Back contact battery, battery assembly and photovoltaic system

Abstract

The utility model 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 which comprises a first polarity doped region and a second polarity doped region which are arranged along a first direction; the first polarity fine grid and the second polarity fine grid are respectively arranged in the first polarity doped region and the second polarity doped region and are arranged along the first direction, and the first polarity fine grid and the second polarity fine grid are spaced; the first polarity fine grid is a positive grid line and comprises a first auxiliary grid and a second auxiliary grid; the first polarity doped region comprises a first doped region, the second polarity doped region comprises a second doped region, the first doped region comprises an overlapping part and a non-overlapping part, the second doped region comprises a body and a protruding part, the body is spaced from the first doped region, and the protruding part protrudes from the body and is overlapped with the overlapping part; the second auxiliary grid is arranged on the non-overlapping part, and the distance between the second auxiliary grid and the adjacent second polarity fine grid is larger than the distance between the first auxiliary grid and the adjacent second polarity fine grid.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and particularly relates to a back contact cell, a cell module and a photovoltaic system. BACKGROUND

[0002] Solar cell power generation is a sustainable clean energy source, which can convert sunlight into electricity by using the photovoltaic effect of a semiconductor p-n junction. In the related art, the solar cell is easily shielded to cause hot spot effect, resulting in poor power generation efficiency. Therefore, how to improve the hot spot effect of the solar cell has become a problem to be solved. CONTENT

[0003] The application provides a back contact cell, a cell module and a photovoltaic system, and aims to solve the problem of how to improve the hot spot effect of the solar cell.

[0004] The back contact cell provided by the application comprises:

[0005] A silicon substrate comprising a plurality of first polarity doped regions and a plurality of second polarity doped regions arranged along a first direction;

[0006] A plurality of first polarity fine grids and a plurality of second polarity fine grids are arranged in the first polarity doped regions and the second polarity doped regions respectively, and are arranged along the first direction, wherein the first polarity fine grids and the second polarity fine grids are spaced apart;

[0007] The first polarity doped regions comprise first doped areas, the second polarity doped regions comprise second doped areas, the first doped areas comprise overlapping parts and non-overlapping parts, the second doped areas comprise a main body and a protruding part, the main body is spaced apart from the first doped areas, and the protruding part protrudes from the main body and overlaps with the overlapping parts; the first polarity fine grids are positive grid lines, and comprise first sub-grids and second sub-grids;

[0008] The second sub-grids are arranged in the non-overlapping parts, the first sub-grids are arranged outside the non-overlapping parts, and the spacing between the second sub-grids and adjacent second polarity fine grids is greater than the spacing between the first sub-grids and adjacent second polarity fine grids.

[0009] Specifically, the spacing between the second sub-grids and adjacent second polarity fine grids is a first spacing, the spacing between the first sub-grids and adjacent second polarity fine grids is a second spacing, and the difference between the first spacing and the second spacing is 0.05-0.1 mm.

[0010] Specifically, the spacing between the second sub-grids and adjacent second polarity fine grids is 0.2 mm-0.8 mm.

[0011] Specifically, the interval between the first sub-grid and the adjacent second polarity fine grid is 0.1mm-0.7mm.

[0012] Specifically, the number of the second sub-grids is multiple, and the number of fine grids between two adjacent second sub-grids is 8-35.

[0013] Specifically, the interval between two adjacent second sub-grids is 6mm-16.8mm.

[0014] Specifically, in the first direction, the depth of the protruding part protruding from the body is 40μm-500μm.

[0015] Specifically, the second sub-grid is provided with a connecting structure, and the width of the connecting structure is greater than the width of the second sub-grid.

[0016] The battery assembly provided in the application comprises the back contact battery of any one of the above.

[0017] The photovoltaic system provided in the application comprises the battery assembly of any one of the above.

[0018] The back contact battery, the battery assembly and the photovoltaic system of the embodiments of the application can form an anti-hot spot structure due to the overlapping of the protruding part of the second doped area and the overlapping part of the first doped area, can reduce the reverse bias, reduce the heating power of the back contact battery when it is shielded in the assembly and becomes a load, and thus can reduce the risk of hot spots. Meanwhile, the interval between the second sub-grid provided in the non-overlapping part of the first doped area and the adjacent fine grid of different polarity is greater than the interval between the first sub-grid and the adjacent fine grid of different polarity, so that enough space can be left for the silicon substrate to set the anti-hot spot structure, and the short circuit risk caused by the contact between the fine grids of different polarities and the doped areas is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic diagram of part of the structure of the back contact battery of an embodiment of the application;

[0020] Figure 2 is an enlarged schematic diagram of part of the structure of the back contact battery of Figure 1

[0021] Figure 3 is a structural schematic diagram of the back contact battery of an embodiment of the application;

[0022] Figure 4 is a schematic diagram of part of the structure of the back contact battery of an embodiment of the application;

[0023] Figure 5 is a schematic diagram of part of the structure of the back contact battery of an embodiment of the application;

[0024] Figure 6 ​is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0025] Figure 7 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0026] Figure 8 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application; Figure 7 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0027] Figure 9 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0028] Figure 10 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0029] Figure 11 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0030] Figure 12 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0031] Figure 13 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0032] Figure 14 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0033] Figure 15 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0034] Figure 16 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0035] Figure 17 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0036] Figure 18 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0037] Figure 19 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0038] Figure 20 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0039] Figure 21 is a schematic diagram of a partial structure of a back contact cell of an embodiment of the present application;

[0040] Figure 22 is an enlarged schematic view of a partial structure of a back contact cell of Figure 21

[0041] Figure 23 is a schematic view of a partial structure of a back contact cell of an embodiment of the present application;

[0042] Figure 24 is a schematic view of a partial structure of a back contact cell of an embodiment of the present application;

[0043] Figure 25 is a schematic view of a partial structure of a back contact cell of an embodiment of the present application;

[0044] Figure 26 is a schematic view of a back contact cell of an embodiment of the present application;

[0045] Figure 27 is a schematic view of a partial structure of a back contact cell of Figure 26

[0046] Main element symbol explanation:

[0047] Back contact cell 10, silicon substrate 101, first conductive structure 1001, second conductive structure 1002, dielectric film layer 1003;

[0048] 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, first auxiliary grid 114, second auxiliary grid 115, connecting structure 116;

[0049] Second polarity fine grid 12, second grid line 121, first main body part 1211, first bending part 1212, fourth grid line 122, third main body part 1221, third bending part 1222, second connecting block 123, second hollowed-out area 1230;

[0050] Length S1 of first connecting block, width w1 of first connecting block, width w2 of first grid line, width w3 of second connecting block, width w4 of fourth grid line; maximum distance d1 of first bending part and first main body part in first direction, maximum distance d2 of second bending part and second main body part in first direction, distance d3 of second connecting block and breakpoint of first grid line, maximum distance d4 of third bending part and third main body part in first direction; distance x1 of first grid line and edge, distance x2 of first connecting block to edge, distance x3 of fourth grid line and edge, distance x4 of second connecting block to edge;

[0051] ​​The first polarity doped region 13, the first doped region 131, the first region 1311, the second region 1312, the third doped region 132, the fifth region 1321, the sixth region 1322, the first doped region 133, the overlapping portion 1331, the non-overlapping portion 1332;

[0052] The second polarity doped region 14, the second doped region 141, the third region 1411, the fourth region 1412, the fourth doped region 142, the seventh region 1421, the eighth region 1422, the ninth region 1423, the second doped region 143, the body 1431, the protruding portion 1432;

[0053] The width W1 of the first region, the width W2 of the second region, the width W3 of the third region, the width W4 of the fourth region; the maximum depth H1 of the second region protruding from the first region, the maximum depth H2 of the fourth region protruding from the third region, the maximum depth H3 of the sixth region protruding from the fifth region, the maximum depth H4 of the eighth region protruding from the seventh region;

[0054] The distance L2 between the first sub-gate and the adjacent second polarity fine gate L1, the distance L2 between the second sub-gate and the adjacent second polarity fine gate, the width L3 of the connecting structure, the width L4 of the second sub-gate, the distance L5 between two adjacent second sub-gates, the depth L6 of the protruding portion protruding from the body, the width L7 of the overlapping portion, the length L8 of the overlapping portion, the distance L9 between the overlapping portion and the connecting structure. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. The examples of the examples are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The examples described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application. In addition, it should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0056] 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 shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as limiting the present application.

[0057] In addition, the terms "first", "second", etc. are used herein only to describe different instances, and do not imply or suggest relative importance or a number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can be detachable connection, or integral connection; can be mechanical connection, or electrical connection or can communicate with each other; 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.

[0058] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can be detachable connection, or integral connection; can be mechanical connection, or electrical connection or can communicate with each other; 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.

[0059] In the present application, unless otherwise 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 "on" of the first feature to the second feature includes the first feature above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "lower", "below" and "under" of the first feature to the second feature includes the first feature below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0060] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements 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.

[0061] Please refer to Figure 1 , Figure 2 and Figure 3 , the back contact battery 10 of the embodiment of the present application comprises:

[0062] Silicon substrate 101;

[0063] a plurality of first-polarity fine grids 11 and a plurality of second-polarity fine grids 12 are arranged on the silicon substrate 101 along a first direction, and the first-polarity fine grids 11 and the second-polarity fine grids 12 are spaced apart;

[0064] The first-polarity fine grid 11 includes 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 is greater than the width w2 of the first grid line 111, and the length s1 of the first connecting block 112 is greater than or equal to 100 μm.

[0065] The second-polarity fine grid 12 includes a second grid line 121, and the second grid line 121 includes a first main body portion 1211 and a first bending portion 1212 connected to each other, the first main body portion 1211 extends along a second direction, the second direction intersects the first direction, and 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 main body portion 1211.

[0066] The back contact battery 10 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 battery 10, and improve the connection stability of the back contact battery 10 and the electrical connecting member, 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 of the first connecting block 112 is greater than or equal to 100 μm. At the same time, the first connecting block 112 can be widened because the first bending portion 1212 of the second grid line 121 bends away from the first connecting block 112 from the first main body portion 1211, and the risk of short circuit caused by too small electrode spacing of the two polarities can be reduced.

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

[0068] The back contact battery 10 is taken as an example for explanation and description herein. It can be understood that the back contact battery 10 can be a back contact battery 10 with a main grid. In the case where the back contact battery 10 is a back contact battery 10 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 and 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 cell 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 cell 10, the first polarity doped layer and the second polarity doped layer are distributed in regions, respectively corresponding to the first polarity doped region 13 and the second polarity doped region 14, as shown in 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 cover the first polarity doped layer and the second polarity doped layer, the first polarity fine grid 11 contacts the first polarity doped layer through the dielectric film layer 1003, and the second polarity fine grid 12 contacts the second polarity doped layer through the dielectric film layer 1003. In this way, the dielectric film layer 1003 is used to achieve electrical isolation of the first polarity doped layer and the second polarity doped layer, and at the same time, the dielectric film layer 1003 can be used to reduce light reflection and recombination. The dielectric film layer 1003 can also be provided 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, in order to better show the first polarity doped regions 13 and the second polarity doped regions 14, Figures 12-20 the part of the dielectric film layer 1003 covering the first polarity doped regions 13 and the second polarity doped regions 14 is omitted.

[0075] Specifically, the first polarity fine grid 11 and the second polarity fine grid 12 can be distributed in the whole region of the silicon substrate 101; the first polarity fine grid 11 and the second polarity fine grid 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 which is not distributed with the first polarity fine grid 11 and the second polarity fine grid 12 can be distributed with other fine grids, can be distributed with main grids, or can not be provided with grid lines.

[0076] Specifically, the first polarity fine grid 11 and the second polarity fine grid 12 are different in polarity. The first polarity fine grid 11 corresponds to the first polarity doped layer, the first polarity doped region 13. The second polarity fine grid 12 corresponds to the second polarity doped layer, the second polarity doped region 14.

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

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

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

[0080] Hereinafter, “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 first auxiliary grid 114 and the second auxiliary grid 115” mean that the first grid line 111, the third grid line 113, the first auxiliary grid 114 and the second auxiliary grid 115 are all fine grids of the first polarity. Hereinafter, “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” 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 present 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 connecting member 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 gate line 111 can be located at a position away from the edge of the silicon substrate 101. For example, the first gate line 111 is the second, third, fourth or other numbered first polarity fine gate 11 from the edge. In this way, the risk of the electrical connector falling off from the middle of the back contact cell 10 can be reduced. In this case, a bent second gate line 121 can be arranged on one side or both sides of the first gate line 111 to avoid the first connecting block 112 provided on the first gate line 111.

[0083] Please refer to Figure 1 、 Figure 2 and Figure 3 , the first connecting block 112 is arranged on the first gate line 111. That is, the first connecting block 112 is connected with the first gate 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 gate line 111. The first connecting block 112 can also be made step by step with the first gate line 111.

[0085] In one example, the first connecting block 112 and the first gate 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 gate 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 includes at least one of a pad and a gate line segment. In this way, the first connecting block 112 has various forms, which is beneficial to meet more production scenarios and needs. For example, the first connecting block 112 includes a pad. For another example, the first connecting block 112 includes a gate line segment. For another example, the first connecting block 112 includes a pad and a gate line segment. It can be understood that in the case where the first connecting block 112 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 first connecting block 112 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.

[0087] Please note that in two adjacent back contact cells 10, the electrical connector electrically connects the fine gate of one polarity in one back contact cell 10 and the fine gate of another polarity in another back contact cell 10. The connection of the electrical connector 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, one electrical connection is connected with fine grids of the same polarity in one back contact cell 10. 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 the 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 the 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 welding, solder paste welding, and physical contact. This is not limited herein.

[0093] Further, the entire area of the first connecting block 112 is connected with the first electrical connection. In this way, the connection area is large, which is beneficial to improve the connection stability. 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 connection.

[0094] Further, the first electrical connection includes at least one of a solder strip and a conductive wire. Herein, the first electrical connection is taken as a solder strip for example. It can be understood that in the case of the first electrical connection being a solder strip, the embodiments of the present application can reduce the risk of the solder strip falling off from the back contact cell 10.

[0095] Specifically, the area covered by the first electrical connection in the back contact cell 10 is a first pre-connection area.

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

[0097] Further, in the first pre-connection region, a first connection block 112 can be provided at each of the first-polarity fine grids 11. A first connection block 112 can also be provided at some of the first-polarity fine grids 11. No limitation is made herein. Figure 3 In the example shown in FIG. 1, a first connection block 112 is provided at each of the first-polarity fine grids 11 at both ends of the first pre-connection region.

[0098] Referring to FIG. 1, Figure 1 and Figure 2 The width w1 of the first connection block 112 refers to the dimension of the first connection block 112 in the first direction. The width w1 of the first connection block 112 can be the same everywhere, can be different everywhere, or can be the same in part. The width w2 of the first gate line 111 refers to the dimension of the first gate line 111 in the first direction. The width w2 of the first gate line 111 can be the same everywhere, can be different everywhere, or can be the same in part.

[0099] Specifically, the width w1 of the first connection block 112 is greater than the width w2 of the first gate line 111, i.e., the width of at least one location of the first connection block 112 is greater than the width of at least one location of the first gate line 111. It can be that the minimum width of the first connection block 112 is greater than the maximum width of the first gate line 111, that the maximum width of the first connection block 112 is greater than the maximum width of the first gate line 111, or that the maximum width of the first connection block 112 is greater than the width of the location where the first gate line 111 and the first connection block 112 are connected. No limitation is made herein.

[0100] Referring to FIG. 1, Figure 2 The length s1 of the first connection block 112 is greater than or equal to 100 μm. For example, the length s1 of the first connection 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 connection block 112 refers to the dimension of the first connection block 112 in the second direction. The length s1 of the first connection block 112 can be the same everywhere, can be different everywhere, or can be the same in part.

[0102] The length s1 of the first connection block 112 is greater than or equal to 100 μm, i.e., the length of at least one location of the first connection block 112 is greater than or equal to 100 μm. It can be that the minimum length of the first connection block 112 is greater than or equal to 100 μm, i.e., the length of each location of the first connection block 112 is greater than or equal to 100 μm, or that the maximum length of the first connection block 112 is greater than or equal to 100 μm. No limitation is made herein.

[0103] Referring to FIG. 1, Figure 2 and Figure 4In some embodiments, the first connecting block 112 is formed with a first hollowed-out area 1120. In this way, the material of the first connecting block 112 can be reduced while the coverage of the first connecting block 112 is ensured, 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 tension, 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 form. It can be understood that in other embodiments, the first connecting block 112 can be in a circular, annular, elliptical, triangular, racetrack-shaped or other form. The specific form of the first connecting block 112 is not limited herein.

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

[0107] Specifically, the connection between the first body part 1211 and the first bending part 1212 means that the first body part 1211 and the first bending part 1212 are electrically conductive and not disconnected.

[0108] Specifically, the extension of the first body part 1211 along the second direction means that the extension direction of the first body part 1211 as a whole is the second direction. This does not represent a limitation on the specific form of the first body part 1211. In the present embodiment, the first body part 1211 is in a straight line form, 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 form, a broken line form or other forms.

[0109] Specifically, the second direction intersects the first direction, meaning that the second direction does not overlap, is not the same as, and is not 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 parallel to two adjacent long sides of the silicon substrate 101, respectively. It can be understood that in other embodiments, the first direction and the second direction can also form an acute angle or an obtuse angle; the first direction and the second direction can also form 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 of the silicon substrate 101 other than the corners, and the arc-shaped sides or short sides formed by rounding or chamfering the corners of the silicon substrate 101 are not considered.

[0110] Specifically, the first bending portion 1212 is arranged corresponding to the first connecting block 112, meaning that, regardless of the thickness of the first bending portion 1212 and the first connecting block 112, in the first direction, the projection of the first bending portion 1212 and the first connecting block 112 on the same plane at least partially overlaps. In other words, the ranges occupied by the first bending portion 1212 and the first connecting block 112 in the second direction at least partially overlap.

[0111] In the present embodiment, the range occupied by the first bending portion 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 portion 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 portion 1212 in the second direction; the range occupied by the first connecting block 112 in the second direction can also completely overlap the range occupied by the first bending portion 1212 in the second direction; or the range occupied by the first connecting block 112 in the second direction can also intersect the range occupied by the first bending portion 1212 in the second direction.

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

[0114] Specifically, the first bending portion 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 portion 1211, and the second bending segment connects the other end of the first connecting segment and the first main body portion 1211. In the present embodiment, the first bending segment and the second bending segment are substantially parallel to each other. Figure 1In the example shown in FIG. 1, the first connection section is a straight line.

[0115] It can be understood that in other examples, the first bending portion 1212 can be wavy, zigzag, or other shapes. The first connection section can be wavy, zigzag, or other shapes. No limitation is made herein.

[0116] Referring to Figure 1 and Figure 2 In some embodiments, the difference between the width w1 of the first connection block 112 and the width w2 of the first gate line 111 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.

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

[0118] Referring to Figure 1 and Figure 2 In some embodiments, the width w1 of the first connection block 112 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.

[0119] In this way, the width w1 of the first connection block 112 is within an appropriate range, which can avoid the width of the contact with the first electrical connection being small due to the width being too small, and the connection stability of the first electrical connection being poor, and can also avoid the series resistance of the first connection block 112 being too large due to the width 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 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.

[0122] Referring to Figure 1 and Figure 2In some embodiments, the maximum distance d1 between 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 between the first bending part 1212 and the first main part 1211 in the first direction is in a suitable range, which can avoid the first bending part 1212 and the first connecting block 112 being too close and the short circuit risk being too large due to the distance being 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 too large due to the distance being too large.

[0124] Please refer 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:

[0125] -100 μm≤w1-w2-d1≤100 μm;

[0126] 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 between the first bending part 1212 and the first main part 1211 in the first direction.

[0127] 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 to the difference between the width of the first connecting block 112 and the first gate line 111 due to the difference being too small, making the series resistance of the second gate line 121 too large while it is difficult to greatly improve the short circuit risk, and can also avoid the maximum bending depth of the first bending part 1212 being too small compared to the difference between the width of the first connecting block 112 and the first gate line 111 due to the difference being too large, the short circuit risk being too large.

[0128] 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.

[0129] 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.

[0130] Please refer to Figure 1 and Figure 2In 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 0.4mm-1mm. For example, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm.

[0131] 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 carriers caused by too large distance.

[0132] Preferably, the distance x1 between the first gate line 111 and the edge is 0.5mm-0.8mm. For example, 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, 0.62mm, 0.65mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, 0.8mm. 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.

[0133] Please refer to Figure 1 and Figure 2 In some embodiments, the distance x2 between the first connecting block 112 and the edge is 0.4mm-50mm. For example, 0.4mm, 0.5mm, 1mm, 5mm, 10mm, 20mm, 30mm, 40mm, 48mm, 50mm.

[0134] In this way, the distance x2 between the first connecting block 112 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 first electrical connecting member caused by too large distance.

[0135] Preferably, the distance x2 between the first connecting block 112 and the edge is 0.8mm-5mm. For example, 0.8mm, 0.82mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, 5mm. In this way, the distance x2 between the first connecting block 112 and the edge is further optimized, so that the connection stability of the back contact battery 10 and the first electrical connecting member is better.

[0136] Please refer to Figure 6 In some embodiments, the first polarity thin gate 11 includes a third gate line 113, the third gate line 113 includes a second main body part 1131 and a second bending part 1132 connected with each other, the second main body part 1131 extends along a 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 main body part 1131.

[0137] In this way, the third grid line 113 that is bent can provide more space for the first connecting block 112 with a larger width and the second grid line 121 that is bent to avoid the first connecting block 112, facilitate the widening of the first connecting block 112, facilitate the bending of the second grid line 121, and reduce the risk of short circuit caused by too small spacing between electrodes of two polarities.

[0138] Specifically, the connection of the second main body part 1131 and the second bent part 1132 means that the second main body part 1131 and the second bent part 1132 are electrically conductive and not disconnected.

[0139] Specifically, the extension of the second main body part 1131 in the second direction means that the extension direction of the second main body part 1131 as a whole is the second direction. This does not represent a limitation on the specific form of the second main body part 1131. In the present embodiment, the second main body part 1131 is in a straight line type, and the extension direction of the second main body part 1131, i.e., the second direction, is the length direction of the second main body part 1131. In other embodiments, the second main body part 1131 can also be in a wavy line type, a broken line type, or other forms.

[0140] Specifically, the second bent part 1132 is arranged corresponding to the first connecting block 112, which means that, regardless of the thickness of the second bent part 1132 and the first connecting block 112, the projection of the second bent part 1132 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 second bent part 1132 and the first connecting block 112 in the second direction at least partially overlaps.

[0141] In the present embodiment, the range occupied by the second bent 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, the second bent part 1132 avoids the first connecting block 112 as much as possible, which 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 spacing between electrodes of two polarities as much as possible.

[0142] 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 bent 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 bent 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 bent part 1132 in the second direction.

[0143] Specifically, the second bending portion 1132 bending from the second main body portion 1131 in a direction away from the first connecting block 112 means that in the first direction, the maximum distance between the second bending portion 1132 and the second main body portion 1131 is greater than 0.

[0144] Specifically, the second bending portion 1132 includes a third bending segment, a second connecting segment, and a fourth bending segment connected in sequence. The third bending segment connects one end of the second main body portion 1131 and the second connecting segment, and the fourth bending segment connects the other end of the second main body portion 1131 and the second connecting segment. Figure 6 In the example, the second connecting segment is a straight line segment.

[0145] It is understood that in other examples, the second bend 1132 may be wavy, zigzag, or other shapes. The second connecting segment may be wavy, zigzag, or other shapes. No limitation is made here.

[0146] Please note that the second grid line 121 is a bent second polar fine grid 12, and the third grid line 113 is a bent first polar fine grid 11. The second grid line 121 may be adjacent to the first grid line 111 or not. The third grid line 113 may be adjacent to the second grid line 121 or not.

[0147] exist Figures 1-5 In the example, there is one second gate line 121, which is adjacent to the first gate line 111, and there is no third gate line 113. That is, the first gate line 111 and the second gate line 121 are arranged sequentially along the direction away from the edge.

[0148] exist Figure 6 In the example, there are two second gate lines 121 and one third gate line 113. 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, along 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.

[0149] It is understandable that in other examples, the first grid line 111, the second grid line 121, the third grid line 113, the second grid line 121, and the third grid line 113 could be arranged sequentially along the direction away from the edge.

[0150] Please see Figure 6 In some embodiments, the bending depth of the first bend 1212 and the second bend 1132 gradually decreases along the direction away from the first connecting block 112.

[0151] In this way, the bending depth of the bending portion gradually decreases in the direction away from the first connecting block 112, which not only avoids the first connecting block 112 or the adjacent bending portion to reduce the risk of short circuit, but also realizes the transition from bending to gentle.

[0152] 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. 11. 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. 11. Figure 6

[0153] In the example shown in FIG. 11, 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 in the direction away from the edge, and the bending depth of the corresponding bending portion gradually decreases. Figure 6 Please refer to

[0154] In some embodiments, for the adjacent second gate line 121 and third gate line 113, the first bending portion 1212 and the second bending portion 1132 satisfy the following formula: Figure 6 50μm≤d1-d2≤150μm;

[0155] 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.

[0156] In this way, the difference between the bending depths of the adjacent second gate line 121 and third gate line 113 is in a suitable range, which can avoid the need to use more bending gate lines to realize the transition from bending to gentle, increase the process complexity, and reduce the production efficiency when the difference is too small, and can avoid the bending depth of one gate line being insufficient, the distance between the bending portions with opposite polarities being close, and the risk of short circuit being large when the difference is too large.

[0157] Specifically, the value of d1-d2 is, for example, 50μm, 52μm, 80μm, 90μm, 100μm, 120μm, 140μm, 150μm.

[0158] Please refer to

[0159] , 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 first conductive structures 1001 is continuous. Figure 3 ​​

[0160] Thus, each row of the first conductive structure 1001 is continuous without any break, so that the power of the back contact battery 10 is better.

[0161] Referring to Figure 1 , Figure 2 and Figure 3 , in some embodiments, each row of the second gate line 121 is continuous.

[0162] Thus, each row of the second gate line 121 is continuous without any break, so that the power of the back contact battery 10 is better.

[0163] Referring 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.

[0164] Thus, 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 from 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.

[0165] Referring 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. Thus, 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 same place and the second electrical connecting member is stronger. Moreover, the design and manufacturing can be concentrated, which is beneficial to improve the manufacturing efficiency.

[0166] Please note that in the case that the fourth gate line 122 and the second gate line 121 are the same second polarity fine grid 12, the fourth gate line 122 and the second gate line 121 can be respectively regarded as part of the structure of the second polarity fine grid 12.

[0167] It can be understood that in other examples, the fourth gate line 122 and the second gate line 121 can also be different second polarity fine grids 12. This is not limited here.

[0168] Specifically, the second connecting block 123 is used to connect the second electrical connecting member.

[0169] Further, the second connecting block 123 and the second electrical connecting member can be electrically conductive through at least one of conductive glue bonding, direct welding, solder paste welding, and physical contact. This is not limited here.

[0170] Further, the second connecting block 123 is connected with the second electric connecting piece in the whole area. 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, the second connecting block 123 can also be connected with the second electric connecting piece in part of the area.

[0171] Further, the second electric connecting piece includes at least one of a solder strip and a conductive wire. Herein, the second electric connecting piece is taken as an example of the solder strip. It can be understood that in the case of the second electric connecting piece being the solder strip, the embodiments of the present application can reduce the risk of the solder strip falling off from the back contact battery 10.

[0172] Specifically, the area of the back contact battery 10 covered by the second electric connecting piece is the second pre-connection area.

[0173] Further, in the battery assembly, the number of the second electric connecting pieces 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. Herein, no limitation is made. 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.

[0174] In some embodiments, the second connecting block 123 includes at least one of a pad and a grid line segment. In this way, the form of the second connecting block 123 is various, which is beneficial to meet more production scenarios and needs. For example, the second connecting block 123 includes the pad. For another example, the second connecting block 123 includes the grid line segment. For another example, the second connecting block 123 includes the pad and the grid line segment. It can be understood that in the case of the second connecting block 123 including the grid line segment, the grid line segment passes through the dielectric film layer 1003 to contact the second polarity doped layer. In the case of the second connecting block 123 including the 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.

[0175] Please refer to Figure 7 and Figure 8 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.

[0176] Specifically, the width w3 of the second connecting block 123 is greater than the width w4 of the fourth gate line 122, i.e., the width of at least one position of the second connecting block 123 is greater than the width of at least one position of the fourth gate line 122. It can be that the minimum width of the second connecting block 123 is greater than the maximum width of the fourth gate line 122; it can also be that the maximum width of the second connecting block 123 is greater than the maximum width of the fourth gate line 122; it can also be that the maximum width of the second connecting block 123 is greater than the width of the position where the fourth gate line 122 is connected to the second connecting block 123. This is not limited herein.

[0177] Referring to Figure 8 and Figure 9 In some embodiments, the second connecting block 123 is formed with a second hollow region 1230. In this way, the material of the second connecting block 123 can be reduced while the coverage of the second connecting block 123 is ensured, which is conducive to reducing the cost while improving the connection stability.

[0178] Referring to Figure 10 In some embodiments, the second connecting block 123 is in a solid shape. 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 of the second connecting block 123 and the electrical connecting member, increase the tension, 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.

[0179] Referring to Figure 7 and Figure 8 In some embodiments, the second connecting block 123 is in a rectangular shape. It can be understood that in other embodiments, the second connecting block 123 can be in a circular shape, an annular shape, an elliptical shape, a triangular shape, a racetrack shape, or other shapes. The specific shape of the second connecting block 123 is not limited herein.

[0180] Referring to Figure 7 and Figure 8 In some embodiments, the difference between the width w3 of the second connecting block 123 and the width w4 of the fourth gate line 122 is 5 μm-290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0181] In this way, the width difference between the second connecting block 123 and the fourth gate line 122 is within an appropriate range, which can avoid the width of the second connecting block 123 being insufficient and the connection stability of the second electrical connecting member being poor due to the difference being too small, and can also avoid the series resistance of the second connecting block 123 being too large and the current loss being too large due to the difference being too large.

[0182] Referring to Figure 7 and Figure 8In some embodiments, the width w3 of the second connecting 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.

[0183] In this way, the width w3 of the second connecting block 123 is in a suitable range, which can avoid the width being too small to cause the contact with the second electrical connecting member to be small and the connection stability of the second electrical connecting member to be poor, and can also avoid the width being too large to cause the series resistance of the second connecting block 123 to be too large and the current loss to be large.

[0184] Please refer 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.

[0185] In this way, the width w4 of the fourth gate line 122 is in a suitable range, which can avoid the width being too small to cause the gate line to be easily disconnected and the effect of guiding the carriers from the silicon substrate 101 to be poor, and can also avoid the width being too large to cause the series resistance to be too large, the current loss to be large, and the cost to be high.

[0186] Please refer to Figure 7 and Figure 8 In some embodiments, the difference between the area of the first connecting block 112 and the area of the second connecting block 123 is -400 μm 2 -400 μm 2 . For example, -400 μm 2 , -400 μm 2 , -400 μm 2 , -400 μm 2 , -400 μm 2 , 400 μm 2 .

[0187] 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 difference being too small or too large to cause the difference between the areas of the first connecting block 112 and the second connecting block 123 to be 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.

[0188] Please refer to Figure 7 and Figure 8In some embodiments, the first polarity grid line adjacent to the second connection block 123 is disconnected at a position corresponding to the second connection block 123, avoiding the second connection block 123, and the spacing d3 between the breakpoint of the second connection block 123 and the first grid line 111 in the second direction is 0.2mm-1mm. For example, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm.

[0189] In this way, the space of the first polarity grid line adjacent to the second connection block 123 makes the range of the second connection block 123 larger, which is conducive to increasing the contact area of the second connection block 123 and the second electrical connection and improving the connection stability. At the same time, the spacing d3 between the breakpoint of the second connection block 123 and the first grid line 111 is in an appropriate range, which can avoid the risk of short circuit caused by too small spacing and the poor carrier collection effect of the interval area caused by too large spacing.

[0190] Specifically, the first polarity grid line adjacent to the second connection block 123 is disconnected at a position corresponding to the second connection block 123, which means that the line connecting the two breakpoints of the first polarity grid line passes through the second connection block 123. In order to avoid the second connection block 123 with opposite polarity, the first polarity grid line is disconnected to form two breakpoints.

[0191] Preferably, the spacing d3 between the breakpoint of the second connection block 123 and the first grid 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 spacing d3 between the breakpoint of the second connection block 123 and the first grid line 111 is further optimized, taking into account the area of the second connection block 123 and the carrier collection, and the overall effect is better.

[0192] Please refer to Figure 7 and Figure 8 In some embodiments, the fourth grid line 122 is the second polarity fine grid 12 closest to the edge of the silicon substrate 101, and the distance x3 between the fourth grid line 122 and the edge is greater than 0.7mm-1.3mm.

[0193] In this way, the distance x3 between the fourth grid line 122 and the edge is in an appropriate range, which can avoid the inconvenience of lamination caused by too small distance and the poor carrier collection effect caused by too large distance.

[0194] Preferably, the distance x3 between the fourth grid 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 grid line 122 and the edge is further optimized, so that the overall effect is better.

[0195] It can be understood that in other embodiments, the fourth grid line 122 can be located away from the edge of the silicon substrate 101. For example, the fourth grid line 122 is the second polarity fine grid 12 of the second, third, fourth or other serial number 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, the first polarity grid line 11 can be arranged on one side or both sides of the fourth grid line 122 to avoid the second connecting block 123 provided on the fourth grid line 122.

[0196] Please refer to Figure 7 and Figure 8 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.

[0197] In this way, the distance x4 between the second connecting block 123 and the edge is within 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.

[0198] Preferably, the distance x4 between the second connecting block 123 and the edge is 1mm-5mm. For example, 1mm, 1.02mm, 1.5mm, 2mm, 3mm, 4mm, 4.5mm, 5mm. In this way, the distance x4 between the second connecting block 123 and the edge is further optimized, so that the connection stability of the back contact battery 10 and the second electrical connector is better.

[0199] Please refer to Figure 11 and Figure 11 In some embodiments, the fourth grid line 122 is the second polarity fine grid 12 closest to the edge of the silicon substrate 101, and the second connecting block 123 is located on the side of the fourth grid line 122 towards the edge.

[0200] 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 connector is improved.

[0201] In some embodiments, the second connecting block 123 protrudes from the fourth grid line 122 to both sides of the fourth grid line 122.

[0202] In this way, the space between the second connecting block 123 and the opposite grid line on both sides 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 member is improved.

[0203] Please refer to Figure 11 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 in 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 at the third bending part 1222.

[0204] In this way, the second connecting block 123 is arranged at the part of the fourth grid line 122 that bends away from the edge of the silicon substrate 101, so that the position of the second connecting block 123 is farther away from the edge of the silicon substrate 101, farther away from the end of the second electrical connecting member, and closer to the middle of the second electrical connecting member. This can avoid the end of the second electrical connecting member being difficult to reach the second connecting block 123 near the edge of the silicon substrate 101 due to offset or cutting error, so that the second connecting block 123 is more easily connected to the second electrical connecting member and has higher connection stability.

[0205] 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 7 In the example, the third connecting segment is a straight line segment.

[0206] It can be understood that in other examples, the third bending part 1222 can be in a wave shape, a polyline shape, or other shapes. The second connecting segment can be in a wave shape, a polyline shape, or other shapes. This is not limited herein.

[0207] Please refer to Figure 12 In some embodiments, the maximum distance d4 between the third bending part 1222 and the third main body part 1221 in the first direction is 5-290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0208] In this way, the maximum distance d4 between the third bending part 1222 and the third main part 1221 in the first direction is within a proper range, which can avoid the third bending part 1222 and the adjacent fine grid of the opposite polarity being too close and the risk of short circuit being too high due to the distance being too small, and can also avoid the total length of the fourth grid line 122 being too large, the series resistance being too large, and the current loss being too large due to the distance being too large.

[0209] Referring to Figure 2 In some embodiments, the fourth grid line 122 and the second connecting block 123 arranged on the fourth grid line 122 form a second conductive structure 1002, and each row of the second conductive structure 1002 is continuous.

[0210] In this way, each row of the second conductive structure 1002 is continuous and has no breakpoints, so that the power of the back contact battery 10 is better.

[0211] Referring to Figure 13 and Figure 14 In some embodiments, the silicon substrate 101 includes a plurality of first polarity doped regions 13 and a plurality of second polarity doped regions 14 arranged along the first direction, the first polarity doped regions 13 are provided with the first polarity fine grid 11, and the second polarity doped regions 14 are provided with the second polarity fine grid 12.

[0212] The first polarity doped region 13 includes a first doped region 131, the first doped region 131 includes a first region 1311 and a second region 1312, 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 polarity doped region 14 includes a second doped region 141, the second doped region 141 includes a third region 1411 and a fourth region 1412, the third region 1411 is provided with the first main part 1211 of the second grid line 121, and the fourth region 1412 is provided with the first bending part 1212 of the second grid line 121.

[0213] In this way, the two types of doped regions correspond to the two types of fine grids, which facilitates the fabrication of the fine grid of the corresponding polarity on the doped region and facilitates the electrical connection between the doped region and the fine grid of the corresponding polarity, and is conducive to reducing the process difficulty, improving the production efficiency, and reducing the cost.

[0214] Specifically, "the first region 1311 is provided with the first grid line 111" means that the first grid line 111 is in electrical contact with the first region 1311.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] Specifically, the first polarity doping region 13 and the second polarity doping region 14 can be formed in the entire region of the silicon substrate 101, so that the first polarity fine gate 11 and the second polarity fine gate 12 are distributed in the entire region of the silicon substrate 101; or the first polarity doping region 13 and the second polarity doping region 14 can be formed in a partial region of the silicon substrate 101, so that the first polarity fine gate 11 and the second polarity fine gate 12 are distributed in a partial region of the silicon substrate 101.

[0219] Specifically, the first polarity doping region 13 and the second polarity doping region 14 have different polarities. The first polarity doping region 13 corresponds to the first polarity doping layer. The second polarity doping region 14 corresponds to the second polarity doping layer.

[0220] Specifically, the number of the first polarity doping region 13 can be 1, 2, 3, 4, or other numbers. The number of the second polarity doping region 14 can be 1, 2, 3, 4, or other numbers. This is not limited herein. The number of the first polarity doping region 13 can be the same as or different from the number of the second polarity doping region 14.

[0221] Specifically, the first polarity doping region 13 and the second polarity doping region 14 are arranged along the first direction, which can be alternatively arranged along the first direction, or non-alternatively arranged; which can be equally spaced along the first direction, or non-equally spaced. This is not limited herein.

[0222] It can be understood that a gap can be formed between adjacent first polarity doping region 13 and second polarity doping region 14, which can be in contact with each other, or other film layer structures can be provided.

[0223] In some embodiments, a dielectric film layer 1003 is provided between at least one pair of adjacent first polarity doping region 13 and second polarity doping region 14, which electrically isolates the first polarity doping region 13 and the second polarity doping region 14.

[0224] In this way, the dielectric film layer 1003 is used to electrically isolate the first doping layer and the second doping layer, and at the same time, the difference in refractive index and the surface passivation effect of the dielectric film layer 1003 can be used to reduce optical loss and carrier recombination.

[0225] Specifically, the dielectric film layer 1003 can be arranged between a pair of adjacent first polarity doped regions 13 and second polarity doped regions 14; or between multiple pairs of adjacent first polarity doped regions 13 and second polarity doped regions 14. In the embodiment, the dielectric film layer 1003 is arranged between all adjacent first polarity doped regions 13 and second polarity doped regions 14.

[0226] 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 regions 13 and the second polarity doped regions 14, part of the dielectric film layer 1003 covering the first polarity doped regions 13 and the second polarity doped regions 14 is omitted in the figure.

[0227] 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.

[0228] In some embodiments, a groove is formed between the first polarity doped regions 13 and the second polarity doped regions 14, and the dielectric film layer 1003 is at least partially arranged in the groove.

[0229] In this way, the first polarity doped regions 13 and the second polarity doped regions 14 can be electrically isolated inside the silicon substrate 101 by the groove, reducing the risk of conduction between the first polarity doped regions 13 and the second polarity doped regions 14.

[0230] Specifically, "the dielectric film layer 1003 is at least partially arranged in the groove" means that part of the dielectric film layer 1003 is arranged in the groove and the rest is arranged outside the groove, or the entire dielectric film layer 1003 is arranged in the groove.

[0231] Specifically, the groove is continuously arranged between the first polarity doped regions 13 and the second polarity doped regions 14. In other words, the first polarity doped regions 13 and the second polarity doped regions 14 are separated by the groove. In this way, it is ensured that the first polarity doped regions 13 and the second polarity doped regions 14 cannot conduct across the groove.

[0232] In some embodiments, a tunneling layer is arranged between at least one pair of adjacent first polarity doped regions 13 and second polarity doped regions 14, and the first polarity doped regions 13 and the second polarity doped regions 14 both contact the tunneling layer.

[0233] In this way, the reverse bias can be reduced, and the heating 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 regions 13 and the second polarity doped regions 14.

[0234] Specifically, the tunneling layer comprises at least one of a silicon oxide layer, an aluminum oxide layer, and a silicon carbide layer.

[0235] In some embodiments, at least one pair of adjacent first-polarity doped regions 13 and second-polarity doped regions 14 are in contact with each other.

[0236] In this way, the reverse bias can be reduced, and the heat generation power of the back contact cell 10 when it is shaded and becomes a load in the assembly can be reduced.

[0237] Specifically, the adjacent first-polarity doped regions 13 and second-polarity doped regions 14 can be in contact with each other in the entire area adjacent to each other, or can be in contact with each other in part of the area adjacent to each other.

[0238] Referring to Figure 13 and Figure 13 In some embodiments, the second region 1312 protrudes from the first region 1311.

[0239] 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 adjacent second-polarity doped region 14 due to a small edge distance between the first connection block 112 with a larger width and the first region 1311 can be reduced.

[0240] Referring to Figure 13 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.

[0241] 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 an appropriate range, which can avoid the insufficient setting area of the first connection block 112 with a smaller width and the greater risk of short circuit, and can also avoid the poor carrier collection effect of another polarity caused by the second region 1312 with an excessively large width.

[0242] 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 short circuit risk and the carrier collection effect, and the overall effect is better.

[0243] 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, greater short circuit risk, and poor carrier collection effect of the first gate line 111 corresponding to the first region 1311, and can also avoid poor carrier collection effect of the other polarity due to too large width.

[0244] 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 short circuit risk and the carrier collection effect of the two polarities, and the overall effect is better.

[0245] 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 13 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 14 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.

[0246] Please refer to Figure 15 In some embodiments, in the first direction, the maximum depth H1 of the second region 1312 protruding from the first region 1311 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.

[0247] 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 connection block 112, greater short circuit risk, and can also avoid being not conducive to collecting carriers of the other polarity due to too large depth.

[0248] Please refer to Figure 16In some embodiments, the fourth region 1412 is recessed from the third region 1411 towards a side of the second region 1312. In this way, the recessed fourth region 1412 cooperates with the protruding second region 1312 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.

[0249] Referring to Figure 16 and Figure 15 In some embodiments, the fourth region 1412 is protruded from the third region 1411 away from a side of the second region 1312.

[0250] 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 the small edge distance between the bent first bending part 1212 and the fourth region 1412 and the too close adjacent opposite doped regions.

[0251] Referring to Figure 16 In some embodiments, the fourth region 1412 is recessed from the third region 1411 towards a side of the second region 1312, and the fourth region 1412 is protruded from the third region 1411 away from a side of the second region 1312.

[0252] In this way, the recessed fourth region 1412 cooperates with the protruding second region 1312 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 the bent first bending part 1212 can be provided with sufficient space, and the risk of short circuit caused by the small edge distance between the bent first bending part 1212 and the fourth region 1412 and the too close adjacent opposite doped regions can be reduced.

[0253] Specifically, the recessed depth of the fourth region 1412 is the same as the protruded depth. In this way, the size of the fourth region 1412 in the second direction is the same as that of the third region 1411, which is conducive to better collection of carriers.

[0254] It can be understood that in other embodiments, the recessed depth of the fourth region 1412 can be greater than the protruded depth, or can be less than the protruded depth. This is not limited here.

[0255] Referring to Figure 14 and Figure 15 In some embodiments, in the first direction, the maximum depth H2 of the fourth region 1412 protruded from the third region 1411 away from a side of the second region 1312 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.

[0256] In this way, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is in a proper range, which can avoid the risk of short circuit caused by the small distance between the first bending part 1212 and the edge of the fourth region 1412 and the adjacent opposite doped region, and can also avoid the poor effect of collecting carriers caused by the too large depth of protrusion.

[0257] 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, and the risk of short circuit and the collection of carriers are considered, and the overall effect is better.

[0258] Specifically, the width of the third region 1411 is the same as that of the fourth region 1412. In this way, it is beneficial to better collect carriers.

[0259] 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 15 , 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 16 . This is not limited here.

[0260] Please refer to Figure 17 and Figure 18 In some embodiments, the side of the second region 1312 away from the fourth region 1412 protrudes from the first region 1311, and the difference between the maximum depth H1 of the second region 1312 protruding from the first region 1311 and the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 in the first direction is 50 μm-200 μm. For example, 50 μm, 52 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm.

[0261] In this way, the difference between the maximum depth of the second region 1312 protruding and the maximum depth of the fourth region 1412 protruding is in a proper range, which can avoid the too small difference between the maximum depth of the fourth region 1412 protruding and the maximum depth of the second region 1312 protruding, which requires the adjacent opposite doped region to be recessed to avoid, and the too large difference between the maximum depth of the fourth region 1412 protruding and the maximum depth of the second region 1312 protruding, which causes the small width of the fourth region 1412, the poor effect of collecting carriers, and the large risk of short circuit.

[0262] Specifically, the maximum depth H2 at which the fourth region 1412 protrudes from the third region 1411 is the same as the maximum depth at which the fourth region 1412 is recessed from the third region 1411. In this way, the difference between the maximum depth at which the second region 1312 protrudes and the maximum depth at which the fourth region 1412 is recessed is within a suitable range, which can avoid the fourth region 1412 having a small width and a poor effect of collecting carriers due to the maximum depth at which the fourth region 1412 is recessed being close to the maximum depth at which the second region 1312 protrudes, and can also avoid the fourth region 1412 having poor space utilization and a poor effect of collecting carriers due to the recess of the fourth region 1412 and the protrusion of the second region 1312 being poorly matched.

[0263] Please refer to Figure 6 , Figure 15 and Figure 16 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 away from the first connecting block 112 from the second main body part 1131.

[0264] 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.

[0265] In this way, the third doped region 132 corresponds to the third grid line 113, which facilitates the manufacturing of the third grid line 113 on the third doped region 132 and facilitates the electrical connection between the third doped region 132 and the third grid line 113, and is beneficial to reduce the process difficulty, improve the manufacturing efficiency, and reduce the cost.

[0266] Specifically, “the fifth region 1321 is provided with the second main body part 1131 of the third grid line 113” means that the second main body part 1131 of the third grid line 113 is in electrical contact with the fifth region 1321.

[0267] Specifically, “the sixth region 1322 is provided with the second bending part 1132 of the third grid line 113” means that the second bending part 1132 of the third grid line 113 is in electrical contact with the sixth region 1322.

[0268] Please refer to Figure 17 and Figure 18In some embodiments, the sixth region 1322 is recessed from the fifth region 1321 towards one side of 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.

[0269] Referring to Figure 18 and Figure 18 In some embodiments, the sixth region 1322 is protruded from the fifth region 1321 away from one side of the second region 1312.

[0270] 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 part 1131, which can provide sufficient space for the bent second bending part 1132, and reduce 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 opposite doped region.

[0271] Referring to Figure 18 In some embodiments, the sixth region 1322 is recessed from the fifth region 1321 towards one side of the second region 1312, and the sixth region 1322 is protruded from the fifth region 1321 away from one side of the second region 1312.

[0272] 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 the sixth region 1322 corresponding to the second bending part 1132 is protruded from the fifth region 1321 provided with the second main part 1131, which can provide sufficient space for the bent second bending part 1132, and reduce 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 opposite doped region.

[0273] Specifically, the recessed depth of the sixth region 1322 is the same as the protruding depth. In this way, the size of the sixth region 1322 in the second direction is the same as that of the fifth region 1321, which is conducive to better collection of carriers.

[0274] It can be understood that in other embodiments, the recessed depth of the sixth region 1322 can be greater than the protruding depth, or less than the protruding depth. This is not limited here.

[0275] Referring to Figure 18 In some embodiments, the fourth region 1412 is protruded from the third region 1411 away from one side of the second region 1312, and the protruding depth of the fourth region 1412 and the sixth region 1322 gradually decreases in the direction away from the second region 1312.

[0276] In this way, the protruding depth gradually decreases in the direction away from the second region 1312, which can realize the transition from protrusion to flatness.

[0277] Specifically, the protruding depth of the fourth region 1412 is the maximum depth at which the fourth region 1412 protrudes from the third region 1411 in the first direction on the side of the fourth region 1412 facing away from the second region 1312, that is, H2 shown in FIG. 13B. Figure 18 The protruding depth of the sixth region 1322 is the maximum depth at which the sixth region 1322 protrudes from the fifth region 1321 in the first direction on the side of the sixth region 1322 facing away from the second region 1312, that is, H3 shown in FIG. 13B. Figure 18

[0278] In the example shown in FIG. 13A, the first doped regions 131, the second doped regions 141, the third doped regions 132, and the second doped regions 141 are arranged in sequence in the direction away from the edge, and the corresponding protruding depths gradually decrease. Figure 19

[0279] Referring to FIG. 13B, in some embodiments, for the adjacent second doped regions 141 and the third doped regions 132, the fourth regions 1412 and the sixth regions 1322 satisfy the following formula: Figure 8

[0280] 50 μm≤ H2-H3≤ 200 μm;

[0281] wherein H2 is the maximum depth at which the fourth region 1412 protrudes from the third region 1411 in the first direction on the side of the fourth region 1412 facing away from the second region 1312, and H3 is the maximum depth at which the sixth region 1322 protrudes from the fifth region 1321 in the first direction on the side of the sixth region 1322 facing away from the second region 1312.

[0282] In this way, the difference between the protruding depths of the adjacent second doped regions 141 and the third doped regions 132 is within a suitable range, which can avoid the need to use more doped regions to protrude to achieve a transition from a bend to a gentle slope, increase the process complexity, and reduce the production efficiency, and can also avoid the situation that the protruding depth of one doped region is not enough, the distance from the doped region edge of the corresponding bend portion is close, and the short circuit risk is large.

[0283] 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, or 200 μm.

[0284] 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 battery 10 is better.

[0285] ​​​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 unbroken, which makes the power of the back contact cell 10 better.

[0286] 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 utilizing the space of the edge, so that the area of the P region is large, which facilitates the collection of carriers.

[0287] 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.

[0288] Referring to Figure 19 and Figure 8 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.

[0289] 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.

[0290] In this way, the fourth doped region 142 corresponds to the fourth grid line 122, which facilitates the fabrication of the fourth grid line 122 on the fourth doped region 142, and is conducive to reducing the process difficulty, improving the fabrication efficiency, and reducing the cost.

[0291] 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.

[0292] Specifically, “the eighth region 1422 corresponds to the second connecting block 123” means that, in the thickness direction of the back contact cell 10, the projection of the second connecting block 123 and the eighth region 1422 on the same plane 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.

[0293] Referring to Figure 19 and Figure 19 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, the integration of 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 connecting piece at this place stronger. Moreover, the design and fabrication can be concentrated, which is conducive to improving the fabrication efficiency.

[0294] It is to be noted that, in the case that the fourth doped region 142 and the second doped region 141 are the same second-polarity doped region 14, the fourth doped region 142 and the second doped region 141 can be regarded as partial structures of the second-polarity doped region 14, respectively.

[0295] It is to 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. No limitation is made herein. Please refer to Figure 20 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.

[0296] In this way, the eighth region 1422 corresponding to the second connecting block 123 protrudes from the seventh region 1421 provided with the fourth gate line 122, which can provide sufficient space for the second connecting block 123 with a larger width. Moreover, in the case that the second connecting block 123 is arranged on 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 different-polarity doped region can be reduced.

[0297] Specifically, the eighth region 1422 can protrude from the seventh region 1421 on one side of the edge of the back contact battery 10, or the eighth region 1422 can protrude from the seventh region 1421 on the 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. No limitation is made herein.

[0298] It is to 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. No limitation is made herein.

[0299] Please refer to Figure 20 In some embodiments, the maximum depth H4 of the protrusion of the eighth region 1422 from the seventh region 1421 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.

[0300] In this way, the maximum depth H4 of the protrusion of the eighth region 1422 from the seventh region 1421 is within an appropriate range, which can avoid the insufficient setting area of the second connecting block 123 and the high risk of short circuit caused by the too small depth, and also can avoid the difficulty in collecting carriers of another polarity caused by the too large depth.

[0301] In some embodiments, each row of the fourth doped region 142 is continuous. In this way, each row of the fourth doped region 142 is not interrupted, so that the power of the back contact battery 10 is better.

[0302] Referring to Figure 21 In some embodiments, the fourth gate line 122 comprises 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 at the third bending portion 1222.

[0303] The fourth doped region 142 comprises a ninth region 1423, and the ninth region 1423 is arranged at the third bending portion 1222.

[0304] 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 fabrication of the fourth gate line 122 on the fourth doped region 142, and is conducive to reducing the process difficulty, improving the fabrication efficiency, and reducing the cost.

[0305] Referring to Figure 22 In some embodiments, the ninth region 1423 protrudes from the seventh region 1421 away from the eighth region 1422.

[0306] In this way, the ninth region 1423 corresponding to the third bending portion 1222 protrudes from the seventh region 1421 provided with the third main body portion 1221, which can provide sufficient space for the bent third bending portion 1222, and reduce the risk of short circuit caused by the small edge distance between the third bending portion 1222 and the ninth region 1423 and the adjacent opposite doped region.

[0307] Referring to Figure 22 and Figure 23 In some embodiments, the first polarity fine gate 11 is a positive gate line, and the first polarity fine gate 11 comprises a first sub-gate 114 and a second sub-gate 115, and the distance L2 between the second sub-gate 115 and the adjacent second polarity fine gate 12 is greater than the distance L1 between the first sub-gate 114 and the adjacent second polarity fine gate 12.

[0308] In this way, since the distance between the second sub-gate 115 and the adjacent opposite fine gate in the first direction is greater than the distance between the first sub-gate 114 and the adjacent opposite fine gate, sufficient space can be left for the anti-hot spot structure on the silicon substrate 101, and the risk of short circuit caused by the contact between the fine gates with different polarities and the doped regions is reduced.

[0309] Specifically, the second sub-grid 115 has a larger spacing L2 with the adjacent second polarity fine grid 12 than the first sub-grid 114 has with the adjacent second polarity fine grid 12, i.e., the second sub-grid 115 has a larger spacing with at least one of the adjacent second polarity fine grids 12 than the first sub-grid 114 has with at least one of the adjacent second polarity fine grids 12. It can be that the second sub-grid 115 has a largest spacing L2 with the adjacent second polarity fine grid 12 that is larger than a smallest spacing L1 that the first sub-grid 114 has with the adjacent second polarity fine grid 12; it can also be that the second sub-grid 115 has a smallest spacing L2 with the adjacent second polarity fine grid 12 that is larger than a largest spacing L1 that the first sub-grid 114 has with the adjacent second polarity fine grid 12. This is not limited herein.

[0310] Please refer to Figure 24 and Figure 25 The first polarity doped region 13 includes a first doped area 133, and the second polarity doped region 14 includes a second doped area 143. The first doped area 133 includes an overlapping portion 1331 and a non-overlapping portion 1332. The second doped area 143 includes a body 1431 and a protruding portion 1432. The body 1431 is spaced apart from the first doped area 133, and the protruding portion 1432 protrudes from the body 1431 and overlaps the overlapping portion 1331. The second sub-grid 115 is arranged at the non-overlapping portion 1332.

[0311] In this way, the protruding portion 1432 of the second doped area 143 overlaps the overlapping portion 1331 of the first doped area 133, so that a hot spot resistant structure can be formed, the reverse bias can be reduced, the heating power of the back contact cell 10 when it is loaded after being shaded in a module can be reduced, and thus the risk of hot spot can be reduced. Meanwhile, the first sub-grid 114 is arranged at the non-overlapping portion 1332, so that the risk of short circuit caused by the contact between the fine grid of different polarity and the doped region is reduced.

[0312] Specifically, the first sub-grid 114 is arranged outside the non-overlapping portion 1332.

[0313] Specifically, the body 1431 can be spaced apart from the first doped area 133 by a groove. The body 1431 can be spaced apart from the non-overlapping portion 1332 by a dielectric film layer 1003. This is not limited herein.

[0314] Specifically, the protruding portion 1432 can have a rectangular, circular, square, triangular, or other shape. This is not limited herein.

[0315] Specifically, the second sub-grid 115 is arranged at the non-overlapping portion 1332, i.e., the second sub-grid 115 is in electrical contact with the non-overlapping portion 1332.

[0316] Please refer to Figure 21 and Figure 22In some embodiments, the second auxiliary grid 115 is provided with a connecting structure 116, and a width L3 of the connecting structure 116 is greater than a width L4 of the second auxiliary grid 115.

[0317] In this way, the contact area between the connecting structure 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.

[0318] Specifically, the second auxiliary grid 115 is provided with the connecting structure 116. That is, the connecting structure 116 is connected with the second auxiliary grid 115.

[0319] Specifically, the connecting structure 116 can pass through the dielectric film layer 1003 to contact the first polarity doped layer. The connecting structure 116 and the first polarity doped layer can also be isolated by the dielectric film layer 1003. The connecting structure 116 can be made together with the second auxiliary grid 115. The connecting structure 116 can also be made step by step with the second auxiliary grid 115.

[0320] In one example, the connecting structure 116 and the second auxiliary grid 115 are made of the same paste, and both pass through the dielectric film layer 1003 to contact the first polarity doped layer. In another example, the paste of the second auxiliary grid 115 passes through the dielectric film layer 1003 to contact the first polarity doped layer, and the paste of the connecting structure 116 does not pass through the dielectric film layer 1003.

[0321] In some embodiments, the connecting structure 116 includes at least one of a pad and a grid line segment. In this way, the connecting structure 116 has various forms, which is beneficial to meet more production scenarios and needs. For example, the connecting structure 116 includes a pad. For another example, the connecting structure 116 includes a grid line segment. For another example, the connecting structure 116 includes a pad and a grid line segment. It can be understood that, in the case where the connecting structure 116 includes a grid line segment, the grid line segment passes through the dielectric film layer 1003 to contact the first polarity doped layer. In the case where the connecting structure 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.

[0322] Specifically, the connecting structure 116 is used to connect the first electrical connecting member.

[0323] Further, the connecting structure 116 and the first electrical connecting member can be electrically connected in at least one of the following manners: conductive glue bonding, direct welding, solder paste welding, and physical contact. This is not limited herein.

[0324] Further, the entire area of the connecting structure 116 can be connected with the first electrical connecting member. Alternatively, part of the area of the connecting structure 116 can be connected with the first electrical connecting member.

[0325] Specifically, the width L3 of the connecting structure 116 refers to the size of the connecting structure 116 in the first direction. The width L3 of the connecting structure 116 can be the same everywhere, can be different everywhere, or can be partially the same. The width L4 of the second sub-grid 115 refers to the size of the second sub-grid 115 in the first direction. The width L4 of the second sub-grid 115 can be the same everywhere, can be different everywhere, or can be partially the same.

[0326] Specifically, the width L3 of the connecting structure 116 is greater than the width L4 of the second sub-grid 115, that is, the width of at least one place of the connecting structure 116 is greater than the width of at least one place of the second sub-grid 115. It can be that the minimum width of the connecting structure 116 is greater than the maximum width of the second sub-grid 115; it can also be that the maximum width of the connecting structure 116 is greater than the maximum width of the second sub-grid 115; it can also be that the maximum width of the connecting structure 116 is greater than the width of the connecting structure 116 at the connection between the second sub-grid 115 and the connecting structure 116. This is not limited here.

[0327] In some embodiments, the connecting structure is formed with a third hollow area. In this way, the material of the connecting structure can be reduced while ensuring the coverage of the connecting structure, which is conducive to reducing costs while improving the connection stability.

[0328] In some embodiments, the connecting structure is in a solid shape. In this way, the area of the connecting structure can be increased as much as possible, thereby increasing the contact area of the connecting structure and the electrical connecting piece, increasing the pulling force, reducing the risk of the electrical connecting piece falling off from the back contact battery 10, and improving the connection stability of the back contact battery 10 and the electrical connecting piece.

[0329] In some embodiments, the connecting structure is in a rectangular shape. It can be understood that in other embodiments, the connecting structure can be in a circular, annular, elliptical, triangular, racetrack, or other shape. The specific shape of the connecting structure is not limited here.

[0330] Please refer to Figure 24 , Figure 21 and Figure 22 In some embodiments, the pitch L2 between the second sub-grid 115 and the adjacent second polarity fine grid 12 is a first pitch, the pitch L1 between the first sub-grid 114 and the adjacent second polarity fine grid 12 is a second pitch, 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.

[0331] 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 due to too small difference, and can avoid poor current carrier collection effect due to too large difference.

[0332] Specifically, the second sub-grid 115 can have a same spacing L2 with the adjacent second polarity fine grid 12, or different spacing L2 with the adjacent second polarity fine grid 12, or part of the same spacing L2 and part of the different spacing L2.

[0333] Specifically, the first sub-grid 114 can have a same spacing L1 with the adjacent second polarity fine grid 12, or different spacing L1 with the adjacent second polarity fine grid 12, or part of the same spacing L1 and part of the different spacing L1.

[0334] Specifically, the difference between the first spacing and the second spacing can be a fixed value within 0.05mm-0.1mm, or fluctuate within 0.05mm-0.1mm.

[0335] Please refer to Figure 24 , Figure 21 and Figure 22 In some embodiments, the second sub-grid 115 has a spacing L2 with the adjacent second polarity fine grid 12 within 0.2mm-0.8mm. For example, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm.

[0336] In this way, the spacing L2 between the second sub-grid 115 and the adjacent second polarity fine grid 12 is within a suitable range, which can avoid insufficient space for setting the anti-hot spot structure caused by too small spacing, and can avoid poor effect of collecting carriers caused by too large spacing.

[0337] Specifically, the second sub-grid 115 can have a same spacing L2 with the adjacent second polarity fine grid 12, or different spacing L2 with the adjacent second polarity fine grid 12, or part of the same spacing L2 and part of the different spacing L2.

[0338] Please refer to Figure 24 , Figure 21 and Figure 21 In some embodiments, the first sub-grid 114 has a spacing L1 with the adjacent second polarity fine grid 12 within 0.1mm-0.7mm.

[0339] In this way, the spacing L1 between the first sub-grid 114 and the adjacent second polarity fine grid 12 is within a suitable range, which can avoid dense grid lines and high cost caused by too small spacing, and can avoid poor effect of collecting carriers caused by too large spacing.

[0340] Specifically, the first sub-grid 114 can have a same spacing L1 with the adjacent second polarity fine grid 12, or different spacing L1 with the adjacent second polarity fine grid 12, or part of the same spacing L1 and part of the different spacing L1.

[0341] Please refer to Figure 23In some embodiments, the number of the second sub-grid 115 is multiple, and the number of the fine grid between the two adjacent second sub-grids 115 is 8-35. For example, 8, 10, 12, 15, 19, 20, 22, 25, 28, 30, 32, 35.

[0342] In this way, the number of the fine grid between the two adjacent second sub-grids 115 is in a suitable range, which can avoid the situation that the number of the second sub-grid 115 is too large and the manufacturing efficiency is low due to the small number of the fine grid between the two adjacent second sub-grids 115, and can also avoid the situation that the effect of reducing the hot spot risk is poor due to the large number of the fine grid between the two adjacent second sub-grids 115.

[0343] Specifically, in the back contact battery 10, the number of the second sub-grid 115 can be multiple, forming multiple pairs of adjacent second sub-grids 115. The number of the fine grid between the multiple pairs of adjacent second sub-grids 115 can be the same, different, or partially the same and partially different.

[0344] Please refer to Figure 23 In some embodiments, the distance L5 between the two adjacent second sub-grids 115 is 6mm-16.8mm. For example, 6mm, 7mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 16.8mm.

[0345] In this way, the distance L5 between the two adjacent second sub-grids 115 is in a suitable range, which can avoid the situation that the number of the second sub-grid 115 is too large and the manufacturing efficiency is low due to the small distance between the two adjacent second sub-grids 115, and can also avoid the situation that the effect of reducing the hot spot risk is poor due to the large distance between the two adjacent second sub-grids 115.

[0346] Specifically, in the back contact battery 10, the number of the second sub-grid 115 can be multiple, forming multiple pairs of adjacent second sub-grids 115. The distance L5 between the multiple pairs of adjacent second sub-grids 115 can be the same, different, or partially the same and partially different.

[0347] Please refer to Figure 23 and 25 In some embodiments, in the first direction, the depth L6 of the protruding part 1432 protruding from the body 1431 is 40μm-500μm. For example, 40μm, 42μm, 44μm, 50μm, 80μm, 100μm, 120μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 480μm, 500μm.

[0348] In this way, the protruding depth L6 of the protruding portion 1432 from the body 1431 is in a proper range, which can avoid the effect of reducing the hot spot risk being poor due to the protruding depth being too small to cause the contact area with the first doped region 133 being insufficient or even difficult to contact the first doped region 133, and can also avoid the risk of short circuit being large due to the protruding depth being too large to cause the distance between the protruding portion 1432 and the second auxiliary gate 115 being close.

[0349] Specifically, the protruding depth L6 of the protruding portion 1432 from the body 1431 can be a fixed value within 40 μm-500 μm, or can fluctuate within 40 μm-500 μm. No limitation is made herein.

[0350] Please refer to Figure 23 and 25 The width L7 of the overlapping portion 1331 is 45 μm-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.

[0351] In this way, the width L7 of the overlapping portion 1331 is in a proper range, which can avoid the effect of reducing the hot spot risk being poor due to the width being too small, and can also avoid the risk of short circuit being large due to the width being too large to cause the distance between the second auxiliary gate 115 and the opposite doped region being close.

[0352] Specifically, the width L7 of the overlapping portion 1331 refers to the size of the overlapping portion 1331 in the first direction.

[0353] Specifically, the width L7 of the overlapping portion 1331 can be a fixed value within 45 μm-500 μm, or can fluctuate within 45 μm-500 μm. No limitation is made herein.

[0354] Please refer to Figure 23 and 25 The length L8 of the overlapping portion 1331 is 10 μm-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.

[0355] In this way, the length L8 of the overlapping portion 1331 is in a proper range, which can avoid the effect of reducing the hot spot risk being poor due to the length being too large or too small.

[0356] 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.

[0357] Please refer to Figure 26 and25 The ratio of the width of the overlapping portion 1331 to the first 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%.

[0358] In this way, the ratio of the width of the overlapping portion 1331 to the first doped region 133 is in a suitable range, which can avoid the effect of reducing the hot spot risk being poor due to the ratio being too small, and can avoid the second auxiliary gate 115 being too close to the hetero-doped region and the short circuit risk being too large due to the ratio being too large.

[0359] Specifically, the width of the first doped region 133 refers to the size of the first doped region 133 in the first direction.

[0360] Please refer to Figure 27 and 25 The distance L9 between the protruding portion 1432 and the connecting structure 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.

[0361] In this way, the distance L9 between the protruding portion 1432 and the connecting structure 116 is in a suitable range, which can avoid the short circuit risk being too large due to the distance being too small, and can avoid the effect of reducing the hot spot risk being poor due to the distance being too large.

[0362] Specifically, the distance L9 between the protruding portion 1432 and the connecting structure 116 can be a fixed value in a range greater than or equal to 50 μm, or can fluctuate in a range greater than or equal to 50 μm. This is not limited here.

[0363] 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, Figure 21 and Figure 22 combine the features of the foregoing embodiments or examples.

[0364] Please refer to ​ and ​ In summary, the back contact battery 10 of the embodiments of the present application comprises:

[0365] The silicon substrate 101 comprises a plurality of first polarity doped regions 13 and a plurality of second polarity doped regions 14 arranged along the first direction;

[0366] A plurality of first-polarity fine grids 11 and a plurality of second-polarity fine grids 12 are arranged along a first direction and are arranged in the first-polarity doped region 13 and the second-polarity doped region 14, respectively, and are spaced apart from each other;

[0367] The first-polarity doped region 13 includes a first doped region 133, and the second-polarity doped region 14 includes a second doped region 143, the first doped region 133 includes an overlapping portion 1331 and a non-overlapping portion 1332, and the second doped region 143 includes a body portion 1431 and a protruding portion 1432, the body portion 1431 is spaced apart from the first doped region 133, and the protruding portion 1432 protrudes from the body portion 1431 and overlaps with the overlapping portion 1331; the first-polarity fine grid 11 is a positive grid line and includes a first sub-grid 114 and a second sub-grid 115;

[0368] The second sub-grid 115 is arranged in the non-overlapping portion 1332, and the first sub-grid 114 is arranged outside the non-overlapping portion 1332, and the spacing between the second sub-grid 115 and the adjacent second-polarity fine grid 12 is greater than the spacing between the first sub-grid 114 and the adjacent second-polarity fine grid 12.

[0369] The back contact cell 10 of the embodiment of the present application can form a hot spot resistant structure, reduce the reverse bias, and reduce the heating power of the back contact cell 10 when it is shaded in the module and becomes a load, thereby reducing the risk of hot spots. At the same time, since the spacing between the second sub-grid 115 arranged in the non-overlapping portion 1332 of the first doped region 133 and the adjacent fine grid of different polarity is greater than the spacing between the first sub-grid 114 and the adjacent fine grid of different polarity, sufficient space can be left for the silicon substrate 101 to set the hot spot resistant structure, thereby reducing the short circuit risk caused by the contact between the fine grids of different polarities and the doped regions.

[0370] The battery module of the embodiment of the present application includes the back contact cell 10 of any one of the above.

[0371] The battery module of the embodiment of the present application can form a hot spot resistant structure, reduce the reverse bias, and reduce the heating power of the back contact cell 10 when it is shaded in the module and becomes a load, thereby reducing the risk of hot spots. At the same time, since the spacing between the second sub-grid 115 arranged in the non-overlapping portion 1332 of the first doped region 133 and the adjacent fine grid of different polarity is greater than the spacing between the first sub-grid 114 and the adjacent fine grid of different polarity, sufficient space can be left for the silicon substrate 101 to set the hot spot resistant structure, thereby reducing the short circuit risk caused by the contact between the fine grids of different polarities and the doped regions.

[0372] 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.

[0373] 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 and the photovoltaic glass, the adjacent battery pieces, etc. as a filler, which 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.

[0374] 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 as much as possible without affecting the efficiency of the back contact cell 10. At the same time, 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.

[0375] 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. The specific setting can be made according to the specific situation, which 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 battery assembly can be installed at the required installation position through the metal frame.

[0376] The photovoltaic system of the embodiment of the application includes the above-mentioned battery assembly.

[0377] The photovoltaic system of the embodiments of the present application can form a hot spot resistance structure, reduce reverse bias, reduce the heating power of the back contact cell 10 when it is shaded and becomes a load, and thus reduce the risk of hot spots. Meanwhile, the second sub-grid 115 arranged at the non-overlapping part 1332 of the first doped region 133 has a larger spacing with the adjacent fine grid of opposite polarity than the first sub-grid 114, so as to leave enough space for the silicon substrate 101 to set the hot spot resistance structure and reduce the risk of short circuit caused by the contact between the fine grids of different polarities and the doped regions.

[0378] In the embodiments, the photovoltaic system can be applied in photovoltaic power stations such as ground power stations, roof power stations, water surface power stations, etc., and can also be applied in devices or apparatuses that generate power by using solar energy, such as user solar power sources, solar street lamps, solar cars, solar buildings, 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 that need to generate power by using solar energy. 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 arrays are connected to the combiner box. The combiner box can combine the currents generated by the photovoltaic arrays. The combined current flows through the inverter to convert into alternating current required by the power grid, and then is connected to the power network to realize solar power supply.

[0379] In the description of the present specification, the description of the terms "some embodiments", "exemplary 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 exemplary 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.

[0380] In addition, the above are only the preferred embodiments of the present application and are not used to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A back contact cell, characterized in that, The application relates to a back contact cell, comprising: a silicon substrate comprising a plurality of first polarity doped regions and a plurality of second polarity doped regions arranged along a first direction; a plurality of first polarity fine grids and a plurality of second polarity fine grids arranged along the first direction, the first polarity fine grids and the second polarity fine grids being spaced apart; the first polarity doped regions comprise first doped areas, the second polarity doped regions comprise second doped areas, the first doped areas comprise overlapping parts and non-overlapping parts, the second doped areas comprise bodies and protruding parts, the bodies being spaced apart from the first doped areas, the protruding parts protruding from the bodies and overlapping the overlapping parts; the first polarity fine grids are positive grid lines, comprising first sub-grids and second sub-grids; the second sub-grids are arranged in the non-overlapping parts, the first sub-grids are arranged outside the non-overlapping parts, the distance between the second sub-grids and adjacent second polarity fine grids is greater than the distance between the first sub-grids and adjacent second polarity fine grids.

2. The back contact cell of claim 1, wherein, The distance between the second sub-grids and adjacent second polarity fine grids is a first distance, the distance between the first sub-grids and adjacent second polarity fine grids is a second distance, the difference between the first distance and the second distance is 0.05-0.1 mm.

3. The back contact cell of claim 1, wherein, The distance between the second sub-grids and adjacent second polarity fine grids is 0.2-0.8 mm.

4. The back contact cell of claim 1, wherein, The distance between the first sub-grids and adjacent second polarity fine grids is 0.1-0.7 mm.

5. The back contact cell of claim 1, wherein, The number of the second sub-grids is multiple, the number of fine grids between adjacent two second sub-grids is 8-35.

6. The back contact cell of claim 1, wherein, The distance between adjacent two second sub-grids is 6-16.8 mm.

7. The back contact cell of claim 1, wherein, In the first direction, the depth of the protruding parts protruding from the bodies is 40-500 microns.

8. The back contact cell of claim 1, wherein, The second sub-grids are provided with connecting structures, the width of the connecting structures is greater than the width of the second sub-grids.

9. A battery assembly characterized by, The application further relates to a back contact cell assembly comprising the back contact cell of any one of claims 1-8.

10. A photovoltaic system characterized by, The application further relates to a battery assembly comprising the battery of claim 9.

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