Back contact battery, battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell, a cell assembly and a photovoltaic system. The back contact battery comprises a silicon substrate, a plurality of first polarity fine grids and a plurality of second polarity fine grids, and the first polarity fine grids and the second polarity fine grids are arranged on the silicon substrate at intervals and arranged in the first direction. The silicon substrate comprises a plurality of first polarity doped regions and a plurality of second polarity doped regions which are arranged along a first direction, the first polarity doped regions are provided with first polarity fine grids, and the second polarity doped regions are provided with second polarity fine grids; the first polarity doped region comprises a first doped region, the first doped region comprises a first region and a second region, and the second region protrudes from the first region; the second polarity doped region comprises a second doped region, the second doped region comprises a third region and a fourth region, and one side, facing the second region, of the fourth region is recessed from the third region. Therefore, carriers can be better collected, and the photoelectric conversion efficiency of the cell is improved.

Description

[0001] The present application claims priority to the Chinese Patent Application No. 2025101619337, filed on February 13, 2025, entitled "A Back Contact Cell, Cell Assembly and Photovoltaic System", and the Chinese Patent Application No. 2025202361898, filed on February 13, 2025, entitled "A Back Contact Cell, Cell Assembly and Photovoltaic System", both of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application belongs to the technical field of solar cells, and particularly relates to a back contact cell, a cell assembly and a photovoltaic system. BACKGROUND

[0003] Solar cell power generation is a sustainable clean energy source, which can convert sunlight into electrical energy by using the photovoltaic effect of a semiconductor p-n junction. In the related art, a solar cell with electrodes of two polarities located on the back surface of the cell is a back contact cell. However, the photoelectric conversion efficiency of the back contact cell needs to be further improved.

[0004] Therefore, how to further improve the photoelectric conversion efficiency of the back contact cell has become a problem to be solved. SUMMARY

[0005] The present application provides a back contact cell, a cell assembly and a photovoltaic system, which aims to solve the problem of how to further improve the photoelectric conversion efficiency of the back contact cell.

[0006] The back contact cell provided by the present application includes a silicon substrate, a plurality of first polarity fine grids and a plurality of second polarity fine grids, the first polarity fine grids and the second polarity fine grids are spaced apart and arranged on the silicon substrate along a first direction. The silicon substrate includes a plurality of first polarity doped regions and a plurality of second polarity doped regions arranged along the first direction, the first polarity fine grids are arranged on the first polarity doped regions, and the second polarity fine grids are arranged on the second polarity doped regions. The first polarity doped regions include a first doped region, the first doped region includes a first area and a second area, and the second area protrudes from the first area; the second polarity doped regions include a second doped region, the second doped region includes a third area and a fourth area, and the fourth area is recessed from the third area towards one side of the second area.

[0007] Specifically, the first polarity fine gate includes a first gate line, the first gate line is provided with a first connecting block, the width of the first connecting block is greater than the width of the first gate line, and the length of the first connecting block is greater than or equal to 100 μm; the first region is provided with the first gate line, and the second region corresponds to the first connecting block. The second polarity fine gate includes a second gate line, the second gate line includes a first main body part and a first bending part connected to each other, the first main body part extends along a second direction, the second direction intersects the first direction, the first bending part is provided corresponding to the first connecting block and bends away from the first connecting block from the first main body part; the third region is provided with the first main body part of the second gate line, and the fourth region is provided with the first bending part of the second gate line.

[0008] Specifically, the difference between the width of the first connecting block and the width of the first gate line is 5 μm-290 μm.

[0009] Specifically, the maximum distance between the first bending part and the first main body part in the first direction is 5 μm-290 μm.

[0010] Specifically, the first gate line, the first connecting block and the second gate line satisfy the following formula: -100 μm≤w1-w2-d1≤100 μm; Wherein, w1 is the width of the first connecting block, w2 is the width of the first gate line, and d1 is the maximum distance between the first bending part and the first main body part in the first direction.

[0011] Specifically, the first gate line is the first polarity fine gate closest to the edge of the silicon substrate, and the distance between the first gate line and the edge is 0.4 mm-1 mm.

[0012] Specifically, the distance between the first connecting block and the edge is 0.4 mm-50 mm.

[0013] Specifically, the first polarity fine gate includes a third gate line, the third gate line includes a second main body part and a second bending part connected to each other, the second main body part extends along the second direction, and the second bending part is provided corresponding to the first connecting block and bends away from the first connecting block from the second main body part.

[0014] Specifically, in the direction away from the first connecting block, the bending depth of the first bending part and the second bending part gradually decreases.

[0015] Specifically, for adjacent second gate lines and third gate lines, the first bending part and the second bending part satisfy the following formula: 50 pm ≤ d1-d2 ≤ 150 pm; wherein d2 is the maximum distance between the second bending portion and the second main portion in the first direction, and d1 is the maximum distance between the first bending portion and the first main portion in the first direction.

[0016] Specifically, the first gate line and the first connecting block arranged on the first gate line form a first conductive structure, and each row of the first conductive structure is continuous. And / or, each row of the second gate line is continuous.

[0017] Specifically, the first connecting block comprises at least one of a pad and a gate line segment.

[0018] Specifically, the first connecting block is formed with a hollow region. Or, the first connecting block is solid.

[0019] Specifically, the second polarity fine gate comprises a fourth gate line, and the fourth gate line is provided with a second connecting block, and the width of the second connecting block is greater than the width of the fourth gate line.

[0020] Specifically, the difference between the width of the second connecting block and the width of the fourth gate line is 5 pm-290 pm.

[0021] Specifically, the difference between the area of the first connecting block and the area of the second connecting block is -400 pm 2 400 pm 2 .

[0022] Specifically, the first polarity gate line adjacent to the second connecting block is disconnected at a position corresponding to the second connecting block, avoiding the second connecting block, and the distance between the second connecting block and the breakpoint of the first gate line in the second direction is 0.2 mm-1 mm.

[0023] Specifically, the fourth gate line is the second polarity fine gate closest to the edge of the silicon substrate, and the distance between the fourth gate line and the edge is greater than 0.7 mm-1.3 mm.

[0024] Specifically, the distance from the second connecting block to the edge of the silicon substrate is 0.7 mm-50 mm.

[0025] Specifically, the fourth gate line is the second polarity fine gate closest to the edge of the silicon substrate, and the second connecting block is located on the side of the fourth gate line facing the edge.

[0026] Specifically, the second connecting block protrudes from the fourth gate line to both sides of the fourth gate line.

[0027] Specifically, the fourth gate line comprises a third main body portion and a third bending portion connected to each other, the third main body portion extends along the second direction, the third bending portion bends from the third main body portion to a direction away from the edge of the silicon substrate, and the second connecting block is arranged on the third bending portion.

[0028] Specifically, the maximum distance between the third bending portion and the third main body portion in the first direction is 5-290 μm.

[0029] Specifically, the fourth gate line and the second gate line are the same second polarity fine gate.

[0030] Specifically, the fourth gate line and the second connecting block arranged on the fourth gate line form a second conductive structure, and each row of the second conductive structure is continuous.

[0031] Specificly, the second connecting block comprises at least one of a pad and a gate line segment.

[0032] Specifically, the second connecting block is formed with a hollow area. Or, the second connecting block is in a solid state.

[0033] Specifically, the second polarity fine gate comprises a second gate line, and the second gate line is arranged in the third region and the fourth region.

[0034] Specifically, the first polarity fine gate comprises a first gate line, the first gate line is provided with a first connecting block, the width of the first connecting block is greater than the width of the first gate line, and the length of the first connecting block is greater than or equal to 100 μm; the first region is provided with the first gate line, and the second region corresponds to the first connecting block. The second gate line comprises a fourth main body portion and a fifth main body portion connected to each other, the fourth main body portion and the fifth main body portion both extend along the second direction, the second direction intersects the first direction, the fifth main body portion is arranged corresponding to the first connecting block and is collinear with the fourth main body portion in the second direction; the third region is provided with the fourth main body portion, and the fourth region is provided with the fifth main body portion.

[0035] Specifically, the second gate line is in a straight line shape, and the widths of the fourth main body portion and the fifth main body portion are the same. Or, the width of the fourth main body portion is less than the width of the fifth main body portion. Specifically, in the first direction, the maximum depth of the second region protruding from the first region is 5-290 μm.

[0036] Specifically, the side of the fourth region away from the second region protrudes from the third region.

[0037] Specifically, in the first direction, the maximum depth of the fourth region protruding from the third region is 1-500 μm.

[0038] Specifically, the side of the second region facing the fourth region protrudes from the first region, and the difference between the maximum depth of the second region protruding from the first region and the maximum depth of the fourth region protruding from the third region in the first direction is 50-200 μm.

[0039] Specifically, the first polarity fine grid includes a third grid line, the third grid line includes a second main body portion and a second bending portion connected in sequence, the second main body portion extends along the second direction, and the second bending portion is arranged corresponding to the first connecting block and bends from the second main body portion to a direction away from the first connecting block. The first polarity doped region includes a third doped region, the third doped region includes a fifth region and a sixth region, the fifth region is provided with the second main body portion of the third grid line, and the sixth region is provided with the second bending portion of the third grid line.

[0040] Specifically, the side of the sixth region away from the second region protrudes from the fifth region.

[0041] Specifically, the side of the fourth region away from the second region protrudes from the third region, and the protruding depth of the fourth region and the sixth region gradually decreases in a direction away from the second region.

[0042] Specifically, for adjacent second doped regions and third doped regions, the fourth region and the sixth region satisfy the following formula: 50 μm≤H2-H3≤200 μm; Wherein, H2 is the maximum depth of the fourth region protruding from the third region in the first direction, and H3 is the maximum depth of the sixth region protruding from the fifth region in the first direction.

[0043] Specifically, each row of the first doped region is continuous; And / or, each row of the second doped region is continuous.

[0044] Specifically, the doped region closest to the edge of the silicon substrate is a P region.

[0045] Specifically, the second polarity fine grid includes a fourth grid line, the fourth grid line is provided with a second connecting block, and the width of the second connecting block is greater than the width of the fourth grid line. The second polarity doped region comprises a fourth doped region, the fourth doped region comprises a seventh region and an eighth region, the seventh region is provided with the fourth gate line, and the eighth region corresponds to the second connecting block.

[0046] Specifically, the eighth region protrudes from the seventh region.

[0047] Specifically, the maximum depth of the eighth region protruding from the seventh region is 5-290 μm.

[0048] Specifically, the fourth doped region and the second doped region are the same second polarity doped region.

[0049] Specifically, each row of the fourth doped region is continuous.

[0050] Specifically, the fourth gate line comprises a third main body portion and a third bending portion connected to each other, the third main body portion extends along the second direction, the third bending portion bends from the third main body portion to a direction away from the edge of the silicon substrate, and the second connecting block is arranged on the third bending portion. The fourth doped region comprises a ninth region, and the ninth region is provided with the third bending portion.

[0051] Specifically, the side of the ninth region away from the eighth region protrudes from the seventh region.

[0052] Specifically, the first polarity fine gate is a positive gate line, the first polarity fine gate comprises a fifth gate line and a sixth gate line, and the interval between the sixth gate line and the adjacent second polarity fine gate is greater than the interval between the fifth gate line and the adjacent second polarity fine gate.

[0053] Specifically, the sixth gate line is provided with a third connecting block, and the width of the third connecting block is greater than the width of the sixth gate line.

[0054] Specifically, the interval between the sixth gate line and the adjacent second polarity fine gate is a first interval, the interval between the fifth gate line and the adjacent second polarity fine gate is a second interval, and the difference between the first interval and the second interval is 0.05-0.1 mm.

[0055] The battery assembly provided in the application comprises the back contact battery of any one of the above.

[0056] The photovoltaic system provided in the application comprises the battery assembly of any one of the above.

[0057] The back contact cell, the battery assembly and the photovoltaic system of the embodiments of the present application are convenient for manufacturing the fine grid of the corresponding polarity on the doped region, convenient for realizing the electrical connection between the doped region and the fine grid of the corresponding polarity, and beneficial to reduce the process difficulty, improve the manufacturing efficiency and reduce the cost, because the two-polarity doped regions correspond to the two-polarity fine grids. Meanwhile, the recessed fourth region cooperates with the protruding second region, the space can be fully utilized, the arrangement of the doped region is more reasonable, and it is beneficial to better collect the carriers and improve the photoelectric conversion efficiency of the cell. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 2 is an enlarged schematic diagram of part of the structure of the back contact cell of Figure 1 Figure 3 is a structural schematic diagram of the back contact cell of an embodiment of the present application; Figure 4 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 5 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 6 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 7 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 8 is an enlarged schematic diagram of part of the structure of the back contact cell of Figure 7 Figure 9 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 10 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 11 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 12 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 13 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 14 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 15 is a schematic diagram of part of the structure of the back contact cell of an embodiment of the present application; Figure 16 ​​is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 17 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 18 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 19 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 20 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 21 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 22 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 21 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 23 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 24 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 25 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 26 is a schematic diagram of a back contact cell of an embodiment of the present application; Figure 27 Figure 26 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 28 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 29 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 30 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Main element symbol explanation: Back contact cell 10, silicon substrate 101, first conductive structure 1001, second conductive structure 1002, dielectric film layer 1003; First polarity fine grid 11, first grid line 111, first connecting block 112, first hollowed-out area 1120, third grid line 113, second main body part 1131, second bending part 1132, fifth grid line 114, sixth grid line 115, third connecting block 116; ​The second polarity fine grid 12, the second grid line 121, the first main body part 1211, the first bending part 1212, the fourth main body part 1213, the fifth main body part 1214, the fourth grid line 122, the third main body part 1221, the third bending part 1222, the second connecting block 123, the second hollow area 1230; The length S1 of the first connecting block, the width w1 of the first connecting block, the width w2 of the first grid line, the width w3 of the second connecting block, the width w4 of the fourth grid line; the maximum distance d1 of the first bending part and the first main body part in the first direction, the maximum distance d2 of the second bending part and the second main body part in the first direction, the distance d3 of the breakpoint of the second connecting block and the first grid line, the maximum distance d4 of the third bending part and the third main body part in the first direction; the distance x1 of the first grid line to the edge, the distance x2 of the first connecting block to the edge, the distance x3 of the fourth grid line to the edge, the distance x4 of the second connecting block to the edge; The first polarity doping region 13, the first doping region 131, the first area 1311, the second area 1312, the third doping region 132, the fifth area 1321, the sixth area 1322, the fifth doping region 133, the overlapping part 1331, the non-overlapping part 1332; The second polarity doping region 14, the second doping region 141, the third area 1411, the fourth area 1412, the fourth doping region 142, the seventh area 1421, the eighth area 1422, the ninth area 1423, the sixth doping region 143, the body 1431, the protruding part 1432; The width W1 of the first area, the width W2 of the second area, the width W3 of the third area, the width W4 of the fourth area; the maximum depth H1 of the second area protruding from the first area, the maximum depth H2 of the fourth area protruding from the third area, the maximum depth H3 of the sixth area protruding from the fifth area, the maximum depth H4 of the eighth area protruding from the seventh area; The distance L2 of the fifth grid line and the adjacent second polarity fine grid L1, the distance L2 of the sixth grid line and the adjacent second polarity fine grid, the width L3 of the third connecting block, the width L4 of the sixth grid line, the distance L5 of the adjacent two sixth grid lines, the depth L6 of the protruding part protruding from the body, the width L7 of the overlapping part, the length L8 of the overlapping part, the distance L9 of the overlapping part and the third connecting block. DETAILED DESCRIPTION

[0059] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein identical or similar labels denote identical or similar elements or elements with identical or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only and are merely intended to explain the present application, and are not to be understood as limiting the present application. In addition, it should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application.

[0060] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0061] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0062] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the "upper", "above" and "above" of the first feature to the second feature includes the vertical above and oblique above of the first feature to the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature includes the vertical below and oblique below of the first feature to the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0064] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, reference numerals and / or reference letters can be repeated in different examples in the present application, and such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0065] Please refer to Figure 1 , Figure 2 and Figure 3 , the back contact battery 10 of the embodiment of the present application comprises: a silicon substrate 101; a plurality of first polarity fine grids 11 and a plurality of second polarity fine grids 12 arranged on the silicon substrate 101 along a first direction, the first polarity fine grids 11 and the second polarity fine grids 12 being spaced apart; The first polarity fine grid 11 comprises a first grid line 111, and the first grid line 111 is provided with a first connecting block 112, the width w1 of the first connecting block 112 being greater than the width w2 of the first grid line 111, and the length S1 of the first connecting block 112 being greater than or equal to 100 μm; The second polarity fine grid 12 comprises a second grid line 121, and the second grid line 121 comprises a first main body part 1211 and a first bending part 1212 connected to each other, the first main body part 1211 extending along a second direction intersecting the first direction, and the first bending part 1212 being arranged corresponding to the first connecting block 112 and bending away from the first connecting block 112 from the first main body part 1211.

[0066] The back contact battery 10 of the embodiment of the present application, because the width w1 of the first connecting block 112 is greater than the width w2 of the first grid line 111 and the length s1 is greater than or equal to 100 μm, can increase the contact area of the first connecting block 112 and the electrical connecting piece, increase the tension, reduce the risk of the electrical connecting piece falling off from the back contact battery 10, and improve the connection stability of the back contact battery 10 and the electrical connecting piece. At the same time, because the first bending part 1212 of the second grid line 121 bends away from the first connecting block 112 from the first main body part 1211, it can provide more space for the first connecting block 112 with a larger width, facilitate the widening of the first connecting block 112, and reduce the risk of short circuit caused by too small electrode spacing of the two polarities.

[0067] Specifically, the back contact battery 10 can be a sliced battery formed by slicing a whole battery. For example, Figure 3The half-piece battery is formed by cutting the whole-piece battery in half. The back contact battery 10 can also be a whole-piece battery that is not cut. The whole-piece back contact battery 10 can include a cutting groove along which the whole-piece battery can be cut to obtain the cut-piece battery as shown in FIG. 1. The whole-piece back contact battery 10 can be asymmetric along the cutting groove or symmetric along the cutting groove. Figure 3

[0068] The back contact battery 10 is explained and described herein as an example of a back contact battery without a main grid. It can be understood that the back contact battery 10 can be a back contact battery with a main grid. In the case where the back contact battery 10 is a back contact battery with a main grid, the main grid can be located in a region other than the first connecting block 112. In this way, the main grid can be prevented from interfering with the connection of the first connecting block 112 to the first electrical connecting member.

[0069] Specifically, the silicon substrate 101 can include a silicon substrate, a first polarity doped layer, a second polarity doped layer, and a dielectric film layer 1003.

[0070] Further, the silicon substrate can be a P-type silicon substrate or an N-type silicon substrate, and can be a single crystal silicon substrate or a polycrystalline silicon substrate. The specific form of the silicon substrate is not limited herein.

[0071] Further, the first polarity doped layer and the second polarity doped layer are disposed on the silicon substrate. The first polarity doped layer and the second polarity doped layer have different doping polarities. The two doped layers can be formed by diffusion to the silicon substrate or can be formed by deposition of a film layer on the silicon substrate.

[0072] It can be understood that, in the thickness direction of the back contact battery 10, the first polarity doped layer is stacked on the silicon substrate and the second polarity doped layer is stacked on the silicon substrate. In a plane perpendicular to the thickness direction of the back contact battery 10, the first polarity doped layer and the second polarity doped layer are distributed in regions corresponding to the first polarity doped region 13 and the second polarity doped region 14, respectively, as shown in FIG. 1. Figures 12-20

[0073] Hereinafter, "the first polarity doped region 13 includes the first doped region 131" and "the first polarity doped region 13 includes the third doped region 132" mean that the first doped region 131 and the third doped region 132 are doped regions of the first polarity. Hereinafter, "the second polarity doped region 14 includes the second doped region 141" and "the second polarity doped region 14 includes the fourth doped region 142" mean that the second doped region 141 and the fourth doped region 142 are doped regions of the second polarity.

[0074] ​​Further, the dielectric film layer 1003 can be covered on the first and second polarity doped layers, the first polarity fine gate 11 contacts the first polarity doped layer through the dielectric film layer 1003, and the second polarity fine gate 12 contacts the second polarity doped layer through the dielectric film layer 1003. In this way, the dielectric film layer 1003 is used to electrically isolate the first and second polarity doped layers, and meanwhile, the dielectric film layer 1003 can be used to reduce light reflection and recombination. The dielectric film layer 1003 can also be arranged between at least one pair of adjacent first polarity doped regions 13 and second polarity doped regions 14 to electrically isolate the first polarity doped regions 13 and the second polarity doped regions 14. Please note that, for better display of the first polarity doped regions 13 and the second polarity doped regions 14, Figures 12-20 The part of the dielectric film layer 1003 covered on the first polarity doped regions 13 and the second polarity doped regions 14 is omitted.

[0075] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 can be distributed in the whole region of the silicon substrate 101; or the first polarity fine gate 11 and the second polarity fine gate 12 can be distributed in a part of the region of the silicon substrate 101. It can be understood that the region of the silicon substrate 101 not distributed with the first polarity fine gate 11 and the second polarity fine gate 12 can be distributed with other fine gates, can be distributed with a main gate, or can not be provided with a gate line.

[0076] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 have different polarities. The first polarity fine gate 11 corresponds to the first polarity doped layer and the first polarity doped region 13. The second polarity fine gate 12 corresponds to the second polarity doped layer and the second polarity doped region 14.

[0077] Specifically, the number of the first polarity fine gate 11 can be 1, 2, 3, 4, or other numbers. The number of the second polarity fine gate 12 can be 1, 2, 3, 4, or other numbers. This is not limited herein. The number of the first polarity fine gate 11 can be the same as or different from the number of the second polarity fine gate 12.

[0078] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 are arranged along a first direction, which can be alternatively arranged along the first direction, or can be non-alternatively arranged along the first direction; which can be equally spaced along the first direction, or can be unequally spaced along the first direction. This is not limited herein.

[0079] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 are spaced, which means that a gap is formed between adjacent first polarity fine gates 11 and second polarity fine gates 12. The gap can be filled with an insulating member, or can be an air gap.

[0080] The "first polarity fine grid 11 includes the first grid line 111", "the first polarity fine grid 11 includes the third grid line 113", and "the first polarity fine grid 11 includes the fifth grid line 114 and the sixth grid line 115" described below mean that the first grid line 111, the third grid line 113, the fifth grid line 114, and the sixth grid line 115 are all fine grids of the first polarity. The "the second polarity fine grid 12 includes the second grid line 121" and "the second polarity fine grid 12 includes the fourth grid line 122" described below mean that the second grid line 121 and the fourth grid line 122 are both fine grids of the second polarity.

[0081] Please refer to Figure 1 , Figure 2 and Figure 3 In the embodiment, the first grid line 111 is the first polarity fine grid 11 closest to the edge of the silicon substrate 101. In this way, the risk of the electrical connection falling off from the end of the back contact battery 10 can be reduced.

[0082] It can be understood that in other embodiments, the first grid line 111 can be located away from the edge of the silicon substrate 101. For example, the first grid line 111 is the second, third, fourth, or other numbered first polarity fine grid 11 from the edge. In this way, the risk of the electrical connection falling off from the middle of the back contact battery 10 can be reduced. In this case, the second grid line 121 can be arranged on one side or both sides of the first grid line 111 to avoid the first connecting block 112 provided on the first grid line 111.

[0083] Please refer to Figure 1 , Figure 2 and Figure 3 The first connecting block 112 is provided on the first grid line 111. That is, the first connecting block 112 is connected to the first grid line 111.

[0084] Specifically, the first connecting block 112 can contact the first polarity doped layer through the dielectric film layer 1003. The first connecting block 112 and the first polarity doped layer can also be isolated by the dielectric film layer 1003. The first connecting block 112 can be made together with the first grid line 111. The first connecting block 112 can also be made in steps with the first grid line 111.

[0085] In one example, the first connecting block 112 and the first grid line 111 are made of the same paste, and both burn through the dielectric film layer 1003 to contact the first polarity doped layer. In another example, the paste of the first grid line 111 burns through the dielectric film layer 1003 to contact the first polarity doped layer, and the paste of the first connecting block 112 does not burn through the dielectric film layer 1003.

[0086] In some embodiments, the first connecting block 112 comprises at least one of a pad and a gate line segment. In this way, the first connecting block 112 is in various forms, which is conducive to meeting more production scenarios and needs. For example, the first connecting block 112 comprises a pad. For another example, the first connecting block 112 comprises a gate line segment. For yet another example, the first connecting block 112 comprises a pad and a gate line segment. It can be understood that, in the case where the first connecting block 112 comprises a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the first polarity doped layer. In the case where the first connecting block 112 comprises a pad, the pad can pass through the dielectric film layer 1003 to contact the first polarity doped layer, or can be isolated from the first polarity doped layer by the dielectric film layer 1003.

[0087] Please note that, in the adjacent two back contact cells 10, the electrical connection electrically connects the fine grid of one kind of polarity in one back contact cell 10, and electrically connects the fine grid of another kind of polarity in another back contact cell 10. The connection of the electrical connection in one back contact cell 10 is discussed herein.

[0088] That is, in one back contact cell 10, the first electrical connection is electrically connected with the first polarity fine grid 11 and is isolated from the second polarity fine grid 12; the second electrical connection is electrically connected with the second polarity fine grid 12 and is isolated from the first polarity fine grid 11. In other words, the fine grid connected by one kind of electrical connection in one back contact cell 10 has the same polarity. It can be understood that this does not mean that the electrical connection has the same polarity as the connected fine grid.

[0089] Specifically, the first electrical connection and the second electrical connection extend along a first direction and are alternately arranged along a second direction.

[0090] Specifically, the second polarity fine grid 12 can be disconnected at the coverage of the first electrical connection to avoid the first electrical connection; the second polarity fine grid 12 can also be continuous at the coverage of the first electrical connection and is electrically isolated from the first electrical connection by an insulating member. Similarly, the first polarity fine grid 11 can be disconnected at the coverage of the second electrical connection to avoid the second electrical connection; the first polarity fine grid 11 can also be continuous at the coverage of the second electrical connection and is electrically isolated from the second electrical connection by an insulating member.

[0091] Specifically, the first connecting block 112 is used to connect the first electrical connection.

[0092] Further, the first connecting block 112 and the first electrical connection can be electrically connected by at least one of conductive adhesive bonding, direct soldering, solder paste soldering, and physical contact. This is not limited herein.

[0093] Further, the whole area of the first connecting block 112 is connected with the first electrical connecting member. In this way, the connecting area is large, which is beneficial to improve the stability of the connection. It can be understood that in other embodiments, part of the area of the first connecting block 112 can also be connected with the first electrical connecting member.

[0094] Further, the first electrical connecting member includes at least one of a solder strip and a conductive wire. In this paper, the first electrical connecting member is taken as a solder strip as an example for description. It can be understood that in the case where the first electrical connecting member is a solder strip, the embodiments of the present application can reduce the risk of the solder strip falling off from the back contact battery 10.

[0095] Specifically, the area of the back contact battery 10 covered by the first electrical connecting member is a first pre-connection area.

[0096] Further, in the battery assembly, the number of the first electrical connecting members connected to the same back contact battery 10 is multiple. In the back contact battery 10, the first connecting block 112 can be arranged at each first pre-connection area, as shown in Figure 3 . The first connecting block 112 can also be arranged at part of the first pre-connection areas, and the remaining first pre-connection areas are not provided with the first connecting block 112.

[0097] Still further, in the first pre-connection area, the first connecting block 112 can be arranged at each first polarity fine grid 11. The first connecting block 112 can also be arranged at part of the first polarity fine grids 11. This is not limited here. In the example shown in Figure 3 , the first connecting block 112 is arranged at the first polarity fine grids 11 at both ends of the first pre-connection area.

[0098] Please refer to Figure 1 and Figure 2 , the width w1 of the first connecting block 112 refers to the size of the first connecting block 112 in the first direction. The width w1 of the first connecting block 112 can be the same everywhere, can be different everywhere, or can be partially the same. The width w2 of the first grid line 111 refers to the size of the first grid line 111 in the first direction. The width w2 of the first grid line 111 can be the same everywhere, can be different everywhere, or can be partially the same.

[0099] Specifically, the width w1 of the first connecting block 112 is greater than the width w2 of the first grid line 111, that is, the width of at least one place of the first connecting block 112 is greater than the width of at least one place of the first grid line 111. It can be that the minimum width of the first connecting block 112 is greater than the maximum width of the first grid line 111; it can also be that the maximum width of the first connecting block 112 is greater than the maximum width of the first grid line 111; it can also be that the maximum width of the first connecting block 112 is greater than the width of the connection between the first grid line 111 and the first connecting block 112. This is not limited here.

[0100] Please refer to Figure 2The length s1 of the first connecting block 112 is greater than or equal to 100 μm. For example, the length s1 of the first connecting block 112 is 100 μm, 101 μm, 110 μm, 150 μm, 200 μm, 500 μm, 800 μm, 1000 μm, 1800 μm, 2000 μm, or 5000 μm.

[0101] Specifically, the length s1 of the first connecting block 112 refers to the dimension of the first connecting block 112 in the second direction. The length s1 of the first connecting block 112 can be the same everywhere, can be different everywhere, or can be partially the same.

[0102] The length s1 of the first connecting block 112 being greater than or equal to 100 μm means that the length of at least one part of the first connecting block 112 is greater than or equal to 100 μm. The minimum length of the first connecting block 112 can be greater than or equal to 100 μm, i.e., the length of the first connecting block 112 everywhere is greater than or equal to 100 μm. Alternatively, the maximum length of the first connecting block 112 can be greater than or equal to 100 μm. No limitation is made herein.

[0103] Referring to Figure 2 and Figure 4 In some embodiments, the first connecting block 112 is formed with a first hollow region 1120. In this way, the coverage of the first connecting block 112 can be ensured while the material of the first connecting block 112 is reduced, which is conducive to reducing the cost while improving the connection stability.

[0104] Referring to Figure 5 In some embodiments, the first connecting block 112 is in a solid form. In this way, the area of the first connecting block 112 can be increased as much as possible, so as to increase the contact area of the first connecting block 112 with the electrical connecting member, increase the pulling force, reduce the risk of the electrical connecting member falling off from the back contact battery 10, and improve the connection stability of the back contact battery 10 and the electrical connecting member.

[0105] Referring to Figure 1 and Figure 2 In some embodiments, the first connecting block 112 is in a rectangular shape. It can be understood that in other embodiments, the first connecting block 112 can be in a circular shape, an annular shape, an elliptical shape, a triangular shape, a racetrack shape, or other shapes. No limitation is made herein to the specific shape of the first connecting block 112.

[0106] Referring to Figure 1 , Figure 2 and Figure 3 The second grid line 121 includes a first body portion 1211 and a first bending portion 1212 connected to each other. The first body portion 1211 extends along the second direction, and the second direction intersects the first direction. The first bending portion 1212 is arranged corresponding to the first connecting block 112 and bends away from the first connecting block 112 from the first body portion 1211.

[0107] Specifically, the first body part 1211 and the first bending part 1212 being connected refers to the first body part 1211 and the first bending part 1212 being electrically conductive, not being disconnected.

[0108] Specifically, the first body part 1211 extending along the second direction refers to the extension direction of the first body part 1211 as a whole being the second direction. This does not represent a limitation on the specific morphology of the first body part 1211. In the present embodiment, the first body part 1211 is in a straight line type, and the extension direction of the first body part 1211, i.e., the second direction, is the length direction of the first body part 1211. In other embodiments, the first body part 1211 can also be in a wavy line type, a broken line type, or other morphologies.

[0109] Specifically, the second direction intersecting the first direction refers to the second direction not overlapping, not being the same, and not being opposite to the first direction. In the present embodiment, the first direction and the second direction are perpendicular to each other. The first direction and the second direction are respectively parallel to two adjacent long sides of the silicon substrate 101. It can be understood that in other embodiments, the first direction and the second direction can also be an acute angle or an obtuse angle; the first direction and the second direction can also be an acute angle or an obtuse angle with the two adjacent long sides of the silicon substrate 101, respectively. This is not limited here. Please note that "two adjacent long sides" here refers to the sides other than the corner of the silicon substrate 101, and the arc-shaped side or the short side formed by rounding or chamfering the corner of the silicon substrate 101 is not considered.

[0110] Specifically, the first bending part 1212 is correspondingly arranged with the first connecting block 112, which means that, without considering the thickness of the first bending part 1212 and the first connecting block 112, the projection of the first bending part 1212 and the first connecting block 112 on the same plane in the first direction at least partially overlaps. In other words, the range occupied by the first bending part 1212 and the first connecting block 112 in the second direction at least partially overlaps.

[0111] In the present embodiment, the range occupied by the first bending part 1212 in the second direction covers and exceeds the range occupied by the first connecting block 112 in the second direction. In this way, by avoiding the first connecting block 112 as much as possible with the first bending part 1212, more space can be provided for the first connecting block 112 with a larger width as much as possible, facilitating the widening of the first connecting block 112, and the risk of short circuit caused by too small electrode spacing between the two polarities can be reduced as much as possible.

[0112] It can be understood that in other embodiments, the range occupied by the first connecting block 112 in the second direction can cover and exceed the range occupied by the first bending part 1212 in the second direction, or the range occupied by the first connecting block 112 in the second direction can completely overlap the range occupied by the first bending part 1212 in the second direction, or the range occupied by the first connecting block 112 in the second direction can intersect the range occupied by the first bending part 1212 in the second direction.

[0113] Specifically, the first bending part 1212 bends away from the first connecting block 112 from the first main body part 1211, that is, in the first direction, the maximum distance between the first bending part 1212 and the first main body part 1211 is greater than 0.

[0114] Specifically, the first bending part 1212 includes a first bending segment, a first connecting segment and a second bending segment connected in sequence, the first bending segment connects one end of the first connecting segment and the first main body part 1211, and the second bending segment connects the other end of the first connecting segment and the first main body part 1211. Figure 1 In the example, the first connecting segment is a straight line segment.

[0115] It can be understood that in other examples, the first bending part 1212 can be wavy, zigzag or other shapes. The first connecting segment can be wavy, zigzag or other shapes. This is not limited here.

[0116] Please refer to Figure 1 and Figure 2 In some embodiments, the difference between the width w1 of the first connecting block 112 and the width w2 of the first gate line 111 is 5 μm-290 μm. For example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, 290 μm.

[0117] In this way, the width difference between the first connecting block 112 and the first gate line 111 is in a suitable range, which can avoid the width of the first connecting block 112 being insufficient and the connection stability of the first electrical connecting member being poor due to the difference being too small, and can also avoid the series resistance of the first connecting block 112 being too large and the current loss being too large due to the difference being too large.

[0118] Please refer to Figure 1 and Figure 2 In some embodiments, the width w1 of the first connecting block 112 is 10 μm-300 μm. For example, 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, 300 μm.

[0119] In this way, the width w1 of the first connecting block 112 is in a proper range, which can avoid the width of the contact with the first electrical connecting piece being too small and the connection stability of the first electrical connecting piece being poor, and can also avoid the series resistance of the first connecting block 112 being too large and the current loss being large.

[0120] Referring to Figure 1 and Figure 2 In some embodiments, the width w2 of the first gate line 111 is 5-250 μm. For example, 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, 250 μm.

[0121] In this way, the width w2 of the first gate line 111 is in a proper range, which can avoid the gate line being easily disconnected and the effect of guiding the carriers from the silicon substrate 101 being poor when the width is too small, and can also avoid the series resistance being too large, the current loss being large, and the cost being high when the width is too large.

[0122] Referring to Figure 1 and Figure 2 In some embodiments, the maximum distance d1 of the first bending part 1212 and the first main part 1211 in the first direction is 5-290 μm. For example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, 290 μm.

[0123] In this way, the maximum distance d1 of the first bending part 1212 and the first main part 1211 in the first direction is in a proper range, which can avoid the first bending part 1212 and the first connecting block 112 being too close and the risk of short circuit being large when the distance is too small, and can also avoid the total length of the second gate line 121 being too large, the series resistance being too large, and the current loss being large when the distance is too large.

[0124] Referring to Figure 1 and Figure 2 In some embodiments, the first gate line 111, the first connecting block 112, and the second gate line 121 satisfy the following formula: -100 μm≤w1-w2-d1≤100 μm; wherein w1 is the width of the first connecting block 112, w2 is the width of the first gate line 111, and d1 is the maximum distance of the first bending part 1212 and the first main part 1211 in the first direction.

[0125] In this way, the difference between the width of the first connecting block 112 and the first gate line 111 and the maximum bending depth of the first bending part 1212 is in a suitable range, which can avoid the maximum bending depth of the first bending part 1212 being too large compared with the difference between the width of the first connecting block 112 and the first gate line 111, and the short circuit risk is difficult to be greatly improved while the series resistance of the second gate line 121 is too large, and can also avoid the maximum bending depth of the first bending part 1212 being too small compared with the difference between the width of the first connecting block 112 and the first gate line 111, and the short circuit risk is large.

[0126] Specifically, the value of w1-w2-d1 is, for example, -100 μm, -80 μm, -50 μm, -20 μm, 0 μm, 10 μm, 20 μm, 50 μm, 80 μm, 100 μm.

[0127] Preferably, the value of w1-w2-d1 is 0. That is, w1-w2=d1. In this way, the short circuit risk and the series resistance are considered, and the overall effect is better.

[0128] Please refer to Figure 1 and Figure 2 In some embodiments, the first gate line 111 is the first polarity thin gate 11 closest to the edge of the silicon substrate 101, and the distance x1 between the first gate line 111 and the edge is 0.4 mm-1 mm. For example, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm.

[0129] In this way, the distance x1 between the first gate line 111 and the edge is in a suitable range, which can avoid the inconvenience of lamination caused by too small distance, and can also avoid the poor effect of collecting charge carriers caused by too large distance.

[0130] Preferably, the distance x1 between the first gate line 111 and the edge is 0.5 mm-0.8 mm. For example, 0.5 mm, 0.52 mm, 0.55 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.65 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.75 mm, 0.78 mm, 0.8 mm. In this way, the distance x1 between the first gate line 111 and the edge is further optimized, so that the overall effect is better.

[0131] Please refer to Figure 6 and Figure 6 In some embodiments, the distance x2 between the first connecting block 112 and the edge is 0.4 mm-50 mm. For example, 0.4 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 48 mm, 50 mm.

[0132] In this way, the distance x2 from the first connecting block 112 to the edge is in a proper range, which can avoid the inconvenience of the lamination caused by too small distance, and can also avoid the poor connection stability of the end region of the back contact battery 10 and the first electrical connecting piece caused by too large distance.

[0133] Preferably, the distance x2 from the first connecting block 112 to the edge is 0.8mm-5mm. For example, it is 0.8mm, 0.82mm, 0.9mm, 1mm, 2mm, 3mm, 4mm or 5mm. In this way, the distance x2 from the first connecting block 112 to the edge is further optimized, so that the connection stability of the back contact battery 10 and the first electrical connecting piece is better.

[0134] Please refer to Figures 1-5 In some embodiments, the first polarity thin grid 11 includes a third grid line 113, the third grid line 113 includes a second body part 1131 and a second bending part 1132 connected in sequence, the second body part 1131 extends along the second direction, and the second bending part 1132 is arranged corresponding to the first connecting block 112 and bends away from the first connecting block 112 from the second body part 1131.

[0135] In this way, the third grid line 113 which is bent can provide more space for the first connecting block 112 which has a larger width and the second grid line 121 which is bent to avoid the first connecting block 112, which facilitates the widening of the first connecting block 112 and the bending of the second grid line 121, and can reduce the risk of short circuit caused by too small electrode pitch between the two polarities.

[0136] Specifically, the connection of the second body part 1131 and the second bending part 1132 means that the second body part 1131 and the second bending part 1132 are electrically conductive and not disconnected.

[0137] Specifically, the extension of the second body part 1131 along the second direction means that the extension direction of the second body part 1131 as a whole is the second direction. This does not represent a limitation on the specific form of the second body part 1131. In the present embodiment, the second body part 1131 is in a straight line type, and the extension direction of the second body part 1131, i.e. the second direction, is the length direction of the second body part 1131. In other embodiments, the second body part 1131 can also be in a wavy line type, a broken line type or other forms.

[0138] Specifically, the corresponding arrangement of the second bending part 1132 and the first connecting block 112 means that, regardless of the thickness of the second bending part 1132 and the first connecting block 112, the projection of the second bending part 1132 and the first connecting block 112 on the same plane in the first direction at least partially overlaps. In other words, the ranges occupied by the second bending part 1132 and the first connecting block 112 in the second direction at least partially overlap.

[0139] In the embodiment, the range occupied by the second bending part 1132 in the second direction covers and exceeds the range occupied by the first connecting block 112 in the second direction. In this way, by avoiding the first connecting block 112 as much as possible by using the second bending part 1132, more space can be provided for the first connecting block 112 with a larger width as much as possible, facilitating the widening of the first connecting block 112, and the risk of short circuit caused by too small electrode spacing of the two polarities can be reduced as much as possible.

[0140] It can be understood that in other embodiments, the range occupied by the first connecting block 112 in the second direction can cover and exceed the range occupied by the second bending part 1132 in the second direction; the range occupied by the first connecting block 112 in the second direction can also completely overlap with the range occupied by the second bending part 1132 in the second direction; or the range occupied by the first connecting block 112 in the second direction can intersect with the range occupied by the second bending part 1132 in the second direction.

[0141] Specifically, the second bending part 1132 bends from the second main body part 1131 to a direction away from the first connecting block 112, that is, in the first direction, the maximum distance between the second bending part 1132 and the second main body part 1131 is greater than 0.

[0142] Specifically, the second bending part 1132 includes a third bending segment, a second connecting segment and a fourth bending segment connected in sequence, the third bending segment connects the second main body part 1131 and one end of the second connecting segment, and the fourth bending segment connects the second main body part 1131 and the other end of the second connecting segment. Figure 6 In the example, the second connecting segment is a straight line segment.

[0143] It can be understood that in other examples, the second bending part 1132 can be wavy, zigzag or other shapes. The second connecting segment can be wavy, zigzag or other shapes. This is not limited here.

[0144] Please note that the second grid line 121 is a bent second polarity fine grid 12, and the third grid line 113 is a bent first polarity fine grid 11. The second grid line 121 can be adjacent to the first grid line 111, or can not be adjacent to the first grid line 111. The third grid line 113 can be adjacent to the second grid line 121, or can not be adjacent to the second grid line 121.

[0145] In the example, the number of second grid lines 121 is 1, adjacent to the first grid line 111, and there is no third grid line 113. That is, in the direction away from the edge, the first grid line 111 and the second grid line 121 are arranged in sequence. Figure 6

[0146] In the example, the number of second grid lines 121 is 1, adjacent to the first grid line 111, and there is no third grid line 113. That is, in the direction away from the edge, the first grid line 111 and the second grid line 121 are arranged in sequence.

[0146] In the example, the number of second grid lines 121 is 1, adjacent to the first grid line 111, and there is no third grid line 113. That is, in the direction away from the edge, the first grid line 111 and the second grid line 121 are arranged in sequence. Figure 6In the example shown in FIG. 1, the number of second gate lines 121 is 2, and the number of third gate lines 113 is 1. One second gate line 121 is adjacent to the first gate line 111, and the third gate line 113 is located between the two second gate lines 121. That is, in the direction away from the edge, the first gate line 111, the second gate line 121, the third gate line 113, and the second gate line 121 are arranged in sequence.

[0147] It can be understood that in other examples, in the direction away from the edge, the first gate line 111, the second gate line 121, the third gate line 113, the second gate line 121, and the third gate line 113 can be arranged in sequence.

[0148] Referring to FIG. 1, Figure 6 In some embodiments, in the direction away from the first connecting block 112, the bending depth of the first bending portion 1212 and the second bending portion 1132 gradually decreases.

[0149] In this way, in the direction away from the first connecting block 112, the bending depth of the bending portion gradually decreases, which can not only avoid the first connecting block 112 or the adjacent bending portion to reduce the risk of short circuit, but also realize the transition from bending to gentle.

[0150] Specifically, the bending depth of the first bending portion 1212 is the maximum distance between the first bending portion 1212 and the first main body portion 1211 in the first direction in the second gate line 121, that is, d1 shown in FIG. 1. Figure 6 The bending depth of the second bending portion 1132 is the maximum distance between the second bending portion 1132 and the second main body portion 1131 in the first direction in the third gate line 113, that is, d2 shown in FIG. 1. Figure 6

[0151] In the example shown in FIG. 1, Figure 1 In the example shown in FIG. 1, in the direction away from the edge, the first gate line 111, the second gate line 121, the third gate line 113, and the second gate line 121 are arranged in sequence, and the bending depth of the corresponding bending portion gradually decreases.

[0152] Referring to FIG. 1, Figure 2 In some embodiments, for adjacent second gate lines 121 and third gate lines 113, the first bending portion 1212 and the second bending portion 1132 satisfy the following formula: 50 μm≤d1-d2≤150 μm; Wherein, d2 is the maximum distance between the second bending portion 1132 and the second main body portion 1131 in the first direction, and d1 is the maximum distance between the first bending portion 1212 and the first main body portion 1211 in the first direction.

[0153] ​In this way, the difference in the bending depth of the adjacent second gate line 121 and third gate line 113 is in a proper range, which can avoid the situation that the difference is too small, and thus more bending gate lines are needed to realize the transition from bending to gentle, which increases the process complexity and reduces the production efficiency, and can also avoid the situation that the difference is too large, and thus the bending depth of one gate line is not enough, the bending parts with opposite polarities are close to each other, and the short circuit risk is high.

[0154] Specifically, the value of d1-d2 is, for example, 50 μm, 52 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, or 150 μm.

[0155] Please refer to Figure 3 , Figure 1 and Figure 2 In some embodiments, the first gate line 111 and the first connecting block 112 arranged on the first gate line 111 form a first conductive structure 1001, and each row of the first conductive structure 1001 is continuous.

[0156] In this way, each row of the first conductive structure 1001 is continuous and has no breakpoints, so that the power of the back contact battery 10 is better.

[0157] Please refer to Figure 3 , Figure 7 and Figure 8 In some embodiments, each row of the second gate line 121 is continuous.

[0158] In this way, each row of the second gate line 121 is continuous and has no breakpoints, so that the power of the back contact battery 10 is better.

[0159] Please refer to Figure 7 and Figure 8 In some embodiments, the second polarity fine grid 12 includes a fourth gate line 122, and the fourth gate line 122 is provided with a second connecting block 123, and the width w3 of the second connecting block 123 is greater than the width w4 of the fourth gate line 122.

[0160] In this way, the contact area between the second connecting block 123 and the second electrical connecting member is increased, the tension is increased, the risk of the second electrical connecting member falling off the back contact battery 10 is reduced, and the connection stability of the back contact battery 10 and the second electrical connecting member is improved.

[0161] Please refer to Figure 7 and Figure 8 In some embodiments, the fourth gate line 122 and the second gate line 121 are the same second polarity fine grid 12. In this way, the first bending part 1212 and the second connecting block 123 are integrated in the same second polarity fine grid 12, so that the connection stability of the second electrical connecting member at this position is stronger. Moreover, the design and manufacturing can be concentrated, which is beneficial to improve the manufacturing efficiency.

[0162] It should be noted that in the case that the fourth grid line 122 and the second grid line 121 are the same second-polarity fine grid 12, the fourth grid line 122 and the second grid line 121 can be regarded as part of the second-polarity fine grid 12, respectively.

[0163] It can be understood that in other examples, the fourth grid line 122 and the second grid line 121 can also be different second-polarity fine grids 12. This is not limited here.

[0164] Specifically, the second connecting block 123 is used to connect the second electrical connecting member.

[0165] Further, the second connecting block 123 and the second electrical connecting member can be electrically connected through at least one of conductive adhesive bonding, direct welding, solder paste welding, and physical contact. This is not limited here.

[0166] Further, the entire area of the second connecting block 123 is connected to the second electrical connecting member. In this way, the connection area is large, which is conducive to improving the connection stability. It can be understood that in other embodiments, part of the area of the second connecting block 123 can also be connected to the second electrical connecting member.

[0167] Further, the second electrical connecting member includes at least one of a solder strip and a conductive wire. Here, the second electrical connecting member is taken as a solder strip for example. It can be understood that in the case that the second electrical connecting member is a solder strip, the embodiments of the present application can reduce the risk of the solder strip falling off from the back contact battery 10.

[0168] Specifically, the area of the back contact battery 10 covered by the second electrical connecting member is a second pre-connection area.

[0169] Further, in the battery assembly, the number of second electrical connecting members connected to the same back contact battery 10 is multiple. In the back contact battery 10, the second connecting block 123 can be arranged at each second pre-connection area. The second connecting block 123 can also be arranged at part of the second pre-connection areas, and the remaining second pre-connection areas are not provided with the second connecting block 123. Further, in the second pre-connection area, the second connecting block 123 can be arranged at each second-polarity fine grid 12. The second connecting block 123 can also be arranged at part of the second-polarity fine grids 12. This is not limited here. In the present embodiment, the second connecting block 123 is arranged at the second-polarity fine grids 12 at both ends of the second pre-connection area.

[0170] In some embodiments, the second connecting block 123 comprises at least one of a pad and a segment of the grid line. In this way, the second connecting block 123 can have various forms, which is conducive to meeting more production scenarios and requirements. For example, the second connecting block 123 comprises a pad. For another example, the second connecting block 123 comprises a segment of the grid line. For yet another example, the second connecting block 123 comprises a pad and a segment of the grid line. It can be understood that, in the case where the second connecting block 123 comprises a segment of the grid line, the segment of the grid line passes through the dielectric film layer 1003 to contact the second polarity-doped layer. In the case where the second connecting block 123 comprises a pad, the pad can pass through the dielectric film layer 1003 to contact the second polarity-doped layer, or can be isolated from the second polarity-doped layer by the dielectric film layer 1003.

[0171] Referring to Figure 8 and Figure 9 , the width w3 of the second connecting block 123 refers to the size of the second connecting block 123 in the first direction. The width w3 of the second connecting block 123 can be the same everywhere, can be different everywhere, or can be partially the same. The width w4 of the fourth grid line 122 refers to the size of the fourth grid line 122 in the first direction. The width w4 of the fourth grid line 122 can be the same everywhere, can be different everywhere, or can be partially the same.

[0172] Specifically, the width w3 of the second connecting block 123 is greater than the width w4 of the fourth grid line 122, that is, the width of at least one place of the second connecting block 123 is greater than the width of at least one place of the fourth grid line 122. It can be that the minimum width of the second connecting block 123 is greater than the maximum width of the fourth grid line 122, or that the maximum width of the second connecting block 123 is greater than the maximum width of the fourth grid line 122, or that the maximum width of the second connecting block 123 is greater than the width of the fourth grid line 122 at the connection between the second connecting block 123 and the fourth grid line 122. This is not limited here.

[0173] Referring to Figure 10 and Figure 7 , in some embodiments, the second connecting block 123 is formed with a second hollowed-out area 1230. In this way, the coverage of the second connecting block 123 can be ensured while the material of the second connecting block 123 is reduced, which is conducive to improving the connection stability while reducing the cost.

[0174] Referring to Figure 8 , in some embodiments, the second connecting block 123 is in a solid form. In this way, the area of the second connecting block 123 can be increased as much as possible, so as to increase the contact area between the second connecting block 123 and the electrical connecting member, increase the pulling force, reduce the risk of the electrical connecting member falling off from the back contact battery 10, and improve the connection stability of the back contact battery 10 and the electrical connecting member.

[0175] Referring to Figure 7 and Figure 8In some embodiments, the second connection block 123 is rectangular. It can be appreciated that in other embodiments, the second connection block 123 can be circular, annular, oval, triangular, racetrack-shaped, or other shapes. The specific shape of the second connection block 123 is not limited herein.

[0176] Referring to Figure 7 and Figure 8 In some embodiments, the difference between the width w3 of the second connection block 123 and the width w4 of the fourth gate line 122 is 5-290 μm. For example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, 290 μm.

[0177] In this way, the width difference between the second connection block 123 and the fourth gate line 122 is within an appropriate range, which can avoid the width of the second connection block 123 being insufficient due to the difference being too small, and the connection stability of the second electrical connection being poor, and can also avoid the series resistance of the second connection block 123 being too large due to the difference being too large, and the current loss being large.

[0178] Referring to Figure 7 and Figure 8 In some embodiments, the width w3 of the second connection block 123 is 10-300 μm. For example, 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, 300 μm.

[0179] In this way, the width w3 of the second connection block 123 is within an appropriate range, which can avoid the width of the contact with the second electrical connection being small due to the width being too small, and the connection stability of the second electrical connection being poor, and can also avoid the series resistance of the second connection block 123 being too large due to the width being too large, and the current loss being large.

[0180] Referring to Figure 7 and Figure 8 In some embodiments, the width w4 of the fourth gate line 122 is 5-250 μm. For example, 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, 250 μm.

[0181] In this way, the width w4 of the fourth gate line 122 is within an appropriate range, which can avoid the gate line being easily disconnected due to the width being too small, and the effect of guiding the carriers from the silicon substrate 101 being poor, and can also avoid the series resistance being too large due to the width being too large, and the current loss being large, and the cost being high.

[0182] Referring to Figure 7 and Figure 8In some embodiments, the difference between the area of the first connecting block 112 and the area of the second connecting block 123 is -400 pm 2 400 pm 2 For example, -400 pm 2 , -400 pm 2 , -400 pm 2 , -400 pm 2 , -400 pm 2 , 400 pm 2 .

[0183] In this way, the difference between the area of the first connecting block 112 and the area of the second connecting block 123 is in a suitable range, which can avoid the area difference between the first connecting block 112 and the second connecting block 123 being too large due to the difference being too small or too large, so that the contact area of the first connecting block 112 with the first electrical connecting member and the contact area of the second connecting block 123 with the second electrical connecting member are substantially the same, thereby making the pulling force of the first electrical connecting member and the second electrical connecting member on the connecting block substantially the same, which is beneficial to improve the connection stability of the electrical connecting member and the back contact battery 10.

[0184] Please refer to Figure 7 and Figure 8 In some embodiments, the first polarity grid line adjacent to the second connecting block 123 is disconnected at a position corresponding to the second connecting block 123 to avoid the second connecting block 123. In the second direction, the spacing d3 between the breakpoint of the second connecting block 123 and the first grid line 111 is 0.2 mm-1 mm. For example, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm.

[0185] In this way, the space of the first polarity grid line adjacent to the second connecting block 123 makes the range of the second connecting block 123 larger, which is beneficial to improve the contact area of the second connecting block 123 with the second electrical connecting member and improve the connection stability. At the same time, the spacing d3 between the breakpoint of the second connecting block 123 and the first grid line 111 is in a suitable range, which can avoid the risk of short circuit due to the distance between the opposite electrodes being too close when the spacing is too small, and can also avoid the poor carrier collection effect of the interval area and the poor efficiency of the battery when the spacing is too large.

[0186] Specifically, the first polarity grid line adjacent to the second connecting block 123 is disconnected at a position corresponding to the second connecting block 123, which means that the line connecting the two breakpoints of the first polarity grid line passes through the second connecting block 123. In order to avoid the second connecting block 123 with opposite polarity, the first polarity grid line is disconnected to form two breakpoints.

[0187] Preferably, the distance d3 between the second connecting block 123 and the breakpoint of the first gate line 111 is 0.3mm-0.6mm. For example, 0.3mm, 0.32mm, 0.4mm, 0.45mm, 0.5mm, 0.58mm, 0.6mm. In this way, the distance d3 between the second connecting block 123 and the breakpoint of the first gate line 111 is further optimized, taking into account the area of the second connecting block 123 and the carrier collection, and the overall effect is better.

[0188] Referring to Figure 7 and Figure 8 In some embodiments, the fourth gate line 122 is the second polar thin gate 12 closest to the edge of the silicon substrate 101, and the distance x3 between the fourth gate line 122 and the edge is greater than 0.7mm-1.3mm.

[0189] In this way, the distance x3 between the fourth gate line 122 and the edge is in a suitable range, which can avoid the inconvenience of lamination caused by too small distance, and can also avoid the poor effect of collecting carriers caused by too large distance.

[0190] Preferably, the distance x3 between the fourth gate line 122 and the edge is 0.8mm-1.1mm. For example, 0.8mm, 0.82mm, 0.85mm, 0.88mm, 0.9mm, 0.95mm, 1mm, 1.02mm, 1.05mm, 1.08mm, 1.1mm. In this way, the distance x3 between the fourth gate line 122 and the edge is further optimized, and the overall effect is better.

[0191] It can be understood that in other embodiments, the fourth gate line 122 can be located away from the edge of the silicon substrate 101. For example, the fourth gate line 122 is the second, third, fourth or other serial number of the second polar thin gate 12 from the edge. In this way, the risk of the electrical connector falling off from the middle of the back contact battery 10 can be reduced. In this case, a bent first polar gate line 11 can be provided on one side or both sides of the fourth gate line 122 to avoid the second connecting block 123 provided on the fourth gate line 122.

[0192] Referring to Figure 11 and Figure 11 In some embodiments, the distance x4 between the second connecting block 123 and the edge of the silicon substrate 101 is 0.7mm-50mm. For example, 0.7mm, 0.8mm, 1mm, 5mm, 10mm, 20mm, 30mm, 40mm, 48mm, 50mm.

[0193] In this way, the distance x4 between the second connecting block 123 and the edge is in a suitable range, which can avoid the inconvenience of lamination caused by too small distance, and can also avoid the poor connection stability of the end area of the back contact battery 10 and the second electrical connector caused by too large distance.

[0194] Preferably, the distance x4 from the second connecting block 123 to the edge is 1mm-5mm. For example, 1mm, 1.02mm, 1.5mm, 2mm, 3mm, 4mm, 4.5mm, 5mm. In this way, the distance x4 from the second connecting block 123 to the edge is further optimized, so that the connection stability of the back contact battery 10 and the second electrical connecting piece is better.

[0195] Referring to Figure 11 and Figure 7 In some embodiments, the fourth grid line 122 is the second polarity thin grid 12 closest to the edge of the silicon substrate 101, and the second connecting block 123 is located on one side of the fourth grid line 122 towards the edge.

[0196] In this way, the space of the edge can be fully utilized, so that the range of the second connecting block 123 is larger, the range of the connecting ribbon is larger, and the connection stability of the back contact battery 10 and the second electrical connecting piece is improved.

[0197] In some embodiments, the second connecting block 123 protrudes from the fourth grid line 122 to both sides of the fourth grid line 122.

[0198] In this way, the space between the second connecting block 123 on both sides and the different polarity grid line can be fully utilized, so that the range of the second connecting block 123 is larger, the range of the connecting ribbon is larger, and the connection stability of the back contact battery 10 and the second electrical connecting piece is improved.

[0199] Referring to Figure 12 In some embodiments, the fourth grid line 122 includes a third main body part 1221 and a third bending part 1222 connected in sequence, the third main body part 1221 extends along the second direction, the third bending part 1222 bends from the third main body part 1221 to a direction away from the edge of the silicon substrate 101, and the second connecting block 123 is arranged on the third bending part 1222.

[0200] In this way, the second connecting block 123 is arranged on the part of the fourth grid line 122 bending towards the direction away from the edge of the silicon substrate 101, which can make the position of the second connecting block 123 further away from the edge of the silicon substrate 101, further away from the end of the second electrical connecting piece, and closer to the middle of the second electrical connecting piece. It can avoid the end of the second electrical connecting piece difficult to reach the second connecting block 123 close to the edge of the silicon substrate 101 due to offset or cutting error, so that the second connecting block 123 is easier to connect with the second electrical connecting piece and the connection stability is higher.

[0201] Specifically, the third bending part 1222 includes a fifth bending segment, a third connecting segment and a sixth bending segment connected in sequence, the fifth bending segment connects the third main body part 1221 and one end of the third connecting segment, and the sixth bending segment connects the third main body part 1221 and the other end of the fourth connecting segment.Figure 2 In the example, the third connecting segment is a straight line segment.

[0202] It is understood that in other examples, the third bend 1222 may be wavy, zigzag, or other shapes. The second connecting segment may be wavy, zigzag, or other shapes. No limitation is made here.

[0203] Please see Figure 13 In some embodiments, the maximum distance d4 between the third bent portion 1222 and the third main body portion 1221 in the first direction is 5μm-290μm. For example, it is 5μm, 8μm, 10μm, 50μm, 80μm, 100μm, 150μm, 200μm, 280μm, or 290μm.

[0204] Thus, the maximum distance d4 between the third bend portion 1222 and the third main body portion 1221 in the first direction is within a suitable range. This avoids the situation where the distance between the third bend portion 1222 and the adjacent non-linear fine gate is too close due to the small distance, resulting in a high risk of short circuit. It also avoids the situation where the total length of the fourth gate line 122 is too large due to the large distance, resulting in too much series resistance and large current loss.

[0205] Please see Figure 14 In some embodiments, the fourth gate line 122 and the second connecting block 123 disposed on the fourth gate line 122 form a second conductive structure 1002, and each row of the second conductive structure 1002 is continuous.

[0206] In this way, the second conductive structure 1002 in each row is not interrupted and has no breaks, which makes the power of the back contact battery 10 better.

[0207] Please see Figure 13 and Figure 13 In some embodiments, the silicon substrate 101 includes a plurality of first polar doped regions 13 and a plurality of second polar doped regions 14 arranged along a first direction. The first polar doped regions 13 are provided with first polar fine gates 11, and the second polar doped regions 14 are provided with second polar fine gates 12. The first polar doped region 13 includes a first doped region 131, which includes a first region 1311 and a second region 1312. The first region 1311 is provided with a first gate line 111, and the second region 1312 corresponds to a first connecting block 112. The second polar doped region 14 includes a second doped region 141, which includes a third region 1411 and a fourth region 1412. The third region 1411 is provided with a first main body portion 1211 of the second gate line 121, and the fourth region 1412 is provided with a first bending portion 1212 of the second gate line 121.

[0208] In this way, the two-polarity doped regions correspond to the two-polarity fine grids, which facilitates the fabrication of fine grids of corresponding polarity on the doped regions and facilitates the electrical connection of the doped regions and the fine grids of corresponding polarity, and is conducive to reducing the process difficulty, improving the manufacturing efficiency and reducing the cost.

[0209] Specifically, "the first region 1311 is provided with the first gate line 111" means that the first gate line 111 is in electrical contact with the first region 1311.

[0210] Specifically, "the second region 1312 corresponds to the first connecting block 112" means that, in the thickness direction of the back contact battery 10, the projection of the first connecting block 112 and the second region 1312 on the same plane at least partially overlaps. The first connecting block 112 can be in electrical contact with the second region 1312. It can also be electrically isolated from the second region 1312.

[0211] Specifically, "the third region 1411 is provided with the first main body part 1211 of the second gate line 121" means that the first main body part 1211 of the second gate line 121 is in electrical contact with the third region 1411.

[0212] Specifically, "the fourth region 1412 is provided with the first bending part 1212 of the second gate line 121" means that the first bending part 1212 of the second gate line 121 is in electrical contact with the fourth region 1412.

[0213] Specifically, the first-polarity doped region 13 and the second-polarity doped region 14 can be formed in the entire region of the silicon substrate 101, so that the first-polarity fine grid 11 and the second-polarity fine grid 12 are distributed in the entire region of the silicon substrate 101; or the first-polarity doped region 13 and the second-polarity doped region 14 can be formed in a partial region of the silicon substrate 101, so that the first-polarity fine grid 11 and the second-polarity fine grid 12 are distributed in a partial region of the silicon substrate 101.

[0214] Specifically, the first-polarity doped region 13 and the second-polarity doped region 14 have different polarities. The first-polarity doped region 13 corresponds to the first-polarity doped layer. The second-polarity doped region 14 corresponds to the second-polarity doped layer.

[0215] Specifically, the number of the first-polarity doped region 13 can be 1, 2, 3, 4 or other number. The number of the second-polarity doped region 14 can be 1, 2, 3, 4 or other number. This is not limited herein. The number of the first-polarity doped region 13 can be the same as or different from the number of the second-polarity doped region 14.

[0216] Specifically, the first-polarity doped region 13 and the second-polarity doped region 14 are arranged along the first direction, which can be alternating arrangement or non-alternating arrangement along the first direction, and can be equidistant arrangement or non-equidistant arrangement along the first direction. This is not limited herein.

[0217] It can be understood that a gap can be formed between the adjacent first polarity doped region 13 and the second polarity doped region 14, the adjacent first polarity doped region 13 and the second polarity doped region 14 can be in contact with each other, or other film layer structures can be provided.

[0218] In some embodiments, a dielectric film layer 1003 is provided between at least one pair of adjacent first polarity doped region 13 and second polarity doped region 14, and the dielectric film layer 1003 electrically isolates the first polarity doped region 13 and the second polarity doped region 14.

[0219] In this way, the dielectric film layer 1003 is used to electrically isolate the first doped layer and the second doped layer, and at the same time, the dielectric film layer 1003 can be used to reduce optical loss and carrier recombination by using the difference in refractive index and the surface passivation effect.

[0220] Specifically, the dielectric film layer 1003 can be provided between one pair of adjacent first polarity doped region 13 and second polarity doped region 14, or between multiple pairs of adjacent first polarity doped region 13 and second polarity doped region 14. In this embodiment, the dielectric film layer 1003 is provided between all adjacent first polarity doped region 13 and second polarity doped region 14.

[0221] Specifically, the dielectric film layer 1003 covers the first doped layer and the second doped layer, the first polarity fine grid 11 contacts the first doped layer through the dielectric film layer 1003, and the second polarity fine grid 12 contacts the second doped layer through the dielectric film layer 1003. In order to better show the first polarity doped region 13 and the second polarity doped region 14, part of the dielectric film layer 1003 covering the first polarity doped region 13 and the second polarity doped region 14 is omitted in the figure.

[0222] Specifically, the dielectric film layer 1003 includes at least one of an aluminum oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbide layer, an amorphous silicon layer, and a silicon oxide layer.

[0223] In some embodiments, a groove is formed between the first polarity doped region 13 and the second polarity doped region 14, and the dielectric film layer 1003 is at least partially provided in the groove.

[0224] In this way, the groove can be used to electrically isolate the first polarity doped region 13 and the second polarity doped region 14 inside the silicon substrate 101, thereby reducing the risk of conduction between the first polarity doped region 13 and the second polarity doped region 14.

[0225] Specifically, "the dielectric film layer 1003 is at least partially provided in the groove" means that part of the dielectric film layer 1003 is provided in the groove and the rest is provided outside the groove, or all of the dielectric film layer 1003 is provided in the groove.

[0226] Specifically, the trench is continuously arranged between the first polarity doped region 13 and the second polarity doped region 14. In other words, the first polarity doped region 13 and the second polarity doped region 14 are separated by the trench. In this way, it is ensured that the first polarity doped region 13 and the second polarity doped region 14 cannot be conducted across the trench.

[0227] In some embodiments, at least one pair of adjacent first polarity doped region 13 and second polarity doped region 14 is provided with a tunneling layer, and the first polarity doped region 13 and the second polarity doped region 14 are both in contact with the tunneling layer.

[0228] In this way, the reverse bias can be reduced, and the heat generation power of the back contact cell 10 when it is shaded in the assembly and becomes a load can be reduced. Moreover, the tunneling layer can play a passivation role, reducing the recombination at the junction of the first polarity doped region 13 and the second polarity doped region 14.

[0229] Specifically, the tunneling layer includes at least one of a silicon oxide layer, an aluminum oxide layer, and a silicon carbide layer.

[0230] In some embodiments, at least one pair of adjacent first polarity doped region 13 and second polarity doped region 14 are in contact with each other.

[0231] In this way, the reverse bias can be reduced, and the heat generation power of the back contact cell 10 when it is shaded in the assembly and becomes a load can be reduced.

[0232] Specifically, adjacent first polarity doped region 13 and second polarity doped region 14 can be in contact with each other in all regions adjacent to each other, or can be in contact with each other in part of the regions adjacent to each other.

[0233] Please refer to Figure 13 and Figure 13 In some embodiments, the second region 1312 protrudes from the first region 1311.

[0234] In this way, the second region 1312 corresponding to the first connection block 112 protrudes from the first region 1311 provided with the first gate line 111, which can provide sufficient space for the first connection block 112 with a larger width. Moreover, in the case where the first connection block 112 is arranged in the second region 1312 and in electrical contact with the second region 1312, the risk of short circuit caused by the first connection block 112 with a larger width being too close to the second polarity doped region 14 adjacent to the first region 1311 due to the small edge distance between the first connection block 112 with a larger width and the first region 1311 can be reduced.

[0235] Please refer to Figure 14 Specifically, the width W2 of the second region 1312 is greater than the width W1 of the first region 1311. In this way, the second region 1312 with a larger width can better correspond to the first connection block 112 with a larger width.

[0236] Specifically, the width W2 of the second region 1312 is 12 μm-2000 μm. For example, 12 μm, 15 μm, 20 μm, 50 μm, 100 μm, 500 μm, 800 μm, 1000 μm, 1500 μm, 1800 μm, 2000 μm. In this way, the width W2 of the second region 1312 is in a suitable range, which can avoid insufficient setting area of the first connecting block 112 and greater risk of short circuit due to small width, and can also avoid poor carrier collection effect of another polarity due to too large width.

[0237] Preferably, the width W2 of the second region 1312 is 500 μm-1500 μm. For example, 500 μm, 510 μm, 600 μm, 800 μm, 1000 μm, 1200 μm, 1400 μm, 1500 μm. In this way, the width W2 of the second region 1312 is further optimized, taking into account the risk of short circuit and the carrier collection effect, and the overall effect is better.

[0238] Specifically, the width W1 of the first region 1311 is 6 μm-800 μm. In this way, the width W1 of the first region 1311 is in a suitable range, which can avoid insufficient setting area of the first gate line 111 and greater risk of short circuit due to small width, and can also avoid poor carrier collection effect of another polarity due to too large width.

[0239] Preferably, the width W1 of the first region 1311 is 10 μm-600 μm. For example, 10 μm, 12 μm, 20 μm, 80 μm, 100 μm, 200 μm, 500 μm, 600 μm. In this way, the width W1 of the first region 1311 is further optimized, taking into account the risk of short circuit and the carrier collection effect of two polarities, and the overall effect is better.

[0240] It can be understood that in other embodiments, the widths of the first region 1311 and the second region 1312 can be the same. For example, based on the example of Figure 15 the upper side of the second region 1312 is recessed, and the recessed depth is equal to the protruded depth of the lower side. In other embodiments, the width W2 of the second region 1312 can be smaller than the width W1 of the first region 1311. For example, based on the example of Figure 16 the upper side of the second region 1312 is recessed, and the recessed depth is greater than the protruded depth of the lower side. This is not limited here.

[0241] Please refer to Figure 16In some embodiments, the maximum depth H1 of the second region 1312 protruding from the first region 1311 in the first direction is 5-290 μm. For example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, 290 μm.

[0242] In this way, the maximum depth H1 of the second region 1312 protruding from the first region 1311 is in a suitable range, which can avoid insufficient setting area of the first connecting block 112 and greater risk of short circuit caused by too small depth, and can also avoid being not conducive to collecting carriers of another polarity caused by too large depth.

[0243] Please refer to Figure 15 In some embodiments, the fourth region 1412 is recessed from the third region 1411 on the side facing the second region 1312. In this way, the recessed fourth region 1412 cooperates with the protruding second region 1312 to make full use of space, so that the arrangement of the doped region is more reasonable, which is conducive to better collecting carriers and improving the photoelectric conversion efficiency of the battery.

[0244] Please refer to Figure 16 and Figure 14 In some embodiments, the fourth region 1412 is protruded from the third region 1411 on the side away from the second region 1312.

[0245] In this way, the fourth region 1412 corresponding to the first bending part 1212 is protruded from the third region 1411 provided with the first main part 1211, which can provide sufficient space for the bent first bending part 1212, and reduce the risk of short circuit caused by too small edge distance between the bent first bending part 1212 and the fourth region 1412 and too close to the adjacent opposite doped region.

[0246] Please refer to Figure 15 In some embodiments, the fourth region 1412 is recessed from the third region 1411 on the side facing the second region 1312, and the fourth region 1412 is protruded from the third region 1411 on the side away from the second region 1312.

[0247] In this way, the recessed fourth region 1412 cooperates with the protruding second region 1312 to make full use of space, so that the arrangement of the doped region is more reasonable, which is conducive to better collecting carriers, and the fourth region 1412 corresponding to the first bending part 1212 is protruded from the third region 1411 provided with the first main part 1211, which can provide sufficient space for the bent first bending part 1212, and reduce the risk of short circuit caused by too small edge distance between the bent first bending part 1212 and the fourth region 1412 and too close to the adjacent opposite doped region.

[0248] Specifically, the fourth region 1412 has the same recess depth and protrusion depth. In this way, the fourth region 1412 has the same size in the second direction as the third region 1411, which is conducive to better carrier collection.

[0249] It can be understood that, in other embodiments, the recess depth of the fourth region 1412 can be greater than the protrusion depth, or less than the protrusion depth. This is not limited here.

[0250] Please refer to Figure 15 and Figure 16 In some embodiments, in the first direction, the maximum depth H2 of the side of the fourth region 1412 away from the second region 1312 protruding from the third region 1411 is 1 μm-500 μm. For example, 1 μm, 2 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm.

[0251] In this way, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is in a suitable range, which can avoid the risk of short circuit caused by the small edge distance between the first bending portion 1212 and the fourth region 1412 and the adjacent differently doped region, and can also avoid the poor carrier collection effect caused by the large protrusion depth.

[0252] Preferably, the maximum depth H2 of the side of the fourth region 1412 away from the second region 1312 protruding from the third region 1411 is 5 μm-190 μm. For example, 5 μm, 6 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 180 μm, 190 μm. In this way, the maximum depth of the fourth region 1412 protruding from the third region 1411 is further optimized, taking into account the risk of short circuit and carrier collection, and the overall effect is better.

[0253] Specifically, the third region 1411 and the fourth region 1412 have the same width. In this way, it is conducive to better carrier collection.

[0254] It can be understood that, in other embodiments, the width W4 of the fourth region 1412 can be less than the width W3 of the third region 1411, as shown in Figure 17 , or the width W4 of the fourth region 1412 can be greater than the width W3 of the third region 1411, as shown in Figure 18 This is not limited here.

[0255] Please refer to Figure 6 and Figure 15In some embodiments, the second region 1312 protrudes from the first region 1311 towards one side of the fourth region 1412, and the difference between the maximum protruding depth H1 of the second region 1312 from the first region 1311 and the maximum protruding depth H2 of the fourth region 1412 from the third region 1411 is 50-200 μm in the first direction. For example, 50 μm, 52 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm.

[0256] In this way, the difference between the maximum protruding depth of the second region 1312 and the maximum protruding depth of the fourth region 1412 is in a suitable range, which can avoid the fourth region 1412 having a maximum protruding depth close to the maximum protruding depth of the second region 1312 due to the difference being too small, and the adjacent differently doped regions needing to be recessed to avoid, which has a large process complexity. In addition, the difference being too large can cause the fourth region 1412 to have a small width, a poor effect of collecting carriers, and a large risk of short circuit.

[0257] Specifically, the maximum protruding depth H2 of the fourth region 1412 from the third region 1411 is the same as the maximum recessed depth of the fourth region 1412 from the third region 1411. In this way, the difference between the maximum protruding depth of the second region 1312 and the maximum recessed depth of the fourth region 1412 is in a suitable range, which can avoid the fourth region 1412 having a maximum recessed depth close to the maximum protruding depth of the second region 1312 due to the difference being too small, the fourth region 1412 having a small width, and a poor effect of collecting carriers. In addition, the difference being too large can cause the recess of the fourth region 1412 and the protrusion of the second region 1312 to be poorly matched, poor space utilization, and a poor effect of collecting carriers.

[0258] Please refer to Figure 16 , Figure 17 and Figure 18 In some embodiments, the first polarity fine grid 11 includes a third grid line 113, the third grid line 113 includes a second main body part 1131 and a second bending part 1132 connected to each other, the second main body part 1131 extends along the second direction, and the second bending part 1132 is arranged corresponding to the first connecting block 112 and bends from the second main body part 1131 to a direction away from the first connecting block 112. The first polarity doped region 13 includes a third doped region 132, the third doped region 132 includes a fifth region 1321 and a sixth region 1322, the fifth region 1321 is provided with the second main body part 1131 of the third grid line 113, and the sixth region 1322 is provided with the second bending part 1132 of the third grid line 113.

[0259] Therefore, the third doped region 132 corresponds to the third gate line 113, which facilitates the fabrication of the third gate line 113 on the third doped region 132 and facilitates the electrical connection between the third doped region 132 and the third gate line 113, thereby reducing the process difficulty, improving the fabrication efficiency, and reducing the cost.

[0260] Specifically, the fifth region 1321 is provided with the second main body part 1131 of the third gate line 113, which means that the second main body part 1131 of the third gate line 113 is in electrical contact with the fifth region 1321.

[0261] Specifically, the sixth region 1322 is provided with the second bending part 1132 of the third gate line 113, which means that the second bending part 1132 of the third gate line 113 is in electrical contact with the sixth region 1322.

[0262] Referring to Figure 18 and Figure 18 In some embodiments, the sixth region 1322 is recessed from the fifth region 1321 on the side facing the second region 1312. In this way, the recessed sixth region 1322 cooperates with the protruding fourth region 1412 to make full use of the space, so that the arrangement of the doped regions is more reasonable, which is conducive to better collection of carriers and improves the photoelectric conversion efficiency of the battery.

[0263] Referring to Figure 18 and Figure 18 In some embodiments, the sixth region 1322 is protruded from the fifth region 1321 on the side away from the second region 1312.

[0264] In this way, the sixth region 1322 corresponding to the second bending part 1132 is protruded from the fifth region 1321 provided with the second main body part 1131, which can provide sufficient space for the bent second bending part 1132, thereby reducing the risk of short circuit caused by the small edge distance between the bent second bending part 1132 and the sixth region 1322 and the too close to the adjacent doped region of the opposite type.

[0265] Referring to Figure 18 In some embodiments, the sixth region 1322 is recessed from the fifth region 1321 on the side facing the second region 1312, and the sixth region 1322 is protruded from the fifth region 1321 on the side away from the second region 1312.

[0266] In this way, it can cooperate with the protruding fourth region 1412 to make full use of the space, so that the arrangement of the doped regions is more reasonable, which is conducive to better collection of carriers, and it can also provide sufficient space for the bent second bending part 1132, thereby reducing the risk of short circuit caused by the small edge distance between the bent second bending part 1132 and the sixth region 1322 and the too close to the adjacent doped region of the opposite type.

[0267] Specifically, the sixth region 1322 has the same recess depth and protrusion depth. In this way, the sixth region 1322 has the same size in the second direction as the fifth region 1321, which is conducive to better collection of carriers.

[0268] It can be understood that, in other embodiments, the recess depth of the sixth region 1322 can be greater than the protrusion depth, or can be less than the protrusion depth. This is not limited here.

[0269] Please refer to Figure 18 In some embodiments, the fourth region 1412 protrudes from the third region 1411 on the side away from the second region 1312, and the protrusion depth of the fourth region 1412 and the sixth region 1322 gradually decreases in the direction away from the second region 1312.

[0270] In this way, the protrusion depth gradually decreases in the direction away from the second region 1312, which can achieve a transition from protrusion to flatness.

[0271] Specifically, the protrusion depth of the fourth region 1412 is the maximum depth in the first direction on the side of the fourth region 1412 away from the second region 1312 and protruding from the third region 1411 in the second doping region 141, that is, H2 shown in FIG. 2. Figure 19 The protrusion depth of the sixth region 1322 is the maximum depth in the first direction on the side of the sixth region 1322 away from the second region 1312 and protruding from the fifth region 1321 in the third doping region 132, that is, H3 shown in FIG. 2. Figure 8

[0272] In Figure 19 In the example of FIG. 2, the first doping region 131, the second doping region 141, the third doping region 132, and the second doping region 141 are arranged in sequence in the direction away from the edge, and the corresponding protrusion depths gradually decrease.

[0273] Please refer to Figure 8 In some embodiments, for adjacent second doping regions 141 and third doping regions 132, the fourth region 1412 and the sixth region 1322 satisfy the following formula: 50 μm≤H2-H3≤200 μm; Wherein, H2 is the maximum depth in the first direction on the side of the fourth region 1412 away from the second region 1312 and protruding from the third region 1411 in the second doping region 141, and H3 is the maximum depth in the first direction on the side of the sixth region 1322 away from the second region 1312 and protruding from the fifth region 1321 in the third doping region 132.

[0274] ​In this way, the difference between the protrusion depths of the adjacent second doped region 141 and the third doped region 132 is in a proper range, which can avoid the situation that the difference is too small, and thus more doped regions need to be protruded to realize the transition from the bending to the gentle, which increases the process complexity and reduces the production efficiency. In addition, the situation that the difference is too large can also be avoided, in which the protrusion depth of one doped region is not enough, and the distance between the corresponding bending part and the edge of the doped region is close, which increases the short circuit risk.

[0275] Specifically, the value of H2-H3 is, for example, 50 μm, 52 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 150 μm, 180 μm, 200 μm.

[0276] In some embodiments, each row of the first doped regions 131 is continuous. In this way, each row of the first doped regions 131 is not interrupted, so that the power of the back contact cell 10 is better.

[0277] In some embodiments, each row of the second doped regions 141 is continuous. In this way, each row of the second doped regions 141 is not interrupted, so that the power of the back contact cell 10 is better.

[0278] In some embodiments, the doped region closest to the edge of the silicon substrate 101 is a P region. In this way, the area of the P region can be increased by using the space of the edge, so that the area of the P region is large, which is convenient for collecting carriers.

[0279] It can be understood that, in other embodiments, the doped region closest to the edge of the silicon substrate 101 can also be an N region.

[0280] Please refer to Figure 19 and Figure 19 In some embodiments, the second polarity fine grid 12 includes a fourth grid line 122, and the fourth grid line 122 is provided with a second connecting block 123, and the width of the second connecting block 123 is greater than the width of the fourth grid line 122. The second polarity doped region 14 includes a fourth doped region 142, and the fourth doped region 142 includes a seventh region 1421 and an eighth region 1422, the seventh region 1421 is provided with the fourth grid line 122, and the eighth region 1422 corresponds to the second connecting block 123.

[0281] In this way, the fourth doped region 142 corresponds to the fourth grid line 122, which is convenient for manufacturing the fourth grid line 122 on the fourth doped region 142, and is conducive to reducing the process difficulty, improving the manufacturing efficiency and reducing the cost.

[0282] Specifically, “the seventh region 1421 is provided with the fourth grid line 122” means that the fourth grid line 122 is in electrical contact with the seventh region 1421.

[0283] Specifically, "the eighth region 1422 corresponds to the second connecting block 123" means that, in the thickness direction of the back contact battery 10, the projection of the second connecting block 123 on the same plane as the eighth region 1422 at least partially overlaps. The second connecting block 123 can be in electrical contact with the eighth region 1422. It can also be electrically isolated from the eighth region 1422.

[0284] Please refer to Figure 20 and Figure 20 In some embodiments, the fourth doped region 142 and the second doped region 141 are the same second polarity doped region 14. In this way, integrating the fourth region 1412 and the eighth region 1422 in the same second polarity doped region 14 can make the connection stability of the second electrical connection there stronger. Moreover, design and production can be concentrated, which is conducive to improving production efficiency.

[0285] Please note that in the case of the fourth doped region 142 and the second doped region 141 being the same second polarity doped region 14, the fourth doped region 142 and the second doped region 141 can be regarded as part of the second polarity doped region 14, respectively.

[0286] It can be understood that in other examples, the fourth doped region 142 and the second doped region 141 can also be different second polarity fine grids 12. This is not limited here. Please refer to Figure 21 In some embodiments, the eighth region 1422 is electrically connected with the second connecting block 123, and the eighth region 1422 protrudes from the seventh region 1421.

[0287] In this way, the eighth region 1422 corresponding to the second connecting block 123 protrudes from the seventh region 1421 provided with the fourth grid line 122, which can provide sufficient space for the second connecting block 123 with a larger width. Moreover, in the case where the second connecting block 123 is arranged in the eighth region 1422 and in electrical contact with the eighth region 1422, the risk of short circuit caused by the small edge distance between the second connecting block 123 with a larger width and the eighth region 1422 and the adjacent opposite doped region can be reduced.

[0288] Specifically, the eighth region 1422 can protrude from the seventh region 1421 on one side towards the edge of the back contact battery 10, or the eighth region 1422 can protrude from the seventh region 1421 on one side away from the edge of the back contact battery 10, or both sides of the eighth region 1422 can protrude from the seventh region 1421. This is not limited here.

[0289] It can be understood that in other embodiments, the eighth region 1422 can also be aligned with the seventh region 1421. The eighth region 1422 can also be recessed from the seventh region 1421. This is not limited here.

[0290] Please refer toFigure 22 In some embodiments, the eighth region 1422 protrudes from the seventh region 1421 by a maximum depth H4 of 5-290 μm. For example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, 290 μm.

[0291] In this way, the maximum depth H4 of the eighth region 1422 protruding from the seventh region 1421 is in a suitable range, which can avoid insufficient setting area of the second connecting block 123 due to too small depth, and can also avoid the disadvantage of collecting carriers of another polarity due to too large depth.

[0292] In some embodiments, each row of the fourth doped regions 142 is continuous. In this way, each row of the fourth doped regions 142 is not interrupted, so that the power of the back contact cell 10 is better.

[0293] Please refer to Figure 22 In some embodiments, the fourth gate line 122 includes a third main body portion 1221 and a third bending portion 1222 connected to each other, the third main body portion 1221 extends along the second direction, the third bending portion 1222 bends from the third main body portion 1221 to a direction away from the edge of the silicon substrate 101, and the second connecting block 123 is arranged on the third bending portion 1222. The fourth doped region 142 includes a ninth region 1423, and the ninth region 1423 is arranged on the third bending portion 1222.

[0294] In this way, the ninth region 1423 of the fourth doped region 142 corresponds to the third bending portion 1222 of the fourth gate line 122, which facilitates the manufacturing of the fourth gate line 122 on the fourth doped region 142, and is conducive to reducing the process difficulty, improving the manufacturing efficiency and reducing the cost.

[0295] Please refer to Figure 23 In some embodiments, the ninth region 1423 protrudes from the seventh region 1421 on a side away from the eighth region 1422.

[0296] In this way, the ninth region 1423 corresponding to the third bending portion 1222 protrudes from the seventh region 1421 where the third main body portion 1221 is arranged, which can provide sufficient space for the bent third bending portion 1222, and reduce the short circuit risk caused by too small edge distance between the bent third bending portion 1222 and the ninth region 1423 and too close to the adjacent opposite doped region.

[0297] Please refer to Figure 24 and Figure 25In some embodiments, the first polarity fine grid 11 is a positive grid line, the first polarity fine grid 11 includes a fifth grid line 114 and a sixth grid line 115, the sixth grid line 115 has a spacing L2 with the adjacent second polarity fine grid 12, which is greater than a spacing L1 of the fifth grid line 114 with the adjacent second polarity fine grid 12.

[0298] Thus, since the spacing of the sixth grid line 115 with the adjacent opposite polarity fine grid in the first direction is greater than the spacing of the fifth grid line 114 with the adjacent opposite polarity fine grid, sufficient space can be left for the silicon substrate 101 to set the anti-hot spot structure, and the risk of short circuit caused by the contact of fine grids with different polarities and doping regions is reduced.

[0299] Specifically, the spacing L2 of the sixth grid line 115 with the adjacent second polarity fine grid 12 is greater than the spacing L1 of the fifth grid line 114 with the adjacent second polarity fine grid 12, that is, the spacing of the sixth grid line 115 with the adjacent second polarity fine grid 12 at at least one place is greater than the spacing of the fifth grid line 114 with the adjacent second polarity fine grid 12 at at least one place. It can be that the minimum spacing L2 of the sixth grid line 115 with the adjacent second polarity fine grid 12 is greater than the maximum spacing L1 of the fifth grid line 114 with the adjacent second polarity fine grid 12; it can also be that the maximum spacing L2 of the sixth grid line 115 with the adjacent second polarity fine grid 12 is greater than the maximum spacing L1 of the fifth grid line 114 with the adjacent second polarity fine grid 12. This is not limited here.

[0300] Please refer to Figure 21 and Figure 22 , the first polarity doping region 13 includes a fifth doping region 133, the second polarity doping region 14 includes a sixth doping region 143, the fifth doping region 133 includes an overlapping part 1331 and a non-overlapping part 1332, the sixth doping region 143 includes a body 1431 and a protruding part 1432, the body 1431 is spaced from the fifth doping region 133, the protruding part 1432 protrudes from the body 1431 and overlaps with the overlapping part 1331; the sixth grid line 115 is arranged on the non-overlapping part 1332.

[0301] Thus, the protruding part 1432 of the sixth doping region 143 overlaps with the overlapping part 1331 of the fifth doping region 133, so that the anti-hot spot structure can be formed, the reverse bias can be reduced, the heating power of the back contact cell 10 when it is shaded in the assembly and becomes a load can be reduced, and thus the hot spot risk can be reduced. At the same time, the fifth grid line 114 is arranged on the non-overlapping part 1332, and the risk of short circuit caused by the contact of fine grids with different polarities and doping regions is reduced.

[0302] Specifically, the first sub-grid 114 is arranged outside the non-overlapping part 1332.

[0303] Specifically, the body 1431 and the fifth doping region 133 can be spaced by a groove. The body 1431 and the non-overlapping part 1332 can be spaced by a dielectric film layer 1003. This is not limited here.

[0304] Specifically, the convex portion 1432 can be in the form of a rectangle, a circle, a square, a triangle, or other forms. No limitation is made herein.

[0305] Specifically, the sixth gate line 115 is arranged at the non-overlapping portion 1332, i.e., the sixth gate line 115 is in electrical contact with the non-overlapping portion 1332.

[0306] Please refer to Figure 24 and Figure 21 In some embodiments, the sixth gate line 115 is provided with a third connecting block 116, and the width L3 of the third connecting block 116 is greater than the width L4 of the sixth gate line 115.

[0307] In this way, the contact area between the third connecting block 116 and the first electrical connecting member can be increased, the pulling force can be increased, the risk of the first electrical connecting member falling off from the back contact battery 10 can be reduced, and the connection stability of the back contact battery 10 and the first electrical connecting member can be improved.

[0308] Specifically, the sixth gate line 115 is provided with the third connecting block 116. That is, the third connecting block 116 is connected with the sixth gate line 115.

[0309] Specifically, the third connecting block 116 can contact the first polarity doped layer through the dielectric film layer 1003. The third connecting block 116 and the first polarity doped layer can also be isolated by the dielectric film layer 1003. The third connecting block 116 can be made together with the sixth gate line 115. The third connecting block 116 can also be made step by step with the sixth gate line 115.

[0310] In one example, the third connecting block 116 and the sixth gate line 115 are made of the same paste, and both burn through the dielectric film layer 1003 to contact the first polarity doped layer. In another example, the paste of the sixth gate line 115 burns through the dielectric film layer 1003 to contact the first polarity doped layer, and the paste of the third connecting block 116 does not burn through the dielectric film layer 1003.

[0311] In some embodiments, the third connecting block 116 includes at least one of a pad and a gate line segment. In this way, the third connecting block 116 has various forms, which is beneficial to meet more production scenarios and needs. For example, the third connecting block 116 includes a pad. For another example, the third connecting block 116 includes a gate line segment. For another example, the third connecting block 116 includes a pad and a gate line segment. It can be understood that, in the case where the third connecting block 116 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the first polarity doped layer. In the case where the third connecting block 116 includes a pad, the pad can pass through the dielectric film layer 1003 to contact the first polarity doped layer, or can be isolated from the first polarity doped layer by the dielectric film layer 1003.

[0312] Specifically, the third connecting block 116 is configured to connect the first electrical connecting member.

[0313] Further, the third connecting block 116 and the first electrical connecting member can be electrically connected by at least one of conductive adhesive, direct soldering, solder paste soldering, and physical contact. No limitation is made herein.

[0314] Further, the entire area of the third connecting block 116 can be connected with the first electrical connecting member. Alternatively, part of the area of the third connecting block 116 can be connected with the first electrical connecting member.

[0315] Specifically, the width L3 of the third connecting block 116 refers to the dimension of the third connecting block 116 in the first direction. The width L3 of the third connecting block 116 can be the same everywhere, different everywhere, or partially the same. The width L4 of the sixth gate line 115 refers to the dimension of the sixth gate line 115 in the first direction. The width L4 of the sixth gate line 115 can be the same everywhere, different everywhere, or partially the same.

[0316] Specifically, the width L3 of the third connecting block 116 is greater than the width L4 of the sixth gate line 115, i.e., the width of at least one location of the third connecting block 116 is greater than the width of at least one location of the sixth gate line 115. It can be that the minimum width of the third connecting block 116 is greater than the maximum width of the sixth gate line 115, or that the maximum width of the third connecting block 116 is greater than the maximum width of the sixth gate line 115, or that the maximum width of the third connecting block 116 is greater than the width of the location where the sixth gate line 115 is connected with the third connecting block 116. No limitation is made herein.

[0317] In some embodiments, the third connecting block is formed with a third hollow region. In this way, the material of the third connecting block can be reduced while the coverage of the third connecting block is ensured, which is conducive to reducing the cost while improving the connection stability.

[0318] In some embodiments, the third connecting block is in a solid form. In this way, the area of the third connecting block can be increased as much as possible, thereby increasing the contact area of the third connecting block and the electrical connecting member, increasing the pulling force, reducing the risk of the electrical connecting member falling off from the back contact battery 10, and improving the connection stability of the back contact battery 10 and the electrical connecting member.

[0319] In some embodiments, the third connecting block is in a rectangular shape. It can be understood that in other embodiments, the third connecting block can be in a circular shape, an annular shape, an elliptical shape, a triangular shape, a racetrack shape, or other shapes. No limitation is made herein on the specific shape of the third connecting block.

[0320] Please refer to Figure 22 , Figure 24 and Figure 21In some embodiments, the sixth gate line 115 has a first pitch L2 with the adjacent second polarity fine gate 12, and the fifth gate line 114 has a second pitch L1 with the adjacent second polarity fine gate 12, and the difference between the first pitch and the second pitch is 0.05mm-0.1mm. For example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm.

[0321] In this way, the difference between the first pitch and the second pitch is in a suitable range, which can avoid insufficient space for setting the anti-hot spot structure caused by too small difference, and can avoid poor effect of collecting carriers caused by too large difference.

[0322] Specifically, the pitch L2 of the sixth gate line 115 with the adjacent second polarity fine gate 12 can be equal everywhere, can be unequal everywhere, or can be partially equal and partially unequal.

[0323] Specifically, the pitch L1 of the fifth gate line 114 with the adjacent second polarity fine gate 12 can be equal everywhere, can be unequal everywhere, or can be partially equal and partially unequal.

[0324] Specifically, the difference between the first pitch and the second pitch can be a fixed value within 0.05mm-0.1mm, or can fluctuate within 0.05mm-0.1mm.

[0325] Please refer to Figure 22 , Figure 24 and Figure 21 In some embodiments, the pitch L2 of the sixth gate line 115 with the adjacent second polarity fine gate 12 is 0.2mm-0.8mm. For example, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm.

[0326] In this way, the pitch L2 of the sixth gate line 115 with the adjacent second polarity fine gate 12 is in a suitable range, which can avoid insufficient space for setting the anti-hot spot structure caused by too small pitch, and can avoid poor effect of collecting carriers caused by too large pitch.

[0327] Specifically, the pitch L2 of the sixth gate line 115 with the adjacent second polarity fine gate 12 can be a fixed value within 0.2mm-0.8mm, or can fluctuate within 0.2mm-0.8mm.

[0328] Please refer to Figure 21 , Figure 23 and Figure 23 In some embodiments, the pitch L1 of the fifth gate line 114 with the adjacent second polarity fine gate 12 is a second pitch, and the second pitch is 0.1mm-0.7mm.

[0329] In this way, the fifth grid line 114 and the adjacent second polarity fine grid 12 have a suitable interval L1, which can avoid the grid line being too dense and the cost being too high due to the interval being too small, and can also avoid the effect of reducing the hot spot risk being too poor due to the interval being too large.

[0330] Specifically, the interval L1 between the fifth grid line 114 and the adjacent second polarity fine grid 12 can be a fixed value within 0.1mm-0.7mm, or can fluctuate within 0.1mm-0.7mm.

[0331] Please refer to Figure 23 In some embodiments, the number of sixth grid lines 115 is a plurality, and the number of fine grids between two adjacent sixth grid lines 115 is 8-35. For example, 8, 10, 12, 15, 19, 20, 22, 25, 28, 30, 32, 35.

[0332] In this way, the number of fine grids between two adjacent sixth grid lines 115 is within a suitable range, which can avoid the number of sixth grid lines 115 being too large and the manufacturing efficiency being too low due to the number of fine grids between two adjacent sixth grid lines 115 being too small, and can also avoid the effect of reducing the hot spot risk being too poor due to the number of fine grids between two adjacent sixth grid lines 115 being too large.

[0333] Specifically, in the back contact battery 10, the number of sixth grid lines 115 can be a plurality, forming a plurality of pairs of adjacent sixth grid lines 115. The number of fine grids between the plurality of pairs of adjacent sixth grid lines 115 can be the same, different, or partially the same and partially different.

[0334] Please refer to Figure 23 In some embodiments, the interval L5 between two adjacent sixth grid lines 115 is 6mm-16.8mm. For example, 6mm, 7mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 16.8mm.

[0335] In this way, the interval L5 between two adjacent sixth grid lines 115 is within a suitable range, which can avoid the number of sixth grid lines 115 being too large and the manufacturing efficiency being too low due to the interval being too small, and can also avoid the effect of reducing the hot spot risk being too poor due to the interval being too large.

[0336] Specifically, in the back contact battery 10, the number of sixth grid lines 115 can be a plurality, forming a plurality of pairs of adjacent sixth grid lines 115. The interval L5 between the plurality of pairs of adjacent sixth grid lines 115 can be the same, different, or partially the same and partially different.

[0337] Please refer to Figure 23 and 25In some embodiments, the protrusion 1432 protrudes from the body 1431 by a depth L6 in the first direction of 40-500 μm. For example, 40 μm, 42 μm, 44 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 480 μm, 500 μm.

[0338] In this way, the depth L6 by which the protrusion 1432 protrudes from the body 1431 is in a suitable range, which can avoid the effect of too small protrusion depth leading to insufficient contact area with the fifth doped region 133 or even difficulty in contacting the fifth doped region 133, and poor reduction of hot spot risk, and can also avoid too large protrusion depth leading to too close distance between the sixth gate line 115 and the sixth gate line 115, and large short circuit risk.

[0339] Specifically, the depth L6 by which the protrusion 1432 protrudes from the body 1431 can be a fixed value within 40-500 μm, or can fluctuate within 40-500 μm. This is not limited here.

[0340] Please refer to Figure 28 and 25 , the width L7 of the overlapping portion 1331 is 45-500 μm. For example, 45 μm, 48 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 480 μm, 500 μm.

[0341] In this way, the width L7 of the overlapping portion 1331 is in a suitable range, which can avoid the effect of too small width leading to poor reduction of hot spot risk, and can also avoid too large width leading to too close distance between the sixth gate line 115 and the sixth gate line 115, and large short circuit risk.

[0342] Specifically, the width L7 of the overlapping portion 1331 refers to the size of the overlapping portion 1331 in the first direction.

[0343] Specifically, the width L7 of the overlapping portion 1331 can be a fixed value within 45-500 μm, or can fluctuate within 45-500 μm. This is not limited here.

[0344] Please refer to Figure 29 and 25 , the length L8 of the overlapping portion 1331 is 10-2000 μm. For example, 10 μm, 12 μm, 50 μm, 100 μm, 300 μm, 500 μm, 800 μm, 1000 μm, 1200 μm, 1500 μm, 1800 μm, 2000 μm.

[0345] In this way, the length L8 of the overlapping portion 1331 is in a proper range, and the effect of reducing the hot spot risk is poor when the length is too large or too small.

[0346] Specifically, the length L8 of the overlapping portion 1331 can be a fixed value within 10 μm-2000 μm, or can fluctuate within 10 μm-2000 μm. No limitation is made herein.

[0347] Please refer to Figure 30 and 25 The width ratio of the overlapping portion 1331 to the fifth doped region 133 is less than or equal to 85%. For example, 85%, 83%, 80%, 75%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 8%, 5%, 1%, 0.1%.

[0348] In this way, the width ratio of the overlapping portion 1331 to the fifth doped region 133 is in a proper range, and the effect of reducing the hot spot risk is poor when the ratio is too small, and the distance between the sixth gate line 115 and the opposite doped region is too close, and the short circuit risk is large when the ratio is too large.

[0349] Specifically, the width of the fifth doped region 133 refers to the size of the fifth doped region 133 in the first direction.

[0350] Please refer to Figure 28 and 25 The distance L9 between the protruding portion 1432 and the third connecting block 116 is greater than or equal to 50 μm. For example, 50 μm, 52 μm, 60 μm, 100 μm, 200 μm, 300 μm, 400 μm, 480 μm, 500 μm.

[0351] In this way, the distance L9 between the protruding portion 1432 and the third connecting block 116 is in a proper range, and the short circuit risk is large when the distance is too small, and the effect of reducing the hot spot risk is poor when the distance is too large.

[0352] Specifically, the distance L9 between the protruding portion 1432 and the third connecting block 116 can be a fixed value within the range greater than or equal to 50 μm, or can fluctuate within the range greater than or equal to 50 μm. No limitation is made herein.

[0353] Please refer to Figure 29 , Figure 30 and Figure 28 In some embodiments, the second polarity fine grid 12 includes a second gate line 121 arranged in the third region 1411 and the fourth region 1412. In this way, the second gate line 121 is arranged in the third region 1411 and the fourth region 1412, so as to facilitate the conduction of the carriers collected in the third region 1411 and the fourth region 1412.

[0354] For example, referring to Figure 29 , Figure 30 and Figure 28 , in some embodiments, the first polar fine grid 11 includes a first grid line 111, the first grid line 111 is provided with a first connecting block 112, the width of the first connecting block 112 is greater than the width of the first grid line 111, and the length of the first connecting block 112 is greater than or equal to 100 μm; the first region 1311 is provided with the first grid line 111, and the second region 1312 corresponds to the first connecting block 112; the second grid line 121 includes a fourth main part 1213 and a fifth main part 1214 connected to each other, the fourth main part 1213 and the fifth main part 1214 both extend along a second direction, the second direction intersects the first direction, the fifth main part 1214 is provided corresponding to the first connecting block 112, and is collinear with the fourth main part 1213 in the second direction; the third region 1411 is provided with the fourth main part 1213, and the fourth region 1412 is provided with the fifth main part 1214.

[0355] In this way, while the first grid line 111 is provided with the first connecting block 112 with a larger width, the fifth main part 1214 corresponding to the first connecting block 112 in the second grid line 121 is collinear with the fourth main part 1213, so that the second grid line 121 can better utilize the space of the second doped region and better collect carriers.

[0356] Specifically, "the fifth main part 1214 is provided corresponding to the first connecting block 112" means that at least one straight line extending along the first direction passes through the fifth main part 1214 and the first connecting block 112 at the same time.

[0357] Specifically, "collinear with the fourth main part 1213 in the second direction" means that at least one straight line extending along the second direction passes through the fifth main part 1214 and the fourth main part 1213 at the same time.

[0358] For example, referring to Figure 29 , in some embodiments, the second grid line 121 is in a straight line shape, and the width of the fourth main part 1213 and the fifth main part 1214 is the same. In this way, the structure of the second grid line 121 is relatively simple and standardized, which is convenient for manufacturing and is conducive to improving the manufacturing efficiency and reducing the production cost.

[0359] For example, referring to Figure 30In some embodiments, the width of the fourth body part 1213 is smaller than the width of the fifth body part 1214. In this way, the width of the fifth body part 1214 corresponding to the first connecting block 112 is larger, reducing the risk of disconnection of the fifth body part 1214, avoiding the difficulty of maintenance of the disconnected fifth body part 1214 blocked by the solder strip after the solder strip is arranged. The explanations and descriptions related to the fifth body part 1214 can be referred to the first connecting block 112, and will not be repeated here to avoid redundancy.

[0360] Please refer to Figure 26 In some embodiments, the width of the fourth body part 1213 is larger than the width of the fifth body part 1214. In this way, the width of the fourth body part 1213 is larger, which is adapted to the third region 1411 with a larger width and can better collect carriers. At the same time, the width of the fifth body part 1214 is smaller, which is adapted to the fourth region 1412 with a smaller width, reducing the risk of the fifth body part 1214 exceeding the fourth region 1412 and contacting the second region 1312, the first gate line 111 or the first connecting block 112. The explanations and descriptions related to the fourth body part 1213 can be referred to the first connecting block 112, and will not be repeated here to avoid redundancy.

[0361] Figure 27 、 ​ and ​ In the corresponding text part, other explanations and descriptions of the first gate line 111, the second gate line 121 and other components can be referred to the foregoing, and will not be repeated here to avoid redundancy.

[0362] Please note that in the description of the present specification, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. For example, ​ and ​ combine the features of the foregoing embodiments or examples.

[0363] The battery assembly of the embodiments of the present application includes the back contact battery 10 of any one of the foregoing.

[0364] The battery assembly of the embodiments of the present application, since the width of the first connecting block 112 is larger than the width of the first gate line 111 and the length is greater than or equal to 100 μm in the back contact battery 10, the contact area of the first connecting block 112 and the electrical connecting piece can be increased, the tension can be increased, the risk of the electrical connecting piece falling off the back contact battery 10 can be reduced, and the connection stability of the back contact battery 10 and the electrical connecting piece can be improved. At the same time, since the first bending part 1212 of the second gate line 121 bends away from the first connecting block 112 from the first body part 1211, more space can be provided for the first connecting block 112 with a larger width, the first connecting block 112 can be widened, and the risk of short circuit caused by too small spacing between electrodes of two polarities can be reduced.

[0365] In the embodiment, the plurality of back contact cells 10 in the battery assembly can be sequentially connected in series to form a battery string, so as to realize the series connection of the current. For example, the connection of the battery pieces can be realized by means of welding strip (bus bar, interconnecting strip), conductive back plate, etc.

[0366] It can be understood that in such an embodiment, the battery assembly can further include a metal frame, a back plate, photovoltaic glass, and a glue film. The glue film can be filled between the front and back surfaces of the back contact cell 10, photovoltaic glass, adjacent battery pieces, etc., and can be a transparent glue with good light transmission performance and aging resistance, for example, the glue film can be EVA glue film or POE glue film, which can be selected according to actual conditions, and is not limited herein.

[0367] The photovoltaic glass can be covered on the glue film on the front surface of the back contact cell 10. The photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of the super white glass can be more than 92%, which can protect the back contact cell 10 without affecting the efficiency of the back contact cell 10 as much as possible. Meanwhile, the glue film can bond the photovoltaic glass and the back contact cell 10 together, and the presence of the glue film can seal and insulate the back contact cell 10 and prevent water and moisture.

[0368] The back plate can be attached to the glue film on the back surface of the back contact cell 10. The back plate can protect and support the back contact cell 10, has reliable insulation, water resistance, and aging resistance, and can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite glue film, etc., which can be set according to specific conditions, and is not limited herein. The whole composed of the back plate, the back contact cell 10, the glue film, and the photovoltaic glass can be arranged on the metal frame, which is the main external supporting structure of the whole battery assembly, and can stably support and install the battery assembly. For example, the metal frame can be used to install the battery assembly at the required installation position.

[0369] The photovoltaic system of the embodiment of the application includes the above-mentioned battery assembly.

[0370] The photovoltaic system of the embodiment of the present application can increase the contact area of the first connecting block 112 and the electrical connecting member, increase the pulling force, reduce the risk of the electrical connecting member falling off from the back contact cell 10, and improve the connection stability of the back contact cell 10 and the electrical connecting member, because the width of the first connecting block 112 is greater than the width of the first grid line 111 and the length is greater than or equal to 100 μm in the back contact cell 10. Meanwhile, the first connecting block 112 with a larger width can be provided with more space because the first bending part 1212 in the second grid line 121 bends away from the first connecting block 112 from the first main part 1211, which facilitates the widening of the first connecting block 112 and reduces the risk of short circuit caused by too small spacing between electrodes of two polarities.

[0371] In the embodiment, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc., and can also be applied in a device or apparatus using solar energy to generate electricity, such as a user solar power source, a solar street lamp, a solar car, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields requiring solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a combiner box, and an inverter, the photovoltaic array can be an array combination of a plurality of cell assemblies, for example, a plurality of cell assemblies can form a plurality of photovoltaic arrays, the photovoltaic array is connected to the combiner box, the combiner box can combine the current generated by the photovoltaic array, the combined current flows through the inverter to convert into alternating current required by a power grid, and then is connected to a power network to realize solar power supply.

[0372] In the description of the present specification, the description of the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0373] In addition, the above is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A back-contact battery, characterized in that, It includes a silicon substrate, a plurality of first polar fine gates and a plurality of second polar fine gates, wherein the first polar fine gates and the second polar fine gates are spaced apart, disposed on the silicon substrate, and arranged along a first direction; The silicon substrate includes a plurality of first polar doped regions and a plurality of second polar doped regions arranged along the first direction. The first polar doped regions are provided with first polar fine gates, and the second polar doped regions are provided with second polar fine gates. The first polar doped region includes a first doped region, which includes a first region and a second region, with the second region protruding from the first region; the second polar doped region includes a second doped region, which includes a third region and a fourth region, with the fourth region recessed from the third region on the side facing the second region.

2. The back contact battery according to claim 1, characterized in that, The first polar fine gate includes a first gate line, the first gate line is provided with a first connecting block, the width of the first connecting block is greater than the width of the first gate line, and the length of the first connecting block is greater than or equal to 100 μm; the first region is provided with the first gate line, and the second region corresponds to the first connecting block; The second polar fine grid includes a second grid line, the second grid line includes a connected first main body portion and a first bent portion, the first main body portion extends along a second direction, the second direction intersects the first direction, the first bent portion is correspondingly disposed with the first connecting block, and bends from the first main body portion in a direction away from the first connecting block; the third region is provided with the first main body portion of the second grid line, and the fourth region is provided with the first bent portion of the second grid line.

3. The back contact battery according to claim 2, characterized in that, The difference between the width of the first connecting block and the width of the first gate line is 5μm-290μm.

4. The back contact battery according to claim 2, characterized in that, The maximum distance between the first bent portion and the first main body portion in the first direction is 5μm-290μm.

5. The back contact battery according to claim 2, characterized in that, The first gate line, the first connecting block, and the second gate line satisfy the following formula: -100μm≤w1-w2-d1≤100μm; Wherein, w1 is the width of the first connecting block, w2 is the width of the first grid line, and d1 is the maximum distance between the first bent portion and the first main body portion in the first direction.

6. The back contact battery according to claim 2, characterized in that, The first gate line is the first polar fine gate closest to the edge of the silicon substrate, and the distance between the first gate line and the edge is 0.4mm-1mm.

7. The back contact battery according to claim 2, characterized in that, The distance from the first connecting block to the edge is 0.4mm-50mm.

8. The back contact battery according to claim 2, characterized in that, The first polar fine grid includes a third grid line, the third grid line including a second main body portion and a second bent portion connected together, the second main body portion extending along the second direction, the second bent portion being disposed corresponding to the first connecting block, and bending from the second main body portion in a direction away from the first connecting block.

9. The back contact battery according to claim 8, characterized in that, Along the direction away from the first connecting block, the bending depth of the first bend and the second bend gradually decreases.

10. The back contact battery according to claim 8, characterized in that, For adjacent second and third gate lines, the first bend and the second bend satisfy the following formula: 50μm≤d1-d2≤150μm; Wherein, d2 is the maximum distance between the second bent portion and the second main body portion in the first direction, and d1 is the maximum distance between the first bent portion and the first main body portion in the first direction.

11. The back contact battery according to claim 2, characterized in that, The first grid line and the first connecting block disposed on the first grid line form a first conductive structure, and each row of the first conductive structure is continuous. And / or, each row of the second gate line is continuous.

12. The back contact battery according to claim 2, characterized in that, The first connection block includes at least one of pads and gate segments.

13. The back contact battery according to claim 2, characterized in that, The first connecting block has a hollow area; Alternatively, the first connecting block may be solid.

14. The back contact battery according to claim 2, characterized in that, The second polar fine gate includes a fourth gate line, the fourth gate line having a second connecting block, the width of the second connecting block being greater than the width of the fourth gate line.

15. The back contact battery according to claim 14, characterized in that, The difference between the width of the second connecting block and the width of the fourth gate line is 5μm-290μm.

16. The back contact battery according to claim 14, characterized in that, The difference between the area of ​​the first connecting block and the area of ​​the second connecting block is -400μm. 2 ~400μm 2 .

17. The back contact battery according to claim 14, characterized in that, The first polar grid line adjacent to the second connecting block is broken at the position corresponding to the second connecting block to avoid the second connecting block. In the second direction, the distance between the break point of the second connecting block and the first grid line is 0.2mm-1mm.

18. The back contact battery according to claim 14, characterized in that, The fourth gate line is the second polar fine gate closest to the edge of the silicon substrate, and the distance between the fourth gate line and the edge is greater than 0.7mm-1.3mm.

19. The back contact battery according to claim 14, characterized in that, The distance from the second connecting block to the edge of the silicon substrate is 0.7mm-50mm.

20. The back contact battery according to claim 14, characterized in that, The fourth gate line is the second polar fine gate closest to the edge of the silicon substrate, and the second connecting block is located on the side of the fourth gate line facing the edge.

21. The back contact battery according to claim 14, characterized in that, The second connecting block protrudes from the fourth gate line to both sides of the fourth gate line.

22. The back contact battery according to claim 14, characterized in that, The fourth gate line includes a connected third main body portion and a third bend portion. The third main body portion extends along the second direction, and the third bend portion bends from the third main body portion toward an edge away from the silicon substrate. The second connecting block is disposed on the third bend portion.

23. The back contact battery according to claim 22, characterized in that, The maximum distance between the third bent portion and the third main body portion in the first direction is 5μm-290μm.

24. The back contact battery according to claim 14, characterized in that, The fourth gate line and the second gate line are the same second polarity fine gate.

25. The back contact battery according to claim 14, characterized in that, The fourth gate line and the second connecting block disposed on the fourth gate line form a second conductive structure, and each row of the second conductive structure is continuous.

26. The back contact battery according to claim 14, characterized in that, The second connection block includes at least one of pads and gate segments.

27. The back contact battery according to claim 14, characterized in that, The second connecting block has a hollow area; Alternatively, the second connecting block may be solid.

28. The back contact battery according to claim 1, characterized in that, The second polar fine gate includes a second gate line, which is disposed in the third region and the fourth region.

29. The back contact battery according to claim 28, characterized in that, The first polar fine gate includes a first gate line, the first gate line is provided with a first connecting block, the width of the first connecting block is greater than the width of the first gate line, and the length of the first connecting block is greater than or equal to 100 μm; the first region is provided with the first gate line, and the second region corresponds to the first connecting block; The second grid line includes a fourth main body portion and a fifth main body portion connected together. The fourth main body portion and the fifth main body portion both extend along a second direction, which intersects with the first direction. The fifth main body portion is correspondingly disposed with the first connecting block and is collinear with the fourth main body portion in the second direction. The third region is provided with the fourth main body portion, and the fourth region is provided with the fifth main body portion.

30. The back contact battery according to claim 29, characterized in that, The second gate line is straight, and the fourth and fifth main body portions have the same width; Alternatively, the width of the fourth main body portion may be smaller than the width of the fifth main body portion.

31. The back contact battery according to claim 1, characterized in that, In the first direction, the maximum depth of the second region protruding from the first region is 5μm-290μm.

32. The back contact battery according to claim 1, characterized in that, The fourth region protrudes from the third region on the side opposite to the second region.

33. The back contact battery according to claim 32, characterized in that, In the first direction, the maximum depth of the fourth region protruding from the third region is 1μm-500μm.

34. The back contact battery according to claim 32, characterized in that, The second region protrudes from the first region on the side facing the fourth region, and in the first direction, the difference between the maximum depth of the second region protruding from the first region and the maximum depth of the fourth region protruding from the third region is 50μm-200μm.

35. The back contact battery according to claim 1, characterized in that, The first polar fine grid includes a third grid line, the third grid line includes a connected second main body portion and a second bent portion, the second main body portion extends along the second direction, and the second bent portion is correspondingly disposed with the first connecting block and bends from the second main body portion in a direction away from the first connecting block; The first polar doped region includes a third doped region, the third doped region includes a fifth region and a sixth region, the fifth region is provided with a second main body portion of the third gate line, and the sixth region is provided with a second bend portion of the third gate line.

36. The back contact battery according to claim 35, characterized in that, The sixth region protrudes from the fifth region on the side opposite to the second region.

37. The back contact battery according to claim 36, characterized in that, The fourth region protrudes from the third region on the side opposite to the second region, and the protrusion depth of the fourth region and the sixth region gradually decreases along the direction away from the second region.

38. The back contact battery according to claim 37, characterized in that, For adjacent second and third doped regions, the fourth and sixth regions satisfy the following formula: 50μm≤H2-H3≤200μm; Wherein, H2 is the maximum depth of the fourth region protruding from the third region on the side away from the second region in the first direction, and H3 is the maximum depth of the sixth region protruding from the fifth region on the side away from the second region in the first direction.

39. The back contact battery according to claim 1, characterized in that, The first doped region in each row is continuous; And / or, each row of the second doped region is continuous.

40. The back contact battery according to claim 1, characterized in that, The doped region closest to the edge of the silicon substrate is the P-region.

41. The back contact battery according to claim 1, characterized in that, The second polar fine gate includes a fourth gate line, the fourth gate line having a second connecting block, the width of the second connecting block being greater than the width of the fourth gate line; The second polar doped region includes a fourth doped region, which includes a seventh region and an eighth region. The seventh region is provided with the fourth gate line, and the eighth region corresponds to the second connection block.

42. The back contact battery according to claim 41, characterized in that, The eighth region protrudes from the seventh region.

43. The back contact battery according to claim 42, characterized in that, The maximum depth of the eighth region protruding from the seventh region is 5μm-290μm.

44. The back contact battery according to claim 41, characterized in that, The fourth doped region and the second doped region are the same second polar doped region.

45. The back contact battery according to claim 41, characterized in that, The fourth doped region in each row is continuous.

46. ​​The back contact battery according to claim 41, characterized in that, The fourth gate line includes a connected third main body portion and a third bend portion. The third main body portion extends along the second direction, and the third bend portion bends from the third main body portion toward an edge away from the silicon substrate. The second connecting block is disposed on the third bend portion. The fourth doped region includes a ninth region, and the ninth region is provided with the third bend.

47. The back contact battery according to claim 46, characterized in that, The ninth region protrudes from the seventh region on the side opposite to the eighth region.

48. The back contact battery according to claim 1, characterized in that, The first polar fine gate is a positive gate line. The first polar fine gate includes a fifth gate line and a sixth gate line. The distance between the sixth gate line and the adjacent second polar fine gate is greater than the distance between the fifth gate line and the adjacent second polar fine gate.

49. The back contact battery according to claim 48, characterized in that, The sixth gate line is provided with a third connecting block, the width of which is greater than the width of the sixth gate line.

50. The back contact battery according to claim 48, characterized in that, The distance between the sixth gate line and the adjacent second polar fine gate is the first distance, and the distance between the fifth gate line and the adjacent second polar fine gate is the second distance. The difference between the first distance and the second distance is 0.05-0.1mm.

51. A battery assembly, characterized in that, Includes the back contact battery as described in any one of claims 1-50.

52. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 51.

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