Back contact battery, battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell, a cell assembly and a photovoltaic system. The back contact cell comprises a silicon substrate, a plurality of first polarity fine grids and a plurality of second polarity fine grids. The silicon substrate comprises a silicon substrate and a plurality of passivation contact structures arranged on the silicon substrate; the first polarity fine grids and the second polarity fine grids are arranged on the silicon substrate at intervals and arranged in the first direction, and at least one of the first polarity fine grids and the second polarity fine grids is electrically connected with the passivation contact structure. The first polarity fine grid comprises a first grid line, the first grid line is provided with a first connecting block, the width of the first connecting block is larger than that of the first grid line, and the length of the first connecting block is larger than or equal to 100 micrometers; the second polarity fine grid comprises a second grid line, the second grid line comprises a first main body part and a first bending part which are connected, the first main body part extends along a second direction, the second direction is crossed with the first direction, and the first bending part is arranged corresponding to the first connecting block and is bent from the first main body part to the direction far away from the first connecting block.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a back-contact cell, a cell assembly and a photovoltaic system. Background Art

[0002] Solar cell power generation is a sustainable source of clean energy. It uses the photovoltaic effect of semiconductor pn junction to convert sunlight into electrical energy. In the related art, electrical connectors such as welding strips are usually used to connect back-contact cells to form a cell string. However, the electrical connectors are easy to fall off from the back-contact cells, resulting in poor connection stability.

[0003] Based on this, how to improve the connection stability between the back contact battery and the electrical connector has become an urgent problem to be solved. Summary of the invention

[0004] The present application provides a back-contact cell, a cell assembly and a photovoltaic system, aiming to solve the problem of how to improve the connection stability between the back-contact cell and the electrical connector.

[0005] The back contact battery provided in the present application comprises: A silicon substrate, comprising a silicon substrate and a plurality of passivation contact structures arranged on the silicon substrate; A plurality of first polarity fine gates and a plurality of second polarity fine gates are disposed on the silicon substrate and arranged along a first direction, wherein the first polarity fine gates and the second polarity fine gates are spaced apart; at least one of the first polarity fine gates and the second polarity fine gates is electrically connected to the passivation contact structure; The first polarity fine gate includes a first gate line, the first gate line is provided with a first connection block, the width of the first connection block is greater than the width of the first gate line, and the length of the first connection block is greater than or equal to 100 μm; The second polarity fine grid includes a second grid line, and the second grid line includes a first main body and a first bending portion connected to each other. The first main body extends along a second direction, and the second direction intersects with the first direction. The first bending portion is arranged corresponding to the first connecting block and bends from the first main body to a direction away from the first connecting block.

[0006] The battery assembly provided in the present application includes any of the back-contact batteries described above.

[0007] The photovoltaic system provided in the present application includes any one of the above-mentioned battery components.

[0008] In the back contact cell, battery assembly and photovoltaic system of the embodiment of the present application, since the width of the first connection block is greater than the width of the first grid line and the length is greater than or equal to 100μm, the contact area between the first connection block and the electrical connector can be increased, the pulling force can be increased, the risk of the electrical connector falling off the back contact cell can be reduced, and the connection stability between the back contact cell and the electrical connector can be improved. At the same time, since the first bent portion in the second grid line bends from the first main body toward the direction away from the first connection block, more space can be provided for the first connection block with a larger width, which is convenient for widening the first connection block and can reduce the risk of short circuit caused by the small distance between the electrodes of the two polarities. Moreover, since at least one of the first polarity fine grid and the second polarity fine grid is electrically connected to the passivation contact structure provided on the silicon substrate, recombination can be reduced, which is beneficial to improving the photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a partial structure of a back contact battery according to an embodiment of the present application; Figure 2 yes Figure 1 Schematic diagram of the partial structure of the back contact battery in the A range; Figure 3 is a schematic structural diagram of a back contact battery according to an embodiment of the present application; Figure 4 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Figure 5 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Figure 6 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Figure 7 is a schematic diagram of a partial structure of a back contact battery according to an embodiment of the present application; Figure 8 yes Figure 7 Schematic diagram of the partial structure of the back contact battery in the B range; Fig. 9 Another embodiment of the present invention is a back contact battery and Figure 7 A schematic diagram of the structure of the part corresponding to the range B in the middle; Fig.10 Another embodiment of the present invention is a back contact battery and Figure 7 A schematic diagram of the structure of the part corresponding to the range B in the middle; Fig.11 Another embodiment of the present invention is a back contact battery and Figure 7 A schematic diagram of the structure of the part corresponding to the range B in the middle; Fig.12 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.13 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.14 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.15 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.16 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.17 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.18 Another embodiment of the present invention is a back contact battery and Figure 1 A schematic diagram of the structure of the part corresponding to the range A in the middle; Fig.19 Another embodiment of the present invention is a back contact battery and Figure 7 A schematic diagram of the structure of the part corresponding to the range B in the middle; Fig. 20 Another embodiment of the present invention is a back contact battery and Figure 7 A schematic diagram of the structure of the part corresponding to the range B in the middle; Fig.21 is a schematic diagram of a partial structure of a back contact battery according to an embodiment of the present application; Fig. 22 yes Fig.21 Schematic diagram of the partial structure of the back contact battery in the C range; Fig.23 Another embodiment of the present invention is a back contact battery and Fig.21 A schematic diagram of the structure of the part corresponding to the C range in the middle; Fig.24 Another embodiment of the present invention is a back contact battery and Fig.21 A schematic diagram of the structure of the part corresponding to the C range in the middle; Fig.25 Another embodiment of the present invention is a back contact battery and Fig.21 A schematic diagram of the structure of the part corresponding to the C range in the middle; Fig.26is a schematic diagram of a back contact battery according to an embodiment of the present application; Fig. 27 yes Fig.26 Schematic diagram of the partial structure of the back contact battery. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0011] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0012] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0013] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0014] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0015] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0016] See also Figure 1 , Figure 2 and Figure 3 The back contact battery 10 of the embodiment of the present application comprises: The silicon substrate 101 includes a silicon substrate and a plurality of passivation contact structures disposed on the silicon substrate; A plurality of first polarity fine gates 11 and a plurality of second polarity fine gates 12 are disposed on the silicon substrate 101 and arranged along a first direction, with the first polarity fine gates 11 and the second polarity fine gates 12 spaced apart; at least one of the first polarity fine gates 11 and the second polarity fine gates 12 is electrically connected to the passivation contact structure; The first polarity fine gate 11 includes a first gate line 111, the first gate line 111 is provided with a first connection block 112, the width w1 of the first connection block 112 is greater than the width w2 of the first gate line 111, and the length s1 of the first connection block 112 is greater than or equal to 100 μm; The second polarity fine grid 12 includes a second grid line 121, and the second grid line 121 includes a first main body 1211 and a first bending portion 1212 connected to each other. The first main body 1211 extends along a second direction, and the second direction intersects the first direction. The first bending portion 1212 is arranged corresponding to the first connecting block 112, and bends from the first main body 1211 to a direction away from the first connecting block 112.

[0017] In the back contact battery 10 of the embodiment of the present application, since the width w1 of the first connection block 112 is greater than the width w2 of the first gate line 111 and the length s1 is greater than or equal to 100 μm, the contact area between the first connection block 112 and the electrical connector can be increased, the pulling force can be increased, the risk of the electrical connector falling off from the back contact battery 10 can be reduced, and the connection stability between the back contact battery 10 and the electrical connector can be improved. At the same time, since the first bending portion 1212 in the second gate line 121 is bent from the first main body 1211 to the direction away from the first connection block 112, more space can be provided for the first connection block 112 with a larger width, which is convenient for widening the first connection block 112 and can reduce the risk of short circuit caused by the small distance between the electrodes of the two polarities. Moreover, since at least one of the first polarity fine grid 11 and the second polarity fine grid 12 is electrically connected to the passivation contact structure provided on the silicon substrate, recombination can be reduced, which is conducive to improving the photoelectric conversion efficiency.

[0018] Specifically, the back contact cell 10 may be a sliced ​​cell formed by cutting a whole cell. Figure 3 The back contact battery 10 may also be a whole battery that has not been cut. The whole back contact battery 10 may include a slicing groove, and the whole battery may be cut along the slicing groove to obtain a half battery. Figure 3 The sliced ​​battery shown. The whole back contact battery 10 can be asymmetrical along the slice groove, or symmetrical along the slice groove.

[0019] This article takes the busbar-free back contact battery 10 as an example for explanation and description. It can be understood that the back contact battery 10 can be a busbar-equipped back contact battery 10. In the case where the back contact battery 10 is a busbar-equipped back contact battery 10, the busbar can be located in an area outside the first connection block 112. In this way, the busbar can be prevented from interfering with the connection between the first connection block 112 and the first electrical connector.

[0020] Specifically, the silicon base 101 may include a silicon substrate, a first polarity doping layer, a second polarity doping layer and a dielectric film layer 1003 .

[0021] Furthermore, the silicon substrate may be a P-type silicon substrate or an N-type silicon substrate, a single crystal silicon substrate or a polycrystalline silicon substrate. The specific form of the silicon substrate is not limited here.

[0022] Furthermore, the first polarity doped layer and the second polarity doped layer are arranged 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 into the silicon substrate or by depositing a film layer on the silicon substrate.

[0023] It can be understood that in the thickness direction of the back contact battery 10, the first polarity doped layer is stacked on the silicon substrate, and the second polarity doped layer is stacked on the silicon substrate. On the plane perpendicular to the thickness direction of the back contact battery 10, the first polarity doped layer and the second polarity doped layer are distributed in different regions, corresponding to the first polarity doped region 13 and the second polarity doped region 14, respectively. Figure 12-Figure 20 shown.

[0024] The following descriptions of “the first polarity doping region 13 includes the first doping region 131” and “the first polarity doping region 13 includes the third doping region 132” refer to that the first doping region 131 and the third doping region 132 are doping regions of the first polarity. The following descriptions of “the second polarity doping region 14 includes the second doping region 141” and “the second polarity doping region 14 includes the fourth doping region 142” refer to that the second doping region 141 and the fourth doping region 142 are doping regions of the second polarity.

[0025] Furthermore, the dielectric film layer 1003 may cover the first polarity doping layer and the second polarity doping layer, the first polarity fine gate 11 passes through the dielectric film layer 1003 to contact the first polarity doping layer, and the second polarity fine gate 12 passes through the dielectric film layer 1003 to contact the second polarity doping layer. In this way, the dielectric film layer 1003 is used to achieve electrical isolation of the first polarity doping layer and the second polarity doping layer, and the dielectric film layer 1003 can also 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 doping regions 13 and second polarity doping regions 14 to electrically isolate the first polarity doping regions 13 and the second polarity doping regions 14. Please note that in order to better display the first polarity doping regions 13 and the second polarity doping regions 14, Figure 12-Figure 20 The portion of the dielectric film layer 1003 covering the first polarity doping region 13 and the second polarity doping region 14 is omitted.

[0026] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 may be distributed in the entire region of the silicon substrate 101; the first polarity fine gate 11 and the second polarity fine gate 12 may be distributed in a partial region of the silicon substrate 101. It can be understood that the region of the silicon substrate 101 where the first polarity fine gate 11 and the second polarity fine gate 12 are not distributed may be distributed with other fine gates, may be distributed with a main gate, or may not be provided with a gate line.

[0027] Specifically, the first polarity fine gate 11 and the second polarity fine gate 12 have different polarities. The first polarity fine gate 11 corresponds to the first polarity doping layer and the first polarity doping region 13. The second polarity fine gate 12 corresponds to the second polarity doping layer and the second polarity doping region 14.

[0028] Specifically, the number of the first polarity fine grids 11 may be 1, 2, 3, 4 or other numbers. The number of the second polarity fine grids 12 may be 1, 2, 3, 4 or other numbers. No limitation is made here. The number of the first polarity fine grids 11 and the number of the second polarity fine grids 12 may be the same or different.

[0029] Specifically, the first polarity fine grids 11 and the second polarity fine grids 12 are arranged along the first direction, and may be arranged alternately or non-alternatingly, and may be arranged at equal intervals or at unequal intervals along the first direction, which is not limited here.

[0030] Specifically, the first polarity fine grid 11 and the second polarity fine grid 12 are spaced apart, which means that a gap is formed between adjacent first polarity fine grids 11 and second polarity fine grids 12. The gap may be filled with an insulating member or may be an air gap.

[0031] The following descriptions of “the first polarity fine gate 11 includes the first gate line 111”, “the first polarity fine gate 11 includes the third gate line 113” and “the first polarity fine gate 11 includes the fifth gate line 114 and the sixth gate line 115” mean that the first gate line 111, the third gate line 113, the fifth gate line 114 and the sixth gate line 115 are all fine gates of the first polarity. The following descriptions of “the second polarity fine gate 12 includes the second gate line 121” and “the second polarity fine gate 12 includes the fourth gate line 122” mean that the second gate line 121 and the fourth gate line 122 are all fine gates of the second polarity.

[0032] See also Figure 1 , Figure 2 and Figure 3 In this embodiment, the first gate line 111 is a first polarity fine gate 11 closest to the edge of the silicon substrate 101. In this way, the risk of the electrical connector falling off from the end of the back contact battery 10 can be reduced.

[0033] It is understood that in other embodiments, the first gate line 111 may 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 position of the back contact battery 10 can be reduced. In this case, a bent second gate line 121 can be set on one side or both sides of the first gate line 111 to avoid the first connection block 112 provided on the first gate line 111.

[0034] See also Figure 1 , Figure 2 and Figure 3 , the first connection block 112 is disposed on the first gate line 111 . That is, the first connection block 112 is connected to the first gate line 111 .

[0035] Specifically, the first connection block 112 may pass through the dielectric film layer 1003 to contact the first polarity doped layer. The first connection block 112 and the first polarity doped layer may also be isolated by the dielectric film layer 1003. The first connection block 112 may be manufactured together with the first gate line 111. The first connection block 112 may also be manufactured in steps with the first gate line 111.

[0036] In one example, the first connection block 112 and the first gate line 111 are made of the same paste, and both are burned through the dielectric film layer 1003 to contact the first polarity doped layer. In another example, the paste of the first gate line 111 is burned through the dielectric film layer 1003 to contact the first polarity doped layer, and the paste of the first connection block 112 is not burned through the dielectric film layer 1003.

[0037] In some embodiments, the first connection block 112 includes at least one of a pad and a gate line segment. In this way, the first connection block 112 is diverse in form, which is conducive to meeting more production scenarios and needs. For example, the first connection block 112 includes a pad. In another example, the first connection block 112 includes a gate line segment. In another example, the first connection block 112 includes a pad and a gate line segment. It can be understood that when the first connection 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. When the first connection block 112 includes a pad, the pad can pass through the dielectric film layer 1003 to contact the first polarity doped layer, and can also be isolated from the first polarity doped layer by the dielectric film layer 1003.

[0038] Note that in two adjacent back-contact cells 10, the electrical connector electrically connects the fine grids of one polarity in one back-contact cell 10, and electrically connects the fine grids of the other polarity in the other back-contact cell 10. This article discusses the connection of the electrical connector in one back-contact cell 10.

[0039] That is, in a back-contact cell 10, the first electrical connector is electrically connected to the first polarity fine grid 11 and isolated from the second polarity fine grid 12; the second electrical connector is electrically connected to the second polarity fine grid 12 and isolated from the first polarity fine grid 11. In other words, the fine grids connected by an electrical connector in a back-contact cell 10 are of the same polarity. It is understood that this does not mean that the electrical connector has the same polarity as the fine grid it is connected to.

[0040] Specifically, the first electrical connector and the second electrical connector extend along the first direction and are alternately arranged along the second direction.

[0041] Specifically, the second polarity fine grid 12 can be disconnected at the covering part of the first electrical connector to avoid the first electrical connector; the second polarity fine grid 12 can also be continuous at the covering part of the first electrical connector and be electrically isolated from the first electrical connector by the insulating part. Similarly, the first polarity fine grid 11 can be disconnected at the covering part of the second electrical connector to avoid the second electrical connector; the first polarity fine grid 11 can also be continuous at the covering part of the second electrical connector and be electrically isolated from the second electrical connector by the insulating part.

[0042] Specifically, the first connection block 112 is used to connect the first electrical connection member.

[0043] Furthermore, the first connection block 112 and the first electrical connector can be electrically connected by at least one of conductive adhesive bonding, direct welding, solder paste welding, and physical contact, which is not limited here.

[0044] Further, the entire area of ​​the first connection block 112 is connected to the first electrical connector. In this way, the connection area is large, which is conducive to improving the connection stability. It can be understood that in other embodiments, a partial area of ​​the first connection block 112 can also be connected to the first electrical connector.

[0045] Further, the first electrical connector includes at least one of a soldering strip and a conductive wire. This article takes the soldering strip as an example for explanation. It can be understood that when the first electrical connector is a soldering strip, the embodiment of the present application can reduce the risk of the soldering strip falling off from the back contact battery 10.

[0046] Specifically, the area of ​​the back contact cell 10 covered by the first electrical connector is the first pre-connection area.

[0047] Furthermore, in the battery assembly, the number of first electrical connectors connected to the same back contact battery 10 is multiple. In the back contact battery 10, a first connection block 112 may be provided in each first pre-connection area, such as Figure 3 As shown, the first connection block 112 may be provided in part of the first pre-connection area, and the first connection block 112 may not be provided in the remaining first pre-connection area.

[0048] Furthermore, in the first pre-connection region, a first connection block 112 may be provided at each first polarity fine grid 11. A first connection block 112 may also be provided at a portion of the first polarity fine grid 11. This is not limited here. Figure 3 In the example of FIG. 1 , first connection blocks 112 are provided at the first polarity fine gates 11 at both ends of the first pre-connection region.

[0049] See also Figure 1 and Figure 2, the width w1 of the first connection block 112 refers to the size of the first connection block 112 in the first direction. The width w1 of the first connection block 112 may be the same everywhere, different everywhere, or partially the same. The width w2 of the first gate line 111 refers to the size of the first gate line 111 in the first direction. The width w2 of the first gate line 111 may be the same everywhere, different everywhere, or partially the same.

[0050] Specifically, the width w1 of the first connection block 112 is greater than the width w2 of the first gate line 111, which means that 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; it can also be that the maximum width of the first connection block 112 is greater than the maximum width of the first gate line 111; it can also be that the maximum width of the first connection block 112 is greater than the width of the connection between the first gate line 111 and the first connection block 112. This is not limited here.

[0051] See also Figure 2 The length s1 of the first connection block 112 is greater than or equal to 100 μm, for example, 100 μm, 101 μm, 110 μm, 150 μm, 200 μm, 500 μm, 800 μm, 1000 μm, 1800 μm, 2000 μm, or 5000 μm.

[0052] Specifically, the length s1 of the first connection block 112 refers to the size of the first connection block 112 in the second direction. The length s1 of the first connection block 112 may be the same everywhere, different everywhere, or partially the same.

[0053] The length s1 of the first connection block 112 is greater than or equal to 100 μm, which means that the length of at least one location of the first connection block 112 is greater than or equal to 100 μm. Alternatively, the minimum length of the first connection block 112 is greater than or equal to 100 μm, that is, the length of each location of the first connection block 112 is greater than or equal to 100 μm; or the maximum length of the first connection block 112 is greater than or equal to 100 μm. This is not limited here.

[0054] See also Figure 2 and Figure 4 In some embodiments, the first connection block 112 is formed with a first hollow area 1120. In this way, the material of the first connection block 112 can be reduced while ensuring the coverage of the first connection block 112, which is conducive to improving the connection stability and reducing the cost.

[0055] See also Figure 5In some embodiments, the first connection block 112 is solid. In this way, the area of ​​the first connection block 112 can be increased as much as possible, thereby increasing the contact area between the first connection block 112 and the electrical connector, increasing the pulling force, reducing the risk of the electrical connector falling off the back contact battery 10, and improving the connection stability between the back contact battery 10 and the electrical connector.

[0056] See also Figure 1 and Figure 2 In some embodiments, the first connection block 112 is rectangular. It is understood that in other embodiments, the first connection block 112 may be circular, annular, elliptical, triangular, racetrack-shaped or other forms. The specific form of the first connection block 112 is not limited here.

[0057] See also Figure 1 , Figure 2 and Figure 3 The second gate line 121 includes a first main body 1211 and a first bending portion 1212 connected to each other. The first main body 1211 extends along a second direction that intersects the first direction. The first bending portion 1212 is arranged corresponding to the first connecting block 112 and bends from the first main body 1211 to a direction away from the first connecting block 112.

[0058] Specifically, the first main body portion 1211 and the first bending portion 1212 are connected, which means that the first main body portion 1211 and the first bending portion 1212 are electrically connected and not disconnected.

[0059] Specifically, the first main body 1211 extending along the second direction means that the overall extending direction of the first main body 1211 is the second direction. This does not represent a limitation on the specific form of the first main body 1211. In this embodiment, the first main body 1211 is linear, and the extending direction of the first main body 1211, that is, the second direction, is the length direction of the first main body 1211. In other embodiments, the first main body 1211 may also be wavy, folded, or other forms.

[0060] Specifically, the second direction intersects with the first direction, which means that the second direction does not overlap, is not the same as, or is not opposite to the first direction. In this 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 may also be at an acute angle or an obtuse angle; the first direction and the second direction may also be at an acute angle or an obtuse angle to two adjacent long sides of the silicon substrate 101, respectively. This is not limited here. Please note that the "two adjacent long sides" here refer to the sides other than the corners of the silicon substrate 101, without considering the arc sides or short sides formed with rounded corners or chamfers at the corners of the silicon substrate 101.

[0061] Specifically, the first bending portion 1212 is arranged corresponding to the first connecting block 112, which means that, regardless of the thickness of the first bending portion 1212 and the first connecting block 112, in the first direction, the projections of the first bending portion 1212 and the first connecting block 112 on the same plane at least partially overlap. In other words, the range occupied by the first bending portion 1212 and the first connecting block 112 in the second direction at least partially overlaps.

[0062] In this embodiment, the range occupied by the first bent portion 1212 in the second direction covers and exceeds the range occupied by the first connection block 112 in the second direction. In this way, the first bent portion 1212 is used to avoid the first connection block 112 as much as possible, so as to provide more space for the first connection block 112 with a larger width, facilitate the widening of the first connection block 112, and reduce the risk of short circuit caused by the small distance between the electrodes of the two polarities as much as possible.

[0063] It can be understood that in other embodiments, the range occupied by the first connecting block 112 in the second direction may 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 may completely overlap with 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 may intersect with the range occupied by the first bending portion 1212 in the second direction.

[0064] Specifically, the first bending portion 1212 bends from the first main body portion 1211 toward a direction away from the first connecting block 112 , which means that in the first direction, a maximum distance between the first bending portion 1212 and the first main body portion 1211 is greater than 0.

[0065] Specifically, the first bending portion 1212 includes a first bending section, a first connecting section, and a second bending section connected in sequence, wherein the first bending section connects the first main body portion 1211 and one end of the first connecting section, and the second bending section connects the first main body portion 1211 and the other end of the first connecting section. Figure 1 In the example, the first connecting segment is a straight line segment.

[0066] It is understood that in other examples, the first bending portion 1212 may be wavy, folded line, or other forms. The first connecting section may be wavy, folded line, or other forms. This is not limited here.

[0067] See also Figure 1 and Figure 2In 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 μm-290 μm, for example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0068] In this way, the width difference between the first connecting block 112 and the first gate line 111 is within an appropriate range, which can avoid the first connecting block 112 being too wide and the poor connection stability of the first electrical connector due to the difference being too small, and can also avoid the first connecting block 112 being too large and the current loss being too large due to the difference being too large.

[0069] See also Figure 1 and Figure 2 In some embodiments, the width w1 of the first connection block 112 is 10 μm-300 μm, for example, 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, or 300 μm.

[0070] In this way, the width w1 of the first connecting block 112 is within an appropriate range, which can avoid the situation where the width is too small, resulting in a smaller contact width with the first electrical connector and poor connection stability of the first electrical connector, and can also avoid the situation where the series resistance of the first connecting block 112 is too large and the current loss is too large, resulting in a larger width.

[0071] See also Figure 1 and Figure 2 In some embodiments, the width w2 of the first gate line 111 is 5 μm-250 μm, for example, 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, or 250 μm.

[0072] 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 and the poor effect of extracting carriers from the silicon substrate 101 due to a too small width, and can also avoid the excessive series resistance, large current loss and high cost due to a too large width.

[0073] See also Figure 1 and Figure 2 In some embodiments, the maximum distance d1 between the first bending portion 1212 and the first main body portion 1211 in the first direction 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, or 290 μm.

[0074] In this way, the maximum distance d1 between the first bending portion 1212 and the first main body portion 1211 in the first direction is within an appropriate range, which can avoid the first bending portion 1212 and the first connecting block 112 with different polarities being close to each other and the risk of short circuit being greater due to too small a spacing, 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 too large a spacing.

[0075] See also 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: -100μm≤w1-w2-d1≤100μm; Wherein, w1 is the width of the first connection block 112 , w2 is the width of the first gate line 111 , and d1 is the maximum distance between the first bending portion 1212 and the first main body portion 1211 in the first direction.

[0076] In this way, the difference in width between the first connecting block 112 and the first gate line 111 and the difference in the maximum bending depth of the first bending portion 1212 are within an appropriate range, which can avoid the situation where the maximum bending depth of the first bending portion 1212 is too large compared to the width difference between the first connecting block 112 and the first gate line 111 due to the difference being too small, and the series resistance of the second gate line 121 is too large while it is difficult to significantly improve the short circuit risk. It can also avoid the situation where the maximum bending depth of the first bending portion 1212 is too small compared to the width difference between the first connecting block 112 and the first gate line 111 due to the difference being too large, and the short circuit risk is greater.

[0077] 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, and 100 μm.

[0078] Preferably, the value of w1-w2-d1 is 0. That is, w1-w2=d1. In this way, both the short circuit risk and the series resistance are taken into consideration, and the overall effect is better.

[0079] See also Figure 1 and Figure 2 In some embodiments, the first gate line 111 is a first polarity fine gate 11 closest to the edge of the silicon substrate 101, and the distance x1 between the first gate line 111 and the edge is 0.4 mm-1 mm, for example, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0080] In this way, the distance x1 between the first gate line 111 and the edge is within an appropriate range, which can avoid the inconvenience of lamination caused by too small a distance, and can also avoid the poor effect of collecting carriers caused by too large a distance.

[0081] Preferably, the distance x1 between the first grid line 111 and the edge is 0.5 mm-0.8 mm, for example 0.5 mm, 0.52 mm, 0.55 mm, 0.58 mm, 0.6 mm, 0.62 mm, 0.65 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.75 mm, 0.78 mm, 0.8 mm. In this way, the distance x1 between the first grid line 111 and the edge is further optimized to achieve a better overall effect.

[0082] See also Figure 1 and Figure 2 In some embodiments, the distance x2 from the first connection block 112 to the edge is 0.4 mm-50 mm, for example, 0.4 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 48 mm, or 50 mm.

[0083] In this way, the distance x2 from the first connecting block 112 to the edge is within a suitable range, which can avoid inconvenience in stacking caused by too small a distance, and can also avoid poor connection stability between the end area of ​​the back contact battery 10 and the first electrical connector caused by too large a distance.

[0084] Preferably, the distance x2 from the first connection block 112 to the edge is 0.8 mm-5 mm, for example 0.8 mm, 0.82 mm, 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm. In this way, the distance x2 from the first connection block 112 to the edge is further optimized, so that the connection stability between the back contact battery 10 and the first electrical connector is better.

[0085] See also Figure 6 In some embodiments, the first polarity fine gate 11 includes a third gate line 113, the third gate line 113 includes a second main body 1131 and a second bending portion 1132 connected to each other, the second main body 1131 extends along the second direction, the second bending portion 1132 is arranged corresponding to the first connecting block 112, and bends from the second main body 1131 to a direction away from the first connecting block 112.

[0086] In this way, the bent third gate line 113 can be used to provide more space for the first connecting block 112 with a larger width and the second gate line 121 bent to avoid the first connecting block 112, so as to facilitate the widening of the first connecting block 112 and the bending of the second gate line 121, and reduce the risk of short circuit caused by the small distance between the electrodes of the two polarities.

[0087] Specifically, the second main body portion 1131 and the second bending portion 1132 are connected, which means that the second main body portion 1131 and the second bending portion 1132 are electrically connected and not disconnected.

[0088] Specifically, the second main body 1131 extending along the second direction means that the second main body 1131 extends in the second direction as a whole. This does not limit the specific form of the second main body 1131. In this embodiment, the second main body 1131 is linear, and the extension direction of the second main body 1131, that is, the second direction, is the length direction of the second main body 1131. In other embodiments, the second main body 1131 may also be wavy, broken, or other forms.

[0089] Specifically, the second bending portion 1132 is arranged corresponding to the first connection block 112, which means that, regardless of the thickness of the second bending portion 1132 and the first connection block 112, in the first direction, the projections of the second bending portion 1132 and the first connection block 112 on the same plane at least partially overlap. In other words, the range occupied by the second bending portion 1132 and the first connection block 112 in the second direction at least partially overlaps.

[0090] In this embodiment, the range occupied by the second bending portion 1132 in the second direction covers and exceeds the range occupied by the first connection block 112 in the second direction. In this way, the second bending portion 1132 is used to avoid the first connection block 112 as much as possible, so as to provide more space for the first connection block 112 with a larger width, facilitate the widening of the first connection block 112, and reduce the risk of short circuit caused by the small distance between the electrodes of the two polarities as much as possible.

[0091] It can be understood that in other embodiments, the range occupied by the first connecting block 112 in the second direction may cover and exceed the range occupied by the second bending portion 1132 in the second direction; the range occupied by the first connecting block 112 in the second direction may completely overlap with the range occupied by the second bending portion 1132 in the second direction; or the range occupied by the first connecting block 112 in the second direction may intersect with the range occupied by the second bending portion 1132 in the second direction.

[0092] Specifically, the second bending portion 1132 is bent from the second main body portion 1131 toward a direction away from the first connecting block 112 , which 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.

[0093] Specifically, the second bending portion 1132 includes a third bending section, a second connecting section and a fourth bending section which are connected in sequence, the third bending section connects one end of the second main body portion 1131 and the second connecting section, and the fourth bending section connects the other end of the second main body portion 1131 and the second connecting section. Figure 6 In the example, the second connecting segment is a straight line segment.

[0094] It is understood that in other examples, the second bending portion 1132 may be wavy, folded line, or other forms. The second connecting section may be wavy, folded line, or other forms. This is not limited here.

[0095] Please note that the second gate line 121 is a bent second polarity thin gate 12, and the third gate line 113 is a bent first polarity thin gate 11. The second gate line 121 may be adjacent to the first gate line 111, or may not be adjacent to the first gate line 111. The third gate line 113 may be adjacent to the second gate line 121, or may not be adjacent to the second gate line 121.

[0096] exist Figure 1-Figure 5 In the example of , the number of the second gate line 121 is one, which is adjacent to the first gate line 111, and there is no third gate line 113. That is, along the direction away from the edge, the first gate line 111 and the second gate line 121 are arranged in sequence.

[0097] exist Figure 6 In the example, the number of second gate lines 121 is 2, the number of third gate line 113 is 1, one second gate line 121 is adjacent to the first gate line 111, and the third gate line 113 is located between two second gate lines 121. That is, in the direction away from the edge, the first gate line 111, the second gate line 121, the third gate line 113, and the second gate line 121 are arranged in sequence.

[0098] It can be understood that in other examples, the first gate line 111 , the second gate line 121 , the third gate line 113 , the second gate line 121 , and the third gate line 113 may be arranged in sequence in a direction away from the edge.

[0099] See also Figure 6 In some embodiments, along the direction away from the first connecting block 112 , the bending depths of the first bending portion 1212 and the second bending portion 1132 gradually decrease.

[0100] In this way, the bending depth of the bending portion gradually decreases along the direction away from the first connecting block 112, which can be used to avoid the first connecting block 112 or the adjacent bending portion and reduce the risk of short circuit, and can also achieve a transition from bending to smoothness.

[0101] 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 second gate line 121 in the first direction, that is, 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, Figure 6 d2 shown in .

[0102] exist Figure 6In the example, 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, and the bending depths of the corresponding bending portions gradually decrease.

[0103] See also Figure 6 In some embodiments, for the adjacent second gate line 121 and the third gate line 113, the first bending portion 1212 and the second bending portion 1132 satisfy the following formula: 50μm≤d1-d2≤150μm; 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.

[0104] In this way, the difference in the bending depths of the adjacent second gate lines 121 and the third gate lines 113 is within an appropriate range, which can avoid the need to use more bent gate lines to achieve a smooth transition from bending, increased process complexity, and low production efficiency due to a difference that is too small. It can also avoid the situation where the bending depth of a gate line is insufficient, the distance to the bending portion with opposite polarity is close, and the risk of short circuit is high due to a difference that is too large.

[0105] Specifically, the value of d1 - d2 is, for example, 50 μm, 52 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, or 150 μm.

[0106] See also Figure 1 , Figure 2 and Figure 3 In some embodiments, the first gate lines 111 and the first connecting blocks 112 disposed on the first gate lines 111 form a first conductive structure 1001 , and each row of the first conductive structures 1001 is continuous.

[0107] In this way, each row of the first conductive structures 1001 is not disconnected or has no breakpoints, so that the power of the back contact battery 10 is better.

[0108] See also Figure 1 , Figure 2 and Figure 3 In some embodiments, each row of second gate lines 121 is continuous.

[0109] In this way, each row of second gate lines 121 is not disconnected or has no breakpoints, so that the power of the back contact battery 10 is better.

[0110] See also Figure 7 and Figure 8In some embodiments, the second polarity fine gate 12 includes a fourth gate line 122 , the fourth gate line 122 is provided with a second connection block 123 , and a width w3 of the second connection block 123 is greater than a width w4 of the fourth gate line 122 .

[0111] In this way, the contact area between the second connection block 123 and the second electrical connector is increased, the pulling force is increased, the risk of the second electrical connector falling off the back contact battery 10 is reduced, and the connection stability between the back contact battery 10 and the second electrical connector is improved.

[0112] See also 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 gate 12. In this way, the first bent portion 1212 and the second connecting block 123 are integrated into the same second polarity fine gate 12, so that the connection stability between the second electric connection member and the fourth gate line 122 and the second gate line 121 is stronger. Moreover, the design and production can be centralized, which is conducive to improving the production efficiency.

[0113] Please note that when the fourth gate line 122 and the second gate line 121 are the same second polarity fine gate 12 , the fourth gate line 122 and the second gate line 121 can be respectively regarded as partial structures of the second polarity fine gate 12 .

[0114] It can be understood that in other examples, the fourth gate line 122 and the second gate line 121 may also be different second polarity fine gates 12. This is not limited here.

[0115] Specifically, the second connection block 123 is used to connect the second electrical connection member.

[0116] Furthermore, the second connection block 123 and the second electrical connector can be electrically connected by at least one of conductive adhesive bonding, direct welding, solder paste welding, and physical contact, which is not limited here.

[0117] Further, the entire area of ​​the second connection block 123 is connected to the second electrical connector. In this way, the connection area is large, which is conducive to improving the connection stability. It can be understood that in other embodiments, a partial area of ​​the second connection block 123 can also be connected to the second electrical connector.

[0118] Further, the second electrical connector includes at least one of a soldering strip and a conductive wire. This article takes the soldering strip as an example for explanation. It can be understood that when the second electrical connector is a soldering strip, the embodiment of the present application can reduce the risk of the soldering strip falling off from the back contact battery 10.

[0119] Specifically, the area of ​​the back contact cell 10 covered by the second electrical connector is the second pre-connection area.

[0120] Furthermore, in the battery assembly, the number of second electrical connectors connected to the same back contact battery 10 is multiple. In the back contact battery 10, a second connection block 123 may be provided in each second pre-connection area. A second connection block 123 may also be provided in part of the second pre-connection areas, and no second connection block 123 may be provided in the remaining second pre-connection areas. Furthermore, in the second pre-connection area, a second connection block 123 may be provided at each second polarity fine grid 12. A second connection block 123 may also be provided at part of the second polarity fine grid 12. This is not limited here. In the present embodiment, second connection blocks 123 are provided at the second polarity fine grids 12 at both ends of the second pre-connection area.

[0121] In some embodiments, the second connection block 123 includes at least one of a pad and a gate line segment. In this way, the second connection block 123 is diversified, which is conducive to meeting more production scenarios and needs. For example, the second connection block 123 includes a pad. In another example, the second connection block 123 includes a gate line segment. In another example, the second connection block 123 includes a pad and a gate line segment. It can be understood that when the second connection block 123 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the second polarity doped layer. When the second connection block 123 includes a pad, the pad can pass through the dielectric film layer 1003 to contact the second polarity doped layer, and can also be isolated from the second polarity doped layer by the dielectric film layer 1003.

[0122] See also Figure 7 and Figure 8 , the width w3 of the second connection block 123 refers to the size of the second connection block 123 in the first direction. The width w3 of the second connection block 123 may be the same everywhere, different everywhere, or partially the same. The width w4 of the fourth gate line 122 refers to the size of the fourth gate line 122 in the first direction. The width w4 of the fourth gate line 122 may be the same everywhere, different everywhere, or partially the same.

[0123] Specifically, the width w3 of the second connection block 123 is greater than the width w4 of the fourth gate line 122, which means that the width of at least one location of the second connection block 123 is greater than the width of at least one location of the fourth gate line 122. It can be that the minimum width of the second connection 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 connection 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 connection block 123 is greater than the width of the connection between the fourth gate line 122 and the second connection block 123. This is not limited here.

[0124] See also Figure 8 and Fig. 9In some embodiments, the second connection block 123 is formed with a second hollow area 1230. In this way, the material of the second connection block 123 can be reduced while ensuring the coverage of the second connection block 123, which is conducive to improving the connection stability and reducing the cost.

[0125] See also Fig.10 In some embodiments, the second connection block 123 is solid. In this way, the area of ​​the second connection block 123 can be increased as much as possible, thereby increasing the contact area between the second connection block 123 and the electrical connector, increasing the pulling force, reducing the risk of the electrical connector falling off the back contact battery 10, and improving the connection stability between the back contact battery 10 and the electrical connector.

[0126] See also Figure 7 and Figure 8 In some embodiments, the second connection block 123 is rectangular. It is understood that in other embodiments, the second connection block 123 may be circular, annular, elliptical, triangular, racetrack-shaped or other forms. The specific form of the second connection block 123 is not limited here.

[0127] See also Figure 7 and Figure 8 In some embodiments, the difference between the width w3 of the second connection block 123 and the width w4 of the fourth gate line 122 is 5 μm-290 μm, for example, 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0128] In this way, the width difference between the second connection block 123 and the fourth gate line 122 is within an appropriate range, which can avoid the second connection block 123 being too wide and the second electrical connection component having poor connection stability due to the difference being too small, and can also avoid the second connection block 123 having too large a series resistance and a large current loss due to the difference being too large.

[0129] See also Figure 7 and Figure 8 In some embodiments, the width w3 of the second connection block 123 is 10 μm-300 μm, for example, 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, or 300 μm.

[0130] In this way, the width w3 of the second connecting block 123 is within an appropriate range, which can avoid the situation where the width is too small, resulting in a smaller contact width with the second electrical connector and poor connection stability of the second electrical connector, and can also avoid the situation where the width is too large, resulting in too large a series resistance of the second connecting block 123 and a larger current loss.

[0131] See also Figure 7 and Figure 8 In some embodiments, the width w4 of the fourth gate line 122 is 5 μm-250 μm, for example, 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, or 250 μm.

[0132] In this way, the width w4 of the fourth gate line 122 is within an appropriate range, which can avoid the gate line being easily disconnected and the poor effect of extracting carriers from the silicon substrate 101 due to a too small width, and can also avoid the excessive series resistance, large current loss and high cost due to a too large width.

[0133] See also Figure 7 and Figure 8 In some embodiments, the difference between the area of ​​the first connection block 112 and the area of ​​the second connection block 123 is -400 μm. 2 ~400μm 2 . For example, -400μm 2 、-400μm 2 、-400μm 2 、-400μm 2 、-400μm 2 , 400μm 2 .

[0134] In this way, the difference between the area of ​​the first connecting block 112 and the area of ​​the second connecting block 123 is within an appropriate range, which can avoid a large difference in the area of ​​the first connecting block 112 and the second connecting block 123 caused by the difference being too small or too large, so that the contact area between the first connecting block 112 and the first electrical connector and the contact area between the second connecting block 123 and the second electrical connector are roughly the same, so that the pulling force of the first electrical connector and the second electrical connector on the connecting blocks is roughly the same, which is beneficial to improving the connection stability between the electrical connector and the back contact battery 10.

[0135] See also Figure 7 and Figure 8 In some embodiments, the first polarity fine grid 11 adjacent to the second connection block 123 is disconnected at a position corresponding to the second connection block 123 to avoid the second connection block 123. In the second direction, the interval d3 between the breakpoint of the second connection block 123 and the first grid line 111 is 0.2 mm-1 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm.

[0136] In this way, the space of the first polarity fine grid 11 adjacent to the second connection block 123 is utilized to make the second connection block 123 larger, which is beneficial to increase the contact area between the second connection block 123 and the second electrical connector and improve the connection stability. At the same time, the distance d3 between the second connection block 123 and the breakpoint of the first grid line 111 is within a suitable range, which can avoid the opposite polarity electrodes being too close and the risk of short circuit being greater due to too small a distance, and can also avoid the poor carrier collection effect of the spacer area and the poor efficiency of the battery due to too large a distance.

[0137] Specifically, the first polarity fine gate 11 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 fine gate 11 passes through the second connection block 123. In order to avoid the second connection block 123 with opposite polarity, the first polarity fine gate 11 is disconnected to form two breakpoints.

[0138] Preferably, the spacing d3 between the breakpoints of the second connection block 123 and the first gate line 111 is 0.3 mm-0.6 mm. For example, it is 0.3 mm, 0.32 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.58 mm, 0.6 mm. In this way, the spacing d3 between the breakpoints of the second connection block 123 and the first gate 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.

[0139] See also Figure 7 and Figure 8 In some embodiments, the fourth gate line 122 is the second polarity fine gate 12 closest to the edge of the silicon substrate 101, and the distance x3 between the fourth gate line 122 and the edge is greater than 0.7 mm-1.3 mm.

[0140] In this way, the distance x3 between the fourth gate line 122 and the edge is within an appropriate range, which can avoid the inconvenience of lamination caused by too small a distance, and can also avoid the poor effect of collecting carriers caused by too large a distance.

[0141] Preferably, the distance x3 between the fourth grid line 122 and the edge is 0.8 mm-1.1 mm, for example 0.8 mm, 0.82 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.95 mm, 1 mm, 1.02 mm, 1.05 mm, 1.08 mm, 1.1 mm. In this way, the distance x3 between the fourth grid line 122 and the edge is further optimized to achieve a better overall effect.

[0142] It can be understood that in other embodiments, the fourth grid line 122 can be located at a position away from the edge of the silicon substrate 101. For example, the fourth grid line 122 is the second, third, fourth or other numbered second polarity fine grid 12 from the edge. In this way, the risk of the electrical connector falling off from the middle position of the back contact battery 10 can be reduced. In this case, a bent first polarity fine grid 11 can be set on one side or both sides of the fourth grid line 122 to avoid the second connection block 123 provided on the fourth grid line 122.

[0143] See also Figure 7 and Figure 8 In some embodiments, the distance x4 from the second connection block 123 to the edge of the silicon substrate 101 is 0.7 mm-50 mm, for example, 0.7 mm, 0.8 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 48 mm, or 50 mm.

[0144] In this way, the distance x4 from the second connecting block 123 to the edge is within a suitable range, which can avoid the inconvenience of stacking caused by too small a distance, and can also avoid the poor connection stability between the end area of ​​the back contact battery 10 and the second electrical connector caused by too large a distance.

[0145] Preferably, the distance x4 from the second connection block 123 to the edge is 1 mm-5 mm, for example 1 mm, 1.02 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 4.5 mm, 5 mm. In this way, the distance x4 from the second connection block 123 to the edge is further optimized, so that the connection stability between the back contact battery 10 and the second electrical connector is better.

[0146] See also Figure 7 and Figure 8 In some embodiments, the fourth gate line 122 is a second polarity fine gate 12 closest to the edge of the silicon substrate 101 , and the second connecting block 123 is located on a side of the fourth gate line 122 facing the edge.

[0147] In this way, the edge space can be fully utilized, so that the second connection block 123 has a larger range and the connection welding strip has a larger range, which is beneficial to improving the connection stability between the back contact battery 10 and the second electrical connector.

[0148] In some embodiments, the second connection blocks 123 protrude from the fourth gate line 122 toward both sides of the fourth gate line 122 .

[0149] In this way, the space between the two sides of the second connection block 123 and the opposite-sex grid lines can be fully utilized, so that the range of the second connection block 123 is larger and the range of the connecting welding strip is larger, which is beneficial to improving the connection stability between the back contact battery 10 and the second electrical connector.

[0150] See also Fig.11 In some embodiments, the fourth gate line 122 includes a third main body portion 1221 and a third bending portion 1222 connected to each other, the third main body portion 1221 extends along the second direction, the third bending portion 1222 bends from the third main body portion 1221 in a direction away from the edge of the silicon substrate 101, and the second connecting block 123 is arranged on the third bending portion 1222.

[0151] In this way, the second connecting block 123 is arranged at the position where the fourth gate line 122 is bent in the direction away from the edge of the silicon substrate 101, so that the position of the second connecting block 123 can be farther away from the edge of the silicon substrate 101, farther away from the end of the second electrical connector, and closer to the middle of the second electrical connector. This can prevent the end of the second electrical connector from being difficult to extend to the second connecting block 123 near the edge of the silicon substrate 101 due to offset or cutting errors, so that the second connecting block 123 is easier to connect to the second electrical connector and the connection stability is higher.

[0152] Specifically, the third bending portion 1222 includes a fifth bending section, a third connecting section and a sixth bending section which are connected in sequence, the fifth bending section connects the third main body portion 1221 and one end of the third connecting section, and the sixth bending section connects the third main body portion 1221 and the other end of the fourth connecting section. Fig.11 In the example, the third connecting segment is a straight line segment.

[0153] It is understood that in other examples, the third bending portion 1222 may be wavy, folded line, or other forms. The second connecting section may be wavy, folded line, or other forms. This is not limited here.

[0154] See also Fig.11 In some embodiments, the maximum distance d4 between the third bending portion 1222 and the third main body portion 1221 in the first direction 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, or 290 μm.

[0155] In this way, the maximum distance d4 between the third bending portion 1222 and the third main body portion 1221 in the first direction is within an appropriate range, which can avoid the third bending portion 1222 and the adjacent opposite-sex fine gate being too close and the risk of short circuit being greater due to too small a spacing, and can also avoid the total length of the fourth gate line 122 being too large, the series resistance being too large, and the current loss being too large due to too large a spacing.

[0156] See also Figure 7 In some embodiments, the fourth gate line 122 and the second connecting block 123 disposed on the fourth gate line 122 form a second conductive structure 1002 , and each row of the second conductive structure 1002 is continuous.

[0157] In this way, each row of the second conductive structures 1002 is not disconnected or has no breakpoints, so that the power of the back contact battery 10 is better.

[0158] See also Fig.12 and Figure 2 In some embodiments, the silicon substrate 101 includes a plurality of first polarity doping regions 13 and a plurality of second polarity doping regions 14 arranged along a first direction, the first polarity doping regions 13 are provided with first polarity fine gates 11, and the second polarity doping regions 14 are provided with second polarity fine gates 12; The first polarity doping region 13 includes a first doping region 131, the first doping region 131 includes a first area 1311 and a second area 1312, the first area 1311 is provided with a first gate line 111, and the second area 1312 corresponds to the first connecting block 112; the second polarity doping region 14 includes a second doping region 141, the second doping region 141 includes a third area 1411 and a fourth area 1412, the third area 1411 is provided with a first main body 1211 of the second gate line 121, and the fourth area 1412 is provided with a first bending portion 1212 of the second gate line 121.

[0159] In this way, the doped regions of two polarities correspond to the fine gates of two polarities, which facilitates the production of fine gates of corresponding polarities on the doped regions and the electrical connection between the doped regions and the fine gates of corresponding polarities, thereby reducing process difficulty, improving production efficiency and reducing costs.

[0160] Specifically, “the first region 1311 is provided with the first gate line 111 ” means that the first gate line 111 is in electrical contact with the first region 1311 .

[0161] Specifically, “the second region 1312 corresponds to the first connection block 112” means that, in the thickness direction of the back contact battery 10, the projections of the first connection block 112 and the second region 1312 on the same plane at least partially overlap. The first connection block 112 may be in electrical contact with the second region 1312. It may also be electrically isolated from the second region 1312.

[0162] Specifically, “the third region 1411 is provided with the first main body 1211 of the second gate line 121 ” means that the first main body 1211 of the second gate line 121 is in electrical contact with the third region 1411 .

[0163] Specifically, “the fourth region 1412 is provided with the first bent portion 1212 of the second gate line 121 ” means that the first bent portion 1212 of the second gate line 121 is in electrical contact with the fourth region 1412 .

[0164] Specifically, the first polarity doping region 13 and the second polarity doping region 14 can be formed in the entire area 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 area of ​​the silicon substrate 101; the first polarity doping region 13 and the second polarity doping region 14 can be formed in a partial area 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 area of ​​the silicon substrate 101.

[0165] 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, and the second polarity doping region 14 corresponds to the second polarity doping layer.

[0166] Specifically, the number of the first polarity doping regions 13 may be 1, 2, 3, 4 or other numbers. The number of the second polarity doping regions 14 may be 1, 2, 3, 4 or other numbers. This is not limited here. The number of the first polarity doping regions 13 and the number of the second polarity doping regions 14 may be the same or different.

[0167] Specifically, the first polarity doping regions 13 and the second polarity doping regions 14 are arranged along the first direction, and may be arranged alternately or non-alternatingly, and may be arranged at equal intervals or at unequal intervals along the first direction, which is not limited here.

[0168] It can be understood that a gap may be formed between adjacent first polarity doping regions 13 and second polarity doping regions 14 , the ... second polarity doping regions 14 may be in contact with each other, or other film layer structures may be provided.

[0169] In some embodiments, a dielectric film layer 1003 is disposed between at least one pair of adjacent first polarity doping regions 13 and second polarity doping regions 14 , and the dielectric film layer 1003 electrically isolates the first polarity doping regions 13 and the second polarity doping regions 14 .

[0170] In this way, the dielectric film layer 1003 is used to achieve electrical isolation between the first doped layer and the second doped layer, and the refractive index difference and surface passivation effect of the dielectric film layer 1003 can be used to reduce optical loss and carrier recombination.

[0171] Specifically, the dielectric film layer 1003 may be disposed between a pair of adjacent first polarity doping regions 13 and second polarity doping regions 14, or between multiple pairs of adjacent first polarity doping regions 13 and second polarity doping regions 14. In this embodiment, the dielectric film layer 1003 is disposed between all adjacent first polarity doping regions 13 and second polarity doping regions 14.

[0172] Specifically, the dielectric film layer 1003 covers the first doped layer and the second doped layer, the first polarity fine gate 11 passes through the dielectric film layer 1003 to contact the first doped layer, and the second polarity fine gate 12 passes through the dielectric film layer 1003 to contact the second doped layer. In order to better show the first polarity doped region 13 and the second polarity doped region 14, the portion of the dielectric film layer 1003 covering the first polarity doped region 13 and the second polarity doped region 14 is omitted in the figure.

[0173] 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.

[0174] In some embodiments, a trench is formed between the first polarity doping region 13 and the second polarity doping region 14 , and the dielectric film layer 1003 is at least partially disposed in the trench.

[0175] In this way, the trench can be used to electrically isolate the first polarity doping region 13 from the second polarity doping region 14 inside the silicon substrate 101 , thereby reducing the risk of conduction between the first polarity doping region 13 and the second polarity doping region 14 .

[0176] Specifically, “the dielectric film layer 1003 is at least partially disposed in the trench” means that a portion of the dielectric film layer 1003 is disposed in the trench and the remaining portion is disposed outside the trench, or the entire dielectric film layer 1003 is disposed in the trench.

[0177] Specifically, the trench is continuously provided between the first polarity doping region 13 and the second polarity doping region 14. In other words, the first polarity doping region 13 and the second polarity doping region 14 are separated by the trench. In this way, it is ensured that the first polarity doping region 13 and the second polarity doping region 14 cannot be conductively connected across the trench.

[0178] In some embodiments, a tunneling layer is disposed between at least one pair of adjacent first polarity doping regions 13 and second polarity doping regions 14 , and both the first polarity doping regions 13 and the second polarity doping regions 14 are in contact with the tunneling layer.

[0179] In this way, the reverse bias voltage can be reduced, and the heat generation power when the back contact cell 10 is shielded in the assembly and becomes a load can be reduced. In addition, the tunneling layer can play a passivation role and reduce the recombination at the junction of the first polarity doping region 13 and the second polarity doping region 14.

[0180] Specifically, the tunneling layer includes at least one of a silicon oxide layer, an aluminum oxide layer, and a silicon carbide layer.

[0181] In some embodiments, at least one pair of adjacent first polarity doping regions 13 and second polarity doping regions 14 are in contact with each other.

[0182] In this way, the reverse bias voltage can be reduced, and the heat generation power when the back contact battery 10 becomes a load after being shielded in the component can be reduced.

[0183] Specifically, the adjacent first polarity doping regions 13 and second polarity doping regions 14 may contact each other in the entire region of the vicinity, or may contact each other in a partial region of the vicinity.

[0184] See also Fig.13 and Fig.14 In some embodiments, the second region 1312 protrudes from the first region 1311 .

[0185] In this way, the second area 1312 corresponding to the first connection block 112 protrudes from the first area 1311 provided with the first gate line 111, which can provide sufficient space for the first connection block 112 with a larger width. In addition, when the first connection block 112 is provided in the second area 1312 and is in electrical contact with the second area 1312, the risk of short circuit caused by the first connection block 112 with a larger width having a smaller distance from the edge of the first area 1311 and being too close to the adjacent second polarity doping area 14 can be reduced.

[0186] See also Fig.13 Specifically, the width W2 of the second area 1312 is greater than the width W1 of the first area 1311. In this way, the second area 1312 with a larger width better corresponds to the first connection block 112 with a larger width.

[0187] Specifically, the width W2 of the second region 1312 is 12 μm-2000 μm. For example, it is 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 within a suitable range, which can avoid the insufficient setting area of ​​the first connecting block 112 and the greater risk of short circuit due to a smaller width, and can also avoid the poor carrier collection effect of the other polarity due to an excessively large width.

[0188] 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 both the short circuit risk and the carrier collection effect, and the overall effect is better.

[0189] 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 within a suitable range, which can avoid insufficient arrangement area of ​​the first gate line 111, greater short circuit risk, and poor carrier collection effect corresponding to the first gate line 111 due to a small width, and can also avoid poor carrier collection effect of another polarity due to an excessively large width.

[0190] 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 both the short circuit risk and the carrier collection effect of the two polarities, and the overall effect is better.

[0191] It is understood that in other embodiments, the widths of the first area 1311 and the second area 1312 may be the same. Fig.13 Based on the example of , the upper side of the second area 1312 is concave, and the concave depth is equal to the convex depth of the lower side. In other embodiments, the width W2 of the second area 1312 can be smaller than the width W1 of the first area 1311. For example, in Fig.13 Based on the example of , the upper side of the second area 1312 is concave, and the concave depth is greater than the convex depth of the lower side. This is not limited here.

[0192] See also Fig.13 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.

[0193] In this way, the maximum depth H1 of the second area 1312 protruding from the first area 1311 is within an appropriate range, which can avoid insufficient setting area of ​​the first connecting block 112 and greater short circuit risk caused by too small a depth, and can also avoid being unfavorable for collecting carriers of the other polarity due to too large a depth.

[0194] See also Fig.14 In some embodiments, the fourth region 1412 is recessed from the third region 1411 on the side facing the second region 1312. In this way, the recessed fourth region 1412 cooperates with the protruding second region 1312 to fully utilize the space, making the arrangement of the doping regions more reasonable, which is conducive to better collection of carriers and improving the photoelectric conversion efficiency of the battery.

[0195] See also Fig.15 and Fig.16In some embodiments, the fourth region 1412 protrudes from the third region 1411 on a side facing away from the second region 1312 .

[0196] In this way, the fourth region 1412 corresponding to the first bending portion 1212 protrudes from the third region 1411 provided with the first main body portion 1211, which can provide sufficient space for the bent first bending portion 1212, thereby reducing the risk of short circuit caused by the small edge spacing between the bent first bending portion 1212 and the fourth region 1412 and being too close to the adjacent hetero-doped region.

[0197] See also Fig.16 In some embodiments, the side of the fourth region 1412 facing the second region 1312 is recessed from the third region 1411 , and the side of the fourth region 1412 facing away from the second region 1312 is protruded from the third region 1411 .

[0198] In this way, it is possible to cooperate with the protruding second area 1312 to fully utilize the space, making the arrangement of the doping areas more reasonable and conducive to better collection of carriers, and to provide sufficient space for the bent first bent portion 1212, thereby reducing the risk of short circuit caused by the small edge spacing between the bent first bent portion 1212 and the fourth area 1412 and being too close to the adjacent oppositely doped area.

[0199] Specifically, the recessed depth and the protruding depth of the fourth region 1412 are the same, so that 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.

[0200] It can be understood that in other embodiments, the concave depth of the fourth region 1412 may be greater than the convex depth, or may be less than the convex depth, which is not limited here.

[0201] See also Fig.15 and Fig.16 In some embodiments, in the first direction, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 on the side facing away from 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, or 500 μm.

[0202] In this way, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is within an appropriate range, which can avoid the risk of short circuit caused by a small edge distance between the first bend portion 1212 and the fourth region 1412 and being too close to the adjacent heterogeneous doped region due to the protrusion depth being too small, and can also avoid the poor carrier collection effect caused by the protrusion depth being too large.

[0203] Preferably, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 on the side away from the second region 1312 is 5 μm-190 μm. For example, 5 μm, 6 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 180 μm, 190 μm. In this way, the maximum depth of the fourth region 1412 protruding from the third region 1411 is further optimized, taking into account both the short circuit risk and the collection of carriers, and the overall effect is better.

[0204] Specifically, the width of the third region 1411 is the same as that of the fourth region 1412. This is beneficial for better collection of carriers.

[0205] It is understood that in other embodiments, the width W4 of the fourth region 1412 may be smaller than the width W3 of the third region 1411. Fig.14 As shown; it may also be that the width W4 of the fourth region 1412 is greater than the width W3 of the third region 1411, as shown Fig.15 No limitation is given here.

[0206] See also Fig.15 and Fig.16 In some embodiments, the second region 1312 protrudes from the first region 1311 toward the side of the fourth region 1412, and in the first direction, 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 is 50 μm-200 μm, for example, 50 μm, 52 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, and 200 μm.

[0207] In this way, the difference between the maximum depth of the protrusion of the second region 1312 and the maximum depth of the protrusion of the fourth region 1412 is within an appropriate range, which can avoid the situation where the maximum depth of the protrusion of the fourth region 1412 is close to the maximum depth of the protrusion of the second region 1312 due to a small difference, the need for adjacent oppositely doped regions to be recessed to avoid each other, and the process complexity is large; it can also avoid the situation where the width of the fourth region 1412 is small, the effect of collecting carriers is poor, and the risk of short circuit is large due to a large difference.

[0208] Specifically, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is the same as the maximum depth of the fourth region 1412 recessed from the third region 1411. In this way, the difference between the maximum depth of the protrusion of the second region 1312 and the maximum depth of the recess of the fourth region 1412 is within a suitable range, which can avoid the situation where the maximum depth of the recess of the fourth region 1412 is similar to the maximum depth of the protrusion of the second region 1312, the width of the fourth region 1412 is small, and the effect of collecting carriers is poor. It can also avoid the situation where the recess of the fourth region 1412 and the protrusion of the second region 1312 are poorly matched, the space utilization is poor, and the effect of collecting carriers is poor due to the difference being too large.

[0209] See also Fig.17 , Fig.18 and Figure 6 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 1131 and a second bending portion 1132 connected to each other, the second main body 1131 extends along the second direction, the second bending portion 1132 is arranged corresponding to the first connecting block 112, and is bent from the second main body 1131 to a direction away from the first connecting block 112; The first polarity doping region 13 includes a third doping region 132 . The third doping region 132 includes a fifth region 1321 and a sixth region 1322 . The fifth region 1321 is provided with a second main portion 1131 of the third gate line 113 . The sixth region 1322 is provided with a second bending portion 1132 of the third gate line 113 .

[0210] In this way, the third doped region 132 corresponds to the third gate line 113, which facilitates the manufacture of the third gate line 113 on the third doped region 132 and the electrical connection between the third doped region 132 and the third gate line 113, thereby reducing process difficulty, improving manufacturing efficiency and reducing costs.

[0211] Specifically, “the fifth region 1321 is provided with the second main portion 1131 of the third gate line 113 ” means that the second main portion 1131 of the third gate line 113 is in electrical contact with the fifth region 1321 .

[0212] Specifically, “the second bending portion 1132 of the third gate line 113 is disposed in the sixth region 1322 ” means that the second bending portion 1132 of the third gate line 113 is in electrical contact with the sixth region 1322 .

[0213] See also Fig.15 and Fig.16In some embodiments, the sixth region 1322 is recessed from the fifth region 1321 on the side facing the second region 1312. In this way, the recessed sixth region 1322 cooperates with the protruding fourth region 1412 to fully utilize the space, making the arrangement of the doping regions more reasonable, which is conducive to better collection of carriers and improving the photoelectric conversion efficiency of the battery.

[0214] See also Fig.17 and Fig.18 In some embodiments, the sixth region 1322 protrudes from the fifth region 1321 on a side facing away from the second region 1312 .

[0215] In this way, the sixth region 1322 corresponding to the second bending portion 1132 protrudes from the fifth region 1321 provided with the second main body portion 1131, which can provide sufficient space for the bent second bending portion 1132, thereby reducing the risk of short circuit caused by the small edge distance between the bent second bending portion 1132 and the sixth region 1322 and being too close to the adjacent heterogeneous doped region.

[0216] See also Fig.18 In some embodiments, the side of the sixth region 1322 facing the second region 1312 is recessed from the fifth region 1321 , and the side of the sixth region 1322 facing away from the second region 1312 is protruded from the fifth region 1321 .

[0217] In this way, it is possible to cooperate with the protruding fourth region 1412 to fully utilize the space, making the arrangement of the doping areas more reasonable and conducive to better collection of carriers, and to provide sufficient space for the bent second bent portion 1132, thereby reducing the risk of short circuit caused by the small edge spacing between the bent second bent portion 1132 and the sixth region 1322 and being too close to the adjacent oppositely doped region.

[0218] Specifically, the recessed depth and the protruding depth of the sixth region 1322 are the same, so that 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.

[0219] It can be understood that in other embodiments, the recessed depth of the sixth region 1322 may be greater than the protruding depth, or may be less than the protruding depth, which is not limited here.

[0220] See also Fig.18 In some embodiments, the fourth region 1412 protrudes from the third region 1411 on a side away from the second region 1312 , and the protrusion depths of the fourth region 1412 and the sixth region 1322 gradually decrease in a direction away from the second region 1312 .

[0221] In this way, the depth of the protrusion gradually decreases in the direction away from the second area 1312, and a transition from protrusion to smoothness can be achieved.

[0222] Specifically, the protrusion depth of the fourth region 1412 is the maximum depth of the fourth region 1412 protruding from the third region 1411 on the side of the second doping region 1412 away from the second region 1312 in the first direction, that is, Fig.18 The protrusion depth of the sixth region 1322 is the maximum depth of the sixth region 1322 protruding from the fifth region 1321 in the third doping region 132 on the side away from the second region 1312 in the first direction, that is, Fig.18 H3 shown in .

[0223] exist Fig.18 In the example, along the direction away from the edge, the first doping region 131, the second doping region 141, the third doping region 132, and the second doping region 141 are arranged in sequence, and the corresponding protrusion depths gradually decrease.

[0224] See also Fig.18 , in some embodiments, for the adjacent second doping region 141 and the third doping region 132 , the fourth region 1412 and the sixth region 1322 satisfy the following formula: 50μm≤H2-H3≤200μm; H2 is the maximum depth of the fourth region 1412 protruding from the third region 1411 on the side away from the second region 1312 in the first direction, and H3 is the maximum depth of the sixth region 1322 protruding from the fifth region 1321 on the side away from the second region 1312 in the first direction.

[0225] In this way, the difference in the protrusion depths of the adjacent second doping regions 141 and the third doping regions 132 is within an appropriate range, which can avoid the situation where the difference is too small and more doping regions need to be protruded to achieve a smooth transition from bending, increased process complexity, and low production efficiency. It can also avoid the situation where the difference is too large and one doping region has an insufficient protrusion depth, the corresponding bending portion is close to the edge of the doping region, and the risk of short circuit is high.

[0226] 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, and 200 μm.

[0227] In some embodiments, each row of the first doping regions 131 is continuous. In this way, each row of the first doping regions 131 is not disconnected, so that the power of the back contact battery 10 is better.

[0228] In some embodiments, each row of the second doping regions 141 is continuous. In this way, each row of the second doping regions 141 is not disconnected, so that the power of the back contact battery 10 is better.

[0229] In some embodiments, the doped region closest to the edge of the silicon substrate 101 is a P region. In this way, the space at the edge can be used to increase the area of ​​the P region, so that the area of ​​the P region is larger, which is convenient for collecting carriers.

[0230] It can be understood that in other embodiments, the doped region closest to the edge of the silicon substrate 101 may also be an N region.

[0231] See also Fig.19 and Figure 8 In some embodiments, the second polarity fine gate 12 includes a fourth gate line 122, the fourth gate line 122 is provided with a second connection block 123, and the width of the second connection block 123 is greater than the width of the fourth gate line 122; The second polarity doping region 14 includes a fourth doping region 142 . The fourth doping region 142 includes a seventh region 1421 and an eighth region 1422 . The seventh region 1421 is provided with a fourth gate line 122 , and the eighth region 1422 corresponds to the second connection block 123 .

[0232] In this way, the fourth doping region 142 corresponds to the fourth gate line 122 , which facilitates manufacturing the fourth gate line 122 on the fourth doping region 142 , thereby reducing process difficulty, improving manufacturing efficiency and reducing costs.

[0233] Specifically, “the seventh region 1421 is provided with the fourth gate line 122 ” means that the fourth gate line 122 is in electrical contact with the seventh region 1421 .

[0234] Specifically, “the eighth region 1422 corresponds to the second connection block 123” means that, in the thickness direction of the back contact battery 10, the second connection block 123 and the projection of the eighth region 1422 on the same plane at least partially overlap. The second connection block 123 may be in electrical contact with the eighth region 1422. It may also be electrically isolated from the eighth region 1422.

[0235] See also Fig.19 and Figure 8 In some embodiments, the fourth doping region 142 and the second doping region 141 are the same second polarity doping region 14. In this way, the fourth region 1412 and the eighth region 1422 are integrated into the same second polarity doping region 14, so that the connection stability between the fourth region 1412 and the second electrical connection member can be stronger. Moreover, the design and production can be centralized, which is conducive to improving the production efficiency.

[0236] Please note that when the fourth doping region 142 and the second doping region 141 are the same second polarity doping region 14 , the fourth doping region 142 and the second doping region 141 can be respectively regarded as partial structures of the second polarity doping region 14 .

[0237] It can be understood that in other examples, the fourth doping region 142 and the second doping region 141 may also be different second polarity fine gates 12. This is not limited here. Fig.19 In some embodiments, the eighth region 1422 is electrically connected to the second connection block 123 , and the eighth region 1422 protrudes from the seventh region 1421 .

[0238] In this way, the eighth region 1422 corresponding to the second connection block 123 protrudes from the seventh region 1421 provided with the fourth gate line 122, which can provide sufficient space for the second connection block 123 with a larger width. In addition, when the second connection block 123 is provided in the eighth region 1422 and is in electrical contact with the eighth region 1422, the risk of short circuit caused by the second connection block 123 with a larger width being too close to the edge of the eighth region 1422 and being too close to the adjacent oppositely doped region can be reduced.

[0239] Specifically, the side of the eighth region 1422 facing the edge of the back contact battery 10 may protrude from the seventh region 1421, or the side of the eighth region 1422 facing away from the edge of the back contact battery 10 may protrude from the seventh region 1421, or both sides of the eighth region 1422 may protrude from the seventh region 1421. This is not limited here.

[0240] It is understood that in other embodiments, the eighth region 1422 may also be aligned with the seventh region 1421. The eighth region 1422 may also be recessed from the seventh region 1421. This is not limited here.

[0241] See also Fig.19 In some embodiments, the maximum depth H4 of the eighth region 1422 protruding 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, or 290 μm.

[0242] In this way, the maximum depth H4 of the eighth region 1422 protruding from the seventh region 1421 is within an appropriate range, which can avoid insufficient setting area of ​​the second connecting block 123 and greater short circuit risk caused by too small a depth, and can also avoid being unfavorable for collecting carriers of the other polarity due to too large a depth.

[0243] In some embodiments, each row of the fourth doping regions 142 is continuous. In this way, each row of the fourth doping regions 142 is not disconnected, so that the power of the back contact battery 10 is better.

[0244] See also Fig. 20In some embodiments, the fourth gate line 122 includes a third main body portion 1221 and a third bending portion 1222 connected to each other, the third main body portion 1221 extends along the second direction, the third bending portion 1222 bends from the third main body portion 1221 in a direction away from the edge of the silicon substrate 101, and the second connecting block 123 is disposed on the third bending portion 1222; The fourth doping region 142 includes a ninth region 1423 , and the ninth region 1423 is provided with a third bending portion 1222 .

[0245] In this way, the ninth region 1423 of the fourth doping region 142 corresponds to the third bending portion 1222 of the fourth gate line 122 , which facilitates manufacturing the fourth gate line 122 on the fourth doping region 142 , thereby reducing process difficulty, improving manufacturing efficiency and reducing costs.

[0246] See also Fig. 20 In some embodiments, the side of the ninth region 1423 facing away from the eighth region 1422 protrudes from the seventh region 1421 .

[0247] In this way, the ninth region 1423 corresponding to the third bending portion 1222 protrudes from the seventh region 1421 on which the third main body portion 1221 is provided, which can provide sufficient space for the bent third bending portion 1222, thereby reducing the risk of short circuit caused by the small edge spacing between the bent third bending portion 1222 and the ninth region 1423 and being too close to the adjacent oppositely doped region.

[0248] See also Fig.21 and Fig. 22 In some embodiments, the first polarity fine gate 11 is a positive gate line, and the first polarity fine gate 11 includes a fifth gate line 114 and a sixth gate line 115 , and a spacing L2 between the sixth gate line 115 and an adjacent second polarity fine gate 12 is greater than a spacing L1 between the fifth gate line 114 and an adjacent second polarity fine gate 12 .

[0249] In this way, since the spacing between the sixth gate line 115 and the adjacent heterosexual fine gate in the first direction is greater than the spacing between the fifth gate line 114 and the adjacent heterosexual fine gate, sufficient space can be reserved on the silicon substrate 101 for setting up an anti-hot spot structure, thereby reducing the risk of short circuit caused by contact between fine gates with different polarities and doped regions.

[0250] Specifically, the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 is greater than the spacing L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12, which means that the spacing between the sixth gate line 115 and at least one of the adjacent second polarity fine gates 12 is greater than the spacing between the fifth gate line 114 and at least one of the adjacent second polarity fine gates 12. It can be that the minimum value of the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 is greater than the maximum value of the spacing L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12; it can also be that the maximum value of the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 is greater than the maximum value of the spacing L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12. It is not limited here.

[0251] See also Fig. 22 and Fig.23 The first polarity doping region 13 includes a fifth doping region 133, the second polarity doping region 14 includes a sixth doping region 143, the fifth doping region 133 includes an overlapping portion 1331 and a non-overlapping portion 1332, the sixth doping region 143 includes a main body 1431 and a protruding portion 1432, the main body 1431 is spaced from the fifth doping region 133, the protruding portion 1432 protrudes from the main body 1431 and overlaps with the overlapping portion 1331; the sixth gate line 115 is arranged at the non-overlapping portion 1332.

[0252] In this way, the protruding portion 1432 of the sixth doping region 143 overlaps the overlapping portion 1331 of the fifth doping region 133, so that an anti-hot spot structure can be formed, which can reduce the reverse bias voltage and reduce the heat generation power when the back contact battery 10 is blocked in the component and becomes a load, thereby reducing the risk of hot spots. At the same time, the fifth gate line 114 is arranged in the non-overlapping portion 1332 to reduce the risk of short circuit caused by the contact between the fine gate and the doping region with different polarities.

[0253] Specifically, the fifth gate line 114 is disposed outside the non-overlapping portion 1332 .

[0254] Specifically, the body 1431 and the fifth doping region 133 may be separated by a trench. The body 1431 and the non-overlapping portion 1332 may be separated by a dielectric film layer 1003. This is not limited here.

[0255] Specifically, the shape of the protrusion 1432 can be rectangular, circular, square, triangular or other shapes, which are not limited here.

[0256] Specifically, the sixth gate line 115 is disposed in the non-overlapping portion 1332 , which means that the sixth gate line 115 is in electrical contact with the non-overlapping portion 1332 .

[0257] See also Fig.24 and Fig.25In some embodiments, the sixth gate line 115 is provided with a third connection block 116 , and a width L3 of the third connection block 116 is greater than a width L4 of the sixth gate line 115 .

[0258] In this way, the contact area between the third connection block 116 and the first electrical connector can be increased, the pulling force can be increased, the risk of the first electrical connector falling off the back contact battery 10 can be reduced, and the connection stability between the back contact battery 10 and the first electrical connector can be improved.

[0259] Specifically, the sixth gate line 115 is provided with a third connection block 116 . That is, the third connection block 116 is connected to the sixth gate line 115 .

[0260] Specifically, the third connection block 116 may pass through the dielectric film layer 1003 to contact the first polarity doped layer. The third connection block 116 and the first polarity doped layer may also be isolated by the dielectric film layer 1003. The third connection block 116 may be manufactured together with the sixth gate line 115. The third connection block 116 may also be manufactured in steps with the sixth gate line 115.

[0261] In one example, the third connection block 116 and the sixth gate line 115 are made of the same paste, and both burn through the dielectric film layer 1003 to contact the first polarity doped layer. In another example, the paste of the sixth gate line 115 burns through the dielectric film layer 1003 to contact the first polarity doped layer, and the paste of the third connection block 116 does not burn through the dielectric film layer 1003.

[0262] In some embodiments, the third connection block 116 includes at least one of a pad and a gate line segment. In this way, the third connection block 116 is diversified, which is conducive to meeting more production scenarios and needs. For example, the third connection block 116 includes a pad. For another example, the third connection block 116 includes a gate line segment. For another example, the third connection block 116 includes a pad and a gate line segment. It can be understood that when the third connection block 116 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the first polarity doped layer. When the third connection block 116 includes a pad, the pad can pass through the dielectric film layer 1003 to contact the first polarity doped layer, and can also be isolated from the first polarity doped layer by the dielectric film layer 1003.

[0263] Specifically, the third connection block 116 is used to connect the first electrical connection member.

[0264] Furthermore, the third connection block 116 and the first electrical connector can be electrically connected to each other by at least one of conductive adhesive bonding, direct welding, solder paste welding, and physical contact, which is not limited here.

[0265] Furthermore, the entire area of ​​the third connection block 116 may be connected to the first electrical connection member. Alternatively, a partial area of ​​the third connection block 116 may be connected to the first electrical connection member.

[0266] Specifically, the width L3 of the third connection block 116 refers to the size of the third connection block 116 in the first direction. The width L3 of the third connection block 116 may be the same everywhere, different everywhere, or partially the same. The width L4 of the sixth gate line 115 refers to the size of the sixth gate line 115 in the first direction. The width L4 of the sixth gate line 115 may be the same everywhere, different everywhere, or partially the same.

[0267] Specifically, the width L3 of the third connection block 116 is greater than the width L4 of the sixth gate line 115, which means that the width of at least one location of the third connection block 116 is greater than the width of at least one location of the sixth gate line 115. Alternatively, the minimum width of the third connection block 116 is greater than the maximum width of the sixth gate line 115; alternatively, the maximum width of the third connection block 116 is greater than the maximum width of the sixth gate line 115; alternatively, the maximum width of the third connection block 116 is greater than the width of the connection between the sixth gate line 115 and the third connection block 116. This is not limited here.

[0268] In some embodiments, the third connection block is formed with a third hollow area, so that the material of the third connection block can be reduced while ensuring the coverage of the third connection block, which is conducive to improving the connection stability and reducing the cost.

[0269] In some embodiments, the third connection block is solid, so that the area of ​​the third connection block can be increased as much as possible, thereby increasing the contact area between the third connection block and the electrical connector, increasing the pulling force, reducing the risk of the electrical connector falling off the back contact battery 10, and improving the connection stability between the back contact battery 10 and the electrical connector.

[0270] In some embodiments, the third connection block is rectangular. It is understood that in other embodiments, the third connection block may be circular, annular, elliptical, triangular, racetrack-shaped or other forms. The specific form of the third connection block is not limited here.

[0271] See also Fig.21 , Fig. 22 and Fig.24 In some embodiments, the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine grid 12 is the first spacing, the spacing L1 between the fifth gate line 114 and the adjacent second polarity fine grid 12 is the second spacing, and the difference between the first spacing and the second spacing is 0.05mm-0.1mm, for example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm.

[0272] In this way, the difference between the first spacing and the second spacing is within an appropriate range, which can avoid insufficient space for setting the anti-hot spot structure due to a too small difference, and can also avoid poor carrier collection effect due to a large difference.

[0273] Specifically, the interval L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 may be equal everywhere, or unequal everywhere, or partially equal and partially unequal.

[0274] Specifically, the interval L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12 may be equal everywhere, or unequal everywhere, or partially equal and partially unequal.

[0275] Specifically, the difference between the first spacing and the second spacing may be a fixed value within a range of 0.05 mm to 0.1 mm, or may fluctuate within a range of 0.05 mm to 0.1 mm.

[0276] See also Fig.21 , Fig. 22 and Fig.24 In some embodiments, the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 is 0.2 mm-0.8 mm, for example, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm.

[0277] In this way, the spacing L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 is within an appropriate range, which can avoid insufficient space for setting the anti-hot spot structure due to too small a spacing, and can also avoid poor carrier collection effect due to too large a spacing.

[0278] Specifically, the interval L2 between the sixth gate line 115 and the adjacent second polarity fine gate 12 may be a fixed value within a range of 0.2 mm to 0.8 mm, or may fluctuate within a range of 0.2 mm to 0.8 mm.

[0279] See also Fig.21 , Fig. 22 and Fig.24 In some embodiments, the interval L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12 is a second interval of 0.1 mm-0.7 mm.

[0280] In this way, the interval L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12 is within an appropriate range, which can avoid dense gate lines and high cost caused by too small intervals, and can also avoid poor carrier collection effect caused by too large intervals.

[0281] Specifically, the interval L1 between the fifth gate line 114 and the adjacent second polarity fine gate 12 may be a fixed value within a range of 0.1 mm to 0.7 mm, or may fluctuate within a range of 0.1 mm to 0.7 mm.

[0282] See also Fig.21In some embodiments, there are multiple sixth gate lines 115 , and the number of fine gates between two adjacent sixth gate lines 115 is 8-35, for example, 8, 10, 12, 15, 19, 20, 22, 25, 28, 30, 32, or 35.

[0283] In this way, the number of fine gates between two adjacent sixth gate lines 115 is within an appropriate range, which can avoid the situation where the number of fine gates between two adjacent sixth gate lines 115 is too small, resulting in a larger number of sixth gate lines 115 as a whole and lower manufacturing efficiency, and can also avoid the situation where the number of fine gates between two adjacent sixth gate lines 115 is too large, resulting in a poor effect on reducing the risk of hot spots.

[0284] Specifically, in the back contact cell 10, there may be multiple sixth gate lines 115, forming multiple pairs of adjacent sixth gate lines 115. The number of grid lines between multiple pairs of adjacent sixth gate lines 115 may be the same, different, or partially the same and the rest different.

[0285] See also Fig.21 In some embodiments, the distance L5 between two adjacent sixth gate lines 115 is 6 mm-16.8 mm, for example, 6 mm, 7 mm, 8 mm, 10 mm, 12 mm, 14 mm, 15 mm, 16 mm, or 16.8 mm.

[0286] In this way, the interval L5 between two adjacent sixth gate lines 115 is within an appropriate range, which can avoid the overall large number of sixth gate lines 115 and low manufacturing efficiency caused by too small an interval, and can also avoid the overall poor effect of reducing the risk of hot spots caused by too large an interval.

[0287] Specifically, in the back contact cell 10, there may be multiple sixth gate lines 115, forming multiple pairs of adjacent sixth gate lines 115. The intervals L5 between the multiple pairs of adjacent sixth gate lines 115 may be the same, different, or partially the same and the rest different.

[0288] See also Fig.23 and 25 In some embodiments, in the first direction, the depth L6 of the protrusion 1432 protruding from the body 1431 is 40 μm-500 μm, for example, 40 μm, 42 μm, 44 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 480 μm, 500 μm.

[0289] In this way, the depth L6 of the protrusion 1432 protruding from the main body 1431 is within an appropriate range, which can avoid the situation where the protrusion depth is too small, resulting in insufficient contact area with the fifth doping region 133 or even difficulty in contacting the fifth doping region 133, and poor effect in reducing the risk of hot spots. It can also avoid the situation where the protrusion depth is too large, resulting in a close distance to the sixth gate line 115 and a greater risk of short circuit.

[0290] Specifically, the depth L6 of the protrusion 1432 from the body 1431 may be a fixed value within a range of 40 μm to 500 μm, or may fluctuate within a range of 40 μm to 500 μm, which is not limited here.

[0291] See also Fig.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.

[0292] In this way, the width L7 of the overlapping portion 1331 is within an appropriate range, which can avoid the poor effect of reducing the risk of hot spots due to a too small width, and can also avoid the sixth gate line 115 being too close to the heterogeneous doped region and the greater risk of short circuit due to a too large width.

[0293] Specifically, the width L7 of the overlapping portion 1331 refers to a dimension of the overlapping portion 1331 in the first direction.

[0294] Specifically, the width L7 of the overlapping portion 1331 may be a fixed value within a range of 45 μm to 500 μm, or may fluctuate within a range of 45 μm to 500 μm, which is not limited herein.

[0295] See also Fig.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, and 2000 μm.

[0296] In this way, the length L8 of the overlapping portion 1331 is within an appropriate range, which can avoid the poor effect of reducing the risk of hot spots caused by excessive or insufficient length.

[0297] Specifically, the length L8 of the overlapping portion 1331 may be a fixed value within a range of 10 μm to 2000 μm, or may fluctuate within a range of 10 μm to 2000 μm, which is not limited herein.

[0298] See also Fig.23 and25 , the width ratio of the overlapping portion 1331 to the fifth doping 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%, or 0.1%.

[0299] In this way, the width ratio of the overlapping portion 1331 to the fifth doped region 133 is within an appropriate range, which can avoid the poor effect of reducing the risk of hot spots caused by a too small ratio, and can also avoid the sixth gate line 115 being too close to the heterogeneous doped region and the greater risk of short circuit caused by a too large ratio.

[0300] Specifically, the width of the fifth doping region 133 refers to a size of the fifth doping region 133 in the first direction.

[0301] See also Fig.23 and 25 The distance L9 between the protrusion 1432 and the third connection block 116 is greater than or equal to 50 μm, for example, 50 μm, 52 μm, 60 μm, 100 μm, 200 μm, 300 μm, 400 μm, 480 μm, or 500 μm.

[0302] In this way, the distance L9 between the protrusion 1432 and the third connecting block 116 is within an appropriate range, which can avoid a greater short circuit risk caused by a too small distance, and can also avoid a poor effect of reducing the risk of hot spots caused by a too large distance.

[0303] Specifically, the distance L9 between the protrusion 1432 and the third connection block 116 may be a fixed value within a range greater than or equal to 50 μm, or may fluctuate within a range greater than or equal to 50 μm, which is not limited here.

[0304] In some embodiments, the silicon base includes a silicon substrate and a plurality of passivation contact structures disposed on the silicon substrate, and at least one of the first polarity fine gate and the second polarity fine gate is electrically connected to the passivation contact structure. In this way, recombination can be reduced, which is beneficial to improving photoelectric conversion efficiency.

[0305] In this embodiment, the passivation contact structure includes a first passivation contact structure and a second passivation contact structure, which are electrically connected to the first polarity fine gate and the second polarity fine gate, respectively. In this way, the recombination at the first polarity fine gate and the recombination at the second polarity fine gate can be reduced, so that the effect of improving the photoelectric conversion efficiency is better.

[0306] Specifically, the first passivation contact structure and the second passivation contact structure may be spaced apart from each other. For example, the first passivation contact structure and the second passivation contact structure are spaced apart by a silicon substrate; for another example, the first passivation contact structure and the second passivation contact structure are spaced apart by an insulating film layer; for another example, a gap is formed between the first passivation contact structure and the second passivation contact structure.

[0307] Specifically, the number of the first passivation contact structures may be 1, 2, 3 or other numbers. All first polarity fine gates may be electrically connected to the first passivation contact structure, or some first polarity fine gates may be electrically connected to the first passivation contact structure, and the remaining first polarity fine gates may not be electrically connected to the first passivation contact structure.

[0308] Similarly, the number of the second passivation contact structures may be 1, 2, 3 or other numbers. All the second polarity fine gates may be electrically connected to the second passivation contact structure, or some of the second polarity fine gates may be electrically connected to the second passivation contact structure, and the remaining second polarity fine gates may not be electrically connected to the second passivation contact structure.

[0309] It is understood that in other embodiments, the first polarity fine gate may be electrically connected to the passivation contact structure, and the second polarity fine gate may not be electrically connected to the passivation contact structure; or the first polarity fine gate may not be electrically connected to the passivation contact structure, and the second polarity fine gate may be electrically connected to the passivation contact structure. This is not limited here.

[0310] In some embodiments, the passivation contact structure includes a first passivation contact structure, the first passivation contact structure includes a first interface passivation layer and a first polarity doping layer sequentially stacked on a silicon substrate, and the first polarity doping layer is electrically connected to the first polarity fine gate. In this way, the first interface passivation layer can be used to achieve a tunneling effect to reduce recombination, and the first polarity doping layer can be used to achieve a field passivation effect to reduce recombination.

[0311] Specifically, the first interface passivation layer includes at least one of a silicon oxide layer, an aluminum oxide layer, a silicon carbide layer, a hydrogenated silicon carbide layer, an amorphous silicon layer, a polycrystalline silicon layer, a nanocrystalline silicon layer, a mixed crystal silicon layer, a silicon oxide carbide layer, a silicon oxide nitride layer, and a carbon and nitride silicon oxide layer.

[0312] Specifically, the first polarity doped layer includes at least one of a doped polysilicon layer, a doped crystalline silicon layer, a doped amorphous silicon layer, a doped nanocrystalline silicon layer, a doped mixed crystal silicon layer, a doped silicon carbide layer, a doped silicon dioxide layer, a doped silicon oxide layer, a doped silicon oxynitride layer, and a doped carbon nitride oxide layer.

[0313] In some embodiments, the passivation contact structure includes a second passivation contact structure, the second passivation contact structure includes a second interface passivation layer and a second polarity doping layer sequentially stacked on the silicon substrate, and the second polarity doping layer is electrically connected to the second polarity fine gate.

[0314] In this way, the second interface passivation layer can be used to achieve a tunneling effect to reduce recombination, and the second polarity doping layer can be used to achieve a field passivation effect to reduce recombination.

[0315] Specifically, the second interface passivation layer includes at least one of a silicon oxide layer, an aluminum oxide layer, a silicon carbide layer, a hydrogenated silicon carbide layer, an amorphous silicon layer, a polycrystalline silicon layer, a nanocrystalline silicon layer, a mixed crystal silicon layer, a silicon oxide carbide layer, a silicon oxide nitride layer, and a carbon and nitride silicon oxide layer.

[0316] Specifically, the second polarity doped layer includes at least one of a doped polycrystalline silicon layer, a doped crystalline silicon layer, a doped amorphous silicon layer, a doped nanocrystalline silicon layer, a doped mixed crystal silicon layer, a doped silicon carbide layer, a doped silicon dioxide layer, a doped silicon oxide layer, a doped silicon oxynitride layer, and a doped carbon nitride silicon oxide layer.

[0317] It can be understood that one of the first polarity doping layer and the second polarity doping layer is a P-type doping layer, and the other is an N-type doping layer.

[0318] In some embodiments, the passivation contact structure includes a first passivation contact structure, which includes a third polarity doping layer, a first interface passivation layer and a first polarity doping layer sequentially stacked on the silicon substrate, and the first polarity doping layer is electrically connected to the first polarity fine gate.

[0319] In this way, not only can the first interface passivation layer be used to achieve the tunneling effect, and the first polarity doping layer be used to achieve the field passivation effect to reduce recombination, but the third polarity doping layer can also be used to form an electric field that enhances the separation of surface electrons and holes, thereby improving the field passivation effect. Moreover, the third polarity doping layer has a different Fermi level from the silicon substrate, which can change the Fermi level, increase the solid concentration of impurities (transition metals), and achieve additional impurity gettering effect.

[0320] Specifically, the third polarity doped layer includes at least one of a doped polycrystalline silicon layer, a doped crystalline silicon layer, a doped amorphous silicon layer, a doped nanocrystalline silicon layer, a doped mixed crystal silicon layer, a doped silicon carbide layer, a doped silicon dioxide layer, a doped silicon oxide layer, a doped silicon oxynitride layer, and a doped carbon nitride oxide silicon layer.

[0321] It is understood that the third polarity doped layer can be stacked on the silicon substrate. For example, the third polarity doped layer is deposited on the silicon substrate. The third polarity doped layer can also be an inner diffusion layer formed by diffusion into the silicon substrate.

[0322] Please note that the materials of the first polarity doping layer and the third polarity doping layer may be the same or different. The explanation and description of the first interface passivation layer and the first polarity doping layer can be referred to above, and will not be repeated here to avoid redundancy.

[0323] In some embodiments, the passivation contact structure includes a second passivation contact structure, which includes a fourth polarity doping layer, a second interface passivation layer, and a second polarity doping layer stacked sequentially on the silicon substrate, and the second polarity doping layer is electrically connected to the second polarity fine gate.

[0324] In this way, not only can the second interface passivation layer be used to achieve the tunneling effect, and the second polarity doping layer be used to achieve the field passivation effect to reduce recombination, but the fourth polarity doping layer can also be used to form an electric field that enhances the separation of surface electrons and holes, thereby improving the field passivation effect. Moreover, the fourth polarity doping layer has a different Fermi level from the silicon substrate, which can change the Fermi level, increase the solid concentration of impurities (transition metals), and achieve additional impurity gettering effect.

[0325] It is understood that the fourth polarity doped layer can be stacked on the silicon substrate. For example, the fourth polarity doped layer is deposited on the silicon substrate. The fourth polarity doped layer can also be an inner diffusion layer formed by diffusion into the silicon substrate.

[0326] Specifically, the fourth polarity doped layer includes at least one of a doped polycrystalline silicon layer, a doped crystalline silicon layer, a doped amorphous silicon layer, a doped nanocrystalline silicon layer, a doped mixed crystal silicon layer, a doped silicon carbide layer, a doped silicon dioxide layer, a doped silicon oxide layer, a doped silicon oxynitride layer, and a doped carbon nitride oxide silicon layer.

[0327] Please note that the materials of the second polarity doping layer and the fourth polarity doping layer can be the same or different. The explanation and description of the second interface passivation layer and the second polarity doping layer can be referred to above, and will not be repeated here to avoid redundancy.

[0328] It can be understood that one of the third polarity doping layer and the fourth polarity doping layer is a P-type doping layer, and the other is an N-type doping layer.

[0329] Please note that in the description of this specification, the specific features, structures, materials or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples. For example, Fig.26 and Fig. 27 In the embodiment, the features of multiple embodiments or examples are combined.

[0330] The battery assembly of the embodiment of the present application includes any of the back-contact batteries 10 described above.

[0331] In the battery assembly of the embodiment of the present application, since the width of the first connection block 112 in the back contact battery 10 is greater than the width of the first grid line 111 and the length is greater than or equal to 100 μm, the contact area between the first connection block 112 and the electrical connector can be increased, the pulling force can be increased, the risk of the electrical connector falling off from the back contact battery 10 can be reduced, and the connection stability between the back contact battery 10 and the electrical connector can be improved. At the same time, since the first bent portion 1212 in the second grid line 121 is bent from the first main body portion 1211 to a direction away from the first connection block 112, more space can be provided for the first connection block 112 with a larger width, which is convenient for widening the first connection block 112 and can reduce the risk of short circuit caused by too small a distance between the electrodes of the two polarities.

[0332] In this embodiment, a plurality of back-contact cells 10 in the battery assembly can be connected in series in sequence to form a battery string, thereby realizing the series bus output of the current. For example, the series connection of the battery cells can be realized by setting welding strips (bus bars, interconnecting strips), conductive back plates, etc.

[0333] It is understandable that in such an embodiment, the battery assembly may further include a metal frame, a back plate, a photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back sides of the back contact battery 10 and the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0334] Photovoltaic glass can cover the adhesive film on the front side of the back contact cell 10. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the back contact cell 10 without affecting the efficiency of the back contact cell 10 as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the back contact cell 10 together. The presence of the adhesive film can seal and insulate the back contact cell 10 and make it waterproof and moisture-proof.

[0335] The backplane can be attached to the adhesive film on the back of the back contact battery 10. The backplane can protect and support the back contact battery 10 and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the backplane, back contact battery 10, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire battery assembly and can stably support and install the battery assembly. For example, the battery assembly can be installed at the required location through the metal frame.

[0336] The photovoltaic system of the embodiment of the present application includes the above-mentioned battery assembly.

[0337] In the photovoltaic system of the embodiment of the present application, since the width of the first connection block 112 in the back contact cell 10 is greater than the width of the first grid line 111 and the length is greater than or equal to 100 μm, the contact area between the first connection block 112 and the electrical connector can be increased, the pulling force can be increased, the risk of the electrical connector falling off the back contact cell 10 can be reduced, and the connection stability between the back contact cell 10 and the electrical connector can be improved. At the same time, since the first bent portion 1212 in the second grid line 121 is bent from the first main body 1211 to the direction away from the first connection block 112, more space can be provided for the first connection block 112 with a larger width, which is convenient for widening the first connection block 112 and can reduce the risk of short circuit caused by too small a distance between the electrodes of the two polarities.

[0338] In this embodiment, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, 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 to say, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery components. For example, multiple battery components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0339] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0340] In addition, the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A back contact battery, characterized in that: include: A silicon substrate, comprising a silicon substrate and a plurality of passivation contact structures arranged on the silicon substrate; A plurality of first polarity fine gates and a plurality of second polarity fine gates are disposed on the silicon substrate and arranged along a first direction, wherein the first polarity fine gates and the second polarity fine gates are spaced apart; at least one of the first polarity fine gates and the second polarity fine gates is electrically connected to the passivation contact structure; The first polarity fine gate includes a first gate line, the first gate line is provided with a first connection block, the width of the first connection block is greater than the width of the first gate line, and the length of the first connection block is greater than or equal to 100 μm; The second polarity fine grid includes a second grid line, and the second grid line includes a first main body and a first bending portion connected to each other. The first main body extends along a second direction, and the second direction intersects with the first direction. The first bending portion is arranged corresponding to the first connecting block and bends from the first main body to a direction away from the first connecting block.

2. The back contact cell according to claim 1, characterized in that: The passivation contact structure includes a first passivation contact structure, which includes a first interface passivation layer and a first polarity doping layer sequentially stacked on the silicon substrate, and the first polarity doping layer is electrically connected to the first polarity fine gate.

3. The back contact battery according to claim 1, characterized in that: The passivation contact structure includes a second passivation contact structure, which includes a second interface passivation layer and a second polarity doping layer sequentially stacked on the silicon substrate, and the second polarity doping layer is electrically connected to the second polarity fine gate.

4. The back contact cell according to claim 1, characterized in that: The passivation contact structure includes a first passivation contact structure, which includes a third polarity doping layer, a first interface passivation layer and a first polarity doping layer sequentially stacked on the silicon substrate, and the first polarity doping layer is electrically connected to the first polarity fine gate.

5. The back contact cell according to claim 1, characterized in that: The passivation contact structure includes a second passivation contact structure, which includes a fourth polarity doping layer, a second interface passivation layer and a second polarity doping layer sequentially stacked on the silicon substrate, and the second polarity doping layer is electrically connected to the second polarity fine gate.

6. The back contact cell according to claim 1, characterized in that: The difference between the width of the first connection block and the width of the first gate line is 5 μm-290 μm.

7. The back contact cell according to claim 1, characterized in that: A maximum distance between the first bending portion and the first main body portion in the first direction is 5 μm-290 μm.

8. The back contact cell according to claim 1, characterized in that: The first gate line, the first connecting block and the second gate line satisfy the following formula: -100μm≤w1-w2-d1≤100μm; Wherein, w1 is the width of the first connecting block, w2 is the width of the first gate line, and d1 is the maximum distance between the first bending portion and the first main body portion in the first direction.

9. The back contact cell according to claim 1, characterized in that: The first gate line is a first polarity thin gate closest to the edge of the silicon substrate, and the distance between the first gate line and the edge is 0.4 mm-1 mm.

10. The back contact cell according to claim 1, characterized in that: The distance from the first connecting block to the edge is 0.4 mm-50 mm.

11. The back contact cell according to claim 1, characterized in that: The first polarity fine grid includes a third grid line, and the third grid line includes a second main body and a second bent portion connected to each other, the second main body extends along the second direction, and the second bent portion is arranged corresponding to the first connecting block and bends from the second main body to a direction away from the first connecting block.

12. The back contact cell according to claim 11, characterized in that: Along the direction away from the first connecting block, the bending depths of the first bending portion and the second bending portion gradually decrease.

13. The back contact cell according to claim 11, characterized in that: For the adjacent second gate line and the third gate line, the first bending portion and the second bending portion satisfy the following formula: 50μm≤d1-d2≤150μm; Wherein, d2 is the maximum distance between the second bending portion and the second main body portion in the first direction, and d1 is the maximum distance between the first bending portion and the first main body portion in the first direction.

14. The back contact cell according to claim 1, characterized in that The first gate lines and the first connecting blocks disposed on the first gate lines form a first conductive structure, and each row of the first conductive structures is continuous; And / or, each row of the second gate lines is continuous.

15. The back contact cell according to claim 14, characterized in that The first connection block includes at least one of a pad and a gate line segment.

16. The back contact cell according to claim 14, characterized in that The first connecting block is formed with a hollow area; Alternatively, the first connecting block is solid.

17. The back contact cell according to claim 1, characterized in that: The second polarity fine gate includes a fourth gate line, the fourth gate line is provided with a second connection block, and the width of the second connection block is greater than the width of the fourth gate line.

18. The back contact cell according to claim 17, characterized in that The difference between the width of the second connection block and the width of the fourth gate line is 5 μm-290 μm.

19. The back contact cell according to claim 17, characterized in that: The difference between the area of ​​the first connection block and the area of ​​the second connection block is -400 μm 2 ~400μm 2 .

20. The back contact cell according to claim 17, characterized in that The first polarity fine grid adjacent to the second connection block is disconnected at a position corresponding to the second connection block to avoid the second connection block. In the second direction, the distance between the second connection block and the breakpoint of the first grid line is 0.2mm-1mm.

21. The back contact cell according to claim 17, characterized in that The fourth gate line is a second polarity fine gate closest to the edge of the silicon substrate, and the distance between the fourth gate line and the edge is greater than 0.7 mm-1.3 mm.

22. The back contact cell according to claim 17, characterized in that The distance between the second connecting block and the edge of the silicon substrate is 0.7 mm-50 mm.

23. The back contact cell according to claim 17, characterized in that The fourth gate line is a second polarity fine gate closest to the edge of the silicon substrate, and the second connecting block is located on a side of the fourth gate line facing the edge.

24. The back contact cell according to claim 17, characterized in that The second connecting block protrudes from the fourth gate line toward two sides of the fourth gate line.

25. The back contact cell according to claim 17, characterized in that The fourth gate line includes a third main body and a third bending portion connected to each other, the third main body extends along the second direction, the third bending portion bends from the third main body toward a direction away from an edge of the silicon substrate, and the second connecting block is disposed at the third bending portion.

26. The back contact cell according to claim 25, characterized in that A maximum distance between the third bending portion and the third main body portion in the first direction is 5 μm-290 μm.

27. The back contact cell according to claim 17, characterized in that The fourth gate line and the second gate line are the same second polarity fine gate.

28. The back contact cell according to claim 17, characterized in that The fourth gate line and the second connecting block disposed on the fourth gate line form a second conductive structure, and each row of the second conductive structure is continuous.

29. The back contact cell according to claim 17, characterized in that The second connection block includes at least one of a pad and a gate line segment.

30. The back contact cell according to claim 17, characterized in that The second connecting block is formed with a hollow area; Alternatively, the second connecting block is solid.

31. The back contact cell according to claim 1, characterized in that The silicon substrate comprises a plurality of first polarity doping regions and a plurality of second polarity doping regions arranged along the first direction, the first polarity doping regions are provided with the first polarity fine gates, and the second polarity doping regions are provided with the second polarity fine gates; The first polarity doping region includes a first doping region, the first doping region includes a first area and a second area, the first area is provided with the first gate line, and the second area corresponds to the first connecting block; The second polarity doping region includes a second doping region, the second doping region includes a third region and a fourth region, the third region is provided with the first main body of the second gate line, and the fourth region is provided with the first bending portion of the second gate line.

32. The back contact cell according to claim 31, characterized in that The second area protrudes from the first area.

33. The back contact cell according to claim 32, characterized in that In the first direction, a maximum depth of the second region protruding from the first region is 5 μm-290 μm.

34. The back contact cell according to claim 31, characterized in that A side of the fourth region facing away from the second region protrudes from the third region.

35. The back contact cell according to claim 34, characterized in that In the first direction, a maximum depth of the fourth region protruding from the third region is 1 μm-500 μm.

36. The back contact cell according to claim 34, characterized in that The second region protrudes from the first region toward a side of the fourth region. In the first direction, a difference between a maximum depth of the second region protruding from the first region and a maximum depth of the fourth region protruding from the third region is 50 μm-200 μm.

37. The back contact cell according to claim 31, characterized in that The first polarity fine grid includes a third grid line, the third grid line includes a second main body portion and a second bent portion connected to each other, the second main body portion extends along the second direction, the second bent portion is arranged corresponding to the first connecting block, and bends from the second main body portion to a direction away from the first connecting block; The first polarity doping region includes a third doping region, the third doping region includes a fifth region and a sixth region, the fifth region is provided with a second main body portion of the third gate line, and the sixth region is provided with the second bending portion of the third gate line.

38. The back contact cell according to claim 37, characterized in that A side of the sixth region facing away from the second region protrudes from the fifth region.

39. The back contact cell according to claim 38, characterized in that The fourth region protrudes from the third region on a side facing away from the second region, and the protrusion depths of the fourth region and the sixth region gradually decrease in a direction away from the second region.

40. The back contact cell according to claim 39, characterized in that For the adjacent second doping region and the third doping region, the fourth region and the sixth region satisfy the following formula: 50μm≤H2-H3≤200μm; Among them, H2 is the maximum depth of the fourth region protruding from the third region on the side away from the second region in the first direction, and H3 is the maximum depth of the sixth region protruding from the fifth region on the side away from the second region in the first direction.

41. The back contact cell according to claim 31, characterized in that The first doped regions in each row are continuous; And / or, the second doping regions in each row are continuous.

42. The back contact cell according to claim 31, characterized in that The doped region closest to the edge of the silicon substrate is a P region.

43. The back contact cell according to claim 31, characterized in that The second polarity fine grid includes a fourth grid line, the fourth grid line is provided with a second connection block, and the width of the second connection block is greater than the width of the fourth grid line; The second polarity doping region includes a fourth doping region, the fourth doping region includes a seventh region and an eighth region, the seventh region is provided with the fourth gate line, and the eighth region corresponds to the second connecting block.

44. The back contact cell according to claim 43, characterized in that The eighth region protrudes from the seventh region.

45. The back contact cell according to claim 44, characterized in that The maximum depth of the eighth region protruding from the seventh region is 5 μm-290 μm.

46. ​​The back contact cell according to claim 43, characterized in that The fourth doping region and the second doping region are the same second polarity doping region.

47. The back contact cell according to claim 43, characterized in that The fourth doping regions in each row are continuous.

48. The back contact cell according to claim 43, characterized in that The fourth gate line includes a third main body portion and a third bending portion connected to each other, the third main body portion extends along the second direction, the third bending portion bends from the third main body portion in a direction away from the edge of the silicon substrate, and the second connecting block is provided at the third bending portion; The fourth doping region includes a ninth area, and the third bending portion is disposed in the ninth area.

49. The back contact cell according to claim 48, characterized in that A side of the ninth region facing away from the eighth region protrudes from the seventh region.

50. The back contact cell according to claim 1, characterized in that The first polarity fine grid is a positive grid line, and the first polarity fine grid includes a fifth grid line and a sixth grid line, and the spacing between the sixth grid line and an adjacent second polarity fine grid is greater than the spacing between the fifth grid line and an adjacent second polarity fine grid.

51. The back contact cell according to claim 50, characterized in that The sixth gate line is provided with a third connection block, and the width of the third connection block is greater than the width of the sixth gate line.

52. The back contact cell according to claim 50, characterized in that The spacing between the sixth grid line and the adjacent second polarity fine grid is a first spacing, the spacing between the fifth grid line and the adjacent second polarity fine grid is a second spacing, and the difference between the first spacing and the second spacing is 0.05-0.1 mm.

53. A battery assembly, characterized in that: A back contact battery comprising any one of claims 1-52.

54. A photovoltaic system, characterized in that: Comprising the battery assembly of claim 53.

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