Solar cell, shingled module and manufacturing method

Abstract

The present application relates to a kind of solar cell piece, shingle assembly and manufacturing method.Solar cell piece includes base piece, top surface grid line being arranged on the top surface of base piece, bottom surface grid line being arranged on the bottom surface of base piece, wherein, the extension direction of top surface grid line and bottom surface grid line on base piece is set to be such that when two solar cell pieces are connected in shingle way, the bottom surface grid line of first solar cell piece in the two solar cell pieces and the top surface grid line of second solar cell piece in the two solar cell pieces cross contact to realize electrical connection.The overall silver paste consumption of the grid line of the solar cell piece of the present application can be less than the silver paste consumption of the grid line of ordinary solar cell piece, but still can meet the demand of positive and negative electrode interconnection reliability.

Description

Technical Field

[0001] The present invention relates to the field of energy, and in particular to a solar cell, a shingled assembly and a manufacturing method. Background Art

[0002] With the accelerating global consumption of conventional fossil fuels such as coal, oil, and natural gas, the ecological environment continues to deteriorate, and greenhouse gas emissions, in particular, leading to increasingly severe global climate change, the sustainable development of human society is under serious threat. Countries around the world are formulating their own energy development strategies to address the limited availability of conventional fossil energy resources and the environmental challenges associated with their development and utilization. Solar energy, with its reliability, safety, widespread availability, longevity, environmental friendliness, and abundant resources, has become one of the most important renewable energy sources and is expected to become a major pillar of future global electricity supply.

[0003] During the new round of energy transformation, my country's photovoltaic industry has grown into a strategic emerging industry with international competitive advantages. However, the photovoltaic industry still faces numerous problems and challenges. Conversion efficiency and reliability are the greatest technical barriers to its development, while cost control and scale-up pose economic constraints. As core components of photovoltaic power generation, improving the conversion efficiency of photovoltaic modules and developing high-efficiency modules is an inevitable trend. A variety of high-efficiency modules are currently emerging on the market, including shingled, half-cell, multi-busbar, and bifacial modules. As the application of photovoltaic modules expands in various locations and regions, the demand for their reliability is becoming increasingly stringent. This is especially true in areas prone to harsh or extreme weather, where high-efficiency and high-reliability photovoltaic modules are required.

[0004] In the context of vigorously promoting and using solar green energy, shingled modules use the electrical principle of low current and low loss (the power loss of photovoltaic modules is directly proportional to the square of the working current) to greatly reduce the power loss of the modules. Shingled modules generate electricity by laying more cells in the cell module by making full use of the cell spacing in the cell module, and the energy density per unit area is higher. In addition, conductive adhesives are used to replace the photovoltaic ribbons used in conventional modules. Photovoltaic ribbons exhibit a higher series resistance in the entire cell, and the resistance of the circuit formed by conductive adhesives is much smaller than that of the method using ribbons. At the same time, under the model using conductive adhesive, ultra-flexible inter-sheet structural interconnection can be achieved, which can effectively reduce fragmentation in the process and use links. Compared with conventional photovoltaic modules, shingled modules have higher conversion efficiency and less risk of fragmentation at the cell and cell interconnection locations after cutting.

[0005] However, existing solar cell and shingled module designs still have some shortcomings. For example, the main grid lines of existing solar cells are usually simple linear designs, resulting in high power consumption on both the front and back sides of the cell, increased production costs, and reduced competitiveness.

[0006] Therefore, it is necessary to provide a solar cell, a shingled assembly and a manufacturing method to at least partially solve the above problems. Summary of the Invention

[0007] The present invention provides a solar cell, a shingled assembly, and a manufacturing method. In the present invention, because adjacent solar cells in the shingled assembly no longer require overlapping, large-area contact electrodes to achieve conductive connection, the overall amount of silver paste used in the grid lines of the solar cell can be less than that used in conventional solar cells, while still meeting the reliability requirements for front-to-back electrode interconnection. Therefore, the solar cell provided by the present invention can reduce top surface main grid line losses, lower production costs, and enhance technological competitiveness.

[0008] Furthermore, the solar cell provided by the present invention can have a variety of grid line structures and combinations, so the solar cell provided by the present invention can reduce grid line loss while meeting the various usage needs of users.

[0009] According to a first aspect of the present invention, a solar cell is provided, comprising a substrate, a top surface grid line arranged on the top surface of the substrate, and a bottom surface grid line arranged on the bottom surface of the substrate, wherein the extension directions of the top surface grid line and the bottom surface grid line on the substrate are set so that when two solar cells are connected in a shingled manner, the bottom surface grid line of a first solar cell of the two solar cells and the top surface grid line of a second solar cell of the two solar cells cross-contact to achieve electrical connection.

[0010] In one embodiment, the extension direction of the top surface grid lines and the bottom surface grid lines on the substrate sheet is set so that when two solar cells are connected in a shingled manner, there is an angle of 5°-175° between the bottom surface grid lines of the first solar cell and the top surface grid lines of the second solar cell that are in contact with each other.

[0011] In one embodiment, the top surface grid lines include top surface secondary grid lines and top surface main grid lines intersecting the top surface secondary grid lines, the bottom surface grid lines include only bottom surface secondary grid lines, and the solar cells are constructed such that when two solar cells are connected in a shingled manner, the bottom surface secondary grid lines of the first solar cell and the top surface main grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection; or

[0012] The top surface grid lines only include top surface auxiliary grid lines, the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines arranged to cross the bottom surface auxiliary grid lines, and the solar cell is constructed so that when two solar cells are connected in a shingled manner, the bottom surface main grid lines of the first solar cell and the top surface auxiliary grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection.

[0013] In one embodiment, the top surface grid lines include top surface auxiliary grid lines and top surface main grid lines that cross the top surface auxiliary grid lines, the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines that cross the bottom surface auxiliary grid lines, and the solar cells are constructed so that when two solar cells are connected in a shingled manner: the bottom surface main grid lines of the first solar cell that is in contact with each other and the top surface auxiliary grid lines of the second solar cell that are in contact with each other cross-contact to achieve electrical connection, or the bottom surface auxiliary grid lines of the first solar cell that are in contact with each other and the top surface main grid lines of the second solar cell that are in contact with each other cross-contact to achieve electrical connection.

[0014] In one embodiment, the top surface grid lines include top surface auxiliary grid lines and top surface main grid lines that cross the top surface auxiliary grid lines, and the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines that cross the bottom surface auxiliary grid lines, and the extension directions of the top surface main grid lines and the bottom surface main grid lines are set so that when two solar cells are connected in a shingled manner, the bottom surface main grid lines of the first solar cell and the top surface main grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection.

[0015] In one embodiment, auxiliary grid lines and main grid lines arranged to cross the auxiliary grid lines are arranged on the top surface and / or bottom surface of the solar cell, and the main grid lines include at least two grid line structures parallel to each other. The solar cell is constructed so that when the two solar cells are connected in a shingled manner, the main grid lines of one solar cell cross-contact with the main grid lines or auxiliary grid lines of another solar cell.

[0016] In one embodiment, the base sheet has a first longitudinal edge, a second longitudinal edge, and two transverse edges;

[0017] The top surface grid lines include top surface bus bars, which are arranged on the top surface of the substrate sheet along or near the first longitudinal edge of the substrate sheet as a whole, and include top surface first bus bars and top surface second bus bars, which both extend along the longitudinal direction of the substrate sheet and are spaced apart in the transverse direction of the substrate sheet.

[0018] The bottom surface grid lines include bottom surface main grid lines, and the bottom surface main grid lines are arranged on the bottom surface of the base sheet along or near the second longitudinal edge of the base sheet as a whole.

[0019] The top surface busbars and the bottom surface busbars are constructed so that when two solar cells are connected in a shingled manner, the bottom surface busbars of the first solar cell can simultaneously contact the top surface first busbars and the top surface second busbars of the second solar cell.

[0020] In one embodiment, the bottom surface main grid lines include a bottom surface first main grid line and a plurality of bottom surface second main grid lines, wherein the bottom surface first main grid lines extend along the longitudinal direction of the substrate sheet; the bottom surface second main grid lines are short strip structures extending along the transverse direction of the substrate sheet, and each bottom surface second main grid line intersects with the bottom surface first main grid line.

[0021] In one embodiment, there is a gap between the first main grid line on the bottom surface and the second longitudinal edge of the substrate sheet, one end of each second main grid line on the bottom surface extends to the second longitudinal edge of the substrate sheet, and the other end of each second main grid line on the bottom surface extends to the first main grid line on the bottom surface or extends to protrude from the first main grid line on the bottom surface.

[0022] In one embodiment, a plurality of connection portions are arranged in the interval between the first busbar on the top surface and the second busbar on the top surface.

[0023] In one embodiment, the positions of the top surface busbars and the bottom surface busbars on the corresponding surfaces are set so that when two solar cells are connected in a shingled manner, each bottom surface second busbar of the first solar cell contacts both the top surface first busbar and the top surface second busbar of the second solar cell.

[0024] In one embodiment, the positions of the top surface busbars and the bottom surface busbars on the corresponding surfaces are set so that when two solar cells are connected in a shingled manner, each bottom surface second busbar of a first solar cell only contacts the top surface second busbar of a second solar cell.

[0025] In one embodiment, a top surface secondary grid line for current collection is provided on the top surface of the substrate, and the top surface main grid line and the top surface secondary grid line are in conductive contact.

[0026] In one embodiment, the solar cell is a double-sided solar cell, the bottom surface of the substrate is provided with a bottom surface secondary grid line for current collection, and the bottom surface main grid line and the bottom surface secondary grid line are in conductive contact.

[0027] According to another aspect of the present invention, a shingled assembly is provided. The shingled assembly includes at least one cell string, each cell string being formed by arranging the solar cells according to any one of the above solutions in a shingled manner.

[0028] In one embodiment, the solar cells in the cell string include top surface busbars and bottom surface busbars, and

[0029] Each pair of adjacent solar cells is a first solar cell and a second solar cell, the top surface busbar of the first solar cell is in conductive contact with the bottom surface busbar of the second solar cell, the first solar cell and the second solar cell are fixed together by an adhesive, and the adhesive is positioned between the first busbar on the top surface and the second busbar on the bottom surface of the first solar cell, and the adhesive bypasses the bottom surface busbar of the second solar cell.

[0030] According to another aspect of the present invention, there is provided a method for manufacturing the solar cell according to any one of the above solutions, the method comprising the steps of manufacturing a large solar cell and splitting the large solar cell into a plurality of solar cells, wherein the step of manufacturing the large solar cell comprises the following steps:

[0031] A large substrate sheet is provided, wherein the large substrate sheet includes a plurality of substrate sheet units connected together, and after the large solar cell sheet is split, each substrate sheet unit forms a substrate sheet of a solar cell;

[0032] Top surface grid lines are printed on the top surface of the large substrate sheet, and bottom surface grid lines are printed on the bottom surface of the large substrate sheet. The printing directions of the top surface grid lines and the bottom surface grid lines are such that when two solar cells are arranged in a shingled manner, the bottom surface grid lines of the first solar cell of the two solar cells cross-contact with the top surface grid lines of the second solar cell of the two solar cells to achieve electrical connection.

[0033] In one embodiment, the method includes the step of providing a PN junction, and when providing the PN junction, the location of the PN junction is such as to bypass the boundary line between the substrate sheet units.

[0034] In one embodiment, the step of manufacturing a large solar cell sheet further includes a sintering step after printing the grid lines.

[0035] According to a fourth aspect of the present invention, there is provided a method for manufacturing a shingled assembly, the method comprising:

[0036] Manufacturing a solar cell according to the method described in any one of the above schemes;

[0037] Arrange multiple solar cells into cell strings in a shingled manner;

[0038] At least one battery string is fixed to form a shingled assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] To better understand the above and other objects, features, advantages, and functions of the present invention, reference may be made to the preferred embodiments shown in the accompanying drawings. Like reference numerals in the accompanying drawings refer to like components. Those skilled in the art should understand that the accompanying drawings are intended to illustrate preferred embodiments of the present invention by way of illustration and are not intended to limit the scope of the present invention. The components in the drawings are not drawn to scale.

[0040] Figure 1 A schematic diagram showing the top surface of a solar cell according to a preferred embodiment of the present invention is shown;

[0041] Figure 2 Shown Figure 1 A partial enlarged view of part A in FIG;

[0042] Figure 3 Shown Figure 1 Schematic diagram of the bottom surface of the solar cell;

[0043] Figure 4 for Figure 3 A partial enlarged view of part D in FIG;

[0044] Figure 5 For the Figure 2 A portion of the cross-sectional view taken along line BB in FIG. 1 is shown, and the cross-sectional view shows the shingled and Figure 2 Another solar cell connected to the solar cell in the embodiment;

[0045] Figure 6 For the Figure 2 A portion of the cross-sectional view taken along line CC in FIG. 1 is shown, and the cross-sectional view shows the shingled and Figure 2 Another solar cell connected to the solar cell in the embodiment;

[0046] Figure 7 Schematic diagram of the bottom surface of a solar cell according to a second preferred embodiment of the present invention;

[0047] Figure 8A and Figure 8B Schematic diagrams of the top and bottom surfaces of a solar cell according to a third preferred embodiment of the present invention;

[0048] Figure 9A and Figure 9B Schematic diagrams of the top and bottom surfaces of a solar cell according to a fourth preferred embodiment of the present invention;

[0049] Figure 10A and Figure 10B Schematic diagrams of the top and bottom surfaces of a solar cell according to a fifth preferred embodiment of the present invention;

[0050] Figure 11A and Figure 11B Schematic diagrams of the top and bottom surfaces of a solar cell according to a sixth preferred embodiment of the present invention;

[0051] Figure 12A and Figure 12B Schematic diagrams of the top and bottom surfaces of a solar cell according to a seventh preferred embodiment of the present invention;

[0052] Figure 13A and Figure 13B Schematic diagrams of the top and bottom surfaces of a solar cell according to an eighth preferred embodiment of the present invention;

[0053] Figure 14A and Figure 14B Schematic diagrams of the top and bottom surfaces of a solar cell according to a ninth preferred embodiment of the present invention;

[0054] Figure 15A and Figure 15B Schematic diagrams of the top and bottom surfaces of a solar cell according to a tenth preferred embodiment of the present invention. DETAILED DESCRIPTION

[0055] Now referring to the accompanying drawings, the specific embodiments of the present invention will be described in detail. What is described here is only the preferred embodiment of the present invention. Those skilled in the art can think of other ways to implement the present invention based on the preferred embodiment, and the other ways also fall within the scope of the present invention.

[0056] The present invention provides a solar cell, a shingled assembly and a manufacturing method. Figure 1-15B Partial structures according to some preferred embodiments of the present invention are shown.

[0057] First reference Figure 1-Figure 3 In a first preferred embodiment of the present invention, a solar cell 1 includes a substrate 11 having two lateral edges extending along a lateral direction D1 and a first longitudinal edge 15 and a second longitudinal edge 16 extending along a longitudinal direction D2. A plurality of secondary grid lines 13 are provided on the top surface of the substrate 11. The plurality of secondary grid lines 13 extend along the lateral direction D1 and are arranged along the longitudinal direction D2. A top surface busbar 12 is also provided on the top surface of the substrate 11, extending along or near the first longitudinal edge 15 of the substrate 11. The top surface busbar 12 contacts all of the secondary grid lines 13 on the top surface, thereby collecting the current of the secondary grid lines 13.

[0058] Figure 2 Shown Figure 1 A partial enlarged view of part A in Figure 2As shown, the top surface busbar 12 includes a first top surface busbar 121 and a second top surface busbar 122. The first top surface busbar 121 and the second top surface busbar 122 are parallel to each other and there is a gap between them in the transverse direction D1. A plurality of connecting portions 123 are arranged in the gap along the longitudinal direction D2. Each connecting portion 123 can conductively connect the first top surface busbar 121 and the second top surface busbar 122. The connecting portions 123 are preferably arranged at equal intervals, or as shown in FIG. Figure 1 The connecting portion 123 may be a point-shaped or strip-shaped connecting portion.

[0059] A bottom surface busbar is provided on the bottom surface of the substrate sheet 11 and extends entirely along or near the second longitudinal edge 16 of the substrate sheet 11. When two solar cells 1 are arranged adjacent to each other in a shingled manner, the bottom surface busbar of one solar cell 1 can simultaneously contact the top surface first busbar 121 and the top surface second busbar 122 of the other solar cell, thereby achieving a conductive connection between the two solar cells 1.

[0060] Preferably, reference Figure 3 and Figure 4 In this embodiment, the bottom surface main grid line 14 includes a bottom surface first main grid line 141 and a bottom surface second main grid line 142. The bottom surface first main grid line 141 extends along the longitudinal direction D2. There are multiple bottom surface second main grid lines 142 arranged along the longitudinal direction D2. Each bottom surface second main grid line 142 is a short strip structure extending along the transverse direction D1. Each bottom surface second main grid line 142 intersects with the bottom surface first main grid line 141.

[0061] Further, continue to refer to Figure 3 and Figure 4 There is a gap between the bottom surface first main grid line 141 and the second longitudinal edge 16 of the base sheet 11, and one end of each bottom surface second main grid line 142 extends to the second longitudinal edge 16 of the base sheet 11 and the other end extends to a position protruding from the bottom surface first main grid line 141.

[0062] Two such Figure 1-4 The cross-sectional view of the solar cell 1 after being connected in a shingled manner is shown in FIG. Figure 5 and Figure 6 Shown in. Figure 5 For the Figure 2 The cross-sectional view of line BB in Figure 6 For the Figure 2 The cross-sectional view of the CC line in FIG. 1 and FIG. 2 show the cross-sectional view of the CC line in FIG. Figure 2 The solar cell 1 in the embodiment is connected to another solar cell 1a in a shingled manner. The bottom surface main grid line 14 of the other solar cell 1a is connected to the main grid line 14 of the other solar cell 1a. Figure 2 The top surface of the solar cell 1 is in contact with the main grid line 12. Figure 5 and Figure 6 The solar cell 1 and the other solar cell 1a have the same structure, and are assigned different numbers only for the convenience of distinction.

[0063] refer to Figure 5 The first busbar 141 and the bottom surface of the other solar cell 1a are Figure 2 Each of the connection portions 123 of the solar cell 1 shown in FIG. 1 is in contact with each other. Figure 6 Each second busbar 142 on the bottom surface of the other solar cell 1a is connected to Figure 2 The top surface first busbar 121 and the top surface second busbar 122 of the solar cell 1 are in contact with each other. However, in other embodiments not shown, each bottom surface second busbar 142 of the other solar cell 1a may only contact the top surface second busbar 122 of the solar cell 1, and not contact the top surface first busbar 121 of the solar cell 1.

[0064] It can be seen that the structures of the top surface busbars 12 and the bottom surface busbars 14 of the solar cell 1 provided in this embodiment are different from the traditional busbar structures. The busbar structure provided in this embodiment can reduce the amount of silver paste used on the basis of being able to connect adjacent solar cells 1, so as to reduce the unit consumption of the top surface busbars 12 and the bottom surface busbars 14.

[0065] When adjacent solar cells 1 are interconnected in a shingled manner, they can be fixed to each other by adhesives, which can be applied to Figure 2 The top surface gap position 124 shown and the Figure 4 In other words, the adhesive is positioned between the top surface first busbar 121 and the bottom surface second busbar 142 of the first solar cell 1 , and the adhesive bypasses the connection portion 123 and the bottom surface busbar 14 of the second solar cell 1 .

[0066] In this embodiment, the bottom surface of the substrate sheet 11 is not provided with a secondary grid line but is provided with a back electric field. In other embodiments not shown, the bottom surface of the substrate sheet 11 may also be provided with a secondary grid line so that the solar cell 1 can be used as a bifacial solar cell 1. When the bottom surface of the substrate sheet 11 is also provided with a secondary grid line, the bottom surface secondary grid line can be consistent with the extension direction of the bottom surface second main grid line 142. Furthermore, the bottom surface second main grid line 142 can overlap with the bottom surface secondary grid line and form a part of the bottom surface secondary grid line.

[0067] This embodiment also provides a shingled assembly, which can be composed of multiple Figure 1-Figure 4 The solar cells 1 shown in FIG are interconnected in a shingled manner. The cross-sectional view of the overlapping position of any two adjacent solar cells 1 in the shingled assembly can be, for example, Figure 5 and Figure 6 shown.

[0068] Figure 7 FIG2 shows a schematic diagram of the bottom surface of a solar cell 2 according to a second embodiment of the present invention. The bottom surface of the substrate 21 of the solar cell 2 is provided with bottom surface busbars 24. The bottom surface busbars 24 include a first bottom surface busbar 241 and a plurality of second bottom surface busbars 242. In this embodiment, one end of the second bottom surface busbars 242 extends to the second longitudinal edge 26 of the solar cell, and the other end extends to the first bottom surface busbar 241, without protruding beyond the first bottom surface busbar 241.

[0069] This embodiment also provides a plurality of Figure 7 The solar cells 2 shown in FIG are interconnected in a shingled manner to form a solar cell. Figure 7 When the solar cells 2 shown in the figure are interconnected in a shingled manner, the second busbar 242 on the bottom surface of one solar cell 2 may only contact the first busbar on the top surface of another solar cell 2, or only contact the second busbar on the top surface of another solar cell 2.

[0070] It can be seen that in the above-described embodiment, when adjacent solar cells are connected in a shingled manner, the angle between the corresponding contacting busbars is 90°. For example, the first busbar 121 on the top surface of the first solar cell 1 and the second busbar 142 on the bottom surface of the second solar cell 1a cross-contact each other, and the angle between them is 90°; the second busbar 122 on the top surface of the first solar cell 1 and the second busbar 142 on the bottom surface of the second solar cell 1a cross-contact each other, and the angle between them is 90°.

[0071] In other preferred embodiments of the present invention, a structure different from that of the above-mentioned embodiment may be provided. For example, in one embodiment, the solar cell includes a substrate sheet, a top surface grid line (including at least one of a top surface main grid line and a top surface auxiliary grid line) arranged on the top surface of the substrate sheet, and a bottom surface grid line (including at least one of a bottom surface main grid line and a bottom surface auxiliary grid line) arranged on the bottom surface of the substrate sheet. Wherein, the extension direction of the top surface grid line and the bottom surface grid line on the substrate sheet is set so that when two solar cells are connected in a shingled manner, the bottom surface grid line of the first solar cell of the two solar cells and the top surface grid line of the second solar cell of the two solar cells cross-contact to achieve electrical connection. Preferably, the bottom surface grid line of the first solar cell that contacts each other and the top surface grid line of the second solar cell have an angle of 5°-175°, and the optimal angle is 90°.

[0072] Figures 8A-15B Some other embodiments of solar cells are shown, which enable top-surface gridlines and bottom-surface gridlines of adjacent solar cells to cross-contact each other at an angle of 5°-175° (preferably 90°).

[0073] refer to Figure 8A and Figure 8B ,in Figure 8A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 8B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 8A , a top surface auxiliary grid line 33 extending along the transverse direction D1 and a top surface main grid line 32 extending along the longitudinal direction D2 and intersecting each top surface auxiliary grid line 33 are provided on the top surface of the solar cell 3; Figure 8B , the bottom surface of the solar cell 3 is only provided with the bottom surface auxiliary grid line 37 extending along the lateral direction D1 without the bottom surface main grid line. Figures 8A-8B When the solar cells 3 are interconnected in a shingled manner, the bottom surface secondary grid lines 37 of the first solar cell can cross-contact (specifically, vertically cross-contact) the top surface main grid lines 32 of the second solar cell to achieve electrical connection.

[0074] refer to Figure 9A and Figure 9B ,in Figure 9A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 9B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 9A, only a top surface secondary grid line 43 extending along the lateral direction D1 is provided on the top surface of the solar cell 4, but no top surface main grid line is provided; Figure 9B The bottom surface of the solar cell 4 is provided with a bottom surface auxiliary grid line 47 extending along the transverse direction D1 and a bottom surface main grid line 44 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 47. Figures 9A-9B When the solar cells are interconnected in a shingled manner, the bottom surface main grid lines 44 of the first solar cell can cross-contact (specifically, vertically cross-contact) the top surface secondary grid lines 43 of the second solar cell to achieve electrical connection.

[0075] refer to Figure 10A and Figure 10B ,in Figure 10A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 10B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 10A , a top surface auxiliary grid line 53 extending along the transverse direction D1 and a top surface main grid line 52 extending along the longitudinal direction D2 and intersecting each top surface auxiliary grid line 53 are provided on the top surface of the solar cell 5; Figure 10B The bottom surface of the solar cell 5 is provided with bottom surface auxiliary grid lines 57 extending along the transverse direction D1 and bottom surface main grid lines 54 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 57. Figures 10A-10B When the solar cells 5 shown are interconnected in a shingled manner, the bottom surface main grid lines 54 of the first solar cell and the top surface auxiliary grid lines 53 of the second solar cell that are in contact with each other cross-contact to achieve electrical connection, or the bottom surface auxiliary grid lines 57 of the first solar cell and the top surface main grid lines 52 of the second solar cell cross-contact to achieve electrical connection.

[0076] refer to Figure 11A and Figure 11B ,in Figure 11A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 11B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 11A The top surface of the solar cell 6 is provided with a top surface auxiliary grid line 63 extending along the transverse direction D1 and a top surface main grid line 62 extending along the longitudinal direction D2 and intersecting each top surface auxiliary grid line 63. The top surface main grid lines 62 are formed into two parallel grid line structures; Figure 11B , the bottom surface of the solar cell 6 is only provided with the bottom surface auxiliary grid line 67 extending along the lateral direction D1 without providing the bottom surface main grid line. Figures 11A-8BWhen the solar cells 3 are interconnected in a shingled manner, the bottom surface secondary grid lines 67 of the first solar cell can cross-contact (specifically, vertically cross-contact) the two grid line structures of the top surface main grid lines 62 of the second solar cell to achieve electrical connection.

[0077] refer to Figure 12A and Figure 12B ,in Figure 12A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 12B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 12A , only a top surface secondary grid line 73 extending along the lateral direction D1 is provided on the top surface of the solar cell 7, but no top surface main grid line is provided; Figure 12B The bottom surface of the solar cell 7 is provided with bottom surface auxiliary grid lines 77 extending along the transverse direction D1 and bottom surface main grid lines 74 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 77. The bottom surface main grid lines 74 are two grid line structures parallel to each other. Figures 12A-12B When the solar cells shown are interconnected in a shingled manner, the two grid line structures (or only one of the two grid line structures) of the main grid line 74 on the bottom surface of the first solar cell can cross-contact (specifically, vertically cross-contact) with the secondary grid line 73 on the top surface of the second solar cell to achieve electrical connection.

[0078] refer to Figure 13A and Figure 13B ,in Figure 13A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 13B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 13A The top surface of the solar cell 8 is provided with a top surface auxiliary grid line 83 extending along the transverse direction D1 and a top surface main grid line 82 extending along the longitudinal direction D2 and intersecting each top surface auxiliary grid line 83. The top surface main grid lines 82 are two grid line structures parallel to each other; Figure 9B The bottom surface of the solar cell 8 is provided with bottom surface auxiliary grid lines 87 extending along the transverse direction D1 and bottom surface main grid lines 84 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 87. Figures 13A-13BWhen the solar cells 8 shown are interconnected in a shingled manner, the bottom surface main grid line 84 of the first solar cell and the top surface auxiliary grid line 83 of the second solar cell in contact with each other cross-contact to achieve electrical connection, or the two grid line structures (or only one of the two grid line structures) of the bottom surface auxiliary grid line 87 of the first solar cell and the top surface main grid line 82 of the second solar cell cross-contact to achieve electrical connection.

[0079] refer to Figure 14A and Figure 14B ,in Figure 14A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 14B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 14A , a top surface secondary grid line 93 extending along the transverse direction D1 and a top surface main grid line 92 extending along the longitudinal direction D2 and intersecting each top surface secondary grid line 93 are provided on the top surface of the solar cell 9; Figure 9B The bottom surface of the solar cell 9 is provided with bottom surface auxiliary grid lines 97 extending along the transverse direction D1 and bottom surface main grid lines 94 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 97. The bottom surface main grid lines 94 are two grid line structures parallel to each other. Figures 14A-14B When the solar cells 9 shown are interconnected in a shingled manner, the bottom surface main grid line 94 of the first solar cell and the top surface auxiliary grid line 93 of the second solar cell in contact with each other cross-contact to achieve electrical connection, or the two grid line structures (or only one of the two grid line structures) of the bottom surface auxiliary grid line 97 of the first solar cell and the top surface main grid line 92 of the second solar cell cross-contact to achieve electrical connection.

[0080] refer to Figure 15A and Figure 15B ,in Figure 15A is a schematic diagram of the top surface of a solar cell according to an embodiment. Figure 15B This is a schematic diagram of the bottom surface of the solar cell after it is rotated 180° around the horizontal axis at its longitudinal center. Figure 15A The top surface of the solar cell 10 is provided with a top surface auxiliary grid line 103 extending along the transverse direction D1 and a top surface main grid line 102 extending along the longitudinal direction D2 and intersecting each top surface auxiliary grid line 103. The top surface main grid lines 102 are two grid line structures parallel to each other; Figure 9B The bottom surface of the solar cell 10 is provided with bottom surface auxiliary grid lines 107 extending along the transverse direction D1 and bottom surface main grid lines 104 extending along the longitudinal direction D2 and contacting each bottom surface auxiliary grid line 107. The bottom surface main grid lines 104 are two grid line structures parallel to each other. Figures 15A-15B When the solar cells 10 shown are interconnected in a shingled manner, the two grid line structures (or only one of the two grid line structures) of the bottom surface main grid line 104 of the first solar cell and the top surface auxiliary grid line 103 of the second solar cell that are in contact with each other cross-contact to achieve electrical connection, or the bottom surface auxiliary grid line 107 of the first solar cell and the two grid line structures (or only one of the two grid line structures) of the top surface main grid line 102 of the second solar cell cross-contact to achieve electrical connection.

[0081] The embodiments provided by the present invention also include a method for manufacturing, for example Figure 1-15B A method for manufacturing a solar cell and a method for manufacturing a shingled assembly, the method for manufacturing a shingled assembly may include a method for manufacturing a solar cell.

[0082] Among them, the method for manufacturing the shingled module mainly includes the following steps: setting a large substrate sheet; printing grid lines on the large substrate sheet; intermediate processing steps; splitting the large solar cell sheet into multiple solar cells; and subsequent processing steps.

[0083] Each step may have a variety of preferred settings. For example, the step of arranging a large substrate sheet may include: arranging a large substrate sheet so that the large substrate sheet includes a plurality of substrate sheet units connected together, and after the large solar cell sheet is split, each substrate sheet unit forms a substrate sheet of a solar cell, and each substrate sheet unit has two longitudinal edges and two transverse edges. The step of arranging a large substrate sheet may further include the following steps: arranging a single crystal silicon wafer; texturing and cleaning the liquid remaining during texturing; passing phosphorus oxychloride to form a PN junction on the surface of the single crystal silicon wafer; etching and dephosphorizing silicon glass; high temperature oxidation to form a silicon dioxide layer on the top and bottom surfaces of the single crystal silicon wafer; forming an aluminum oxide film on the surface of the silicon dioxide layer; forming a silicon nitride film on the surface of the aluminum oxide film to generate a large substrate sheet; and laser grooving the bottom surface of the large substrate sheet.

[0084] Preferably, the PN junction is positioned so as to bypass the boundary between the substrate sheet units. The steps of manufacturing the large solar cell sheet also include a sintering step after printing the grid lines. The method also includes the following steps before splitting: confirming whether the front and back sides of the large solar cell sheet are the predetermined sides. If not, the control mechanism controls the robot to flip the large solar cell sheet.

[0085] Among them, the step of printing the grid lines includes: printing top surface grid lines on the top surface of the large substrate sheet, and printing bottom surface grid lines on the bottom surface of the large substrate sheet, and the printing direction of the top surface grid lines and the bottom surface grid lines is such that when two solar cells are arranged in a shingled manner, the bottom surface grid lines of the first solar cell of the two solar cells and the top surface grid lines of the second solar cell of the two solar cells cross-contact to achieve electrical connection.

[0086] Intermediate processing steps may include, for example, sintering, passing through a light decay furnace or an electric injection furnace to reduce light-induced degradation of the cell, testing and binning, and the like.

[0087] Subsequent processing steps after the solar cell cracking may include: arranging the individual solar cells into cell strings in a shingled manner, automatically arranging and converging the strings, applying the adhesive film and backsheet, mid-stage inspection, laminating, trimming, framing, intermediate junction box, curing, cleaning, testing and other steps to complete the shingled module packaging.

[0088] The above steps can be further expanded. For example, a complete manufacturing process may include the following steps:

[0089] The surface of single crystal silicon wafers is textured to obtain a good textured structure, thereby increasing the specific surface area to receive more photons (energy) while reducing the reflection of incident light;

[0090] Clean the residual liquid during texturing to reduce the impact of acidic and alkaline substances on battery formation;

[0091] Phosphorus oxychloride reacts with silicon wafers to produce phosphorus atoms. Over time, the phosphorus atoms enter the surface layer of the silicon wafer and diffuse into the interior of the silicon wafer through the gaps between silicon atoms, forming the interface between the N-type semiconductor and the P-type semiconductor.

[0092] Since the diffusion junction forms a short-circuit channel at the edge of the silicon wafer, the photogenerated electrons collected on the front of the PN junction will flow along the edge area where phosphorus atoms are diffused to the back of the PN junction, causing a short circuit. The edge PN junction is etched away by plasma etching to avoid the short circuit caused by the edge;

[0093] Since the diffusion bonding process will form a layer of phosphosilicate glass on the surface of the silicon wafer, the effect on the efficiency of the shingled cell can be reduced by removing the phosphosilicate glass.

[0094] After etching the silicon wafer to remove the phosphorus silicon glass, a layer of silicon dioxide is produced on the front and back surfaces of the cell through an oxygen high-temperature furnace at a certain temperature;

[0095] Then, a layer of aluminum oxide passivation film is deposited by ALD or PECVD;

[0096] A layer of silicon nitride film is stacked on the aluminum oxide film layer. The silicon nitride on the front surface plays a role in reducing reflection and passivation, while the silicon nitride film on the back protects the aluminum oxide.

[0097] Laser grooving on the back of the silicon wafer after coating;

[0098] The back and front printing is completed by screen printing. After the printed pattern is cut, the front and back electrodes of the small piece are staggered at the front and back, and then the sintering process is carried out.

[0099] Reduce the light-induced degradation of the battery cell through a light decay furnace or an electric injection furnace

[0100] Finally, the battery is tested and classified.

[0101] For the sintered whole-piece shingled solar cells, an online laser cutting and scribing process is added. The sintered shingled solar cells enter the scribing inspection position for appearance inspection and visual positioning of OK cells (poor appearance inspection will be automatically diverted to the NG position). According to the online production rhythm, multi-track scribing machines or preset cache stacking areas can be freely set to achieve online continuous feeding operations. According to the optimal effect of cutting and scribing, the relevant parameters of the laser are set to achieve faster cutting speed, narrower cutting heat-affected zone and cutting line width, better uniformity and predetermined cutting depth, etc. After the automatic cutting is completed, the automatic breaking mechanism of the online laser scribing machine is used to complete the splitting at the cutting position to achieve the natural separation of the shingled small solar cells (the laser cutting surface is away from the PN junction side to avoid damage to the PN junction and leakage current. It is necessary to confirm the direction of the front and back of the solar cell before scribing and loading. If the direction is opposite, a separate 180° reversing device needs to be added);

[0102] Then the small pieces are interconnected and grouped into strings;

[0103] After the strings are assembled, the packaging of the shingled photovoltaic modules is completed through the steps of automatic string layout and convergence, film and backboard laying, mid-term inspection, lamination, trimming, framing, intermediate junction box, curing, cleaning, and testing.

[0104] Since the steps of manufacturing a large substrate sheet can include the steps of setting a PN junction, tunnel junction, or heterojunction, the printed gate lines can also have preferred settings related to the PN junction, tunnel junction, or heterojunction. For example, the first auxiliary gate line burns through the passivation structure layer on the surface of the PN junction, tunnel junction, or heterojunction of the substrate sheet and forms a conductive contact with the PN junction, tunnel junction, or heterojunction; and / or, the second auxiliary gate line burns through the passivation structure layer on the surface of the PN junction, tunnel junction, or heterojunction of the substrate sheet and forms a conductive contact with the PN junction, tunnel junction, or heterojunction; and / or, the main gate line arranged on the top surface of the substrate sheet burns through the PN junction, tunnel junction, or heterojunction of the PN junction of the heterojunction substrate sheet. For another example, the first secondary gate line does not burn through the passivation structure layer on the surface of the PN junction, tunnel junction or heterojunction of the substrate; and / or, the second secondary gate line does not burn through the passivation structure layer on the surface of the PN junction, tunnel junction or heterojunction of the substrate; and / or, the main gate line arranged on the top surface of the substrate does not burn through the passivation structure layer on the surface of the PN junction, tunnel junction or heterojunction.

[0105] The solution provided by the present invention can reduce the amount of silver paste used for the gridlines compared to conventional solar cells, while still meeting the reliability requirements for front and back electrode interconnection. Therefore, the solar cells provided by the present invention can reduce gridline losses, lower production costs, and enhance technological competitiveness.

[0106] Furthermore, the top surface grid lines and bottom surface grid lines of the solar cell provided by the present invention can have a variety of structural combinations, so that the solar cell provided by the present invention can further reduce grid line losses and meet the various usage needs of users.

[0107] The above description of various embodiments of the present invention is provided for the purpose of description to one of ordinary skill in the relevant art. It is not intended to exclude or limit the present invention to a single disclosed embodiment. As mentioned above, a person of ordinary skill in the field of the above teachings will understand the various substitutions and variations of the present invention. Therefore, although some alternative embodiments are specifically described, a person of ordinary skill in the art will understand or relatively easily develop other embodiments. The present invention is intended to include all substitutions, modifications and variations of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention described above.

Claims

1. A solar cell, characterized in that: The solar cell includes a substrate, a top surface grid line arranged on the top surface of the substrate, and a bottom surface grid line arranged on the bottom surface of the substrate, wherein the extension directions of the top surface grid line and the bottom surface grid line on the substrate are set so that when two solar cells are connected in a shingled manner, the bottom surface grid line of a first solar cell of the two solar cells and the top surface grid line of a second solar cell of the two solar cells vertically cross and contact to achieve electrical connection between the two solar cells connected in the shingled manner.

2. The solar cell according to claim 1, wherein: The top surface grid lines include top surface secondary grid lines and top surface main grid lines intersecting the top surface secondary grid lines, the bottom surface grid lines include only bottom surface secondary grid lines, and the solar cells are configured such that when two solar cells are connected in a shingled manner, the bottom surface secondary grid lines of the first solar cell and the top surface main grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection; or The top surface grid lines only include top surface auxiliary grid lines, the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines arranged to cross the bottom surface auxiliary grid lines, and the solar cell is constructed so that when two solar cells are connected in a shingled manner, the bottom surface main grid lines of the first solar cell and the top surface auxiliary grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection.

3. The solar cell according to claim 1, wherein: The top surface grid lines include top surface auxiliary grid lines and top surface main grid lines that cross the top surface auxiliary grid lines, the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines that cross the bottom surface auxiliary grid lines, and the solar cell sheets are constructed so that when two solar cells are connected in a shingled manner: the bottom surface main grid lines of the first solar cell sheet that is in contact with each other and the top surface auxiliary grid lines of the second solar cell sheet that are in contact with each other cross-contact to achieve electrical connection, or the bottom surface auxiliary grid lines of the first solar cell sheet that are in contact with each other cross-contact to achieve electrical connection.

4. The solar cell according to claim 1, wherein: The top surface grid lines include top surface auxiliary grid lines and top surface main grid lines that are arranged to cross the top surface auxiliary grid lines, and the bottom surface grid lines include bottom surface auxiliary grid lines and bottom surface main grid lines that are arranged to cross the bottom surface auxiliary grid lines, and the extension directions of the top surface main grid lines and the bottom surface main grid lines are set so that when two solar cells are connected in a shingled manner, the bottom surface main grid lines of the first solar cell that are in contact with each other and the top surface main grid lines of the second solar cell that are in contact with each other cross and contact to achieve electrical connection.

5. The solar cell according to claim 1, wherein: Auxiliary grid lines and main grid lines arranged to cross the auxiliary grid lines are arranged on the top surface and / or bottom surface of the solar cell. The main grid lines include at least two grid line structures parallel to each other. The solar cell is constructed so that when the two solar cells are connected in a shingled manner, the main grid lines of one solar cell cross-contact with the main grid lines or auxiliary grid lines of another solar cell.

6. The solar cell according to claim 1, wherein: The base sheet has a first longitudinal edge, a second longitudinal edge, and two transverse edges; The top surface grid lines include top surface bus bars, which are arranged on the top surface of the substrate sheet along or near the first longitudinal edge of the substrate sheet as a whole, and include top surface first bus bars and top surface second bus bars, which both extend along the longitudinal direction of the substrate sheet and are spaced apart in the transverse direction of the substrate sheet. The bottom surface grid lines include bottom surface main grid lines, and the bottom surface main grid lines are arranged on the bottom surface of the base sheet along or near the second longitudinal edge of the base sheet as a whole. The top surface busbars and the bottom surface busbars are constructed so that when two solar cells are connected in a shingled manner, the bottom surface busbars of the first solar cell can simultaneously contact the top surface first busbars and the top surface second busbars of the second solar cell.

7. The solar cell according to claim 6, characterized in that: The bottom surface main grid lines include a bottom surface first main grid line and multiple bottom surface second main grid lines. The bottom surface first main grid lines extend along the longitudinal direction of the substrate sheet; the bottom surface second main grid lines are short strip structures extending along the transverse direction of the substrate sheet, and each bottom surface second main grid line intersects with the bottom surface first main grid line.

8. The solar cell according to claim 7, wherein: There is a gap between the first main grid line on the bottom surface and the second longitudinal edge of the substrate sheet, one end of each second main grid line on the bottom surface extends to the second longitudinal edge of the substrate sheet, and the other end of each second main grid line on the bottom surface extends to the first main grid line on the bottom surface or extends to protrude from the first main grid line on the bottom surface.

9. The solar cell according to claim 6, wherein: A plurality of connection portions are arranged in the interval between the first top surface bus bar and the second top surface bus bar.

10. The solar cell according to claim 8, characterized in that: The positions of the top surface busbars and the bottom surface busbars on the corresponding surfaces are set so that when two solar cells are connected in a shingled manner, each bottom surface second busbar of the first solar cell contacts both the top surface first busbar and the top surface second busbar of the second solar cell.

11. The solar cell according to claim 8, wherein: The positions of the top surface busbars and the bottom surface busbars on the corresponding surfaces are set so that when two solar cells are connected in a shingled manner, each bottom surface second busbar of the first solar cell only contacts the top surface second busbar of the second solar cell.

12. The solar cell according to claim 6, wherein: A top surface sub-gridline for current collection is provided on the top surface of the base sheet, and the top surface main gridline and the top surface sub-gridline are in conductive contact.

13. The solar cell according to claim 12, wherein: The solar cell is a double-sided solar cell. The bottom surface of the substrate is provided with a bottom surface secondary grid line for current collection. The bottom surface main grid line and the bottom surface secondary grid line are in conductive contact.

14. A shingled assembly, characterized in that: The shingled assembly comprises at least one cell string, and each cell string is formed by arranging the solar cells according to any one of claims 7 to 8 and 10 in a shingled manner.

15. The shingled assembly according to claim 14, wherein: The solar cells in the cell string include top surface busbars and bottom surface busbars, and Each pair of adjacent solar cells is a first solar cell and a second solar cell, the top surface busbar of the first solar cell is in conductive contact with the bottom surface busbar of the second solar cell, the first solar cell and the second solar cell are fixed together by an adhesive, and the adhesive is positioned between the first busbar on the top surface and the second busbar on the bottom surface of the first solar cell, and the adhesive bypasses the bottom surface busbar of the second solar cell.

16. A method for manufacturing a solar cell according to any one of claims 1 to 13, characterized in that: The method includes the steps of manufacturing a large solar cell and splitting the large solar cell into a plurality of solar cells. The step of manufacturing the large solar cell includes the following steps: A large substrate sheet is provided, wherein the large substrate sheet includes a plurality of substrate sheet units connected together, and after the large solar cell sheet is split, each substrate sheet unit forms a substrate sheet of a solar cell; Top surface grid lines are printed on the top surface of the large substrate sheet, and bottom surface grid lines are printed on the bottom surface of the large substrate sheet. The printing directions of the top surface grid lines and the bottom surface grid lines are such that when two solar cells are arranged in a shingled manner, the bottom surface grid lines of the first solar cell of the two solar cells cross-contact with the top surface grid lines of the second solar cell of the two solar cells to achieve electrical connection.

17. The method according to claim 16, characterized in that The method comprises the steps of arranging a PN junction, and when arranging the PN junction, the position of the PN junction is made to bypass the boundary line between the substrate sheet units.

18. The method according to claim 16, characterized in that The steps of manufacturing a large cell also include a sintering step after printing the grid lines.

19. A method for manufacturing a shingled assembly, characterized in that the method include: Manufacturing a solar cell according to the method according to any one of claims 17-18; Arrange multiple solar cells into cell strings in a shingled manner; At least one battery string is fixed to form a shingled assembly.

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