Electrode structure, back contact solar cells and photovoltaic modules
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-21
- Publication Date
- 2026-08-14
AI Technical Summary
然而，该技术的大规模产业化面临的主要障碍是其高昂的制造成本
[0035]本领域技术人员能够理解的是，本申请的电极结构通过将第一主栅和第二主栅设计为银栅线以及将第一副栅和第二副栅设计为铜栅线，一方面能够降低制造成本，另一方面还能够充分利用铜栅线优异的导电性和接触特性，从而有效地提升背接触太阳能电池的发电效率。
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Figure CN224638403U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic module technology, specifically providing an electrode structure, a back-contact solar cell, and a photovoltaic module. Background Technology
[0002] Back-contact solar cells integrate all positive and negative metal contacts on the back surface of the cell, achieving a grid-free design on the light-receiving surface, thereby improving solar absorption and photoelectric conversion efficiency. However, the main obstacle to the large-scale industrialization of this technology is its high manufacturing cost. Specifically, the main and sub-grid lines of back-contact solar cells are highly dependent on silver paste, and the cost of silver paste accounts for a significant portion of the total manufacturing cost. This prominent cost issue urgently needs to be addressed.
[0003] Therefore, a new technical solution is needed in this field to solve the above problems. Utility Model Content
[0004] This invention aims to solve the aforementioned technical problem, namely, how to reduce the manufacturing cost of back-contact solar cells. To this end, this invention provides an electrode structure, which includes:
[0005] First insulating layer;
[0006] A first electrode, the first electrode comprising a plurality of first main gates and a plurality of first sub-gates connected to the first main gates;
[0007] A second electrode with polarity opposite to that of the first electrode, the second electrode comprising a plurality of second main gates and a plurality of second sub-gates connected to the second main gates; and
[0008] The first main gate and the second main gate are arranged alternately along a first direction, and the first sub-gate and the second sub-gate are distributed alternately along a second direction; a first insulating layer is provided at the intersection of the first main gate and the second sub-gate, as well as at the intersection of the second main gate and the first sub-gate; the first main gate and the second main gate are both silver grid lines, and the first sub-gate and the second sub-gate are both copper grid lines.
[0009] In the preferred embodiment of the above electrode structure, the first sub-gate is a first metal layer; or
[0010] The first sub-gate includes a first seed layer and a first metal layer stacked together, and the first main gate is disposed on the side of the first metal layer opposite to the first seed layer.
[0011] In the preferred embodiment of the above electrode structure, the material of the first metal layer is copper or a copper alloy;
[0012] The material of the first seed layer is selected from copper, aluminum, nickel, titanium and their alloys.
[0013] In the preferred embodiment of the above electrode structure, the second sub-gate is a second metal layer; or
[0014] The second sub-gate includes a second seed layer and a second metal layer stacked together, and the second main gate is disposed on the side of the second metal layer opposite to the second seed layer.
[0015] In the preferred embodiment of the above electrode structure, the material of the second metal layer is copper or a copper alloy;
[0016] The material of the second seed layer is selected from copper, aluminum, nickel, titanium and their alloys.
[0017] In the preferred embodiment of the above electrode structure, the metal layer is formed by electroplating.
[0018] In the preferred embodiment of the above electrode structure, the first main grid and the second main grid are each formed independently by one of screen printing, laser transfer printing or inkjet printing.
[0019] In the preferred embodiment of the above electrode structure, the first sub-gate and the second sub-gate are formed by electroplating; and / or
[0020] The first main grid and the second main grid are each formed independently using one of the following methods: screen printing, laser transfer printing or inkjet printing.
[0021] In the preferred embodiment of the above electrode structure, the first main gate is made of silver or silver-plated copper; and / or
[0022] The second main gate is made of silver or silver-plated copper.
[0023] This application also provides a back-contact solar cell, the back-contact solar cell comprising:
[0024] The substrate includes a backlight surface, wherein the backlight surface is provided with a first polar layer and a second polar layer alternately distributed along a second direction;
[0025] An electrode structure includes a first electrode and a second electrode. The first electrode includes multiple first main gates and multiple first sub-gates, with the first sub-gates disposed on a first polarity layer. The second electrode includes multiple second main gates and multiple second sub-gates, with the second sub-gates disposed on a second polarity layer. The first main gates and second main gates are alternately distributed on the first sub-gates and second sub-gates along a first direction. The polarities of the second electrode and the first electrode are opposite. A first insulating layer is disposed at the intersection of the first main gate and the second sub-gate, and at the intersection of the second main gate and the first sub-gate. The first main gate and the second main gate are silver gate lines, and the first sub-gate and the second sub-gate are copper gate lines.
[0026] In the preferred embodiment of the aforementioned back-contact solar cell, a second insulating layer is provided between adjacent first polarity layers and second polarity layers; or
[0027] A first trench is provided between adjacent first polar layers and second polar layers.
[0028] In the preferred embodiment of the aforementioned back-contact solar cell, the first polar layer comprises:
[0029] A first conductive layer and a first doped layer, wherein the first conductive layer is disposed on the backlight surface and the first doped layer is disposed between the first sub-gate and the first conductive layer;
[0030] In the preferred embodiment of the aforementioned back-contact solar cell, the first conductive layer comprises an ITO layer, an IMO layer, an AZO layer, and a SnO layer. X One or more of the layers.
[0031] In the preferred embodiment of the aforementioned back-contact solar cell, the second polar layer comprises:
[0032] A second conductive layer and a second doped layer are disposed on the backlight surface, and the second doped layer is disposed between the second sub-gate and the second conductive layer.
[0033] In the preferred embodiment of the aforementioned back-contact solar cell, the second conductive layer includes an ITO layer, an IMO layer, an AZO layer, and a SnO layer. X One or more of the layers.
[0034] This application also provides a photovoltaic module, which includes the back-contact solar cell described in the preferred embodiment above.
[0035] Those skilled in the art will understand that the electrode structure of this application, by designing the first and second main grids as silver grid lines and the first and second sub-grids as copper grid lines, can reduce manufacturing costs on the one hand, and make full use of the excellent conductivity and contact characteristics of copper grid lines on the other hand, thereby effectively improving the power generation efficiency of back contact solar cells.
[0036] Furthermore, the first sub-gate can be a first metal layer, or a first seed layer and a first metal layer. Both of these structures can provide excellent conductivity and contact characteristics, which not only effectively improves the power generation efficiency of the back contact solar cell, but also ensures that the first main gate can be set on the first sub-gate with low contact resistance.
[0037] Furthermore, by defining the materials of the first metal layer and the first seed layer, the first sub-gate can be made to have excellent conductivity and contact characteristics.
[0038] Furthermore, the second sub-gate can be a second metal layer, or a second seed layer and a second metal layer. Both of these structures provide excellent conductivity and contact characteristics, which not only effectively improves the power generation efficiency of the back contact solar cell, but also ensures that the second main gate can be set on the second sub-gate with low contact resistance.
[0039] Furthermore, by defining the materials of the second metal layer and the second seed layer, the second sub-gate can be made to have excellent conductivity and contact characteristics.
[0040] Those skilled in the art will understand that the back-contact solar cell of this application, by alternately arranging a first polarity layer and a second polarity layer with opposite conductivity types on the back surface of the substrate, and by setting a first electrode on the first polarity layer and a second electrode on the second polarity layer, facilitates the collection of charge carriers by the first electrode and the second electrode, effectively reducing carrier recombination losses and improving charge collection efficiency. Furthermore, by designing the first main grid in the first electrode and the second main grid in the second electrode as silver grid lines, and designing the first sub-grid in the first electrode and the second sub-grid in the second electrode as copper grid lines, manufacturing costs can be reduced, and the excellent conductivity and contact characteristics of copper grid lines can be fully utilized, thereby effectively improving the power generation efficiency of the back-contact solar cell.
[0041] Furthermore, by setting a second insulating layer or a first trench between adjacent first and second polarity layers, isolation between adjacent polarity layers can be achieved, thereby avoiding short circuits or leakage problems, ensuring that the back contact solar cell maintains stable electrical performance under long-term operating conditions, and extending the service life of the back contact solar cell. Attached Figure Description
[0042] The preferred embodiments of this application will now be described with reference to the accompanying drawings, in which:
[0043] Figure 1 This is a schematic diagram of the back-contact solar cell of this application;
[0044] Figure 2 for Figure 1 Partial cross-sectional view at point AA;
[0045] Figure 3 for Figure 1 Partial cross-sectional view at point BB.
[0046] Explanation of reference numerals in the attached figures:
[0047] 1. Electrode structure; 11. First electrode; 111. First main gate; 112. First sub-gate; 12. Second electrode; 121. Second main gate; 122. Second sub-gate; 13. First insulating layer; 2. Substrate; 21. Light-receiving surface; 22. Backlighting surface; 3. First polar layer; 31. First conductive layer; 32. First doped layer; 4. Second polar layer; 41. Second conductive layer; 42. Second doped layer; 5. Second insulating layer; 6. Passivation layer; 7. Anti-reflection layer. Detailed Implementation
[0048] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. It should be noted that in the description of this application, terms such as "upper," "lower," "left," "right," "inner," and "outer," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0049] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0050] See Figure 1-3 The back-contact solar cell of this application is described below.
[0051] like Figure 1-3 As shown, the back-contact solar cell includes a substrate 2, a first polar layer 3, a second polar layer 4, and an electrode structure 1. The substrate 2 includes a light-receiving surface 21 and a back-lighting surface 22 disposed opposite to each other. The back-lighting surface 22 is a polished surface, on which the first polar layer 3 and the second polar layer 4 are disposed alternately along a second direction, with opposite polarities. The first polar layer 3 includes a first conductive layer 31 and a first doped layer 32 stacked together. The first conductive layer 31 is disposed on the back-lighting surface 22, and the first doped layer 32 is disposed on the side of the first conductive layer 31 away from the substrate 2. The second polar layer 4 includes a second conductive layer 41 and a second doped layer 42 stacked together. The second conductive layer 41 is disposed on the back-lighting surface 22, and the second doped layer 42 is disposed on the side of the second conductive layer 41 away from the substrate 2. In the above configuration, multiple first conductive layers 31 and multiple first doped layers 32 are arranged at intervals along the second direction, and multiple second conductive layers 41 and multiple second doped layers 42 are arranged at intervals along the second direction, thereby making multiple first conductive layers 31 and multiple second conductive layers 41 alternately arranged along the second direction, and multiple first doped layers 32 and multiple second doped layers 42 alternately arranged along the second direction.
[0052] It should be noted that the first direction refers to, for example, Figure 1 The X-direction shown includes both the positive and negative directions indicated by the arrow. The second direction refers to... Figure 1-3 The Y-direction shown includes both the positive and negative directions indicated by the arrow. It should also be noted that substrate 2 can be either an N-type substrate 2 or a P-type substrate 2.
[0053] In the exemplary embodiments, the structure of the backlight surface 22 is not fixed and can be adjusted as needed by those skilled in the art. For example, the backlight surface 22 can also be a velvety surface; or, the backlight surface 22 corresponding to the first polar layer 3 can be a velvety surface and the backlight surface 22 corresponding to the second polar layer 4 can be a polished surface; or, the backlight surface 22 corresponding to the first polar layer 3 can be a polished surface and the backlight surface 22 corresponding to the second polar layer 4 can be a velvety surface.
[0054] In exemplary embodiments, this application does not limit the specific polarity of the first polar layer 3 and the second polar layer 4, as long as the first polar layer 3 and the second polar layer 4 are opposite. For example, the first polar layer 3 is an N-type polar layer and the second polar layer 4 is a P-type polar layer; or, the first polar layer 3 is a P-type polar layer and the second polar layer 4 is an N-type polar layer. Wherein, when the first polar layer 3 includes a stacked first conductive layer 31 and a first doped layer 32, and the second polar layer 4 includes a stacked second conductive layer 41 and a second doped layer 42, the first doped layer 32 is an N-type doped layer and the second doped layer 42 is a P-type doped layer; or, the first doped layer 32 is a P-type doped layer and the second doped layer 42 is an N-type doped layer. Wherein, because the polarities of the first polar layer 3 and the second polar layer 4 are similar, the polarities of the first electrode 11 and the second electrode 12 are opposite.
[0055] In exemplary embodiments, this application does not limit the specific types of the first conductive layer 31 and the second conductive layer 41, as long as they can function as conductors. For example, the first conductive layer 31 may include one or more of ITO, IMO, AZO, and SnOx layers. And / or, the second conductive layer 41 may include one or more of ITO, IMO, AZO, and SnOx layers. When the first conductive layer 31 and / or the second conductive layer 41 include multiple of ITO, IMO, AZO, and SnOx layers, these layers are stacked along the thickness direction of the substrate 2, and the specific stacking order can be adjusted according to the configuration requirements.
[0056] See next Figure 1-3 A second insulating layer 5 is provided between adjacent first doped layer 32 and second doped layer 42. The second insulating layer 5 is used to isolate the first doped layer 32 and the second doped layer 42, thereby achieving isolation between adjacent doped layers, which can avoid short circuit or leakage problems, ensure that the back contact solar cell maintains stable electrical performance under long-term working conditions, and extend the service life of the back contact solar cell.
[0057] In exemplary embodiments, the isolation method for the first doped layer 32 and the second doped layer 42 is not fixed, as long as it can prevent adjacent first doped layers 32 and second doped layers 42 from contacting. For example, a trench is provided between the first doped layer 32 and the second doped layer 42.
[0058] It should be noted that an insulating layer or trench may also be provided between adjacent first conductive layers 31 and second conductive layers 41, or they may be in contact with each other. When an insulating layer or trench is provided between adjacent first conductive layers 31 and second conductive layers 41, the insulating layer or trench is the second insulating layer 5 and the trench between adjacent first doped layers 32 and second doped layers 42.
[0059] See next Figure 1-3 Electrode structure 1 includes a first electrode 11, a second electrode 12, and a first insulating layer 13. The first electrode 11 includes multiple first main gates 111 and multiple first sub-gates 112. Each of the multiple first sub-gates 112 corresponds to a first doped layer 32 and is disposed on the side of the corresponding first doped layer 32 away from the substrate 2, for collecting the current of the first polar layer 3. The second electrode 12 includes multiple second main gates 121 and multiple second sub-gates 122. Each of the multiple second sub-gates 122 corresponds to a second doped layer 42 and is disposed on the side of the corresponding second doped layer 42 away from the substrate 2, for collecting the current of the second polar layer 4. The polarities of the first electrode 11 and the second electrode 12 are opposite due to the opposite doping types of the first doped layer 32 and the second doped layer 42.
[0060] It should be noted that this application does not limit the form of the first main gate 111 and the second main gate 121, as long as the main gate can be formed on the sub-gate. For example, the first main gate 111 can be formed by screen printing, laser transfer or inkjet printing; and / or the second main gate 121 can be formed by screen printing, laser transfer or inkjet printing.
[0061] It should be noted that the first sub-gate 112 and the second sub-gate 122 are formed using an electroplating process. By employing electroplating, all sub-gates can be fabricated in one step on the backlight surface 22. Based on the position of the gate lines on the backlight surface 22, these synchronously formed gate lines are respectively defined as the first sub-gate 112 and the second sub-gate 122. Furthermore, this application does not limit the specific structural form of the first sub-gate 112 and the second sub-gate 122. For example, the first sub-gate 112 may be a first metal layer; or the first sub-gate 112 may include a first seed layer and a first metal layer stacked together, with a first main gate 111 disposed on the side of the first metal layer facing away from the first seed layer. And / or, the second sub-gate 122 may be a second metal layer; or the second sub-gate 122 may include a second seed layer and a second metal layer stacked together, with a second main gate 121 disposed on the side of the second metal layer facing away from the second seed layer.
[0062] See next Figure 1-3The first main gate 111 and the second main gate 121 are alternately distributed on the first sub-gate 112 and the second sub-gate 122 along a first direction. A first insulating layer 13 is provided at the intersections of the first main gate 111 and the second sub-gate 122, and at the intersections of the second main gate 121 and the first sub-gate 112. The first insulating layer 13 prevents the first main gate 111 and the second sub-gate 122 from contacting each other, thereby avoiding the risk of short circuits. Furthermore, this arrangement allows the first main gate 111 to collect the current collected by the first sub-gate 112, and the second main gate 121 to collect the current collected by the second sub-gate 122, ensuring that the current transmission between the first electrode 11 and the second electrode 12 does not interfere with each other. The first main grid 111 and the second main grid 121 are both silver grid lines, and the first sub-grid 112 and the second sub-grid 122 are both copper grid lines. By designing the first main grid 111 and the second main grid 121 as silver grid lines and the first sub-grid 112 and the second sub-grid 122 as copper grid lines, the manufacturing cost can be reduced on the one hand, and the excellent conductivity and contact characteristics of copper grid lines can be fully utilized on the other hand, thereby effectively improving the power generation efficiency of the back contact solar cell.
[0063] In an exemplary embodiment, the material of the silver grid lines in this application is not limited to pure silver, but may also be silver-plated copper. Specifically, the material of the first main grid 111 is silver or silver-plated copper; and / or the material of the second main grid 121 is silver or silver-plated copper.
[0064] In exemplary embodiments, the material of the copper grid lines is not limited to pure copper; other elements may be added to the copper. Specifically, when the first sub-gate 112 is a first metal layer, the material of the copper grid lines is not limited to pure copper; it may also be a copper alloy. When the first sub-gate 112 includes a first seed layer and a first metal layer stacked together, the material of the first metal layer is copper or a copper alloy, and the material of the first seed layer is selected from copper, aluminum, nickel, titanium, and their alloys. When the second sub-gate 122 is a second metal layer, the material of the copper grid lines is not limited to pure copper; a copper alloy may also be used. When the second sub-gate 122 includes a second seed layer and a second metal layer stacked together, the material of the second metal layer and the material of the second seed layer are selected from copper, aluminum, nickel, titanium, and their alloys.
[0065] See next Figure 2-3 The light-receiving surface 21 has a textured surface and is provided with a passivation layer 6 and an antireflection layer 7 stacked together. The passivation layer 6 is disposed on the light-receiving surface 21, and the antireflection layer 7 is disposed on the side of the passivation layer 6 away from the substrate 2. The passivation layer 6 is used to reduce the surface recombination rate and improve the carrier lifetime. The antireflection layer 7 is used to reduce the reflection loss of incident light and enhance light absorption.
[0066] In the exemplary embodiments, this application does not limit the specific type of passivation layer 6, as long as it can reduce the surface recombination rate and improve the carrier lifetime. For example, passivation layer 6 can be an Al2O3 layer, or a stacked intrinsic amorphous silicon layer and a doped amorphous layer, or a stacked intrinsic amorphous silicon layer and a doped microcrystalline layer, or a stacked intrinsic amorphous silicon layer and a doped polycrystalline layer.
[0067] In the exemplary embodiments, this application does not limit the structure of the antireflection layer 7, as long as it can reduce the reflection loss of incident light and enhance light absorption. For example, the antireflection layer 7 can be one or more layers. The antireflection layer 7 can be a silicon nitride layer, or a stacked silicon oxide layer and a silicon nitride layer, or a stacked silicon nitride layer and a magnesium fluoride layer.
[0068] Combination Figure 1-3 The following describes the fabrication process of the back-contact solar cell of this application:
[0069] A substrate 2 is provided. A passivation layer 6 and an antireflection layer 7 are sequentially prepared on the light-receiving surface 21 of the substrate 2, and a conductive layer is prepared on the backlight surface 22 of the substrate 2. An insulating adhesive is printed on the conductive layer by screen printing and thermally cured to form a second insulating layer 5 arranged at intervals along the second direction. A first doped layer 32 and a second doped layer 42 arranged alternately along the second direction are prepared between adjacent second insulating layers 5.
[0070] A metal seed layer is deposited on the entire backlight surface 22, and a first doped layer 32 and a second doped layer 42 are covered thereon. A protective film is covered on the surface of the metal seed layer. A first copper seed layer is formed on the first doped layer 32 and a second copper seed layer is formed on the second doped layer 42 by masking, exposure and development processes. A first metal layer is formed on the first copper seed layer by electroplating copper process, thereby obtaining the first sub-gate 112 and a second metal layer is formed on the second copper seed layer, thereby obtaining the second sub-gate 122.
[0071] Insulating adhesive is printed at intervals along a first direction on the first sub-gate 112 and the first main gate 111, and a first insulating layer 13 is formed by a thermosetting process; wherein the first insulating layer 13 on the first sub-gate 112 and the second sub-gate 122 is staggered along the first direction.
[0072] The silver main grid is prepared by screen printing and then cured to form a first main grid 111 and a second main grid 121 arranged alternately along a first direction. The first main grid 111 passes through the first insulating layer 13 on the second sub-grid 122, and the second main grid 121 passes through the first insulating layer 13 on the first sub-grid 112.
[0073] Those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.
[0074] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.
Claims
1. An electrode structure, characterized by, The electrode structure (1) includes: First insulating layer (13); The first electrode (11) includes a plurality of first main gates (111) and a plurality of first sub-gates (112) connected to the first main gates (111); A second electrode (12) with the opposite polarity to the first electrode (11), the second electrode (12) comprising a plurality of second main gates (121) and a plurality of second sub-gates (122) connected to the second main gates (121); and The first main gate (111) and the second main gate (121) are arranged alternately along a first direction, and the first sub-gate (112) and the second sub-gate (122) are distributed alternately along a second direction; a first insulating layer (13) is provided at the intersection of the first main gate (111) and the second sub-gate (122) and at the intersection of the second main gate (121) and the first sub-gate (112); the first main gate (111) and the second main gate (121) are both silver grid lines, and the first sub-gate (112) and the second sub-gate (122) are both copper grid lines.
2. The electrode structure of claim 1, wherein The first subgate (112) is a first metal layer; or The first sub-gate (112) includes a first seed layer and a first metal layer stacked together, and the first main gate (111) is disposed on the side of the first metal layer opposite to the first seed layer.
3. The electrode structure of claim 2, wherein The first metal layer is made of copper or a copper alloy; The material of the first seed layer is selected from copper, aluminum, nickel, titanium and their alloys.
4. The electrode structure of claim 1, wherein The second sub-gate (122) is a second metal layer; or The second sub-gate (122) includes a second seed layer and a second metal layer stacked together, and the second main gate (121) is disposed on the side of the second metal layer opposite to the second seed layer.
5. The electrode structure of claim 4, wherein The second metal layer is made of copper or a copper alloy; The material of the second seed layer is selected from copper, aluminum, nickel, titanium and their alloys.
6. The electrode structure according to claim 2 or 4, characterized by The metal layer is formed by electroplating.
7. The electrode structure of claim 1, wherein The first main grid (111) and the second main grid (121) are each formed independently by one of screen printing, laser transfer or inkjet printing.
8. The electrode structure of claim 1, wherein The first sub-gate (112) and the second sub-gate (122) are formed by electroplating; and / or The first main grid (111) and the second main grid (121) are each formed independently by one of screen printing, laser transfer or inkjet printing.
9. The electrode structure of claim 1, wherein The first main gate (111) is made of silver or silver-plated copper; and / or The second main gate (121) is made of silver or silver-plated copper.
10. A back contact solar cell, characterized by, The back-contact solar cell includes: The substrate (2) includes a backlight surface (22), and the backlight surface (22) is provided with a first polar layer (3) and a second polar layer (4) that are alternately distributed along a second direction; An electrode structure (1) includes a first electrode (11) and a second electrode (12). The first electrode (11) includes a plurality of first main gates (111) and a plurality of first sub-gates (112), and the first sub-gates (112) are disposed on the first polar layer (3). The second electrode (12) includes a plurality of second main gates (121) and a plurality of second sub-gates (122), and the second sub-gates (122) are disposed on the second polar layer (4). The first main gates (111) and the second main gates (121) are connected along the first polar layer (3). The first main gate (111) and the second main gate (122) are alternately distributed in one direction; the second electrode (12) and the first electrode (11) have opposite polarities; a first insulating layer (13) is provided at the intersection of the first main gate (111) and the second main gate (122) and at the intersection of the second main gate (121) and the first main gate (112); the first main gate (111) and the second main gate (121) are silver grid lines, and the first main gate (112) and the second main gate (122) are copper grid lines.
11. The back contact solar cell of claim 10, wherein, A second insulating layer (5) is provided between adjacent first polar layer (3) and second polar layer (4); or A first trench is provided between adjacent first polar layer (3) and second polar layer (4).
12. The back contact solar cell according to claim 10 or 11, characterized in that, The first polar layer (3) includes: A first conductive layer (31) and a first doped layer (32) are provided, wherein the first conductive layer (31) is disposed on the backlight surface (22) and the first doped layer (32) is disposed between the first sub-gate (112) and the first conductive layer (31).
13. The back contact solar cell of claim 12, wherein, The first conductive layer (31) comprises one or several of an ITO layer, an IMO layer, an AZO layer and a SnO X layer.
14. The back contact solar cell of claim 10 or 11, wherein, The second polar layer (4) includes: The second conductive layer (41) and the second doped layer (42) are disposed on the backlight surface (22) and the second doped layer (42) are disposed between the second sub-gate (122) and the second conductive layer (41).
15. The back contact solar cell of claim 14, wherein, The second conductive layer (41) includes one or several of an ITO layer, an IMO layer, an AZO layer, and a SnO X layer.
16. A photovoltaic module, characterized by The photovoltaic module includes the back-contact solar cell as described in any one of claims 11-15.