the manufacturing cost of the solar cell, but also ensures that the silver-copper electrode 50 has a low overall resistance and improves its conductivity, which helps to reduce the power consumption of the metal electrode and improve the photoelectric conversion efficiency of the solar cell.

[0074] Furthermore, the mass content of copper component in the silver-copper electrode 50 can be 35%-45%.

[0075] In one embodiment, the diameter of the first silver particle 511 is 5nm-30nm. For example, the diameter of the first silver particle 511 can be 5nm, 6nm, 8nm, 10nm, 12nm, 15nm, 16nm, 18nm, 20nm, 22nm, 25nm, 28nm, or 30nm; the diameter of the silver-coated copper particle 512 is 1μm-10μm. For example, the diameter of the silver-coated copper particle 512 can be 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 4μm, 5.5μm, 6μm, 7μm, 8μm, 9μm, or 10μm; the diameter of the second silver particle 513 is 30nm-100nm. For example, the diameter of the second silver particle 513 can be 30nm, 35nm, 40nm, or 50nm, 60nm, 70nm, 80nm, 90nm, or 100nm.

[0076] In one embodiment, the diameter of the first silver particle 511 is 10nm-25nm; the diameter of the silver-coated copper particle 512 is 2μm-8μm; and the diameter of the second silver particle 513 is 40nm-85nm.

[0077] In one embodiment, the diameter of the first silver particle 511 is 15nm-20nm; the diameter of the silver-coated copper particle 512 is 4μm-6μm; and the diameter of the second silver particle 513 is 50nm-70nm.

[0078] In one embodiment, the silver-coated copper layer 52 further includes an adhesive layer 53, in which the silver-coated copper particles 512 and the second silver particles 513 are dispersed and bonded together.

[0079] In one embodiment, the silver-copper electrode 50 is formed by printing silver-copper paste, and the first silver particles 511, the silver-coated copper particles 512, and the second silver particles 513 are layered to form a silver contact layer 51 and a silver-coated copper layer 52, respectively.

[0080] In one embodiment, reference Figure 7 The first gate electrode 20 includes a first main gate 21, which is connected to a plurality of first fine gates 22. The first fine gates 22 penetrate the first passivation antireflection layer 11 and contact the substrate 10. At least one of the first main gate 21 and the first fine gates 22 is a silver-copper electrode 50. The plurality of first fine gates 22 are arranged at intervals along the extension direction of the first main gate 21 and are connected to the first main gate 21. The first fine gates 22 at least partially penetrate the first passivation antireflection layer 11 and contact the substrate 10.

[0081] In one example, the first main gate 21 of the first gate electrode 20 is a silver-copper electrode 50, and the first fine gate 22 is another metal electrode. For example, the material of the first fine gate 22 may include at least one of copper, silver, nickel or aluminum.

[0082] In another example, the first main gate 21 of the first gate electrode 20 is another metal electrode, such as the material of the first main gate 21 may include at least one of copper, silver, nickel or aluminum, and the first fine gate 22 of the first gate electrode 20 is a silver-copper electrode 50.

[0083] In one embodiment, reference Figure 8 The second gate electrode 30 includes a second main gate 31, which is connected to a plurality of second fine gates 32. The second fine gates 32 penetrate the second passivation antireflection layer 12 and contact the substrate 10. At least one of the second main gate 31 and the second fine gates 32 is a silver-copper electrode 50. The plurality of second fine gates 32 are arranged at intervals along the extension direction of the second main gate 31 and are connected to the second main gate 31. The second fine gates 32 at least partially penetrate the second passivation antireflection layer 12 and contact the substrate 10.

[0084] In one example, the second main gate 31 of the second gate electrode 30 is a silver-copper electrode 50, and the second fine gate 32 is another metal electrode. For example, the material of the second fine gate 32 may include at least one of copper, silver, nickel or aluminum.

[0085] In another example, the second main gate 31 of the second gate electrode 30 is another metal electrode, such as the material of the second main gate 31 may include at least one of copper, silver, nickel or aluminum, and the first fine gate 22 of the second gate electrode 30 is a silver-copper electrode 50.

[0086] In one embodiment, reference Figure 5 The first main gate 21 and the first fine gate 22 of the first gate electrode 20 are both silver-copper electrodes 50, and the second main gate 31 and the second fine gate 32 of the second gate electrode 30 are both other metal electrodes. For example, the second gate electrode 30 may include at least one of copper, silver, nickel or aluminum.

[0087] For example, the second grid electrode 30 can be a silver electrode, a silver-aluminum electrode, a copper electrode, a silver-nickel electrode, etc.

[0088] In one embodiment, reference Figure 6 The first main gate 21 and the first fine gate 22 of the first gate electrode 20 are both silver electrodes, and the second main gate 31 and the second fine gate 32 of the second gate electrode 30 are both other metal electrodes. For example, the second gate electrode 30 may include at least one of copper, silver, nickel or aluminum.

[0089] For example, the first grid electrode 20 can be a silver electrode, a silver-aluminum electrode, a copper electrode, a silver-nickel electrode, etc.

[0090] In one embodiment, the number of first gate line electrodes 20 is greater than or equal to the number of second gate line electrodes 30. In one example, such as... Figure 1 As shown, the number of first gate line electrodes 20 is greater than the number of second gate line electrodes 30. In another example, as... Figure 3 As shown, the number of first gate line electrodes 20 is greater than the number of second gate line electrodes 30.

[0091] In this embodiment, the first grid electrode 20 is a silver electrode or a silver-copper electrode 50, and the second grid electrode 30 is a silver-copper electrode 50. In this way, by reducing the number of second grid electrodes 30 on the second surface 10b and setting the second grid electrodes 30 on the second surface 10b as silver-copper electrodes 50, the consumption of metallic silver in the second grid electrodes 30 is reduced, thereby reducing the manufacturing cost of the solar cell.

[0092] In one embodiment, reference Figure 1 , Figure 3In the direction perpendicular to the first surface 10a, the first gate electrode 20 and the second gate electrode 30 at least partially overlap. That is, when viewed from the first surface 10a toward the second surface 10b, part of the second gate electrode 30 is obscured by the first gate electrode 20 and cannot be observed; another part of the second gate electrode 30 is exposed outside the first gate electrode 20 and can be observed.

[0093] In one embodiment, reference Figure 1 , Figure 3 In a direction perpendicular to the first surface 10a, the first grid electrode 20 covers the second grid electrode 30. That is, when viewed from the first surface 10a towards the second surface 10b, the second grid electrode 30 is completely obscured by the first grid electrode 20 and cannot be observed. Thus, reducing the total area of ​​the solar cell obscured by the first grid electrode 20 and the second grid electrode 30 helps to increase the effective area for photoelectric conversion in the solar cell, thereby improving the photoelectric conversion efficiency.

[0094] In one embodiment, reference Figure 4 Along a direction parallel to the first surface 10a of the substrate 10, the first grid electrode 20 and the second grid electrode 30 are spaced apart by a first distance d1, which is less than 30 μm. Thus, the first grid electrode 20 and the second grid electrode 30 can be fabricated in a single laser sintering process, which helps to save fabrication steps and reduce the production cost of solar cells.

[0095] The solar cell provided in this application is the solar cell of Embodiment 1. The first grid electrode 20 and the second grid electrode 30 of the solar cell of Embodiment 1 are both silver-copper electrodes 50. The silver-copper electrode 50 includes a silver contact layer 51 and a silver-copper clad layer 52, and the number of the first grid electrodes 20 is greater than the number of the second grid electrodes 30.

[0096] A solar cell of Comparative Example 1 is provided. The first grid line electrode and the second gate electrode of the solar cell of Comparative Example 1 are both silver electrodes made of silver paste. The number of the first grid line electrode and the second gate electrode of the solar cell of Comparative Example 1 is the same as the number of the second grid line electrode 30 of the first grid line electrode 20 of the solar cell of Example 1.

[0097] A solar cell of Comparative Example 2 is provided. The first grid line electrode and the second grid line electrode of the solar cell of Comparative Example 2 are both metal electrodes made of silver-copper paste. The metal electrodes only include a silver-coated copper layer, and the number of the first grid line electrodes of the solar cell of Comparative Example 2 is less than the number of the second grid line electrodes.

[0098] The performance of the solar cell in Example 1 was tested, and the performance of the semiconductor structure solar cells in Comparative Example 1 and Comparative Example 2 was also tested. The performance test results are shown in Table 1.

[0099] Table 1 Performance test results of the solar cell of Example 1 and the solar cells of Comparative Examples 1 and 2

[0100]

[0101] According to the performance test results recorded in Table 1, the solar cell of this application embodiment can avoid the adverse effects that may occur with the solar cell of Comparative Example 2 by improving the electrode structure of the silver-copper electrode and the layout of the first grid electrode and the second grid electrode.

[0102] Compared with the conventional silver electrode in Comparative Example 1, the solar cell of this application embodiment has a 20% lower power consumption, a 0.04% higher Eta, a 0.2% higher FF, and a 0.001% lower series resistance. The silver-copper electrode of the solar cell of this application embodiment has a good substitution effect compared with the conventional silver electrode, and can reduce battery cost, improve performance, and effectively improve the photoelectric conversion efficiency of the solar cell.

[0103] According to an exemplary embodiment, this embodiment provides a method for manufacturing a solar cell, such as... Figure 9 As shown, the method for manufacturing a solar cell includes the following steps:

[0104] Step S10: Provide a substrate 10, which includes a first surface 10a and a second surface 10b disposed opposite to each other. A first passivation antireflection layer 11 is formed on the first surface 10a, and a second passivation antireflection layer 12 is formed on the second surface 10b.

[0105] Reference Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 6 The substrate 10 is an n-type silicon substrate. A first passivation antireflection layer 11 is formed on the first surface 10a of the substrate 10. The first passivation antireflection layer 11 can be a single layer or a multilayer structure. For example, the first passivation antireflection layer 11 can include a silicon oxide layer, a nitride layer, or a stacked silicon oxide layer and a silicon nitride layer. A tunneling layer 13, a semiconductor layer, and a second passivation antireflection layer 12 are sequentially formed on the second surface 10b of the substrate 10. The second passivation antireflection layer 12 can be a single layer or a multilayer structure. For example, the second passivation antireflection layer 12 can include a silicon oxide layer, a nitride layer, or a stacked silicon oxide layer and a silicon nitride layer.

[0106] At least one of the first face 10a or the second face 10b of the base 10 can form a pyramid structure.

[0107] Step S20: A first gate electrode 20 is formed on the side of the first passivation antireflection layer 11 away from the first surface 10a. The first gate electrode 20 at least partially penetrates the first passivation antireflection layer 11 and contacts the substrate 10. A second gate electrode 30 is formed on the side of the second passivation antireflection layer 12 away from the second surface 10b. The second gate electrode 30 at least partially penetrates the second passivation antireflection layer 12 and contacts the substrate 10.

[0108] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 At least one of the first gate electrode 20 and the second gate electrode 30 includes a silver-copper electrode 50; wherein the silver-copper electrode 50 includes a silver contact layer 51 and a silver-clad copper layer 52; the silver contact layer 51 is disposed on the substrate 10 and includes first silver particles 511; the silver-clad copper layer 52 is disposed on the silver contact layer 51 and contacts the substrate 10 through the silver contact layer 51, the silver-clad copper layer 52 includes silver-clad copper particles 512 and second silver particles 513, the silver-clad copper particles 512 are copper particles inside and coated with second silver particles 513 on the outside; the mass content of copper component in the silver-copper electrode 50 is greater than 30%.

[0109] The statement that the mass content of copper component in silver-copper electrode 50 is greater than 30% means that the mass of copper component in silver-copper electrode 50 is greater than 30% of the total mass of copper component and silver component. For example, the mass content of copper component in silver-copper electrode 50 can be 30%, 35%, 40%, 45%, 50%, or 55%.

[0110] In one embodiment, the copper component in the silver-copper electrode 50 has a mass content of 30%-50%. This not only reduces the manufacturing cost of the solar cell, but also ensures that the silver-copper electrode 50 has a low overall resistance and improves its conductivity, which helps to reduce the power consumption generated by the electrode and improve the photoelectric conversion efficiency of the solar cell.

[0111] Furthermore, the mass content of copper component in the silver-copper electrode 50 can be 35%-45%.

[0112] In the method for manufacturing a solar cell in this embodiment, at least one of the first grid electrode 20 and the second grid electrode 30 is formed to include a silver-copper electrode 50, wherein the mass content of the copper component in the silver-copper electrode 50 is greater than 30%, thereby reducing the total amount of silver metal consumed in the first grid electrode 20 and the second grid electrode 30 and reducing the manufacturing cost of the solar cell; at the same time, by designing the structure of the silver-copper electrode 50, the silver contact layer 51 of the silver-copper electrode 50 is made to contact the substrate 10, ensuring that the silver-copper electrode 50 and the substrate 10 have low contact resistance, which is beneficial to ensuring that the solar cell has good photoelectric conversion efficiency.

[0113] In one embodiment, step S20 involves forming a first gate electrode 20 on the side of the first passivation antireflection layer 11 away from the first surface 10a, the first gate electrode 20 at least partially penetrating the first passivation antireflection layer 11 and contacting the substrate 10; and forming a second gate electrode 30 on the side of the second passivation antireflection layer 12 away from the second surface 10b, the second gate electrode 30 at least partially penetrating the second passivation antireflection layer 12 and contacting the substrate 10, such as... Figure 10 As shown, the specific steps include:

[0114] Step S201: Print the conductive paste of the first gate electrode 20 on the side of the first passivation antireflection layer 11 away from the first surface 10a;

[0115] Reference Figure 1 , Figure 7 Conductive paste of the first gate electrode 20 is printed on the side of the first passivation antireflection layer 11 away from the first surface 10a to form multiple first gate electrodes 20 on the first surface 10a of the substrate 10.

[0116] The conductive paste of the first gate electrode 20 may include silver-copper paste, or it may include other metal pastes, such as silver paste, silver-aluminum paste, copper paste, silver-nickel paste, etc.

[0117] Step S202: Print the conductive paste of the second gate electrode 30 on the side of the second passivation antireflection layer 12 away from the second surface 10b. At least one of the conductive paste of the first gate electrode 20 and the conductive paste of the second gate electrode 30 includes silver-copper paste.

[0118] Reference Figure 1 , Figure 8 Conductive paste for the second gate electrode 30 is printed on the side of the second passivation antireflection layer 12 away from the second surface 10b, so as to form multiple second gate electrodes 30 on the first surface 10a of the substrate 10. The number of first gate electrodes 20 is greater than or equal to the number of second gate electrodes 30.

[0119] The conductive paste of the second gate electrode 30 may include silver-copper paste, or it may include other metal pastes, such as silver paste, silver-aluminum paste, copper paste, silver-nickel paste, etc.

[0120] In this embodiment, at least one of the conductive paste of the first gate electrode 20 and the conductive paste of the second gate electrode 30 includes silver-copper paste.

[0121] Reference Figure 2 The silver-copper paste includes silver-coated copper particles 512, second silver particles 513, first silver particles 511, and a binder, with the silver-coated copper particles 512, second silver particles 513, and first silver particles 511 dispersed in the binder;

[0122] Among them, the diameter of the first silver particle 511 is 5nm-30nm; the diameter of the silver-coated copper particle 512 is 1μm-10μm; and the diameter of the second silver particle 513 is 30nm-100nm.

[0123] For example, the diameter of the first silver particle 511 can be 5nm, 6nm, 8nm, 10nm, 12nm, 15nm, 16nm, 18nm, 20nm, 22nm, 25nm, 28nm, or 30nm; the diameter of the silver-coated copper particle 512 is 1μm-10μm, for example, the diameter of the silver-coated copper particle 512 can be 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 4μm, 5.5μm, 6μm, 7μm, 8μm, 9μm, or 10μm; the diameter of the second silver particle 513 is 30nm-100nm, for example, the diameter of the second silver particle 513 can be 30nm, 35nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, or 100nm.

[0124] Step S203: Dry the conductive paste of the first gate electrode 20 and the conductive paste of the second gate electrode 30;

[0125] The conductive paste of the first grid electrode 20 and the conductive paste of the second grid electrode 30 can be dried at a temperature of 100℃~700℃. The drying time is set to 1min-20min, which allows the conductive paste of the first grid electrode 20 and the conductive paste of the second grid electrode 30 to solidify. The adhesive solidifies to form an adhesive layer 53, and the silver-coated copper particles 512, the second silver particles 513, and the first silver particles 511 are bonded together through the adhesive layer 53.

[0126] In this embodiment, the conductive paste of the first grid electrode 20 and the conductive paste of the second grid electrode 30 are dried at a temperature of 200°C to 50°C for the silver-copper electrode.

[0127] Step S204: The conductive paste of the dried first gate electrode 20 is subjected to laser sintering treatment, and a first reverse bias is applied between the first gate electrode 20 and the second gate electrode 30, so that the first gate electrode 20 at least partially penetrates the first passivation antireflection layer 11 and contacts the substrate 10.

[0128] The first reverse voltage is 10V~20V. For example, the first reverse voltage can be 10V, 12V, 15V, 18V or 20V. This embodiment does not impose specific limitations.

[0129] The light source for laser sintering can be infrared light, red light, green light, or a combination of multiple light sources.

[0130] Reference Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 6 The first gate electrode 20 is at least partially burned through the first passivation antireflection layer 11, and the first gate electrode 20 extends to the first surface 10a of the substrate 10 and contacts the first surface 10a of the substrate 10.

[0131] Step S205: The conductive paste of the dried second gate electrode 30 is subjected to laser sintering treatment, and a second reverse bias is applied between the first gate electrode 20 and the second gate electrode 30, so that the second gate electrode 30 at least partially penetrates the second passivation antireflection layer 12 and contacts the substrate 10.

[0132] The second reverse voltage is 10V~20V. For example, the second reverse voltage can be 10V, 12V, 15V, 18V or 20V. This embodiment does not impose specific limitations.

[0133] The light source for laser sintering can be infrared light, red light, green light, or a combination of multiple light sources.

[0134] The second gate electrode 30 at least partially burns through the second passivation antireflection layer 12, and the first gate electrode 20 extends to the second surface 10b of the substrate 10 and contacts the semiconductor doped layer 14, and contacts the second surface 10b of the substrate 10 through the semiconductor doped layer 14.

[0135] Among them, reference Figure 2 The first gate electrode 20 and the second gate electrode 30 include portions of silver-copper paste. After drying and laser sintering, the silver-copper paste burns through the first passivation antireflection layer 11 or the second passivation antireflection layer 12 and contacts the substrate 10. The first silver particles 511 in the silver-copper paste precipitate to the surface of the substrate 10, forming a silver contact layer 51 that contacts the substrate 10. The remaining silver-copper paste forms a silver-copper-clad layer 52 on the silver contact layer 51.

[0136] It is understood that in this embodiment, by reasonably adjusting the size difference between the silver-coated copper particles 512, the second silver particles 513, and the first silver particles 511 in the silver-copper paste, the size of the first silver particles 511 is smaller than the size of the silver-coated copper particles 512 and the size of the second silver particles 513. This allows the silver-copper paste to be dried and laser sintered, so that the first silver particles 511, the silver-coated copper particles 512, and the second silver particles 513 are separated into layers. The smaller first silver particles 511 precipitate from the adhesive layer 53 to the bottom surface of the adhesive layer 53, and extend towards the substrate 10 as the silver-copper paste burns through the first passivation antireflection layer 11 or the second passivation antireflection layer 12, forming a silver contact layer 51 that contacts the substrate 10.

[0137] Reference Figure 2 The silver-copper electrode 50 contacts the substrate 10 through the silver contact layer 51. By utilizing the good conductivity of metallic silver, the contact resistance between the silver-copper electrode 50 and the substrate 10 is reduced, which can reduce the overall resistance of the silver-copper electrode 50, reduce the production cost of the solar cell, and at the same time reduce the resistance of the silver-copper electrode 50 while taking into account the photoelectric conversion efficiency of the solar cell.

[0138] Using the second gate electrode 30 as the silver-copper electrode 50, the silver-copper electrode 50 formed in this embodiment is tested. Before laser processing, the first silver particles 511 have not precipitated to form a silver contact layer 51, and the contact resistance between the silver-copper electrode 50 and the semiconductor doped layer 14 is ≥2 mΩ. 2 The second gate electrode 30 is laser-sintered, causing the first silver particles 511 to precipitate and form a silver contact layer 51. The silver-copper electrode 50 contacts the semiconductor doped layer 14 through the silver contact layer 51, and the contact resistance between the silver-copper electrode 50 and the semiconductor doped layer 14 is <1.5 mΩ / cm. 2 .

[0139] In one embodiment, the diameter of the first silver particle 511 is 10nm-25nm; the diameter of the silver-coated copper particle 512 is 2μm-8μm; and the diameter of the second silver particle 513 is 40nm-85nm.

[0140] In one embodiment, the diameter of the first silver particle 511 is 15nm-20nm; the diameter of the silver-coated copper particle 512 is 4μm-6μm; and the diameter of the second silver particle 513 is 50nm-70nm.

[0141] In one embodiment, reference Figure 1 , Figure 3 In a direction perpendicular to the first surface 10a, the first gate electrode 20 and the second gate electrode 30 at least partially overlap.

[0142] During the manufacturing process, steps S204 and S205 are executed sequentially. After laser sintering is performed on the first gate electrode 20 of the first surface 10a, laser sintering is performed on the second gate electrode 30 of the second surface 10b. This ensures that the first gate electrode 20 can burn through the first passivation antireflection layer 11 and the second gate electrode 30 can burn through the second passivation antireflection layer 12, thus avoiding the overlapping area of ​​the first gate electrode 20 and the second gate electrode 30 from blocking and affecting the laser sintering effect.

[0143] Thus, the solar cell formed in this embodiment can reduce the area of ​​the first grid electrode 20 and the second grid electrode 30 that obstructs the substrate 10, which is beneficial to increasing the effective area of ​​the solar cell for photoelectric conversion and improving the photoelectric conversion efficiency of the solar cell.

[0144] In this embodiment, the first grid electrode 20 covers the second grid electrode 30 in a direction perpendicular to the first surface 10a. This reduces the total area of ​​the solar cell obscured by the first grid electrode 20 and the second grid electrode 30, which helps to further increase the effective area for photoelectric conversion of the solar cell and improve its photoelectric conversion efficiency.

[0145] In another embodiment, refer to Figure 4 Along a direction parallel to the first surface 10a of the substrate 10, the first gate electrode 20 and the second gate electrode 30 are spaced apart by a first distance d1 on the substrate 10, the first distance d1 being less than 30 μm.

[0146] During the manufacturing process, only one laser sintering process can be performed. After drying the conductive paste of the first gate electrode 20 and the conductive paste of the second gate electrode 30, a laser is irradiated onto the first gate electrode 20 and the second gate electrode 30 on the first surface 10a or the second surface 10b of the substrate 10. At the same time, a first reverse bias voltage is applied between the first gate electrode 20 and the second gate electrode 30, so that the first gate electrode 20 at least partially penetrates the first passivation antireflection layer 11 and contacts the substrate 10, and the second gate electrode 30 at least partially penetrates the second passivation antireflection layer 12 and contacts the substrate 10.

[0147] Thus, the first grid electrode 20 and the second grid electrode 30 can be manufactured in a single laser sintering process, which helps to save manufacturing steps and reduce the production cost of solar cells.

[0148] In one embodiment, the conductive paste of the first grid electrode 20 and the conductive paste of the second grid electrode 30 are both silver-copper pastes. The first grid electrode 20 and the second grid electrode 30 of the solar cell are both silver-copper electrodes 50, which minimizes the manufacturing cost of the metallization process.

[0149] In one embodiment, the conductive paste of the first grid electrode 20 is a silver-copper paste, and the second grid electrode 30 is a silver paste. The first grid electrode 20 of the solar cell is a silver-copper electrode 50, and the second grid electrode 30 is a silver electrode.

[0150] In one embodiment, the conductive paste of the second grid electrode 30 is silver paste, and the second grid electrode 30 is silver-copper paste. The first grid electrode 20 of the solar cell is a silver electrode, and the second grid electrode 30 is a silver-copper electrode 50.

[0151] In one embodiment, step S201, printing the conductive paste of the first gate electrode 20 on the side of the first passivation antireflection layer 11 away from the first surface 10a, includes:

[0152] Step S201-1: Print conductive paste of the first main gate 21 on the first passivation antireflection layer 11 to form the first main gate 21;

[0153] Step S201-2: Print conductive paste of first fine gate 22 on the first passivation antireflection layer 11 to form the first fine gate 22, and the first main gate 21 connects multiple first fine gates 22; wherein, at least one of the conductive paste of the first main gate 21 and the conductive paste of the first fine gate 22 includes silver-copper paste, and at least one of the first main gate 21 and the first fine gate 22 is a silver-copper electrode 50.

[0154] Reference Figure 7 This embodiment is applicable to the fabrication of first grid line electrodes 20 made of different materials for the first main grid 21 and the first fine grid 22.

[0155] In one example, the first main gate 21 of the first gate electrode 20 is a silver-copper electrode 50, and the first fine gate 22 is another metal electrode. For example, the material of the first fine gate 22 may include at least one of copper, silver, nickel, or aluminum. Silver-copper paste can be printed on the first passivation antireflection layer 11 to form the first main gate 21, and then other metal pastes can be printed to form the first fine gate 22.

[0156] In another example, the first main gate 21 of the first gate electrode 20 is another metal electrode. For example, the material of the first main gate 21 may include at least one of copper, silver, nickel, or aluminum, and the first fine gate 22 of the first gate electrode 20 is a silver-copper electrode 50. Other metal pastes can be printed on the first passivation antireflection layer 11 to form the first main gate 21, and then other silver-copper pastes can be printed to form the first fine gate 22.

[0157] In this embodiment, when performing the laser sintering process in step S204, the first fine gate 22 is irradiated with a laser, causing the first fine gate 22 to at least partially burn through the first passivation antireflection layer 11 and contact the first surface 10a of the substrate 10.

[0158] In one embodiment, step S202: printing the conductive paste of the second gate electrode 30 on the side of the second passivation antireflection layer 12 away from the second surface 10b, including:

[0159] Step S202-1: Print conductive paste of the second main gate 31 on the second passivation antireflection layer 12 to form the first main gate 21;

[0160] Step S202-2: Print conductive paste of second fine grid 32 on the second passivation antireflection layer 12 to form second fine grid 32, and connect multiple second fine grids 32 to the second main grid 31; wherein, at least one of the conductive paste of the second main grid 31 and the conductive paste of the second fine grid 32 includes silver-copper paste, and at least one of the second main grid 31 and the second fine grid 32 is a silver-copper electrode 50.

[0161] Similarly, refer to Figure 8 This embodiment is applicable to the fabrication of second grid line electrodes 30 made of different materials for the second main grid 31 and the second fine grid 32.

[0162] In one example, the second main gate 31 of the second gate electrode 30 is a silver-copper electrode 50, and the second fine gate 32 is another metal electrode. For example, the material of the second fine gate 32 may include at least one of copper, silver, nickel or aluminum.

[0163] In another example, the second main gate 31 of the second gate electrode 30 is another metal electrode, such as the material of the second main gate 31 may include at least one of copper, silver, nickel or aluminum, and the first fine gate 22 of the second gate electrode 30 is a silver-copper electrode 50.

[0164] In this embodiment, when performing the laser sintering process in step S205, the second fine gate 32 is irradiated with a laser, causing the second fine gate 32 to at least partially burn through the second passivation antireflection layer 12 and contact the second surface 10b of the substrate 10.

[0165] Thirdly, this disclosure provides a photovoltaic module, including a solar cell as described in the first aspect, or a solar cell manufactured by a method as described in the second aspect.

[0166] In this embodiment of the photovoltaic module, at least one of the first grid electrode 20 and the second grid electrode 30 of the solar cell is configured to include a silver-copper electrode 50, wherein the mass content of the copper component in the silver-copper electrode 50 is greater than 30%, thereby reducing the total amount of silver metal consumed in the first grid electrode 20 and the second grid electrode 30 and reducing the cost of the photovoltaic module; at the same time, by designing the structure of the silver-copper electrode 50, the silver contact layer 51 of the silver-copper electrode 50 is made to contact the substrate 10, ensuring that the silver-copper electrode 50 and the substrate 10 have low contact resistance, which is beneficial to ensuring that the photovoltaic module has good photoelectric conversion efficiency.

[0167] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0168] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the scope of protection of this disclosure. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, include: A substrate includes a first surface and a second surface disposed opposite to each other. The second surface is provided with a second gate electrode electrically connected to the substrate. The second gate electrode is at least partially composed of a silver-copper electrode. The silver-copper electrode includes: A silver contact layer is disposed on the substrate, the silver contact layer comprising first silver particles; A silver-clad copper layer is disposed on the silver contact layer, and the silver-clad copper layer is electrically connected to the substrate through the silver contact layer. The silver-clad copper layer includes silver-clad copper particles and second silver particles. The copper component in the silver-copper electrode has a mass content greater than 30%.

2. The solar cell according to claim 1, characterized in that, The diameter of the first silver particle is 5nm-30nm.

3. The solar cell according to claim 1, characterized in that, The diameter of the silver-coated copper particles is 1μm-10μm.

4. The solar cell according to claim 1, characterized in that, The diameter of the second silver particle is 30nm-100nm.

5. The solar cell according to claim 1, characterized in that, The copper component in the silver-copper electrode has a mass content of 30%-50%; and / or, the diameter of the first silver particle is 10nm-25nm; and / or, the diameter of the silver-coated copper particle is 2μm-8μm; and / or, the diameter of the second silver particle is 40nm-85nm.

6. The solar cell according to claim 1, characterized in that, The copper component in the silver-copper electrode has a mass content of 35%-45%; and / or, the diameter of the first silver particle is 15nm-20nm; and / or, the diameter of the silver-coated copper particle is 4μm-6μm; and / or, the diameter of the second silver particle is 50nm-70nm.

7. The solar cell according to claim 1, characterized in that, The silver-coated copper layer further includes an adhesive layer, in which the silver-coated copper particles and the second silver particles are dispersed.

8. The solar cell according to claim 1, characterized in that, The second gate electrode includes a second main gate, which is connected to a plurality of second fine gates. The second fine gates are electrically connected to the substrate, and at least one of the second main gate and the second fine gates is the silver-copper electrode.

9. The solar cell according to any one of claims 1-8, characterized in that, The first surface is provided with a first gate line electrode electrically connected to the substrate, and the first gate line electrode is at least partially composed of a silver-copper electrode.

10. The solar cell according to claim 9, characterized in that, The first gate electrode includes a first main gate, which is connected to a plurality of first fine gates. The first fine gates are electrically connected to the substrate, and at least one of the first main gate and the first fine gates is the silver-copper electrode.

11. The solar cell according to claim 9, characterized in that, The number of the first gate electrode is greater than or equal to the number of the second gate electrode.

12. The solar cell according to claim 9, characterized in that, In a direction perpendicular to the first surface, the first gate electrode and the second gate electrode at least partially overlap.

13. The solar cell according to claim 12, characterized in that, In a direction perpendicular to the first surface, the first gate electrode covers the second gate electrode.

14. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 1-13.

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