Back contact solar cells and solar cell modules

Abstract

The application 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. 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 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 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. 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. 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, in particular, to a back contact solar cell and a solar cell module. BACKGROUND

[0002] With the rapid development of new energy technology, solar cells have become one of the important energy supply methods. An edge soldering point is usually arranged at the edge position of a back contact cell, which is mainly used for connecting cell pieces, transmitting current and improving the efficiency of a cell panel. Since the edge soldering point is concentrated at the edge position of the back contact cell, stress is concentrated, which causes the cell pieces to be easily 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 cell piece. SUMMARY

[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 piece in the prior art.

[0005] According to an 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 fine 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, 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 / or, 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; wherein the first direction is the extension direction from the first edge to the second edge, and the first direction is perpendicular to the thickness direction of the silicon wafer.

[0006] Optionally, in the first direction, a distance between a center line of a main gate line of the first edge gate line substructure and a center line of a main gate line of an adjacent intermediate gate line substructure is a first distance, a distance between a center line of a main gate line of the second edge gate line substructure and a center line of a main gate line of an adjacent intermediate gate line substructure is a second distance, and a distance between center lines of main gate lines of any two adjacent intermediate gate line substructures is a third distance, a ratio of the first distance to the third distance is greater than 1 and less than or equal to 1.5, and a 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 further comprises a doping structure between the silicon wafer and the gate line structure, the doping structure comprises a plurality of intermediate doping layers arranged along the 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 between the first edge doping layer and the second edge doping layer, in the first direction, a distance between a center line of the first edge doping layer and a center line of an adjacent intermediate doping layer is greater than a distance between center lines of any two adjacent intermediate doping layers, and / or a distance between a center line of the second edge doping layer and a center line of an adjacent intermediate doping layer is greater than a distance between center lines of any two adjacent intermediate doping layers.

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

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

[0010] Optionally, each of the first intermediate gate line portions comprises a first main gate line and a plurality of first fine gate lines, one end of each of the first fine gate lines is connected with the first main gate line and is arranged in a second direction in a spaced manner, the second edge gate line sub-structure comprises a second main gate line and a plurality of second fine gate lines, one end of each of the second fine gate lines is connected with the second main gate line and is arranged in the second direction in a spaced manner, in the first direction, a width of any one of the first main gate lines is greater than a width of the second main gate line.

[0011] Optionally, each of the second intermediate gate line portions comprises a third main gate line and a plurality of third fine gate lines, one end of each of the third fine gate lines is connected with the third main gate line and is arranged in a second direction in a spaced manner, the first edge gate line sub-structure comprises a fourth main gate line and a plurality of fourth fine gate lines, one end of each of the fourth fine gate lines is connected with the fourth main gate line and is arranged in the second direction in a spaced manner, in the first direction, a width of any one of the third main gate lines is greater than a width of the fourth main gate line.

[0012] Optionally, in the first direction, a width of the first main gate line is a first width, a width of the second main gate line is a second width, a width of the third main gate line is a third width, a width of the fourth main gate line is a fourth width, a ratio of the second width to the first width is greater than or equal to 0.2 and less than 1, a 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 comprises a first connecting portion and a plurality of second connecting portions, one end of each of the second connecting portions is connected with the first connecting portion and is arranged in a second direction in a spaced manner, the second edge doped layer comprises a third connecting portion and a plurality of fourth connecting portions, one end of each of the fourth connecting portions is connected with the third connecting portion and is arranged in the second direction in a spaced manner, 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.

[0014] Optionally, each of the second sub-doped layers comprises a fifth connecting portion and a plurality of sixth connecting portions, one end of each of the sixth connecting portions is connected with the fifth connecting portion and is arranged in a second direction in a spaced manner, the first edge doped layer comprises a seventh connecting portion and a plurality of eighth connecting portions, one end of each of the eighth connecting portions is connected with the seventh connecting portion and is arranged in the second direction in a spaced manner, in the first direction, a width of at least one of the fifth connecting portions is greater than a width of the seventh connecting portion.

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

[0016] Optionally, 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.

[0017] Optionally, the intermediate grid line substructure adjacent to the first edge grid line substructure is a first predetermined grid line substructure, the first predetermined grid line substructure comprising a first predetermined main grid line, a plurality of first predetermined fine grid lines and a plurality of second predetermined fine grid lines, one end of one of the first predetermined fine grid lines and one end of one of the second predetermined fine grid lines being connected to the same position of the first predetermined main grid line, and the first predetermined fine grid lines and the second predetermined fine grid lines being located on two sides of the first predetermined main grid line, the second predetermined fine grid lines being located on the side of the first predetermined fine grid lines closer to the first edge grid line substructure, the width of the second predetermined fine grid lines being greater than the width of the first predetermined fine grid lines.

[0018] Optionally, the intermediate grid line substructure adjacent to the second edge grid line substructure is a second predetermined grid line substructure, the second predetermined grid line substructure comprising a second predetermined main grid line, a plurality of third predetermined fine grid lines and a plurality of fourth predetermined fine grid lines, one end of one of the third predetermined fine grid lines and one end of one of the fourth predetermined fine grid lines being connected to the same position of the second predetermined main grid line, and the third predetermined fine grid lines and the fourth predetermined fine grid lines being located on two sides of the second predetermined main grid line, the fourth predetermined fine grid lines being located on the side of the third predetermined fine grid lines closer to the second edge grid line substructure, the width of the fourth predetermined fine grid lines being greater than the width of the third predetermined fine grid lines.

[0019] According to another aspect of the present application, there is provided a solar cell module comprising any one of the back contact solar cells.

[0020] The technical scheme is applied to provide a back contact solar cell, which comprises a silicon wafer and a grid line structure, the grid line structure comprises a main grid line and a fine grid line connected with 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, a distance between a center line of the main grid line of the first edge grid line substructure and a center line of the 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 a 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 an adjacent intermediate grid line substructure is greater than a distance between center lines of any two adjacent intermediate grid line substructures. Since 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 are increased, a sufficient area can be reserved for setting an edge soldering point, so that the edge soldering point is away from the silicon wafer edge, and the problem of stress concentration of the silicon wafer edge caused by the fact that the component soldering point is close to the edge is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the application. The use of these drawings in explaining the application is in no way intended as a limitation on the full scope of the present application, and the drawings are instead meant only to aid in understanding which are explained in the specification.

[0022] Figure 1 A structural schematic diagram of a back contact solar cell according to an embodiment of the present application is shown;

[0023] Figure 2 A structural schematic diagram of another back contact solar cell provided according to an embodiment of the present application is shown;

[0024] Figure 3 A structural schematic diagram of still another back contact solar cell provided according to an embodiment of the present application is shown;

[0025] Figure 4 A structural schematic diagram of a doping structure provided according to an embodiment of the present application is shown.

[0026] In the above drawings, the following reference signs are used:

[0027] 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, doped structure; 108, gate line structure; 109, first middle gate line part; 110, second middle gate line part; 111, first sub-doped layer; 112, second sub-doped 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 soldering point; 32, second edge soldering point; 41, first connecting electrode; 42, second connecting electrode; 51, first main gate; 52, second main gate. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed description is merely exemplary in nature and is not intended to limit the application according to the embodiments of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs.

[0029] It should be noted that the terms used herein are merely exemplary in nature and are not intended to limit the application according to the embodiments of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0030] It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can also be present.

[0031] It should be noted that the embodiments described are merely exemplary in nature and are not intended to limit the application according to the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0032] It should be understood that the term "and / or" as used herein merely describes an associated relationship between associated objects, and can represent three relationships, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0033] As introduced in the background, the edge stress of the battery sheet in the prior art is concentrated, which is easy to cause the battery damage. To solve the above problem, the embodiments of the present application provide a back contact solar cell and a solar cell module.

[0034] Figure 1 is a structural schematic diagram of a back contact solar cell according to the embodiments of the present application. As shown in Figure 1 The back contact solar cell includes a silicon sheet and a grid line structure arranged on one side of the silicon sheet. The grid line structure includes a main grid line and a fine grid line connected with the main grid line. The grid line structure includes a plurality of intermediate grid line substructures 100 arranged along a first direction D1, a first edge grid line substructure 101 closest to a first edge, and a second edge grid line substructure 102 closest to a second edge. The plurality of intermediate grid line substructures 100 are located between the first edge grid line substructure 101 and the second edge grid line substructure 102. 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 intermediate grid line substructure 100 is greater than the distance between the center lines of the main grid lines of any two adjacent intermediate grid line substructures 100; and / or, 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 intermediate grid line substructure 100 is greater than the distance between the center lines of any two adjacent intermediate grid line substructures 100. 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 sheet.

[0035] Specifically, the back contact solar cell moves the front electrode of the battery to the back of the battery, thereby reducing the shading and reflection of the front, and improving the photoelectric conversion efficiency of the battery. This design can reduce the shading loss of the front of the battery and improve the photoelectric conversion efficiency of the battery. The main grid line in the grid line structure functions to collect the current generated by the photoelectric conversion of the battery and then transmit it to the output end of the battery. The fine grid line is a metal line connecting the main grid line and the surface of the battery. Their function is to collect the current on the surface of the battery and then transmit it to the main grid line. There is a certain interval between the adjacent first edge grid line substructures and the intermediate grid line substructures, or between the adjacent first edge grid line substructures and the intermediate grid line substructures. In addition, the first edge and the second edge are not limited to the above Figure 1The settings shown can also be other settings, which will not be described here. Figure 2 is another structure diagram of a back contact solar cell according to an embodiment of the present application, as shown in the figure, Figure 2 As shown, the back contact solar cell includes: a first grid line 10 (i.e. the fine grid line of the first edge grid line substructure described above) for collecting the first polarity region; a second grid line 20 (i.e. the fine grid line of the second edge grid line substructure described above) for collecting the second polarity region; a first main grid 51 (i.e. the main grid line of the first edge grid line substructure described above) arranged on the side of the back contact cell close to the first edge and connected to the first grid line 10; a first edge soldering point 31; a first connecting electrode 41 connected to the first main grid 51 and the first edge soldering point 31 respectively; wherein the distance between the first edge soldering 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 line of the second edge grid line substructure described above) is arranged on the side of the back contact cell close to the second edge and connected to the second grid line 20, and the second edge is opposite to the first edge; a second edge soldering point 32; a second connecting electrode 42 connected to the second main grid 52 and the second edge soldering point 32 respectively; wherein the distance between the second edge soldering point 32 and the second edge is greater than the distance between the second main grid 52 and the second edge. Due to the increased spacing between the first edge grid line substructure and the intermediate grid line substructure and the increased spacing between the second edge grid line substructure and the intermediate grid line substructure, sufficient area can be reserved for arranging the first edge soldering point 31 and the second edge soldering point 32, so that the edge soldering point is far away from the edge of the silicon wafer, avoiding the problem of stress concentration of the silicon wafer edge caused by the proximity of the module soldering point to the edge.

[0036] Through the embodiment, a back contact solar cell is provided, including a silicon wafer and a grid line structure, the grid line structure includes a main grid line and a fine 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 a first edge, and a second edge grid line substructure closest to a 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 increased spacing between the first edge grid line substructure and the intermediate grid line substructure and the increased spacing between the second edge grid line substructure and the intermediate grid line substructure, sufficient area can be reserved for arranging the edge soldering point, so that the edge soldering point is far away from the edge of the silicon wafer, avoiding the problem of stress concentration of the silicon wafer edge caused by the proximity of the module soldering point to the edge.

[0037] In the specific implementation process, for example,Figure 1 As shown, in the above-mentioned first direction D1, the distance between the center line of the main grid line of the above-mentioned first edge grid line substructure 101 and the center line of the main grid line of the adjacent above-mentioned middle grid line substructure 100 is a first distance L1, the distance between the center line of the main grid line of the above-mentioned second edge grid line substructure 102 and the center line of the main grid line of the adjacent middle grid line substructure 100 is a second distance L2, and the distance between the center line of the main grid line of any two adjacent above-mentioned middle grid line substructures 100 is a third distance L3. The ratio of the above-mentioned first distance L1 to the above-mentioned third distance L3 is greater than 1 and less than or equal to 1.5, and the ratio of the above-mentioned second distance L2 to the above-mentioned third distance L3 is greater than 1 and less than or equal to 1.5. The above-mentioned arrangement 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 are neither too large nor too small, while taking into account the avoidance of stress concentration on the edge of the silicon wafer and the manufacturing cost of the battery piece caused by the welding point of the component being close to the edge.

[0038] In practical applications, the above-mentioned first distance and the second distance can be the same or different.

[0039] In order to further improve the photoelectric conversion efficiency of the solar cell, as shown, Figure 3 The above-mentioned back contact solar cell of the present application further comprises a doping structure 107, which is located between the above-mentioned silicon wafer 106 and the above-mentioned grid line structure 108, as shown, Figure 4 The above-mentioned doping structure comprises a plurality of middle doping layers 103 arranged along a first direction, a first edge doping layer 104 closest to the above-mentioned first edge, and a second edge doping layer 105 closest to the above-mentioned second edge. The plurality of above-mentioned middle doping layers 103 are located between the above-mentioned first edge doping layer 104 and the above-mentioned second edge doping layer 105. In the above-mentioned first direction, the distance between the center line of the above-mentioned first edge doping layer 104 and the center line of the adjacent above-mentioned middle doping layer 103 is greater than the distance between the center line of any two adjacent above-mentioned middle doping layers 103, and / or the distance between the center line of the above-mentioned second edge doping layer 105 and the center line of the adjacent middle doping layer 103 is greater than the distance between the center line of any two adjacent above-mentioned middle doping layers 103.

[0040] Specifically, the doping layer is obtained by doping impurity elements to change the electrical conductivity of the semiconductor material, thereby improving the photoelectric conversion efficiency of the solar cell piece. In the solar cell piece, the doping layer is n-type and p-type, and a PN junction is formed by the combination of n-type and p-type doping layers. When sunlight shines on the solar cell piece, the photon energy causes the electrons and holes in the PN junction to separate, generating a photo-generated current, thereby realizing photoelectric conversion. In practical applications, the above-mentioned grid line structure can be arranged one by one with the above-mentioned doping structure, or can have partial overlap.

[0041] As shown in Figure 1 The plurality of intermediate gate line substructures 100 include first intermediate gate line portions 109 and second intermediate gate line portions 110 arranged alternately along the first direction D1, wherein the polarity of the first intermediate gate line portions 109 is different from the polarity of the second intermediate gate line portions 110, the polarity of the first edge gate line substructure 101 is different from the polarity of the second edge gate line substructure 102, the polarity of the first intermediate gate line portions 109 is different from the polarity of the first edge gate line substructure 101, and the polarity of the second intermediate gate line portions 110 is different from the polarity of the second edge gate line substructure 102. In this structure, the alternating arrangement of the polarity can reduce the series resistance inside the cell, thereby reducing energy loss and further improving the overall efficiency of the solar cell.

[0042] Specifically, in the first direction, the polarity of the first edge gate line substructure, the plurality of first intermediate gate line portions and second intermediate gate line portions, and the second edge gate line substructure is arranged alternately, for example: first edge gate line substructure (positive) - first intermediate gate line portion (negative) - second intermediate gate line portion (positive) - … first intermediate gate line portion (negative) - second intermediate gate line portion (positive) - second edge gate line substructure (negative).

[0043] In some embodiments, as shown in Figure 4 The plurality of intermediate doped layers 103 include first sub-doped layers 111 and second sub-doped layers 112 arranged alternately along the first direction D1, wherein the doping type of the first sub-doped layers 111 is different from the doping type of the second sub-doped layers 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 layers 111 is different from the doping type of the first edge doped layer 104, and the doping type of the second sub-doped layers 112 is different from the doping type of the second edge doped layer 105. In this structure, the alternating arrangement of the doping type can reduce the series resistance inside the cell, thereby reducing energy loss and further improving the overall efficiency of the solar cell.

[0044] Specifically, in the first direction, the doping type of the first edge doped layer, the plurality of first sub-doped layers and second sub-doped layers, and the second edge doped layer is arranged alternately, for example: first edge doped layer (P-type) - first sub-doped layer (N-type) - second sub-doped layer (P-type) - … first sub-doped layer (N-type) - second sub-doped layer (P-type) - second edge doped layer (N-type).

[0045] In some other embodiments, each of the first intermediate busbar portions includes a first main busbar and a plurality of first fine busbars, one end of each of the first fine busbars is connected to the first main busbar and is arranged along the second direction, the second edge busbar substructure includes a second main busbar and a plurality of second fine busbars, one end of each of the second fine busbars is connected to the second main busbar and is arranged along the second direction, and in the first direction, the width of any one of the first main busbars is greater than the width of the second main busbar. Compared with the solar cell piece with the same width of the first main busbar and the second main busbar, the structure can save the amount of metal of the second main busbar, and further reduce the manufacturing cost of the back contact solar cell.

[0046] Specifically, the polarity of the first intermediate busbar portion is the same as the polarity of the second edge busbar substructure. The widths of the first main busbars can be the same or different. The widths of the first fine busbars can be the same or different.

[0047] Each of the second intermediate busbar portions includes a third main busbar and a plurality of third fine busbars, one end of each of the third fine busbars is connected to the third main busbar and is arranged along the second direction, the first edge busbar substructure includes a fourth main busbar and a plurality of fourth fine busbars, one end of each of the fourth fine busbars is connected to the fourth main busbar and is arranged along the second direction, and in the first direction, the width of any one of the third main busbars is greater than the width of the fourth main busbar. Compared with the solar cell piece with the same width of the third main busbar and the fourth main busbar, the structure can save the amount of metal of the fourth main busbar, and further reduce the manufacturing cost of the back contact solar cell.

[0048] Specifically, the polarity of the second intermediate busbar portion is the same as the polarity of the first edge busbar substructure. The widths of the third main busbars can be the same or different. The widths of the third fine busbars can be the same or different.

[0049] As shown in Figure 1 In the first direction D1, the width of the first main busbar is a first width W1, the width of the second main busbar is a second width W2, the width of the third main busbar is a third width W3, the width of the fourth main busbar is a 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 setting 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 are not too large or too small, and further reduce the manufacturing cost of the cell piece.

[0050] Specifically, the width of the third main grid line can be the same as or different from the width of the first main grid line. Similarly, the width of the second main grid line can be the same as or different from the width of the fourth main grid line.

[0051] Each of the first sub-doped layers includes a first connecting part and a plurality of second connecting parts, one end of each of the second connecting parts is connected to the first connecting part and is arranged at intervals along the second direction, each of the second edge doped layers includes a third connecting part and a plurality of fourth connecting parts, one end of each of the fourth connecting parts is connected to the third connecting part and is arranged at intervals along the second direction, and in the first direction, the width of at least one of the first connecting parts is greater than the width of the third connecting part. This structure can further improve the photoelectric conversion efficiency of the solar cell.

[0052] In practical applications, the first sub-doped layer can be arranged one-to-one corresponding to the first intermediate grid line part, or can only have partial overlap. The second edge doped layer can be arranged one-to-one corresponding to the second edge grid line substructure, or can only have partial overlap.

[0053] Each of the second sub-doped layers includes a fifth connecting part and a plurality of sixth connecting parts, one end of each of the sixth connecting parts is connected to the fifth connecting part and is arranged at intervals along the second direction, each of the first edge doped layers includes a seventh connecting part and a plurality of eighth connecting parts, one end of each of the eighth connecting parts is connected to the seventh connecting part and is arranged at intervals along the second direction, and in the first direction, the width of at least one of the fifth connecting parts is greater than the width of any one of the seventh connecting parts. This structure can further improve the photoelectric conversion efficiency of the solar cell.

[0054] Specifically, the second sub-doped layer can be arranged one-to-one corresponding to the second intermediate grid line part, or can only have partial overlap. The first edge doped layer can be arranged one-to-one corresponding to the first edge grid line substructure, or can only have partial overlap.

[0055] In the second direction, the width of at least one of the first fine grid lines is less 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 part is less 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 transmission loss of the edge fine grid, further improving the efficiency of the back contact cell.

[0056] Specifically, the widths of the plurality of first fine grid lines can be the same or different. Similarly, the widths of the plurality of second fine grid lines can be the same or different.

[0057] In the second direction described above, the width of at least one of the third fine gate lines is smaller than the width of at least one of the fourth fine gate lines. The width of the fine gate line in the second intermediate gate line portion is smaller than the width of the fine gate line in the first edge gate line substructure, which can reduce the resistance at the first edge, thereby reducing the edge fine gate transmission loss and further improving the efficiency of the back contact battery.

[0058] Specifically, the widths of the multiple third fine grid lines can be the same or different. Similarly, the widths of the multiple fourth fine grid lines can be the same or different.

[0059] like Figure 1 As shown, in the second direction D2, the width of the first fine gate line is the fifth width W5, the width of the second fine gate line is the sixth width W6, the width of the third fine gate line is the seventh width W7, and the width of the fourth fine gate line is the eighth width W8.

[0060] Specifically, the fifth width and the seventh width mentioned above can be the same or different. The sixth width and the eighth width mentioned above can be the same or different.

[0061] The intermediate gate substructure adjacent to the first edge gate substructure is a first predetermined gate substructure. This first predetermined gate 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 one of the second predetermined fine gate lines are connected to the same position as the first predetermined main gate line. The first and second predetermined fine gate lines are located on opposite sides of the first predetermined main gate line, with the second predetermined fine gate line located on the side of the first predetermined fine gate line closest to the first edge gate substructure. The width of the second predetermined fine gate line is greater than the width of the first predetermined fine gate line. This structure further avoids stress concentration at the silicon wafer edge caused by the component solder joints being close to the edge.

[0062] Specifically, the width of the second predetermined fine gate line closer to the first edge gate line substructure is greater than the width of the first predetermined fine gate line farther away from the first edge gate line substructure.

[0063] The middle busbar substructure adjacent to the second edge busbar substructure is a second predetermined busbar substructure, the second predetermined busbar substructure comprises a second predetermined main busbar, a plurality of third predetermined fine busbars and a plurality of fourth predetermined fine busbars, one end of the third predetermined fine busbar and one end of the fourth predetermined fine busbar are connected to the same position of the second predetermined main busbar, and the third predetermined fine busbar and the fourth predetermined fine busbar are located on both sides of the second predetermined main busbar, the fourth predetermined fine busbar is located on the side of the third predetermined fine busbar close to the second edge busbar substructure, and the width of the fourth predetermined fine busbar is greater than the width of the third predetermined fine busbar. This structure can further avoid the problem of stress concentration of the silicon wafer edge caused by the proximity of the component welding point to the edge.

[0064] Specifically, the width of the fourth predetermined fine busbar close to the second edge busbar substructure is greater than the width of the third predetermined fine busbar away from the second edge busbar substructure.

[0065] According to the embodiments of the present application, a solar cell module is also provided, comprising any one of the above-mentioned back contact solar cells.

[0066] Through the embodiments, a solar cell module is provided, comprising any one of the above-mentioned back contact solar cells, comprising a silicon wafer and a busbar structure, the busbar structure comprises a main busbar and a fine busbar connected to the main busbar, the busbar structure comprises a plurality of middle busbar substructures arranged along a first direction, a first edge busbar substructure closest to a first edge and a second edge busbar substructure closest to a second edge, the distance between the center line of the main busbar of the first edge busbar substructure and the center line of the main busbar of the adjacent middle busbar substructure is greater than the distance between the center lines of the main busbars of any two adjacent middle busbar substructures, and the distance between the center line of the main busbar of the second edge busbar substructure and the center line of the main busbar of the adjacent middle busbar substructure is greater than the distance between the center lines of any two adjacent middle busbar substructures. Since the distance between the first edge busbar substructure and the middle busbar substructure and the distance between the second edge busbar substructure and the middle busbar substructure are increased, sufficient area can be reserved for setting the edge welding point, so that the edge welding point is away from the edge of the silicon wafer, and the problem of stress concentration of the silicon wafer edge caused by the proximity of the component welding point to the edge is avoided.

[0067] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0068] 1) The back contact solar cell of the present application comprises a silicon wafer and a grid structure, the grid structure comprises main grid lines and thin grid lines connected to the main grid lines, the grid 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, 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 of 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, a sufficient area can be reserved for setting the edge soldering point, so that the edge soldering point is away from the edge of the silicon wafer, and the problem of stress concentration of the silicon wafer edge caused by the proximity of the component soldering point to the edge is avoided.

[0069] 2) The solar cell module of the present application comprises any one of the above-mentioned back contact solar cells, which comprises a silicon wafer and a grid structure, the grid structure comprises main grid lines and thin grid lines connected to the main grid lines, the grid 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, 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 of 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, a sufficient area can be reserved for setting the edge soldering point, so that the edge soldering point is away from the edge of the silicon wafer, and the problem of stress concentration of the silicon wafer edge caused by the proximity of the component soldering point to the edge is avoided.

[0070] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A back contact solar cell, characterized by, The application relates to a silicon wafer and a gate line structure arranged on one side of the silicon wafer, the gate line structure comprising main gate lines and thin gate lines connected to the main gate lines, the gate line structure comprising 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 being 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 being greater than the distance between the center lines of any two adjacent intermediate gate line substructures, and 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 being greater than the distance between the center lines of any two adjacent intermediate gate line substructures, wherein the first direction is the extension direction from the first edge to the second edge, the first direction being perpendicular to the thickness direction of the silicon wafer, the plurality of intermediate gate line substructures comprising first intermediate gate line portions and second intermediate gate line portions arranged alternately along the first direction, each first intermediate gate line portion comprising a first main gate line and a plurality of first thin gate lines, one end of each first thin gate line being connected to the first main gate line and being arranged at intervals along a second direction, the second edge gate line substructure comprising a second main gate line and a plurality of second thin gate lines, one end of each second thin gate line being connected to the second main gate line and being arranged at intervals along the second direction, in the second direction, the width of at least one first thin gate line being less than the width of at least one second thin gate line, and in the first direction, the width of any one first main gate line being greater than the width of the second main gate line.

2. The back contact solar cell of claim 1, wherein, 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 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 intermediate gate line substructure is a second distance, and the distance between the center lines of any two adjacent intermediate gate line substructures is a third distance, the ratio of the first distance to the third distance being greater than 1 and less than or equal to 1.5, and the ratio of the second distance to the third distance being greater than 1 and less than or equal to 1.

5.

3. The back contact solar cell of claim 1, wherein, The back contact solar cell further comprises a doped structure between the silicon wafer and the grid line structure, the doped structure comprising a plurality of intermediate doped layers arranged along a first direction, a first edge doped layer closest to the first edge, and a second edge doped layer closest to the second edge, the plurality of intermediate doped layers being between the first edge doped layer and the second edge doped layer, in the first direction, a distance between a center line of the first edge doped layer and a center line of an adjacent intermediate doped layer being greater than a distance between center lines of any two adjacent intermediate doped layers, and a distance between a center line of the second edge doped layer and a center line of an adjacent intermediate doped layer being greater than a distance between center lines of any two adjacent intermediate doped layers.

4. The back contact solar cell of claim 3, wherein, The polarity of the first intermediate grid line part is different from the polarity of the second intermediate grid line part, the polarity of the first edge grid line substructure is different from the polarity of the second edge grid line substructure, the polarity of the first intermediate grid line part is different from the polarity of the first edge grid line substructure, and the polarity of the second intermediate grid line part is different from the polarity of the second edge grid line substructure.

5. The back contact solar cell of claim 4, wherein, The plurality of intermediate doped layers comprise first sub-doped layers and second sub-doped layers arranged alternately along the first direction, the first sub-doped layers having a different doping type from the second sub-doped layers, the first edge doped layer having a different doping type from the second edge doped layer, the first sub-doped layers having a different doping type from the first edge doped layer, and the second sub-doped layers having a different doping type from the second edge doped layer.

6. The back contact solar cell of claim 1, wherein, Each of the second intermediate grid line parts comprises a third main grid line and a plurality of third fine grid lines, one end of each of the third fine grid lines being connected to the third main grid line and being arranged spaced apart along a second direction, the first edge grid line substructure comprises a fourth main grid line and a plurality of fourth fine grid lines, one end of each of the fourth fine grid lines being connected to the fourth main grid line and being arranged spaced apart along the second direction, and in the first direction, a width of any one of the third main grid lines is greater than a width of the fourth main grid line.

7. The back contact solar cell of claim 6, wherein, In the first direction, a width of the first main grid line is a first width, a width of the second main grid line is a second width, a width of the third main grid line is a third width, and a width of the fourth main grid line is a fourth width, a ratio of the second width to the first width being greater than or equal to 0.2 and less than 1, and a ratio of the fourth width to the third width being greater than or equal to 0.2 and less than 1.

8. The back contact solar cell of claim 5, wherein, Each of the first sub-doped layers comprises a first connecting part and a plurality of second connecting parts, one end of each of the second connecting parts being connected to the first connecting part and being arranged spaced apart along a second direction, the second edge doped layer comprises a third connecting part and a plurality of fourth connecting parts, one end of each of the fourth connecting parts being connected to the third connecting part and being arranged spaced apart along the second direction, and in the first direction, a width of at least one of the first connecting parts is greater than a width of the third connecting part.

9. The back contact solar cell of claim 5, wherein, Each of the second sub-doped layers comprises a fifth connecting part and a plurality of sixth connecting parts, one end of each of the sixth connecting parts is connected with the fifth connecting part and is arranged at intervals along the second direction, the first edge doped layer comprises a seventh connecting part and a plurality of eighth connecting parts, one end of each of the eighth connecting parts is connected with the seventh connecting part and is arranged at intervals along the second direction, in the first direction, the width of at least one of the fifth connecting parts is greater than the width of the seventh connecting part.

10. The back contact solar cell of claim 6, wherein, In the second direction, the width of at least one of the third fine grid lines is less than the width of at least one of the fourth fine grid lines.

11. The back contact solar cell of claim 10, wherein, The intermediate grid line substructure adjacent to the first edge grid line substructure is a first predetermined grid line substructure, the first predetermined grid line substructure comprises a first predetermined main grid line, a plurality of first predetermined fine grid lines and a plurality of second predetermined fine grid lines, one end of one of the first predetermined fine grid lines and one end of one of the second predetermined fine grid lines are connected with the same position of the first predetermined main grid line, and the first predetermined fine grid lines and the second predetermined fine grid lines are located on both sides of the first predetermined main grid line, the second predetermined fine grid lines are located on the side of the first predetermined fine grid lines close to the first edge grid line substructure, the width of the second predetermined fine grid lines is greater than the width of the first predetermined fine grid lines.

12. The back contact solar cell of claim 10, wherein, The intermediate grid line substructure adjacent to the second edge grid line substructure is a second predetermined grid line substructure, the second predetermined grid line substructure comprises a second predetermined main grid line, a plurality of third predetermined fine grid lines and a plurality of fourth predetermined fine grid lines, one end of one of the third predetermined fine grid lines and one end of one of the fourth predetermined fine grid lines are connected with the same position of the second predetermined main grid line, and the third predetermined fine grid lines and the fourth predetermined fine grid lines are located on both sides of the second predetermined main grid line, the fourth predetermined fine grid lines are located on the side of the third predetermined fine grid lines close to the second edge grid line substructure, the width of the fourth predetermined fine grid lines is greater than the width of the third predetermined fine grid lines.

13. A solar cell module characterized by comprising: A back contact solar cell comprising any one of claims 1 to 12.

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