Back contact solar cell and solar cell module

Abstract

Provided in the present disclosure are a back contact solar cell and a solar cell module. The back contact solar cell comprises a silicon wafer and a gridline structure, the gridline structure comprising busbars and fingers connected to the busbars, and the gridline structure comprising a plurality of intermediate gridline substructures arranged along a first direction, a first edge gridline substructure which is closest to a first edge, and a second edge gridline substructure which is closest to a second edge. The distance between the center line of the busbar of the first edge gridline substructure and the center line of the busbar of an adjacent intermediate gridline substructure is greater than the distance between the center lines of the busbars of any two adjacent intermediate gridline substructures, and the distance between the center line of the busbar of the second edge gridline substructure and the center line of the busbar of an adjacent intermediate gridline substructure is greater than the distance between the center lines of any two adjacent intermediate gridline substructures. The back contact solar cell solves the problem of damage caused by stress concentration at the edges of a cell piece.

Description

Back contact solar cell and solar cell module

[0001] Cross Reference to Related Applications

[0002] The present disclosure claims priority to the Chinese patent application No. 2024113200781, filed on September 20, 2024, entitled “Back contact solar cell and solar cell module”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the field of solar cells, and in particular, to a back contact solar cell and solar cell module. BACKGROUND

[0004] With the rapid development of new energy technology, solar cells have become one of the important energy supply methods. The edge soldering points are often arranged at the edge position of the back contact cell, which are mainly used for connecting the cell, transmitting current and improving the efficiency of the cell panel. Since the edge soldering points are concentrated at the edge position of the back contact cell, stress is concentrated, which causes the cell to be easily damaged.

[0005] Therefore, there is an urgent need for a method to solve the problem of cell edge stress concentration leading to damage. SUMMARY

[0006] The main purpose of the present disclosure is to provide a back contact solar cell and solar cell module to at least solve the problem of cell edge stress concentration leading to damage in the prior art.

[0007] According to an aspect of the present disclosure, a back contact solar cell is provided, comprising a silicon wafer and a grid line structure disposed on one side of the silicon wafer, the grid line structure comprising main grid lines and fine grid lines connected to the main grid lines, 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, the back contact solar cell satisfying at least one of the following: 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 any two adjacent intermediate grid line substructures; in the first direction, 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.

[0008] Optionally, 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 a first distance, 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 a second distance, a distance between center lines of any two adjacent intermediate grid 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.

[0009] Optionally, the back contact solar cell further comprises a doping structure located between the silicon wafer and the grid line structure, the doping structure comprising 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 being located between the first edge doping layer and the second edge doping layer, the back contact solar cell satisfying at least one of the following: 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; in the first direction, 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.

[0010] Optionally, the plurality of intermediate gate line substructures comprise 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, the polarity of the first intermediate gate line portions is different from a polarity of the first edge gate line substructure, and the polarity of the second intermediate gate line portions is different from a polarity of the second edge gate line substructure.

[0011] Optionally, the plurality of intermediate doped layers comprise first sub-doped layers and second sub-doped layers arranged alternately along the first direction, wherein a doping type of the first sub-doped layers is different from a doping type of the second sub-doped layers, a doping type of the first edge doped layer is different from a doping type of the second edge doped layer, the doping type of the first sub-doped layers is different from a doping type of the first edge doped layer, and the doping type of the second sub-doped layers is different from a doping type of the second edge doped layer.

[0012] 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 to the first main gate line and is arranged spaced apart along a second direction, the second edge gate line substructure 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 to the second main gate line and is arranged spaced apart along the second direction, and 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.

[0013] 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 to the third main gate line and is arranged spaced apart along a second direction, the first edge gate line substructure 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 to the fourth main gate line and is arranged spaced apart along the second direction, and 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.

[0014] 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, and 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, and a ratio of the fourth width to the third width is greater than or equal to 0.2 and less than 1.

[0015] 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 along a second direction, each of the second edge doped layers 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 along the second direction, 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.

[0016] 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 along a second direction, each of the first edge doped layers 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 along the second direction, 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.

[0017] Optionally, in the second direction, a width of at least one of the first fine grid lines is less than a width of at least one of the second fine grid lines.

[0018] Optionally, in the second direction, a width of at least one of the third fine grid lines is less than a width of at least one of the fourth fine grid lines.

[0019] Optionally, in the second direction, a width of the first fine grid lines is a fifth width, a width of the second fine grid lines is a sixth width, a width of the third fine grid lines is a seventh width, a width of the fourth fine grid lines is an eighth width, a ratio of the fifth width to the sixth width is greater than 1 and less than or equal to 2.5, and a ratio of the seventh width to the eighth width is greater than 1 and less than or equal to 2.5.

[0020] 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 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 of the first predetermined fine grid lines and one of the second predetermined fine grid lines are collinear, and the first predetermined fine grid line and the second predetermined fine grid line are located on two sides of the first predetermined main grid line, the second predetermined fine grid line is located on a side of the first predetermined fine grid line close to the first edge grid line substructure, and a width of the second predetermined fine grid line is greater than a width of the first predetermined fine grid line.

[0021] Optionally, 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 with 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.

[0022] According to another aspect of the present disclosure, a solar cell module is provided, comprising any one of the back contact solar cells.

[0023] According to the technical solution of the present disclosure, a back contact solar cell is provided, comprising a silicon wafer and a busbar structure, the busbar structure comprises a main busbar and a fine busbar connected with 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. Due to the increased 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, a sufficient area can be reserved for setting an edge soldering point, so that the edge soldering point is away from the edge of the silicon wafer, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the proximity of the module soldering point to the edge. BRIEF DESCRIPTION OF DRAWINGS

[0024] The drawings constituting a part of the present disclosure serve to provide further understanding of the present disclosure, the illustrative embodiments of the present disclosure and the description thereof serve to explain the present disclosure, and do not constitute improper limitations on the present disclosure. In the drawings:

[0025] Fig. 1 shows a structural schematic diagram of a back contact solar cell according to an embodiment of the present disclosure;

[0026] Fig. 2 shows a structural schematic diagram of another back contact solar cell provided according to an embodiment of the present disclosure;

[0027] Fig. 3 shows a structural schematic diagram of still another back contact solar cell provided according to an embodiment of the present disclosure;

[0028] FIG. 4 shows a structural schematic diagram of a doping structure according to an embodiment of the present disclosure.

[0029] Wherein, the above figures include the following reference signs:

[0030] 100, intermediate 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, intermediate doping layer; 104, first edge doping layer; 105, second edge doping layer; 106, silicon wafer; 107, doping structure; 108, gate line structure; 109, first intermediate gate line part; 110, second intermediate gate line part; 111, first sub-doping layer; 112, second sub-doping layer; W1, first width; W2, second width; W3, third width; W4, fourth width; D2, second direction; 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

[0031] It should be noted that the following detailed description is merely exemplary in nature and is intended to provide further description of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0032] It is also important to note that the use of the term "example" herein does not necessarily mean that any examples given are preferred embodiments or that any example given encompasses all structural, mechanical, chemical, architectural, and / or electrical permutations. 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. Furthermore, to the extent that the terms "includes", "including", "contains", "containing", "has", "having" or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0033] 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, it should be understood that when an element is referred to as being "connected" to or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can also be present.

[0034] It should be noted that the embodiments described are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present disclosure.

[0035] It should be understood that the term "and / or" used herein only describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which 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 associated objects before and after it.

[0036] As introduced in the background, the edge stress of the battery piece in the prior art is concentrated, which is easy to cause damage to the battery. To solve the above problems, the embodiments of the present disclosure provide a back contact solar cell and a solar cell module.

[0037] FIG. 1 is a structural schematic diagram of a back contact solar cell according to an embodiment of the present disclosure. As shown in FIG. 1, the back contact solar cell includes a silicon wafer and a grid line structure arranged on one side of the silicon wafer, 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; wherein the first direction D1 is an 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.

[0038] Specifically, the back contact solar cell reduces the shading and reflection of the front surface of the cell by moving the front surface electrode to the back surface of the cell, thereby improving the photoelectric conversion efficiency of the cell. This design can reduce the shading loss of the front surface of the cell and improve the photoelectric conversion efficiency of the cell. The main grid lines in the grid line structure are used 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 lines 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 spacing between the adjacent first edge grid line substructure and the middle grid line substructure, or between the adjacent first edge grid line substructure and the middle grid line substructure. In addition, the above-mentioned first edge and second edge are not limited to the arrangement shown in FIG. 1, but can also be other arrangements, which will not be described here. FIG. 2 is a schematic diagram of another structure of a back contact solar cell according to an embodiment of the present disclosure. As shown in FIG. 2, 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 a 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 a second polarity region; a first main grid 51 (i.e. the main grid line of the first edge grid line substructure described above) disposed on one 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 respectively connected to the first main grid 51 and the first edge soldering point 31; 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 disposed on one 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 respectively connected to the second main grid 52 and the second edge soldering point 32; 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 middle grid line substructure and the spacing between the second edge grid line substructure and the middle grid line substructure, sufficient area can be reserved for the arrangement of the first edge soldering point 31 and the second edge soldering point 32, so that the edge soldering point is away from the edge of the silicon wafer, avoiding the problem of stress concentration of the edge of the silicon wafer caused by the proximity of the component soldering point to the edge.

[0039] Specifically, the center line of the main grid line is a center line of the main grid line parallel to the second direction D2.

[0040] The embodiment provides a back contact solar cell, which 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, 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 distances between the first edge grid line substructure and the intermediate grid line substructure and 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 far 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.

[0041] In the implementation process, as shown in FIG. 1, in the first direction D1, a distance between a center line of the main grid line of the first edge grid line substructure 101 and a center line of the main grid line of an adjacent intermediate grid line substructure 100 is a first distance L1, a distance between a center line of the main grid line of the second edge grid line substructure 102 and a center line of the main grid line of an adjacent intermediate grid line substructure 100 is a second distance L2, and a distance between center lines of main grid lines of any two adjacent intermediate grid line substructures 100 is a third distance L3, a ratio of the first distance L1 to the third distance L3 is greater than 1 and less than or equal to 1.5, and a 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 are neither too large nor too small, and meanwhile, the problems of stress concentration of the silicon wafer edge caused by the fact that the component soldering point is close to the edge and the manufacturing cost of the solar cell wafer are avoided.

[0042] In actual application, the first distance and the second distance can be the same or different.

[0043] To further improve the photoelectric conversion efficiency of the solar cell, the back contact solar cell of the present disclosure further comprises a doping structure 107 between the silicon wafer 106 and the grid line structure 108, as shown in FIG. 4, the doping structure comprises 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 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.

[0044] Specifically, the doping layer changes the electrical properties of the semiconductor material by doping impurity elements, thereby improving the photoelectric conversion efficiency of the solar cell. In a solar cell, 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, the photon energy causes the electrons and holes in the PN junction to separate, generating a photogenerated current, thereby realizing photoelectric conversion. In practical applications, the grid line structure can be arranged one-to-one with the doping structure, or can have partial overlap.

[0045] Specifically, the center line of the first edge doping layer 104 is the center line of the doping layer in the first edge doping layer 104 parallel to the second direction D2. The center line of the intermediate doping layer 103 is the center line of the doping layer in the intermediate doping layer 103 parallel to the second direction D2. The center line of the second edge doping layer 105 is the center line of the doping layer in the second edge doping layer 105 parallel to the second direction D2.

[0046] As shown in FIG. 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 polarities can reduce the series resistance inside the cell, thereby reducing energy loss and further improving the overall efficiency of the solar cell.

[0047] Specifically, in the first direction, the polarities 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 are 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).

[0048] In some embodiments, as shown in FIG. 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 types can reduce the series resistance inside the cell, thereby reducing energy loss and further improving the overall efficiency of the solar cell.

[0049] Specifically, in the first direction, the doping types of the first edge doped layer, the plurality of first sub-doped layers and second sub-doped layers, and the second edge doped layer are 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).

[0050] In some 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, thereby further reducing the manufacturing cost of the back contact solar cell.

[0051] 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.

[0052] 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, thereby further reducing the manufacturing cost of the back contact solar cell.

[0053] 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.

[0054] As shown in FIG. 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, thereby further reducing the manufacturing cost of the solar cell piece.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Specifically, the width of the plurality of first fine grid lines can be the same or different. Similarly, the width of the plurality of second fine grid lines can be the same or different.

[0062] In the second direction, the width of the at least one third fine grid line is smaller than the width of the at least one fourth fine grid line. The width of the fine grid lines in the second intermediate grid line part is smaller than the width of the fine grid lines in the first edge grid line substructure, which can reduce the resistance at the first edge, thereby reducing the transmission loss of the edge fine grid and further improving the efficiency of the back contact cell.

[0063] Specifically, the widths of the plurality of third fine grid lines can be the same or different. Similarly, the widths of the plurality of fourth fine grid lines can be the same or different.

[0064] As shown in FIG. 1, in the second direction D2, the width of the first fine grid line is a fifth width W5, the width of the second fine grid line is a sixth width W6, the width of the third fine grid line is a seventh width W7, and the width of the fourth fine grid line is an 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 arrangement 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 are not too large or too small, while taking into account improving the efficiency of the back contact cell and reducing the manufacturing cost of the cell sheet.

[0065] Specifically, the fifth width and the seventh width can be the same or different. The sixth width and the eighth width can be the same or different.

[0066] 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 includes a first predetermined main grid line, a plurality of first predetermined fine grid lines, and a plurality of second predetermined fine grid lines, one first predetermined fine grid line and one second predetermined fine grid line are collinear, and the first predetermined fine grid line and the second predetermined fine grid line are located on both sides of the first predetermined main grid line, the second predetermined fine grid line is located on the side of the first predetermined fine grid line close to the first edge grid line substructure (that is, the second predetermined fine grid line is closer to the edge of the cell sheet than the first predetermined fine grid line), and the width of the second predetermined fine grid line is greater than the width of the first predetermined fine grid line. This structure can further avoid the problem of stress concentration of the silicon wafer edge caused by the assembly soldering point close to the edge, and reduce the transmission loss of the fine grid.

[0067] Specifically, the width of the second predetermined fine grid line close to the first edge grid line substructure is greater than the width of the first predetermined fine grid line away from the first edge grid line substructure.

[0068] The middle busbar substructure adjacent to the second edge busbar substructure is a second predetermined busbar substructure, the second predetermined busbar substructure includes 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 (that is, the fourth predetermined fine busbar is closer to the edge of the cell than the third predetermined fine busbar), 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 module soldering point to the edge, and reduce the transmission loss of the fine busbar.

[0069] 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.

[0070] According to the embodiments of the present disclosure, a solar cell module is also provided, which includes any one of the above-mentioned back contact solar cells.

[0071] Through the embodiments, a solar cell module is provided, which includes any one of the above-mentioned back contact solar cells, includes a silicon wafer and a busbar structure, the busbar structure includes a main busbar and a fine busbar connected to the main busbar, the busbar structure includes 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. Because 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, 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 module soldering point to the edge is avoided.

[0072] From the above description, it can be seen that the above-mentioned embodiments of the present disclosure achieve the following technical effects:

[0073] 1) The back contact solar cell of the present disclosure 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 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, 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, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the proximity of the component soldering point to the edge.

[0074] 2) The solar cell module of the present disclosure 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 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, 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, avoiding the problem of stress concentration on the edge of the silicon wafer caused by the proximity of the component soldering point to the edge.

[0075] The above only describes the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art can make various modifications and changes to the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A back contact solar cell, wherein, The back contact solar cell includes a silicon wafer and a gate line structure arranged on one side of the silicon wafer, the gate line structure includes main gate lines and fine gate lines connected with the main gate lines, 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, and the plurality of intermediate gate line substructures are located between the first edge gate line substructure and the second edge gate line substructure, and the back contact solar cell satisfies at least one of the following conditions: 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 any two adjacent main gate lines of the intermediate gate line substructures; In the first direction, 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 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.

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 main gate lines of the intermediate 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 of claim 1, wherein, The back contact solar cell further includes a doping structure 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, and the plurality of intermediate doping layers are located between the first edge doping layer and the second edge doping layer, and the back contact solar cell satisfies at least one of the following conditions: 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; In the first direction, 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 of claim 3, wherein, 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 polarities of the first intermediate gate line portions and the second intermediate gate line portions are different, a polarity of the first edge gate line substructure and a polarity of the second edge gate line substructure are different, a polarity of the first intermediate gate line portions and a polarity of the first edge gate line substructure are different, a polarity of the second intermediate gate line portions and a polarity of the second edge gate line substructure are different.

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

6. The back contact solar cell of claim 4, wherein, 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 to the first main gate line and is arranged spaced apart along a second direction, the second edge gate line substructure 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 to the second main gate line and is arranged spaced apart along the second direction, 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.

7. The back contact solar cell of claim 6, wherein, 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 to the third main gate line and is arranged spaced apart along a second direction, the first edge gate line substructure 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 to the fourth main gate line and is arranged spaced apart along the second direction, 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.

8. The back contact solar cell of claim 7, wherein, 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.

9. The back contact solar cell of claim 5, wherein, Each of the first sub-doping layers comprises 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 is arranged spaced apart along a second direction, the second edge doping layer comprises 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 is arranged spaced apart along the second direction, 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 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 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 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.

11. The back contact solar cell of claim 7, wherein, 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.

12. The back contact solar cell of claim 11, 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.

13. The back contact solar cell of claim 12, wherein, In the second direction, the width of the first fine grid line is a fifth width, the width of the second fine grid line is a sixth width, the width of the third fine grid line is a seventh width, and the width of the fourth fine grid line is an 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 of claim 12, 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 of the first predetermined fine grid lines and one of the second predetermined fine grid lines are collinear, and the first predetermined fine grid line and the second predetermined fine grid line are located on both sides of the first predetermined main grid line, the second predetermined fine grid line is located on the side of the first predetermined fine grid line close to the first edge grid line substructure, and the width of the second predetermined fine grid line is greater than the width of the first predetermined fine grid line.

15. The back contact solar cell of claim 12, 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 line and the fourth predetermined fine grid line are located on both sides of the second predetermined main grid line, the fourth predetermined fine grid line is located on the side of the third predetermined fine grid line close to the second edge grid line substructure, and the width of the fourth predetermined fine grid line is greater than the width of the third predetermined fine grid line.

16. A solar cell module, wherein, The back contact solar cell comprises the back contact solar cell according to any one of claims 1 to 15.

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