Solar cell and solar cell module

Abstract

The invention 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 thin 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 invention also discloses a solar cell module.

Description

[0001] Priority Information

[0002] This application claims priority to and the benefit of the filing date of the patent application with the China National Intellectual Property Office, filed on September 23, 2024, with the patent application number 202411328046.6, entitled "Solar Cell and Solar Cell Module", and incorporates it herein in its entirety by reference. 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, pollution-free and resource-rich. Therefore, solar energy is gradually becoming a core clean energy to replace fossil energy. Since the solar cell module has good photoelectric conversion efficiency, the solar cell module has become the development focus of clean energy utilization.

[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 are easy to cause the formation of broken lines at the intersections of the main grid lines and the fine grid lines, thereby causing the power of the solar cell to decrease and the overall power of the solar cell module to be lost. 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, which comprises a semiconductor substrate and an electrode structure arranged on the semiconductor substrate, and 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 thereof;

[0010] wherein the main grid lines intersect the fine grid lines at the connecting branches and the broken sections, respectively, and the electrode structure further comprises a widened short line at the intersection, and the main grid lines and the fine grid lines are electrically connected through the connecting branches and the widened short line.

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

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

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

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

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

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

[0017] In one embodiment, the connecting branch includes the widened stub and a tapered segment extending from both sides of the widened stub, and the length of the widened stub is greater than the width of the break.

[0018] In one embodiment, the thin grid line includes end portions on both sides of the break, the width of the end portions is tapered, and the length of the tapered segment is greater than the tapered region of the end portions.

[0019] The application also discloses a solar cell module including a solder strip and a plurality of solar cell pieces connected by the solder strip, the main grid line of the solar cell piece further includes a fishing-tackle portion at both ends of the main rod and a plurality of solder pads distributed at intervals 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 connecting branch and the widened stub, avoiding 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] Figure 1 FIG. 1 is a schematic view of the cross-sectional structure of the solar cell piece of the application;

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

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

[0024] Figure 4 for Figure 2 Enlarged view of center circle A;

[0025] Figure 5 for Figure 2 Enlarged view of center circle B;

[0026] Figure 6 This is a schematic diagram of the planar structure of the fine grid lines of the electrode structure of the solar cell of this application;

[0027] Figure 7 for Figure 6 An enlarged view of the center circle C;

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

[0029] Figure 9 This is a schematic diagram of the planar structure of the main grid lines of the electrode structure of the solar cell of this application;

[0030] Figure 10 for Figure 9 Enlarged view of center circle E;

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

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

[0033] Figure 13 for Figure 12 A schematic diagram of the intersection of the main grid lines and the fine grid lines in a solar cell.

[0034] Figure 14 for Figure 13 A partial schematic diagram of the fine grid lines;

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

[0036] Figure 16 for Figure 15 A schematic diagram of the intersection of the main grid lines and the fine grid lines in a solar cell.

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

[0038] For the purposes of this application, a more complete understanding of the application can be obtained by reference to the following description in connection with the accompanying drawings. The drawings are provided for purposes of illustration only and merely depict preferred embodiments of the application. However, the application can be implemented 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 noted that when a component is referred to as being "on" another component, it can be directly on the other component or intervening components can also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components can also be present. The terms "vertical", "horizontal", "left", "right", and similar expressions as used herein are for illustrative purposes only and are not meant to be limiting.

[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 of the application herein is for describing particular embodiments only and is not intended to be limiting of the application. The use herein of the terms "and / or" includes a set of one or more 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 which ranges from 20 μm to 80 μm, and the length L1 of which ranges from 200 μm to 800 μm. The rectangular widened short line prevents the 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 ranges from 8 μm to 18 μm. 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 the yield.

[0044] Further, the widened stub is arranged at the break and spaced apart from both end portions, 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 both end portions, and the spacing range can be 80 μm to 150 μm, 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, and the spacing range can be 160 μm to 300 μm, further ensuring the subsequent connectivity.

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

[0047] In one embodiment, the connecting branch includes a 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 the 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 the 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. 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 spaced apart at the end of the fork portion. The welding base, the fork portion, the fishbone portion, and the whisk portion are respectively electrically connected to the fine grid line. The two sides of the pad extend with a soldering leg, and the soldering leg is electrically connected to the fine grid line.

[0050] The application also discloses a solar cell module, which comprises a solder strip and a plurality of solar cell pieces connected by the solder strip.

[0051] The following Figures 1 to 17 The application is described below by way of example. In the drawings, only some structures are shown for the sake of brevity.

[0052] The following Figures 1 to 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 arranged at intervals along the extension direction thereof and a plurality of discontinuities 21. 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 welding, ensuring the yield and quality stability of the solar cell piece 100, improving the power of the solar cell piece 100, and thus 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 of the discontinuity 21. The width of the end portion 22 is gradually changed. In the embodiment, the widened stub 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 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, which is the width of the fine grid line. 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 between the main grid line 1 and the fine grid line 2.

[0054] The following Figures 1 to 11The main grid line 1 further comprises a fish-tail 13 at both ends of the main rod 11 and a plurality of pads 14 distributed along the main rod 11. The fish-tail 13 comprises a welding base 131, two opposite fork parts 132 extending from the welding base 131, a fishbone part 133 between the two fork parts 132, and a whisk part 134 arranged between the two fork parts 132. The welding base 131, the fork parts 132, the fishbone part 133, and the whisk part 134 are electrically connected to the fine grid line 2. The pads 14 are provided with soldering pins 141 extending from both sides of the pads 14. The soldering pins 141 have a width of more than 80 μm and gradually decrease in width, thereby ensuring the electrical connection with the fine grid line 2.

[0055] The present application further discloses a solar cell module (not shown) comprising the soldering ribbon and a plurality of solar cell pieces 100 connected by the soldering ribbon. One side or both sides of the semiconductor substrate 101 of the solar cell piece 100 are provided with the electrode structure 102, and the soldering ribbon is welded to the pads 14 to realize the connection of the plurality of solar cell pieces 100 to form the solar cell module, thereby achieving a high yield and power.

[0056] Please refer to Figures 12 to 14 The present application further discloses another solar cell piece 200. The solar cell piece 200 comprises a semiconductor substrate 201 and an electrode structure 202 arranged on the semiconductor substrate 201. The electrode structure 202 comprises a main grid line 4, a fine grid line 5, and a widened short line 6. The solar cell piece 200 of the present embodiment is different from the solar cell piece 100 in that the widened short line 6 is arranged as a part of the fine grid line 5, the fine grid line 5 comprises a first end part 521 and a second end part 522 arranged on both sides of a break 51, the widened short line 6 is arranged at the break 51 and connected to the first end part 521 and spaced apart from the second end part 522. The length direction of the widened short line 6 extends along the first direction X, and the center line of the widened short line 6 overlaps with the center line of the fine grid line 5, thereby becoming a part of the fine grid line 5. The distance L2 between the widened short line 6 and the second end part 522 is 200 μm, and the width of the second end part 522 gradually changes. The width of the first end part 521 is arranged as the width of the fine grid line 5 and does not gradually change. The main rod 41 of the main grid line 4 penetrates the center of the widened short line 6, and the connecting branch 42 extends from the intersection to both sides to be electrically connected to the widened short line 6, the first end part 521, the second end part 522, and the fine grid line 5, thereby avoiding the problem of broken lines during sintering or welding, thereby ensuring the yield and quality stability of the solar cell piece 200 and improving the power of the solar cell piece 200, and further ensuring the power of the solar cell module.

[0057] Please refer to Figures 15 to 17Another solar cell 300 is disclosed. The solar cell 300 comprises a semiconductor substrate 301 and an electrode structure 302 disposed on the semiconductor substrate 301. The electrode structure 302 comprises main grid lines 7, thin grid lines 8 and widened stubs 9. The solar cell 300 of the embodiment is different from the solar cell 100 in that the widened stubs 9 are part of the main grid lines 7. The connecting branches 72 comprise the widened stubs 9 and the tapered sections 721 extending from both sides of the widened stubs 9. The widened stubs 9 are arranged to cross the main stems 71 and are symmetrically arranged relative to the main stems 71. The thin grid lines 8 comprise end portions 82 on both sides of the breaks 81, and the width of the end portions 82 is tapered. The length of the widened stubs 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 embodiment, the length L1 of the widened stubs 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 and improving the power of the solar cell 300, and thus the power of the solar cell module.

[0058] In order to make the above objectives, features and advantages of the present application more apparent, the above detailed description of the specific embodiments of the present application is made in conjunction with the accompanying drawings. In the above description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than the embodiments described above, 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 specific embodiments disclosed above. Furthermore, the technical features of the above-described embodiments can be combined in any manner, and in order to make the description brief, not all possible combinations of the technical features of the above-described embodiments are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered to be within the scope of the present application.

[0059] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to 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 in that, It includes a semiconductor substrate and an electrode structure disposed on the semiconductor substrate, the electrode structure including: Multiple main grid lines are arranged at intervals along a first direction, and each main grid line includes a main rod extending along a second direction and a number of connecting branches spaced at intervals along the main rod. Multiple fine grid lines are arranged at intervals along a second direction, and the fine grid lines extend along a first direction and are provided with several breaks at intervals along their extension direction. The main grid line intersects the fine grid line at the connecting branch and at the break point. The electrode structure also includes a widened short line located at the intersection. The main grid line and the fine grid line are electrically connected through the connecting branch and the widened short line.

2. The solar cell according to claim 1, characterized in that, 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, and its length direction extends along the first direction.

3. The solar cell according to claim 2, characterized in that, The widened short line is rectangular in shape.

4. The solar cell according to claim 2, characterized in that, The widened short line is set as part of the fine grid line, the fine grid line including ends located on both sides of the break, and the widened short line is located at the break and spaced apart from at least one of the ends.

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

6. The solar cell according to claim 4, characterized in that, The widened short line is located at the break and connected to the end on one side, while the width of the end on the other side is gradually changed.

7. The solar cell according to claim 2, characterized in that, The widened short line forms the connecting branch.

8. The solar cell according to claim 7, characterized in that, The connecting branch includes the widened short line and a gradient segment extending from both sides of the widened short line, wherein the length of the widened short line is greater than the width of the break.

9. The solar cell according to claim 8, characterized in that, The fine grid line includes ends located on both sides of the break, the width of the ends being gradually varied, and the length of the gradually varied segment being greater than the gradually varied area of ​​the ends.

10. A solar cell module, characterized in that, It includes a solder strip and a plurality of solar cells as claimed in any one of claims 1 to 9 connected by the solder strip, wherein the main grid line of the solar cell further includes a fork portion located at both ends of the main rod and a plurality of pads spaced apart along the main rod, and the solder strip is soldered to the pads.

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