Solar cell and solar cell module

Abstract

The utility model discloses a solar cell, which comprises a semiconductor substrate and an electrode structure arranged on the semiconductor substrate, and the electrode structure comprises a plurality of main grid lines and a plurality of fine grid lines. The main grid lines are arranged at intervals in the first direction. Each main grid line comprises a main rod extending in the second direction and a plurality of connecting branches arranged along the main rod at intervals. The fine grid lines are arranged at intervals in the second direction. The fine grid lines extend in the first direction and are provided with a plurality of fractures at intervals in the extending direction. Wherein the main grid lines intersect with the thin grid lines at the fractures at the connecting branches, the electrode structure further comprises widened small short lines located at the intersection positions, the main grid lines and the thin grid lines are electrically connected through the connecting branches and the widened small short lines, and the problem of line breakage during sintering or welding is avoided. In addition, the utility model also discloses a solar cell module.

Description

[0001] Priority information

[0002] This application claims priority and benefits of patent application number 202422320295.2, entitled “Solar Cell and Solar Cell Module”, filed with the State Intellectual Property Office of China on September 23, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a solar cell assembly. Background Art

[0004] Fossil energy sources pollute the atmosphere and have limited reserves, while solar energy offers advantages such as cleanliness, pollution-free operation, and abundant resources. Therefore, solar energy is gradually becoming a core clean energy alternative to fossil energy. Due to the high photoelectric conversion efficiency of solar cell modules, they have become a key focus of clean energy development.

[0005] Conventional solar cells are printed with multiple fine grid lines and multiple main grid lines. The fine grid lines are used to collect the current generated by light, while the main grid lines are used to collect the current flowing through the fine grid lines. Multiple solar cells are connected via welding ribbons to form a solar cell module. However, during the production process of solar cells and solar cell modules, the sintering of the fine grid lines, the sintering of the main grid lines, and the welding of the welding ribbons can easily lead to broken wires at the intersection of the main grid lines and fine grid lines, resulting in reduced power consumption of the solar cell and, in turn, overall power loss of the solar cell module. Summary of the Invention

[0006] Based on this, it is necessary to provide a solar cell and a solar cell assembly to solve the above technical problems.

[0007] A technical solution of the present application is: a solar cell comprising a semiconductor substrate and an electrode structure provided on the semiconductor substrate, wherein the electrode structure comprises:

[0008] A plurality of main grid lines are arranged at intervals along a first direction, wherein the main grid lines include a main bar extending along a second direction and a plurality of connecting branches arranged at intervals along the main bar;

[0009] A plurality of fine grid lines are arranged at intervals along the second direction, wherein the fine grid lines extend along the first direction and have a plurality of breaks spaced apart along the extending direction;

[0010] The main grid line intersects the thin grid line at the connection branch at the break, and the electrode structure further includes a widened short line at the intersection. The main grid line and the thin grid line are electrically connected through the connection branch and the widened short line.

[0011] In one embodiment, the width D1 of the widened short line is in the range of 20 μm≤D1≤80 μm, the length L1 is in the range of 200 μm≤L1≤800 μm, and the length direction thereof extends along the first direction.

[0012] In one embodiment, the widened short line is rectangular.

[0013] In one embodiment, the widened short line is set as a part of the fine grid line, and the fine grid line includes ends located on both sides of the break. The widened short line is located in the break and is spaced apart from the end on at least one side.

[0014] In one embodiment, the widened short line is located at the fracture and is spaced apart from the ends on both sides, and the widths of the ends are gradually changed.

[0015] In one embodiment, the widened short line is located at the fracture and connected to the end portion on one side, and the width of the end portion on the other side is gradually changed.

[0016] In one embodiment, the widened short line is formed as the connecting branch.

[0017] In one embodiment, the connecting branch includes the widened short line and gradient segments extending from both sides of the widened short line, and the length of the widened short line is greater than the width of the fracture.

[0018] In one embodiment, the thin grid line includes end portions located on both sides of the break, the width of the end portions is gradually changed, and the length of the gradual change section is greater than the gradual change region of the end portions.

[0019] The present utility model also discloses a solar cell assembly, which includes a welding ribbon and a plurality of solar cells as described above connected by the welding ribbon. The main grid line of the solar cell also includes a harpoon portion located at both ends of the main rod and a plurality of welding pads distributed at intervals along the main rod. The welding ribbon is welded to the welding pads.

[0020] The beneficial effects of this application are: the main grid lines and the thin grid lines are electrically connected through connecting branches and widened short lines, avoiding the problem of wire breakage during sintering or welding, thereby ensuring the yield and quality stability of the solar cell cells, improving the power of the solar cell cells, and thus ensuring the power of the solar cell modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the cross-sectional structure of a solar cell of the present application;

[0022] Figure 2This is a schematic planar structural diagram of the electrode structure of the solar cell of this application;

[0023] Figure 3 for Figure 2 Schematic diagram of the intersection of the middle main grid line and the fine grid line;

[0024] Figure 4 for Figure 2 Enlarged schematic diagram of the middle circle A;

[0025] Figure 5 for Figure 2 Enlarged schematic diagram of the middle circle B;

[0026] Figure 6 A schematic diagram of the planar structure of the fine grid lines of the electrode structure of the solar cell of the present application;

[0027] Figure 7 for Figure 6 Enlarged schematic diagram of the middle circle C;

[0028] Figure 8 It is an enlarged schematic diagram of circle D in circle 6;

[0029] Figure 9 A schematic planar structural diagram of the main grid lines of the electrode structure of the solar cell of the present application;

[0030] Figure 10 for Figure 9 Enlarged schematic diagram of the middle circle E;

[0031] Figure 11 for Figure 9 Enlarged schematic diagram of the middle circle F;

[0032] Figure 12 This is another schematic diagram of the cross-sectional structure of the solar cell of the present application;

[0033] Figure 13 for Figure 12 Schematic diagram of the intersection of the main grid line and the fine grid line of the solar cell;

[0034] Figure 14 for Figure 13 Partial schematic diagram of the medium and fine grid lines;

[0035] Figure 15 This is another schematic diagram of the cross-sectional structure of the solar cell of the present application;

[0036] Figure 16 for Figure 15 Schematic diagram of the intersection of the main grid line and the fine grid line of the solar cell;

[0037] Figure 17 for Figure 15 Partial schematic diagram of the main grid line. DETAILED DESCRIPTION

[0038] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described below. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0039] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementations.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] The utility model discloses a solar cell, which includes a semiconductor substrate and an electrode structure arranged on the semiconductor substrate, wherein the electrode structure includes a plurality of main grid lines and a plurality of fine grid lines. The plurality of main grid lines are arranged at intervals along a first direction. The main grid lines include a main rod extending along a second direction and a plurality of connecting branches arranged at intervals along the main rod. The plurality of fine grid lines are arranged at intervals along the second direction. The fine grid lines extend along the first direction and are provided with a plurality of fractures at intervals along the direction of extension thereof. The main grid lines intersect with the fine grid lines at the fractures at the connecting branches, and the electrode structure further includes a widened short line at the intersection. The main grid lines and the fine grid lines are electrically connected through the connecting branches and the widened short line, thereby avoiding the problem of broken wires during sintering or welding, thereby ensuring the yield and quality stability of the solar cell, improving the power of the solar cell, and further ensuring the power of the solar cell module.

[0042] Furthermore, the width D1 of the widened short line is in the range of 20μm ≤ D1 ≤ 80μm, and the length L1 is in the range of 200μm ≤ L1 ≤ 800μm, with its length direction extending along the first direction. In one embodiment, the widened short line is rectangular, with a width D1 set to 20μm ≤ D1 ≤ 80μm; and a length L1 set to 200μm ≤ L1 ≤ 800μm. The rectangular shape of the widened short line prevents disconnection caused by sintering or welding, ensuring electrical connection between the main and fine gate lines.

[0043] In one embodiment, the widened short line is set as a part of the fine grid line, and the fine grid line includes ends located on both sides of the fracture. The widened short line is located at the fracture and is spaced apart from the end on at least one side. The length direction of the widened short line extends along the first direction, and its center line overlaps with the center line of the fine grid line, becoming a part of the fine grid line. The range of the width D2 of the fine grid line is 8μm≤D2≤18μm. After the fine grid line is added with the widened short line located at the fracture, the problem of broken wires at the intersection caused by process factors such as sintering or welding can be avoided, thereby improving the yield rate.

[0044] Furthermore, the widened short lines are located at the fracture and spaced apart from the ends on both sides, with the width of the ends gradually decreasing. The ends are widest at the end and gradually taper to the width of the fine grid lines. The widened short lines are spaced apart from the two ends, with the spacing ranging from 80μm to 150μm, further ensuring subsequent connectivity.

[0045] Furthermore, the widened short line is located at the fracture and connected to the end on one side, and the width of the end on the other side is gradually set. The widened short line and the end on the other side are spaced apart, and the spacing range can be 160-300μm, further ensuring subsequent connectivity.

[0046] In one embodiment, the widened short line is formed into a connecting branch. The connecting branch is set as the widened short line and is located at the end of the fracture to connect the two sides, which can avoid the problem of wire breakage at the intersection caused by process factors such as sintering or welding, and improve the yield rate.

[0047] In one embodiment, the connecting branch includes a widened short line and gradient segments extending from either side of the widened short line. The widened short line is longer than the width of the fracture. The fine grid line includes end portions on either side of the fracture, with the width of the end portions gradually changing. The gradient segments are longer than the gradient regions at the end portions. This can avoid wire breakage at the intersection caused by process factors such as sintering or welding, thereby improving yield.

[0048] In one embodiment, the widened short lines are separately provided and belong neither to the main grid lines nor to the fine grid lines. The widened short lines assist in the electrical connection between the main grid lines and the fine grid lines, thereby preventing line breakage and improving yield.

[0049] Furthermore, the main grid line also includes a harpoon portion located at each end of the main rod and a number of solder pads spaced apart along the main rod. The harpoon portion includes a solder base, two opposing forks extending from the solder base, a fishbone portion located between the two forks, and whiskers spaced apart at the ends of the forks. The solder base, forks, fishbone portion, and whiskers are each electrically connected to the fine grid lines. Solder feet extend from both sides of the solder pads and are electrically connected to the fine grid lines.

[0050] The utility model also discloses a solar cell assembly, which comprises a welding ribbon and a plurality of solar cells as described above connected by the welding ribbon. The welding ribbon is welded to the welding pad, and has a high yield and power.

[0051] Please refer to the following Figures 1 to 17 , the solar cell of the present invention is described with an example. Due to space limitations, only part of the structure is shown in the figure.

[0052] Please refer to Figures 1 to 11 The utility model discloses a solar cell 100. The solar cell 100 includes a semiconductor substrate 101 and an electrode structure 102 arranged on the semiconductor substrate 101. The electrode structure 102 includes a plurality of main grid lines 1 and a plurality of fine grid lines 2. In this embodiment, the direction in which the main grid lines 1 extend is defined as the second direction Y, and the plurality of main grid lines 1 are arranged at intervals along a first direction X perpendicular to the second direction Y. The main grid lines 1 include a main rod 11 extending along the second direction Y and a plurality of connecting branches 12 arranged at intervals along the main rod 11. The plurality of fine grid lines 2 are arranged at intervals along the second direction Y. The fine grid lines 2 extend along the first direction X and are provided with a plurality of fractures 21 at intervals along the extension direction thereof. Among them, the main grid line 1 intersects with the fine grid line 2 at the break 21 at the connecting branch 12, and the electrode structure 102 also includes a widened short line 3 located at the intersection. The main grid line 1 and the fine grid line 2 are electrically connected through the connecting branch 12 and the widened short line 3, avoiding the problem of wire breakage during sintering or welding, thereby ensuring the yield and quality stability of the solar cell 100, improving the power of the solar cell 100, and thus ensuring the power of the solar cell module.

[0053] In this embodiment, the widened short line 3 is set as a part of the fine grid line 2, and the fine grid line 2 includes end portions 22 located on both sides of the fracture 21. The widened short line 3 is located at the fracture 21 and is spaced apart from the end portions 22 on both sides. The width of the end portion 22 is set gradually. Taking this embodiment as an example, the widened short line 3 is rectangular, with a width D1 of 30 μm and a length L1 of 500 μm. The width D2 of the fine grid line 2 is 10 μm, and the distance L2 between the two sides of the widened short line 3 and the end portion 22 is 100 μm respectively. The terminal width of the end portion 22 is 20 μm and gradually changes to the width of the fine grid line 10 μm. The width D3 of the main rod 11 of the main grid line 1 is 30 μm, and the connecting branch 12 is perpendicular to the main rod 11 and extends along the first direction X. The connecting branch 12 is symmetrically arranged relative to the main rod 11, and the length L3 of the connecting branch 12 is 1300 μm. The connecting branches 12 are provided corresponding to the break 21 , and can substantially cover the widened short lines 3 and the tapered ends 22 , thereby ensuring electrical connection between the main grid lines 1 and the thin grid lines 2 .

[0054] Please continue to participate Figures 1 to 11The main grid line 1 also includes a harpoon portion 13 located at both ends of the main rod 11 and a number of welding pads 14 distributed at intervals along the main rod 11. The harpoon portion 13 includes a welding base 131, two oppositely arranged forks 132 extending from the welding base 131, a fishbone portion 133 located between the two forks 132, and whiskers 134 spaced apart at the ends of the forks 132. The welding base 131, the fork 132, the fishbone portion 133, and the whiskers 134 are electrically connected to the fine grid line 2 respectively. Welding feet 141 extend on both sides of the welding pad 14. The widest width of the welding foot 141 reaches more than 80μm and gradually becomes smaller to ensure electrical connection with the fine grid line 2.

[0055] The present invention also discloses a solar cell assembly (not shown) comprising a soldering ribbon and a plurality of solar cells 100 connected by the soldering ribbon. Electrode structures 102 are provided on one or both sides of a semiconductor substrate 101 of each solar cell 100. The soldering ribbon is welded to solder pads 14 to connect the plurality of solar cells 100 to form a solar cell assembly, achieving high yield and power efficiency.

[0056] Please refer to Figures 12 to 14 The present invention discloses another solar cell 200. The solar cell 200 includes a semiconductor substrate 201 and an electrode structure 202 arranged on the semiconductor substrate 210. The electrode structure 202 includes a main grid line 4, a fine grid line 5 and a widened short line 6. The difference between the solar cell 200 of this embodiment and the solar cell 100 is that the widened short line 6 is set as a part of the fine grid line 5, and the fine grid line 5 includes a first end 521 and a second end 522 located on both sides of the fracture 51. The widened short line 6 is located at the fracture 51, and is connected to the first end 521 and spaced apart from the second end 522. The length direction of the widened short line 6 extends along the first direction X, and its center line overlaps with the center line of the fine grid line 5, becoming a part of the fine grid line 5. The distance L2 between the widened short line 6 and the second end 522 is 200μm, and the width of the second end 522 is gradually set. The width of the first end 521 is set to the width of the fine grid line 5, and is not gradually set. The main rod 41 of the main grid line 4 passes through the center of the widened short line 6, and the connecting branch 42 extends from the intersection to both sides and is electrically connected to the widened short line 6, the first end 521, the second end 522 and the fine grid line 5, avoiding the problem of wire breakage during sintering or welding, thereby ensuring the yield and quality stability of the solar cell 200, improving the power of the solar cell 200, and thus ensuring the power of the solar cell module.

[0057] Please refer to Figures 15 to 17The utility model discloses another solar cell 300. The solar cell 300 includes a semiconductor substrate 301 and an electrode structure 302 arranged on the semiconductor substrate 301. The electrode structure 302 includes a main grid line 7, a thin grid line 8 and a widened short line 9. The difference between the solar cell 300 of this embodiment and the solar cell 100 is that the widened short line 9 is a part of the main grid line 7. The connecting branch 72 includes the widened short line 9 and a gradient section 721 extending from both sides of the widened short line 9. The widened short line 9 is arranged to cross the main rod 71 and is symmetrically arranged relative to the main rod 71. The thin grid line 8 includes end portions 82 located on both sides of the fracture 81, and the width of the end portions 82 is gradually set. The length of the widened short line 9 is greater than the width of the fracture 81, and the length of the connecting branch 72 is greater than the sum of the width of the fracture 81 and the length of the two gradient end portions 82. Specifically, in this embodiment, the length L1 of the widened short line 9 is 300 μm, the width L4 of the fracture 81 is 200 μm, the length L5 of the tapered end 82 is 300 μm, and the length L6 of the tapered section 721 is 500 μm. This ensures electrical connection and prevents wire breakage during sintering or welding, thereby guaranteeing the yield and quality stability of the solar cell 300, increasing the power output of the solar cell 300 and, in turn, guaranteeing the power output of the solar cell module.

[0058] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail above with reference to the accompanying drawings. In the above description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described above, and those skilled in the art can make similar improvements without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed above. In addition, the various technical features of the embodiments described above can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A solar cell, characterized in that: The device comprises a semiconductor substrate and an electrode structure provided on the semiconductor substrate, wherein the electrode structure comprises: A plurality of main grid lines are arranged at intervals along a first direction, wherein the main grid lines include a main bar extending along a second direction and a plurality of connecting branches arranged at intervals along the main bar; A plurality of fine grid lines are arranged at intervals along the second direction, wherein the fine grid lines extend along the first direction and have a plurality of breaks spaced apart along the extending direction; The main grid line intersects the thin grid line at the connection branch at the break, and the electrode structure further includes a widened short line at the intersection. The main grid line and the thin grid line are electrically connected through the connection branch and the widened short line.

2. The solar cell according to claim 1, wherein: The width D1 of the widened short line is in the range of 20 μm≤D1≤80 μm, the length L1 is in the range of 200 μm≤L1≤800 μm, and the length direction thereof extends along the first direction.

3. The solar cell according to claim 2, wherein: The widened short line is rectangular.

4. The solar cell according to claim 2, wherein: The widened short line is set as a part of the thin grid line, and the thin grid line includes ends located on both sides of the break. The widened short line is located in the break and is spaced apart from the end on at least one side.

5. The solar cell according to claim 4, characterized in that: The widened short line is located at the fracture and is spaced apart from the ends on both sides, and the widths of the ends are gradually changed.

6. The solar cell according to claim 4, wherein: The widened short line is located at the fracture and connected to the end on one side, and the width of the end on the other side is gradually changed.

7. The solar cell according to claim 2, wherein: The widened short lines are formed as the connecting branches.

8. The solar cell according to claim 7, wherein: The connecting branch includes the widened short line and gradient segments extending from both sides of the widened short line, and the length of the widened short line is greater than the width of the fracture.

9. The solar cell according to claim 8, characterized in that: The thin grid line includes end portions located on both sides of the fracture, the width of the end portions is gradually changed, and the length of the gradual change section is greater than the gradual change area of ​​the end portions.

10. A solar cell module, characterized in that: It includes a welding strip and several solar cells according to any one of claims 1 to 9 connected by the welding strip, the main grid line of the solar cell also includes a harpoon portion located at both ends of the main rod and several welding pads distributed at intervals along the main rod, and the welding strip is welded to the welding pads.

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