Solar cell and solar cell module

Abstract

The present application discloses a solar cell, comprising a semiconductor substrate and an electrode structure arranged on the semiconductor substrate. The electrode structure comprises a plurality of busbars and a plurality of fingers. The plurality of busbars are arranged at intervals along a first direction. Each busbar comprises a main trunk extending in a second direction and a plurality of connection branches arranged at intervals along the main trunk. The plurality of fingers are arranged at intervals in the second direction. The fingers extend along the first direction and each finger is provided with a plurality of gaps at intervals in the extension direction thereof. The connection branches of the busbars intersect the gaps of the fingers. The electrode structure further comprises widened small short lines located at the intersections. The busbars are electrically connected to the fingers by means of the connection branches and the widened small short lines, thereby avoiding the problem of line breakage during sintering or welding. In addition, the present application further discloses a solar cell module.

Description

Solar cell and solar cell module

[0001] Priority information

[0002] The present application claims priority and benefit of patent application No. 202411328046.6, filed on September 23, 2024, entitled "Solar cell and solar cell module" and patent application No. 202411401264.8, filed on October 9, 2024, entitled "Solar cell and solar cell module" with the State Intellectual Property Office of China, and incorporates herein by reference in its entirety. TECHNICAL FIELD

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

[0004] Fossil energy exists atmospheric pollution and limited reserves, while solar energy has the advantages of clean, non-polluting and resource-rich. Therefore, solar energy is gradually becoming a core clean energy to replace fossil energy, and solar cell modules have become the development focus of clean energy utilization due to their good photoelectric conversion efficiency.

[0005] The surface of a conventional solar cell is printed with a plurality of fine grid lines and a plurality of main grid lines. The fine grid lines are used to collect the current generated after being illuminated, and the main grid lines are used to collect the current on the fine grid lines. A plurality of solar cells are connected by a solder strip to form a solar cell module. However, during the production process of the solar cell and the solar cell module, the sintering of the fine grid lines, the sintering of the main grid lines and the welding of the solder strip can easily cause the main grid lines and the fine grid lines to form broken lines at the intersection, thereby reducing the power of the solar cell and causing the overall power loss of the solar cell module. SUMMARY

[0006] Therefore, it is necessary to provide a solar cell and a solar cell module to solve the above technical problems.

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

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

[0009] a plurality of fine grid lines arranged at intervals along the second direction, wherein the fine grid lines extend along the first direction and are arranged at intervals along the extension direction of the fine grid lines;

[0010] The main grid line crosses the thin grid line at the breakage and the electrode structure further comprises a widened stub at the intersection, and the main grid line and the thin grid line are electrically connected through the connection branch and the widened stub.

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

[0012] In one embodiment, the widened stub has a rectangular shape.

[0013] In one embodiment, the widened stub is arranged as a part of the thin grid line, and the thin grid line comprises end portions on both sides of the breakage, and the widened stub is arranged at the breakage and spaced apart from the end portion on one side.

[0014] In one embodiment, the widened stub is arranged at the breakage and spaced apart from the end portions on both sides, and the width of the end portions is gradually changed.

[0015] In one embodiment, the widened stub is arranged at the breakage and connected to the end portion on one side, and the width of the end portion spaced apart on the other side is gradually changed.

[0016] In one embodiment, the widened stub is formed as the connection branch.

[0017] In one embodiment, the connection branch comprises the widened stub and a gradually changed section extending from both sides of the widened stub, and the length of the widened stub is greater than the width of the breakage.

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

[0019] The application further discloses a solar cell module comprising a solder strip and a plurality of solar cell pieces connected by the solder strip, and the main grid line of the solar cell piece further comprises a fishing-tackle portion at both ends of the main rod and a plurality of solder pads distributed along the main rod, and the solder strip is welded to the solder pads.

[0020] The application has the following beneficial effects: the main grid line and the thin grid line are electrically connected through the connection branch and the widened stub, which avoids the problem of broken lines during sintering or welding, thereby ensuring the yield and quality stability of the solar cell piece, improving the power of the solar cell piece, and further ensuring the power of the solar cell module. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 is a schematic diagram of a cross-sectional structure of a solar cell according to the present application;

[0022] Fig. 2 is a schematic diagram of a planar structure of an electrode structure of a solar cell according to the present application;

[0023] Fig. 3 is a schematic diagram of an intersection of a main grid line and a fine grid line in Fig. 2;

[0024] Fig. 4 is an enlarged schematic diagram of circle A in Fig. 2;

[0025] Fig. 5 is an enlarged schematic diagram of circle B in Fig. 2;

[0026] Fig. 6 is a schematic diagram of a planar structure of a fine grid line of an electrode structure of a solar cell according to the present application;

[0027] Fig. 7 is an enlarged schematic diagram of circle C in Fig. 6;

[0028] Fig. 8 is an enlarged schematic diagram of circle D in Fig. 6;

[0029] Fig. 9 is a schematic diagram of a planar structure of a main grid line of an electrode structure of a solar cell according to the present application;

[0030] Fig. 10 is an enlarged schematic diagram of circle E in Fig. 9;

[0031] Fig. 11 is an enlarged schematic diagram of circle F in Fig. 9;

[0032] Fig. 12 is a schematic diagram of another cross-sectional structure of a solar cell according to the present application;

[0033] Fig. 13 is a schematic diagram of an intersection of a main grid line and a fine grid line of the solar cell in Fig. 12;

[0034] Fig. 14 is a partial schematic diagram of the fine grid line in Fig. 13;

[0035] Fig. 15 is a schematic diagram of another cross-sectional structure of a solar cell according to the present application;

[0036] Fig. 16 is a schematic diagram of an intersection of a main grid line and a fine grid line of the solar cell in Fig. 15;

[0037] Fig. 17 is a partial schematic diagram of the main grid line in Fig. 15. DETAILED DESCRIPTION

[0038] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. There is shown in the drawings, a preferred embodiment of the application. However, it should be understood that the application can be practiced in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0039] It is to be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. 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. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] 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 application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] The application discloses a solar cell, which comprises a semiconductor substrate and an electrode structure arranged on the semiconductor substrate. The electrode structure comprises 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 line comprises a main stem extending along a second direction and a plurality of connecting branches arranged at intervals along the main stem. The plurality of fine grid lines are arranged at intervals along the second direction. The fine grid line extends along the first direction and is arranged at intervals along the extension direction of the fine grid line. The main grid line and the fine grid line intersect at the connecting branch and the break, respectively. The electrode structure further comprises a widened short line at the intersection. The main grid line and the fine grid line are electrically connected through the connecting branch and the widened short line, thereby avoiding the problem of broken lines during sintering or welding, 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] Further, the width D1 of the widened short line ranges from 20 μm to 80 μm, and the length L1 ranges from 200 μm to 800 μm, and the length direction of the widened short line extends along the first direction. In an embodiment, the widened short line is in a rectangular shape, the width D1 of the rectangular shape ranges from 20 μm to 80 μm, and the length L1 of the rectangular shape ranges from 200 μm to 800 μm. The rectangular widened short line prevents the problem of broken lines caused by sintering or welding, and ensures the electrical connection between the main grid line and the fine grid line.

[0043] In one embodiment, the widened stub is arranged as a part of the fine grid line, the fine grid line includes end portions located on both sides of the break, and the widened stub is arranged at the break and spaced apart from at least one of the end portions. The length direction of the widened stub extends along the first direction, and the center line of the widened stub overlaps the center line of the fine grid line to form a part of the fine grid line. The width D2 of the fine grid line is in a range of 8 μm≤D2≤18 μm, and the fine grid line with the widened stub at the break can avoid the problem of disconnection at the intersection caused by process factors such as sintering or welding, thereby improving yield.

[0044] Further, the widened stub is arranged at the break and spaced apart from the end portions on both sides, and the width of the end portion is gradually changed. The end portion is widest at the end and gradually decreases to the width of the fine grid line. The widened stub is spaced apart from the end portions on both sides by a spacing in a range of 80 μm-150 μm, thereby further ensuring the subsequent connectivity.

[0045] Further, the widened stub is arranged at the break and connected to one of the end portions, and the width of the other end portion is gradually changed. The widened stub is spaced apart from the other end portion by a spacing in a range of 160-300 μm, thereby further ensuring the subsequent connectivity.

[0046] In one embodiment, the widened stub is formed as a connecting branch. The connecting branch is arranged as the widened stub and connects the end portions on both sides at the break, thereby avoiding the problem of disconnection at the intersection caused by process factors such as sintering or welding, thereby improving yield.

[0047] In one embodiment, the connecting branch includes the widened stub and a gradually changed segment extending from both sides of the widened stub, and the length of the widened stub is greater than the width of the break. The fine grid line includes end portions located on both sides of the break, and the width of the end portion is gradually changed. The length of the gradually changed segment is greater than the gradually changed region of the end portion, thereby avoiding the problem of disconnection at the intersection caused by process factors such as sintering or welding, thereby improving yield.

[0048] In one embodiment, the widened stub is arranged separately and does not belong to the main grid line or the fine grid line. The widened stub assists the electrical connection of the main grid line and the fine grid line, prevents disconnection, and improves yield.

[0049] Further, the main grid line further includes a fishhook portion at both ends of the main rod and a plurality of pads distributed along the main rod at intervals. The fishhook portion includes a welding base, two oppositely arranged fork portions extending from the welding base, a fishbone portion between the two fork portions, and a whisk portion arranged at the end of the fork portion. The welding base, the fork portion, the fishbone portion, and the whisk portion are electrically connected to the fine grid line. The pads have pads extending on both sides, and the pads are electrically connected to the fine grid line.

[0050] The application further discloses a solar cell module which comprises a solder strip and a plurality of solar cell pieces connected by the solder strip, and the solder strip is connected with the solder pad by soldering, so that the yield is high and the power of the solar cell module is ensured.

[0051] The solar cell piece of the application is described below by way of example with reference to Figs. 1-17. In the drawings, only some structures are shown by way of example due to the length of the description.

[0052] Referring to Figs. 1-11, the application discloses a solar cell piece 100. The solar cell piece 100 comprises a semiconductor substrate 101 and an electrode structure 102 arranged on the semiconductor substrate 101. The electrode structure 102 comprises a plurality of main grid lines 1 and a plurality of fine grid lines 2. In the embodiment, the direction in which the main grid lines 1 extend is defined as a 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 line 1 comprises a main stem 11 extending along the second direction Y and a plurality of connecting branches 12 arranged at intervals along the main stem 11. The plurality of fine grid lines 2 are arranged at intervals along the second direction Y. The fine grid line 2 extends along the first direction X and is provided with a plurality of discontinuities 21 at intervals along the extension direction thereof. The main grid line 1 intersects the fine grid line 2 at the connecting branch 12 and the discontinuity 21, respectively. The electrode structure 102 further comprises a widened stub 3 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 stub 3, thereby avoiding the problem of disconnection during sintering or soldering, ensuring the yield and quality stability of the solar cell piece 100, improving the power of the solar cell piece 100, and further ensuring the power of the solar cell module.

[0053] In the embodiment, the widened stub 3 is arranged as part of the fine grid line 2. The fine grid line 2 comprises end portions 22 on both sides of the discontinuity 21, and the widened stub 3 is arranged at intervals from the end portions 22 on both sides. The width of the end portion 22 is gradually changed. In the embodiment, the widened stub 3 is rectangular, the width D1 thereof is 30 μm, and the length L1 thereof is 500 μm. The width D2 of the fine grid line 2 is 10 μm, and the distance L2 from the end portion 22 on both sides of the widened stub 3 is 100 μm. The width of the end portion 22 gradually changes from 20 μm to 10 μm. The width D3 of the main stem 11 of the main grid line 1 is 30 μm. The connecting branch 12 is perpendicular to the main stem 11 and extends along the first direction X. The connecting branch 12 is symmetrically arranged relative to the main stem 11. The length L3 of the connecting branch 12 is 1300 μm. The connecting branch 12 is arranged corresponding to the discontinuity 21, and the connecting branch 12 basically covers the widened stub 3 and the gradually changed end portion 22, thereby ensuring the electrical connection of the main grid line 1 and the fine grid line 2.

[0054] Please continue to see FIG. 1 to FIG. 11, the main grid line 1 also includes the fishhook part 13 located at both ends of the main rod 11 and several pads 14 distributed along the main rod 11. The fishhook part 13 includes a welding base 131, two oppositely arranged fork parts 132 extending from the welding base 131, a fishbone part 133 located between the two fork parts 132, and a whisk part 134 arranged at intervals at the ends of the fork parts 132. The welding base 131, the fork part 132, the fishbone part 133, and the whisk part 134 are respectively electrically connected with the fine grid line 2. The pads 14 extend on both sides with soldering pins 141. The widest width of the soldering pin 141 reaches more than 80 μm and gradually decreases, ensuring electrical connection with the fine grid line 2.

[0055] The application also discloses a solar cell module (not shown), which includes a solder strip and several solar cell pieces 100 connected by the solder strip. One side or both sides of the semiconductor substrate 101 of the solar cell piece 100 are provided with an electrode structure 102, and the solder strip is welded with the pads 14 to realize the connection of the several solar cell pieces 100 to form the solar cell module, which has a higher yield and power.

[0056] Please see FIG. 12 to FIG. 14, the application discloses another solar cell piece 200. The solar cell piece 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 small short line 6. The difference between the solar cell piece 200 of the embodiment and the solar cell piece 100 lies in that the widened small short line 6 is arranged as a part of the fine grid line 5, the fine grid line 5 includes a first end part 521 and a second end part 522 located on both sides of a break 51, the widened small short line 6 is located at the break 51 and is connected with the first end part 521 and arranged at intervals with the second end part 522. The length direction of the widened small short line 6 extends along the first direction X, and the center line thereof 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 small short line 6 and the second end part 522 is 200 μm, and the width of the second end part 522 is gradually changed. The width of the first end part 521 is arranged as the width of the fine grid line 5 and is not gradually changed. The main rod 41 of the main grid line 4 penetrates the center of the widened small short line 6, and the connecting branch 42 extends to both sides from the intersection and is electrically connected with the widened small short line 6, the first end part 521, the second end part 522, and the fine grid line 5, avoiding the problem of broken line during sintering or welding, thereby ensuring the yield and quality stability of the solar cell piece 200, improving the power of the solar cell piece 200, and further ensuring the power of the solar cell module.

[0057] Please refer to FIG. 15 to FIG. 17, another solar cell 300 is disclosed in the present application. The solar cell 300 comprises a semiconductor substrate 301 and an electrode structure 302 arranged on the semiconductor substrate 301. The electrode structure 302 comprises main grid lines 7, thin grid lines 8 and widened short lines 9. The solar cell 300 of the present embodiment is different from the solar cell 100 in that the widened short lines 9 are part of the main grid lines 7. The connecting branches 72 comprise the widened short lines 9 and the tapered sections 721 extending from both sides of the widened short lines 9. The widened short lines 9 are arranged crossing the main stems 71 and symmetrically relative to the main stems 71. The thin grid lines 8 comprise end portions 82 arranged on both sides of the breaks 81, and the width of the end portions 82 is tapered. The length of the widened short lines 9 is greater than the width of the breaks 81, and the length of the connecting branches 72 is greater than the width of the breaks 81 and the sum of the lengths of the tapered end portions 82. Specifically, in the present embodiment, the length L1 of the widened short lines 9 is 300 μm, the width L4 of the breaks 81 is 200 μm, the length L5 of the tapered end portions 82 is 300 μm, and the length L6 of the tapered sections 721 is 500 μm. The electrical connection is ensured, and the problem of disconnection during sintering or welding is avoided, thereby ensuring the yield and quality stability of the solar cell 300, improving the power of the solar cell 300, and further ensuring the power of the solar cell module.

[0058] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the above detailed description of the specific embodiments of the present application is combined with the drawings. In the above description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from the above description, and those skilled in the art can make similar improvements without departing from the concept of the present application, and therefore the present application is not limited to the above disclosed specific embodiments. Moreover, each technical feature of the above described embodiments can be combined arbitrarily, and in order to make the description simple, each technical feature of the above described embodiments is not described in all possible combinations, however, as long as the combinations of these technical features do not exist, they should be considered as the scope of the present application.

[0059] The above described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A solar cell, characterized by, It includes a semiconductor substrate and an electrode structure arranged on the semiconductor substrate, the electrode structure comprising: a plurality of main grid lines arranged at intervals along a first direction, the main grid lines comprising a main stem extending along a second direction and a plurality of connecting branches arranged at intervals along the main stem; a plurality of fine grid lines arranged at intervals along the second direction, the fine grid lines extending along the first direction and being arranged at intervals along their extension direction with a plurality of breaks; wherein the main grid lines intersect the fine grid lines at the connecting branches and the breaks, and the electrode structure further comprises widened stubs at the intersections, the main grid lines and the fine grid lines being electrically connected through the connecting branches and the widened stubs.

2. The solar cell according to claim 1, wherein The width D1 of the widened stubs ranges from 20 μm to 80 μm, and the length L1 ranges from 200 μm to 800 μm, the length direction of the widened stubs extending along the first direction.

3. The solar cell according to claim 2, wherein, The widened stubs are in a rectangular shape.

4. The solar cell of claim 2, wherein, The widened stubs are arranged as part of the fine grid lines, the fine grid lines comprising end portions on both sides of the breaks, the widened stubs being arranged at the breaks and at least at intervals from the end portions on one side.

5. The solar cell of claim 4, wherein, The widened stubs are arranged at the breaks and at intervals from the end portions on both sides, the width of the end portions being arranged to gradually change.

6. The solar cell of claim 4, wherein, The widened stubs are arranged at the breaks and connected to the end portions on one side, the width of the end portions on the other side being arranged to gradually change.

7. The solar cell of claim 2, wherein, The widened stubs are formed as the connecting branches.

8. The solar cell of claim 7, wherein, The connecting branches comprise the widened stubs and gradually changing segments extending from both sides of the widened stubs, the length of the widened stubs being greater than the width of the breaks.

9. The solar cell of claim 8, wherein, The fine grid lines comprise end portions on both sides of the breaks, the width of the end portions being arranged to gradually change, the length of the gradually changing segments being greater than the gradually changing region of the end portions.

10. A solar cell module characterized by comprising: It includes a solder strip and a plurality of solar cell pieces connected by the solder strip, the solar cell pieces being as claimed in any one of claims 1 to 9, the main grid lines of the solar cell pieces further comprising a fishing-tackle portion at both ends of the main stem and a plurality of solder pads arranged at intervals along the main stem, the solder strip being soldered to the solder pads.

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