Back contact solar cell and solar cell module

Abstract

The invention provides a back contact solar cell and a solar cell module, the back contact solar cell comprises a silicon wafer and a grid line structure, and the grid line structure comprises main grid lines and fine grid lines connected with the main grid lines. The grid line structure comprises a plurality of middle grid line sub-structures arranged in the first direction, a first edge grid line sub-structure closest to the first edge and a second edge grid line sub-structure closest to the second edge. The distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent middle grid line substructure is larger than the distance between the center lines of the main grid lines of any two adjacent middle grid line substructures. The distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent middle grid line substructure is larger than the distance between the center lines of any two adjacent middle grid line substructures. The back contact solar cell solves the problem of damage caused by stress concentration at the edge of the cell.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a back-contact solar cell and a solar cell module. Background Art

[0002] With the rapid development of new energy technologies, solar cells have become one of the important energy supply methods. Edge welding points are often set at the edge of the back contact battery, mainly used to connect the battery cells, transmit current and improve the efficiency of the battery panel. Since the edge welding points are concentrated at the edge of the back contact battery, stress is concentrated, which makes the battery cells easy to be damaged.

[0003] Therefore, there is an urgent need for a method to solve the problem of damage caused by stress concentration at the edge of the battery cell. Summary of the invention

[0004] The main purpose of the present application is to provide a back-contact solar cell and a solar cell module to at least solve the problem of damage caused by stress concentration at the edge of the cell in the prior art.

[0005] According to one aspect of the present application, a back-contact solar cell is provided, comprising a silicon wafer and a grid line structure arranged on one side of the silicon wafer, the grid line structure comprising a main grid line and a thin grid line connected to the main grid line, the grid line structure comprising a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to a first edge, and a second edge grid line substructure closest to a second edge, the plurality of intermediate grid line substructures being located between the first edge grid line substructure and the second edge grid line substructure, in the first direction, a distance between a center line of a main grid line of the first edge grid line substructure and a center line of a main grid line of an adjacent intermediate grid line substructure is greater than a distance between center lines of main grid lines of any two adjacent intermediate grid line substructures; and / or a distance between a center line of a main grid line of the second edge grid line substructure and a center line of a main grid line of an adjacent intermediate grid line substructure is greater than a distance between center lines of any two adjacent intermediate grid line substructures; wherein the first direction is an extension direction from the first edge to the second edge, and the first direction is perpendicular to a thickness direction of the silicon wafer.

[0006] Optionally, in the first direction, the distance between the center line of the main gate line of the first edge gate line substructure and the center line of the main gate line of the adjacent middle gate line substructure is a first distance, the distance between the center line of the main gate line of the second edge gate line substructure and the center line of the main gate line of the adjacent middle gate line substructure is a second distance, the distance between the center lines of the main gate lines of any two adjacent middle gate line substructures is a third distance, the ratio of the first distance to the third distance is greater than 1 and less than or equal to 1.5, and the ratio of the second distance to the third distance is greater than 1 and less than or equal to 1.5.

[0007] Optionally, the back-contact solar cell also includes a doping structure, which is located between the silicon wafer and the gate line structure. The doping structure includes a plurality of intermediate doping layers arranged along a first direction, a first edge doping layer closest to the first edge, and a second edge doping layer closest to the second edge. The plurality of intermediate doping layers are located between the first edge doping layer and the second edge doping layer. In the first direction, the distance between the center line of the first edge doping layer and the center line of the adjacent intermediate doping layer is greater than the distance between the center lines of any two adjacent intermediate doping layers, and / or the distance between the center line of the second edge doping layer and the center line of the adjacent intermediate doping layer is greater than the distance between the center lines of any two adjacent intermediate doping layers.

[0008] Optionally, the plurality of intermediate gate line substructures include a first intermediate gate line portion and a second intermediate gate line portion alternately arranged along the first direction, wherein the polarity of the first intermediate gate line portion is different from the polarity of the second intermediate gate line portion, the polarity of the first edge gate line substructure is different from the polarity of the second edge gate line substructure, the polarity of the first intermediate gate line portion is different from the polarity of the first edge gate line substructure, and the polarity of the second intermediate gate line portion is different from the polarity of the second edge gate line substructure.

[0009] Optionally, the multiple intermediate doping layers include a first sub-doping layer and a second sub-doping layer arranged alternately along the first direction, the doping type of the first sub-doping layer is different from the doping type of the second sub-doping layer, the doping type of the first edge doping layer is different from the doping type of the second edge doping layer, the doping type of the first sub-doping layer is different from the doping type of the first edge doping layer, and the doping type of the second sub-doping layer is different from the doping type of the second edge doping layer.

[0010] Optionally, each of the first intermediate gate line sections includes a first main gate line and a plurality of first fine gate lines, one end of each of the first fine gate lines is respectively connected to the first main gate line and arranged at intervals along the second direction, and the second edge gate line substructure includes a second main gate line and a plurality of second fine gate lines, one end of each of the second fine gate lines is respectively connected to the second main gate line and arranged at intervals along the second direction, and in the first direction, the width of any one of the first main gate lines is greater than the width of the second main gate line.

[0011] Optionally, each of the second intermediate gate line sections includes a third main gate line and a plurality of third fine gate lines, one end of each of the third fine gate lines is respectively connected to the third main gate line and are arranged at intervals along the second direction, and the first edge gate line substructure includes a fourth main gate line and a plurality of fourth fine gate lines, one end of each of the fourth fine gate lines is respectively connected to the fourth main gate line and are arranged at intervals along the second direction, and in the first direction, the width of any one of the third main gate lines is greater than the width of the fourth main gate line.

[0012] Optionally, in the first direction, the width of the first main gate line is a first width, the width of the second main gate line is a second width, the width of the third main gate line is a third width, the width of the fourth main gate line is a fourth width, the ratio of the second width to the first width is greater than or equal to 0.2 and less than 1, and the ratio of the fourth width to the third width is greater than or equal to 0.2 and less than 1.

[0013] Optionally, each of the first sub-doped layers includes a first connecting portion and a plurality of second connecting portions, one end of each of the second connecting portions is respectively connected to the first connecting portion and the connecting portions are arranged at intervals along the second direction, and the second edge doped layers include a third connecting portion and a plurality of fourth connecting portions, one end of each of the fourth connecting portions is respectively connected to the third connecting portion and the connecting portions are arranged at intervals along the second direction, and in the first direction, the width of at least one of the first connecting portions is greater than the width of the third connecting portion.

[0014] Optionally, each of the second sub-doped layers includes a fifth connecting portion and a plurality of sixth connecting portions, one end of each of the sixth connecting portions is respectively connected to the fifth connecting portion and are arranged at intervals along the second direction, and the first edge doped layers include a seventh connecting portion and a plurality of eighth connecting portions, one end of each of the eighth connecting portions is respectively connected to the seventh connecting portion and are arranged at intervals along the second direction, and in the first direction, the width of at least one of the fifth connecting portions is greater than the width of the seventh connecting portion.

[0015] Optionally, in the second direction, a width of at least one of the first thin gate lines is smaller than a width of at least one of the second thin gate lines.

[0016] Optionally, in the second direction, a width of at least one of the third thin gate lines is smaller than a width of at least one of the fourth thin gate lines.

[0017] Optionally, in the second direction, the width of the first fine gate line is the fifth width, the width of the second fine gate line is the sixth width, the width of the third fine gate line is the seventh width, the width of the fourth fine gate line is the eighth width, the ratio of the fifth width to the sixth width is greater than 1 and less than or equal to 2.5, and the ratio of the seventh width to the eighth width is greater than 1 and less than or equal to 2.5.

[0018] Optionally, the intermediate gate line substructure adjacent to the first edge gate line substructure is a first predetermined gate line substructure, the first predetermined gate line substructure includes a first predetermined main gate line, a plurality of first predetermined fine gate lines and a plurality of second predetermined fine gate lines, one end of one of the first predetermined fine gate lines and one end of the second predetermined fine gate line are connected to the same position of the first predetermined main gate line, and the first predetermined fine gate line and the second predetermined fine gate line are located on both sides of the first predetermined main gate line, the second predetermined fine gate line is located on a side of the first predetermined fine gate line close to the first edge gate line substructure, and the width of the second predetermined fine gate line is greater than the width of the first predetermined fine gate line.

[0019] Optionally, the intermediate gate line substructure adjacent to the second edge gate line substructure is a second predetermined gate line substructure, the second predetermined gate line substructure includes a second predetermined main gate line, a plurality of third predetermined fine gate lines and a plurality of fourth predetermined fine gate lines, one end of a third predetermined fine gate line and one end of a fourth predetermined fine gate line are connected to the same position of the second predetermined main gate line, and the third predetermined fine gate line and the fourth predetermined fine gate line are located on both sides of the second predetermined main gate line, the fourth predetermined fine gate line is located on the side of the third predetermined fine gate line close to the second edge gate line substructure, and the width of the fourth predetermined fine gate line is greater than the width of the third predetermined fine gate line.

[0020] According to another aspect of the present application, a solar cell module is provided, comprising any one of the back-contact solar cells described above.

[0021] By applying the technical solution of the present application, a back-contact solar cell is provided, comprising a silicon wafer and a grid line structure, wherein the grid line structure comprises a main grid line and a thin grid line connected to the main grid line, the grid line structure comprises a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to a first edge, and a second edge grid line substructure closest to a second edge, wherein the distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures, and the distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of any two adjacent intermediate grid line substructures. Due to the increase in the spacing between the first edge grid line substructure and the intermediate grid line substructure and the spacing between the second edge grid line substructure and the intermediate grid line substructure, sufficient area can be reserved for setting edge welding points, so that the edge welding points are kept away from the edge of the silicon wafer, thereby avoiding the problem of stress concentration at the edge of the silicon wafer caused by the component welding points being close to the edge. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 A schematic structural diagram of a back-contact solar cell according to an embodiment of the present application is shown;

[0024] Figure 2 A schematic structural diagram of another back-contact solar cell provided according to an embodiment of the present application is shown;

[0025] Figure 3 A schematic structural diagram of another back-contact solar cell provided according to an embodiment of the present application is shown;

[0026] Figure 4 A schematic structural diagram of a doping structure provided according to an embodiment of the present application is shown.

[0027] The above drawings include the following reference numerals:

[0028] 100, middle gate line substructure; 101, first edge gate line substructure; 102, second edge gate line substructure; D1, first direction; L1, first distance; L2, second distance; L3, third distance; 103, middle doped layer; 104, first edge doped layer; 105, second edge doped layer; 106, silicon wafer; 107, doping structure; 108, gate line structure; 109, first middle gate line portion; 110, second middle gate line portion; 111, first Sub-doping layer; 112, second sub-doping layer; W1, first width; W2, second width; W3, third width; W4, fourth width; D2, second width; W5, fifth width; W6, sixth width; W7, seventh width; W8, eighth width; 10, first gate line; 20, second gate line; 31, first edge welding point; 32, second edge welding point; 41, first connecting electrode; 42, second connecting electrode; 51, first main gate; 52, second main gate. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0032] It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0034] As introduced in the background technology, in the prior art, stress concentration occurs at the edge of the cell, which can easily lead to cell damage. To solve the above problem, the embodiments of the present application provide a back-contact solar cell and a solar cell module.

[0035] Figure 1 Schematic diagram of the structure of a back-contact solar cell according to an embodiment of the present application. Figure 1 As shown, a back-contact solar cell includes a silicon wafer and a gridline structure arranged on one side of the silicon wafer, the gridline structure includes a main gridline and a thin gridline connected to the main gridline, the gridline structure includes a plurality of intermediate gridline substructures 100 arranged along a first direction D1, a first edge gridline substructure 101 closest to a first edge, and a second edge gridline substructure 102 closest to a second edge, the plurality of intermediate gridline substructures 100 are located between the first edge gridline substructure 101 and the second edge gridline substructure 102, and in the first direction D1, the main gridlines of the first edge gridline substructures 101 are located between the first edge gridline substructures 101 and the second edge gridline substructures 102. The distance between the center line of the line and the center line of the main gate line of the adjacent intermediate gate line substructure 100 is greater than the distance between the center lines of any two adjacent intermediate gate line substructures 100; and / or, the distance between the center line of the main gate line of the second edge gate line substructure 102 and the center line of the main gate line of the adjacent intermediate gate line substructure 100 is greater than the distance between the center lines of any two adjacent intermediate gate line substructures 100; wherein the first direction D1 is the extension direction from the first edge to the second edge, and the first direction D1 is perpendicular to the thickness direction of the silicon wafer.

[0036] Specifically, the back-contact solar cell moves the front electrode of the cell to the back of the cell, thereby reducing shading and reflection on the front side and improving the photoelectric conversion efficiency of the cell. This design can reduce the shading loss on the front side of the cell and improve the photoelectric conversion efficiency of the cell. The function of the main grid line in its grid line structure is to collect the current generated by the photoelectric conversion of the cell and then transmit it to the output end of the cell. The fine grid lines are metal wires connecting the main grid lines and the surface of the cell. Their function is to collect the current on the surface of the cell and then transmit it to the main grid lines. There is a certain interval between adjacent first edge grid line substructures and intermediate grid line substructures or between adjacent first edge grid line substructures and intermediate grid line substructures. In addition, the above-mentioned first edge and second edge are not limited to the above-mentioned Figure 1The settings shown may also be other settings, which will not be described in detail here. Figure 2 is a schematic structural diagram of another back contact solar cell according to an embodiment of the present application, such as Figure 2 As shown, the back-contact solar cell includes: a first grid line 10 for collecting a first polarity region (i.e., a thin grid line of the above-mentioned first edge grid line substructure); a second grid line 20 for collecting a second polarity region (i.e., a thin grid line of the above-mentioned second edge grid line substructure); a first main grid 51 (i.e., a main grid line of the above-mentioned first edge grid line substructure) arranged on a side of the back-contact cell close to the first edge and connected to the above-mentioned first grid line 10; a first edge welding point 31; a first connecting electrode 41 respectively connecting the above-mentioned first main grid 51 and the above-mentioned first edge welding point 31; wherein the distance between the first edge welding point 31 and the first edge is greater than the distance between the first main grid 51 and the first edge. A second main grid 52 (i.e., the main grid of the second edge grid substructure) is arranged on one side of the back contact battery close to the second edge and connected to the second grid line 20, the second edge and the first edge are opposite to each other; a second edge welding point 32; a second connection electrode 42 respectively connected to the second main grid 52 and the second edge welding point 32; wherein the distance between the second edge welding point 32 and the second edge is greater than the distance between the second main grid 52 and the second edge. Due to the increase in the spacing between the first edge grid substructure and the middle grid substructure and the spacing between the second edge grid substructure and the middle grid substructure, sufficient area can be reserved for setting the first edge welding point 31 and the second edge welding point 32, so that the edge welding point is away from the edge of the silicon wafer, avoiding the problem of stress concentration at the edge of the silicon wafer caused by the component welding point being close to the edge.

[0037] Through this embodiment, a back-contact solar cell is provided, including a silicon wafer and a grid line structure, the grid line structure including a main grid line and a thin grid line connected to the main grid line, the grid line structure including a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to the first edge, and a second edge grid line substructure closest to the second edge, the distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures, and the distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of any two adjacent intermediate grid line substructures. Due to the increase in the spacing between the first edge grid line substructure and the intermediate grid line substructure and the spacing between the second edge grid line substructure and the intermediate grid line substructure, sufficient area can be reserved for setting edge welding points, so that the edge welding points are away from the edge of the silicon wafer, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the component welding points being close to the edge.

[0038] In the specific implementation process, Figure 1 As shown, in the first direction D1, the distance between the center line of the main grid line of the first edge grid line substructure 101 and the center line of the main grid line of the adjacent middle grid line substructure 100 is the first distance L1, the distance between the center line of the main grid line of the second edge grid line substructure 102 and the center line of the main grid line of the adjacent middle grid line substructure 100 is the second distance L2, the distance between the center lines of any two adjacent middle grid line substructures 100 is the third distance L3, the ratio of the first distance L1 to the third distance L3 is greater than 1 and less than or equal to 1.5, and the ratio of the second distance L2 to the third distance L3 is greater than 1 and less than or equal to 1.5. The above setting can further ensure that the ratio of the first distance to the third distance and the ratio of the second distance to the third distance will not be too large or too small, while taking into account the avoidance of stress concentration on the edge of the silicon wafer due to the component welding point being close to the edge and the production cost of the battery cell.

[0039] In practical applications, the first distance and the second distance may be the same or different.

[0040] In order to further improve the photoelectric conversion efficiency of solar cells, Figure 3 As shown, the back contact solar cell of the present application further includes a doping structure 107, and the doping structure 107 is located between the silicon wafer 106 and the gate line structure 108. Figure 4 As shown, the doping structure includes a plurality of intermediate doping layers 103 arranged along a first direction, a first edge doping layer 104 closest to the first edge, and a second edge doping layer 105 closest to the second edge. The plurality of intermediate doping layers 103 are located between the first edge doping layer 104 and the second edge doping layer 105. In the first direction, the distance between the center line of the first edge doping layer 104 and the center line of the adjacent intermediate doping layer 103 is greater than the distance between the center lines of any two adjacent intermediate doping layers 103, and / or the distance between the center line of the second edge doping layer 105 and the center line of the adjacent intermediate doping layer 103 is greater than the distance between the center lines of any two adjacent intermediate doping layers 103.

[0041] Specifically, the doping layer is to change the conductive properties of the semiconductor material by doping impurity elements, thereby improving the photoelectric conversion efficiency of the solar cell. In the solar cell, the doping layer is of two types: n-type and p-type, and a PN junction is formed by the combination of n-type and p-type doping layers. When sunlight irradiates the solar cell, the photon energy separates the electrons and holes in the PN junction, generating photocurrent, thereby realizing photoelectric conversion. In practical applications, the above-mentioned gate line structure can be set one-to-one with the above-mentioned doping structure, or it can have partial overlap.

[0042] like Figure 1 As shown, the plurality of intermediate gridline substructures 100 include first intermediate gridline portions 109 and second intermediate gridline portions 110 alternately arranged along the first direction D1, wherein the polarity of the first intermediate gridline portion 109 is different from the polarity of the second intermediate gridline portion 110, the polarity of the first edge gridline substructure 101 is different from the polarity of the second edge gridline substructure 102, the polarity of the first intermediate gridline portion 109 is different from the polarity of the first edge gridline substructure 101, and the polarity of the second intermediate gridline portion 110 is different from the polarity of the second edge gridline substructure 102. In this structure, the alternating polarity arrangement can reduce the series resistance inside the battery, thereby reducing energy loss, and further improving the overall efficiency of the solar cell.

[0043] Specifically, in the first direction, the polarities of the first edge gate line substructure, the multiple first intermediate gate line portions and the second intermediate gate line portions, and the second edge gate line substructure are arranged alternately, for example: the first edge gate line substructure (positive pole) - the first intermediate gate line portion (negative pole) - the second intermediate gate line portion (positive pole) - ... the first intermediate gate line portion (negative pole) - the second intermediate gate line portion (positive pole) - the second edge gate line substructure (negative pole).

[0044] In some embodiments, such as Figure 4 As shown, the plurality of intermediate doped layers 103 include first sub-doped layers 111 and second sub-doped layers 112 alternately arranged along the first direction D1, the doping type of the first sub-doped layer 111 is different from the doping type of the second sub-doped layer 112, the doping type of the first edge doped layer 104 is different from the doping type of the second edge doped layer 105, the doping type of the first sub-doped layer 111 is different from the doping type of the first edge doped layer 104, and the doping type of the second sub-doped layer 112 is different from the doping type of the second edge doped layer 105. In this structure, the alternating arrangement of doping types can reduce the series resistance inside the battery, thereby reducing energy loss, and further improving the overall efficiency of the solar cell.

[0045] Specifically, in the first direction, the doping types of the first edge doping layer, the multiple first sub-doping layers and the second sub-doping layer, and the second edge doping layer are arranged alternately, for example: the first edge doping layer (P type) - the first sub-doping layer (N type) - the second sub-doping layer (P type) - ... the first sub-doping layer (N type) - the second sub-doping layer (P type) - the second edge doping layer (N type).

[0046] In some other embodiments, each of the first intermediate grid lines includes a first main grid line and a plurality of first fine grid lines, one end of each of the first fine grid lines is connected to the first main grid line and arranged at intervals along the second direction, and the second edge grid line substructure includes a second main grid line and a plurality of second fine grid lines, one end of each of the second fine grid lines is connected to the second main grid line and arranged at intervals along the second direction, and in the first direction, the width of any one of the first main grid lines is greater than the width of the second main grid line. Compared with a solar cell with the same width of the first main grid line and the second main grid line, this structure can save the metal usage of the second main grid line, thereby further reducing the manufacturing cost of the back contact solar cell.

[0047] Specifically, the polarity of the first intermediate gate line portion is the same as the polarity of the second edge gate line substructure. The widths of the plurality of first main gate lines may be the same or different. The widths of the plurality of first fine gate lines may be the same or different.

[0048] Each of the second intermediate grid lines includes a third main grid line and a plurality of third fine grid lines, one end of each of the third fine grid lines is connected to the third main grid line and arranged at intervals along the second direction, and the first edge grid line substructure includes a fourth main grid line and a plurality of fourth fine grid lines, one end of each of the fourth fine grid lines is connected to the fourth main grid line and arranged at intervals along the second direction, and in the first direction, the width of any of the third main grid lines is greater than the width of the fourth main grid line. Compared with a solar cell with the same width of the third main grid line and the fourth main grid line, this structure can save the metal usage of the fourth main grid line, thereby further reducing the manufacturing cost of the back contact solar cell.

[0049] Specifically, the polarity of the second intermediate gate line portion is the same as the polarity of the first edge gate line substructure. The widths of the plurality of third main gate lines may be the same or different. The widths of the plurality of third thin gate lines may be the same or different.

[0050] like Figure 1 As shown, in the first direction D1, the width of the first main grid line is the first width W1, the width of the second main grid line is the second width W2, the width of the third main grid line is the third width W3, the width of the fourth main grid line is the fourth width W4, the ratio of the second width W2 to the first width W1 is greater than or equal to 0.2 and less than 1, and the ratio of the fourth width W4 to the third width W3 is greater than or equal to 0.2 and less than 1. The above settings can further ensure that the ratio of the second width to the first width and the ratio of the fourth width to the third width will not be too large or too small, further reducing the production cost of the battery cell.

[0051] Specifically, the width of the third main grid line may be the same as or different from the width of the first main grid line. Similarly, the width of the second main grid line may be the same as or different from the width of the fourth main grid line.

[0052] Each of the first sub-doped layers includes a first connection portion and a plurality of second connection portions, one end of each of the second connection portions is connected to the first connection portion and arranged at intervals along the second direction, and the second edge doped layers include a third connection portion and a plurality of fourth connection portions, one end of each of the fourth connection portions is connected to the third connection portion and arranged at intervals along the second direction, and in the first direction, the width of at least one of the first connection portions is greater than the width of the third connection portion. This structure can further improve the photoelectric conversion efficiency of the solar cell.

[0053] In practical applications, the first sub-doped layer can be arranged one-to-one with the first intermediate gate line portion, or can only partially overlap. The second edge doped layer can be arranged one-to-one with the second edge gate line substructure, or can only partially overlap.

[0054] Each of the second sub-doped layers includes a fifth connection portion and a plurality of sixth connection portions, one end of each of the sixth connection portions is connected to the fifth connection portion and arranged at intervals along the second direction, and the first edge doped layer includes a seventh connection portion and a plurality of eighth connection portions, one end of each of the eighth connection portions is connected to the seventh connection portion and arranged at intervals along the second direction, and in the first direction, the width of at least one of the fifth connection portions is greater than the width of any of the seventh connection portions. This structure can further improve the photoelectric conversion efficiency of the solar cell.

[0055] Specifically, the second sub-doped layer may be disposed in one-to-one correspondence with the second intermediate gate line portion, or may only partially overlap. The first edge doped layer may be disposed in one-to-one correspondence with the first edge gate line substructure, or may only partially overlap.

[0056] In the second direction, the width of at least one of the first fine grid lines is smaller than the width of at least one of the second fine grid lines. The width of the fine grid lines of the first intermediate grid line portion is smaller than the width of the fine grid lines of the second edge grid line substructure, which can reduce the resistance at the second edge, thereby reducing the edge fine grid transmission loss, and further improving the efficiency of the back contact battery.

[0057] Specifically, the widths of the plurality of first thin gate lines may be the same or different. Similarly, the widths of the plurality of second thin gate lines may be the same or different.

[0058] In the second direction, the width of at least one of the third fine grid lines is smaller than the width of at least one of the fourth fine grid lines. The width of the fine grid lines of the second intermediate grid line portion is smaller than the width of the fine grid lines of the first edge grid line substructure, which can reduce the resistance at the first edge, thereby reducing the edge fine grid transmission loss, and further improving the efficiency of the back contact battery.

[0059] Specifically, the widths of the plurality of third thin gate lines may be the same or different. Similarly, the widths of the plurality of fourth thin gate lines may be the same or different.

[0060] like Figure 1 As shown, in the second direction D2, the width of the first thin grid line is the fifth width W5, the width of the second thin grid line is the sixth width W6, the width of the third thin grid line is the seventh width W7, the width of the fourth thin grid line is the eighth width W8, the ratio of the fifth width W5 to the sixth width W6 is greater than 1 and less than or equal to 2.5, and the ratio of the seventh width W7 to the eighth width W8 is greater than 1 and less than or equal to 2.5. The above settings can further ensure that the ratio of the fifth width to the sixth width and the ratio of the seventh width to the eighth width will not be too large or too small, while taking into account both improving the efficiency of the back contact battery and reducing the production cost of the battery cell.

[0061] Specifically, the fifth width and the seventh width may be the same or different. The sixth width and the eighth width may be the same or different.

[0062] The intermediate gate line substructure adjacent to the first edge gate line substructure is a first predetermined gate line substructure, the first predetermined gate line substructure includes a first predetermined main gate line, a plurality of first predetermined fine gate lines and a plurality of second predetermined fine gate lines, one end of one of the first predetermined fine gate lines and one end of the second predetermined fine gate line are connected to the same position of the first predetermined main gate line, and the first predetermined fine gate line and the second predetermined fine gate line are located on both sides of the first predetermined main gate line, the second predetermined fine gate line is located on the side of the first predetermined fine gate line close to the first edge gate line substructure, and the width of the second predetermined fine gate line is greater than the width of the first predetermined fine gate line. This structure can further avoid the problem of stress concentration on the edge of the silicon wafer caused by the component welding point being close to the edge.

[0063] Specifically, the width of the second predetermined thin gate line close to the first edge gate line substructure is greater than the width of the first predetermined thin gate line far from the first edge gate line substructure.

[0064] The above-mentioned intermediate gate line substructure adjacent to the above-mentioned second edge gate line substructure is a second predetermined gate line substructure, and the above-mentioned second predetermined gate line substructure includes a second predetermined main gate line, a plurality of third predetermined fine gate lines, and a plurality of fourth predetermined fine gate lines, one end of the above-mentioned third predetermined fine gate line and one end of the above-mentioned fourth predetermined fine gate line are connected to the same position of the above-mentioned second predetermined main gate line, and the above-mentioned third predetermined fine gate line and the above-mentioned fourth predetermined fine gate line are located on both sides of the above-mentioned second predetermined main gate line, and the above-mentioned fourth predetermined fine gate line is located on the side of the above-mentioned third predetermined fine gate line close to the above-mentioned second edge gate line substructure, and the width of the above-mentioned fourth predetermined fine gate line is greater than the width of the above-mentioned third predetermined fine gate line. This structure can further avoid the problem of stress concentration on the edge of the silicon wafer caused by the component welding point being close to the edge.

[0065] Specifically, the width of the fourth predetermined thin gate line close to the second edge gate line substructure is greater than the width of the third predetermined thin gate line far from the second edge gate line substructure.

[0066] According to an embodiment of the present application, a solar cell assembly is also provided, comprising: any one of the above-mentioned back-contact solar cells.

[0067] Through this embodiment, a solar cell assembly is provided, including any one of the above-mentioned back-contact solar cells, including a silicon wafer and a grid line structure, the grid line structure including a main grid line and a thin grid line connected to the main grid line, the grid line structure including a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to the first edge, and a second edge grid line substructure closest to the second edge, the distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures, and the distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of any two adjacent intermediate grid line substructures. Due to the increase in the spacing between the first edge grid line substructure and the intermediate grid line substructure and the spacing between the second edge grid line substructure and the intermediate grid line substructure, sufficient area can be reserved for setting edge welding points, so that the edge welding points are away from the edge of the silicon wafer, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the component welding points being close to the edge.

[0068] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0069] 1) The back-contact solar cell of the present application includes a silicon wafer and a grid line structure, wherein the grid line structure includes a main grid line and a thin grid line connected to the main grid line, and the grid line structure includes a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to the first edge, and a second edge grid line substructure closest to the second edge, wherein the distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures, and the distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of any two adjacent intermediate grid line substructures. As the spacing between the first edge grid line substructure and the intermediate grid line substructure and the spacing between the second edge grid line substructure and the intermediate grid line substructure increase, sufficient area can be reserved for setting edge welding points, so that the edge welding points are away from the edge of the silicon wafer, thereby avoiding the problem of stress concentration on the edge of the silicon wafer caused by the component welding points being close to the edge.

[0070] 2) The solar cell assembly of the present application includes any one of the above-mentioned back-contact solar cells, including a silicon wafer and a grid line structure, the grid line structure includes a main grid line and a thin grid line connected to the main grid line, the grid line structure includes a plurality of intermediate grid line substructures arranged along a first direction, a first edge grid line substructure closest to the first edge, and a second edge grid line substructure closest to the second edge, the distance between the center line of the main grid line of the first edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures, and the distance between the center line of the main grid line of the second edge grid line substructure and the center line of the main grid line of the adjacent intermediate grid line substructure is greater than the distance between the center lines of any two adjacent intermediate grid line substructures. As the spacing between the first edge grid line substructure and the intermediate grid line substructure and the spacing between the second edge grid line substructure and the intermediate grid line substructure increase, sufficient area can be reserved for setting edge welding points, so that the edge welding points are away from the edge of the silicon wafer, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the component welding points being close to the edge.

[0071] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A back contact solar cell, characterized in that: It includes a silicon wafer and a gate line structure arranged on one side of the silicon wafer, the gate line structure includes a main gate line and a thin gate line connected to the main gate line, the gate line structure includes a plurality of intermediate gate line substructures arranged along a first direction, a first edge gate line substructure closest to a first edge, and a second edge gate line substructure closest to a second edge, the plurality of intermediate gate line substructures are located between the first edge gate line substructure and the second edge gate line substructure, in the first direction, the distance between the center line of the main gate line of the first edge gate line substructure and the center line of the main gate line of the adjacent intermediate gate line substructure is greater than the distance between the center lines of the main gate lines of any two adjacent intermediate gate line substructures; and / or the distance between the center line of the main gate line of the second edge gate line substructure and the center line of the main gate line of the adjacent intermediate gate line substructure is greater than the distance between the center lines of any two adjacent intermediate gate line substructures; wherein the first direction is an extension direction from the first edge to the second edge, and the first direction is perpendicular to the thickness direction of the silicon wafer.

2. The back contact solar cell according to claim 1, characterized in that: In the first direction, the distance between the center line of the main gate line of the first edge gate line substructure and the center line of the main gate line of the adjacent middle gate line substructure is a first distance, the distance between the center line of the main gate line of the second edge gate line substructure and the center line of the main gate line of the adjacent middle gate line substructure is a second distance, the distance between the center lines of the main gate lines of any two adjacent middle gate line substructures is a third distance, the ratio of the first distance to the third distance is greater than 1 and less than or equal to 1.5, and the ratio of the second distance to the third distance is greater than 1 and less than or equal to 1.

5.

3. The back contact solar cell according to claim 1, characterized in that: The back-contact solar cell also includes a doping structure, which is located between the silicon wafer and the gate line structure. The doping structure includes a plurality of intermediate doping layers arranged along a first direction, a first edge doping layer closest to the first edge, and a second edge doping layer closest to the second edge. The plurality of intermediate doping layers are located between the first edge doping layer and the second edge doping layer. In the first direction, the distance between the center line of the first edge doping layer and the center line of the adjacent intermediate doping layer is greater than the distance between the center lines of any two adjacent intermediate doping layers, and / or the distance between the center line of the second edge doping layer and the center line of the adjacent intermediate doping layer is greater than the distance between the center lines of any two adjacent intermediate doping layers.

4. The back contact solar cell according to claim 3, characterized in that: The multiple intermediate gate line substructures include a first intermediate gate line portion and a second intermediate gate line portion alternately arranged along the first direction, wherein the polarity of the first intermediate gate line portion is different from the polarity of the second intermediate gate line portion, the polarity of the first edge gate line substructure is different from the polarity of the second edge gate line substructure, the polarity of the first intermediate gate line portion is different from the polarity of the first edge gate line substructure, and the polarity of the second intermediate gate line portion is different from the polarity of the second edge gate line substructure.

5. The back contact solar cell according to claim 4, characterized in that: The multiple intermediate doped layers include a first sub-doped layer and a second sub-doped layer alternately arranged along the first direction, the doping type of the first sub-doped layer is different from the doping type of the second sub-doped layer, the doping type of the first edge doped layer is different from the doping type of the second edge doped layer, the doping type of the first sub-doped layer is different from the doping type of the first edge doped layer, and the doping type of the second sub-doped layer is different from the doping type of the second edge doped layer.

6. The back contact solar cell according to claim 4, characterized in that: Each of the first intermediate gate line sections includes a first main gate line and a plurality of first fine gate lines, one end of each of the first fine gate lines is respectively connected to the first main gate line and arranged at intervals along the second direction, and the second edge gate line substructure includes a second main gate line and a plurality of second fine gate lines, one end of each of the second fine gate lines is respectively connected to the second main gate line and arranged at intervals along the second direction, and in the first direction, the width of any one of the first main gate lines is greater than the width of the second main gate line.

7. The back contact solar cell according to claim 6, characterized in that: Each of the second intermediate gate line sections includes a third main gate line and a plurality of third fine gate lines, one end of each of the third fine gate lines is respectively connected to the third main gate line and are arranged at intervals along the second direction. The first edge gate line substructure includes a fourth main gate line and a plurality of fourth fine gate lines, one end of each of the fourth fine gate lines is respectively connected to the fourth main gate line and are arranged at intervals along the second direction. In the first direction, the width of any one of the third main gate lines is greater than the width of the fourth main gate line.

8. The back contact solar cell according to claim 7, characterized in that: In the first direction, the width of the first main gate line is the first width, the width of the second main gate line is the second width, the width of the third main gate line is the third width, and the width of the fourth main gate line is the fourth width. The ratio of the second width to the first width is greater than or equal to 0.2 and less than 1, and the ratio of the fourth width to the third width is greater than or equal to 0.2 and less than 1.

9. The back contact solar cell according to claim 5, characterized in that: Each of the first sub-doped layers includes a first connecting portion and a plurality of second connecting portions, one end of each of the second connecting portions is connected to the first connecting portion and the connecting portions are arranged at intervals along the second direction, and the second edge doped layers include a third connecting portion and a plurality of fourth connecting portions, one end of each of the fourth connecting portions is connected to the third connecting portion and the connecting portions are arranged at intervals along the second direction, and in the first direction, a width of at least one of the first connecting portions is greater than a width of the third connecting portion.

10. The back contact solar cell according to claim 5, characterized in that: Each of the second sub-doped layers includes a fifth connecting portion and a plurality of sixth connecting portions, one end of each of the sixth connecting portions is connected to the fifth connecting portion and the connecting portions are arranged at intervals along the second direction, and the first edge doped layers include a seventh connecting portion and a plurality of eighth connecting portions, one end of each of the eighth connecting portions is connected to the seventh connecting portion and the connecting portions are arranged at intervals along the second direction, and in the first direction, the width of at least one of the fifth connecting portions is greater than the width of the seventh connecting portion.

11. The back contact solar cell according to claim 7, characterized in that: In the second direction, a width of at least one of the first thin gate lines is smaller than a width of at least one of the second thin gate lines.

12. The back contact solar cell according to claim 11, characterized in that: In the second direction, a width of at least one of the third thin gate lines is smaller than a width of at least one of the fourth thin gate lines.

13. The back contact solar cell according to claim 12, characterized in that: In the second direction, the width of the first fine gate line is the fifth width, the width of the second fine gate line is the sixth width, the width of the third fine gate line is the seventh width, and the width of the fourth fine gate line is the eighth width. The ratio of the fifth width to the sixth width is greater than 1 and less than or equal to 2.5, and the ratio of the seventh width to the eighth width is greater than 1 and less than or equal to 2.

5.

14. The back contact solar cell according to claim 12, characterized in that: The intermediate gate line substructure adjacent to the first edge gate line substructure is a first predetermined gate line substructure, the first predetermined gate line substructure includes a first predetermined main gate line, multiple first predetermined fine gate lines and multiple second predetermined fine gate lines, one end of one of the first predetermined fine gate lines and one end of the second predetermined fine gate line are connected to the same position of the first predetermined main gate line, and the first predetermined fine gate line and the second predetermined fine gate line are located on both sides of the first predetermined main gate line, the second predetermined fine gate line is located on the side of the first predetermined fine gate line close to the first edge gate line substructure, and the width of the second predetermined fine gate line is greater than the width of the first predetermined fine gate line.

15. The back contact solar cell according to claim 12, characterized in that: The intermediate gate line substructure adjacent to the second edge gate line substructure is a second predetermined gate line substructure, the second predetermined gate line substructure includes a second predetermined main gate line, a plurality of third predetermined fine gate lines and a plurality of fourth predetermined fine gate lines, one end of a third predetermined fine gate line and one end of a fourth predetermined fine gate line are connected to the same position of the second predetermined main gate line, and the third predetermined fine gate line and the fourth predetermined fine gate line are located on both sides of the second predetermined main gate line, the fourth predetermined fine gate line is located on the side of the third predetermined fine gate line close to the second edge gate line substructure, and the width of the fourth predetermined fine gate line is greater than the width of the third predetermined fine gate line.

16. A solar cell module, characterized in that: A back-contact solar cell comprising the method of any one of claims 1 to 15.

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