Back contact cell, back contact laminated cell and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a back contact cell, a back contact laminated cell and a photovoltaic module, and the back contact cell comprises a cell substrate which comprises at least one isolation region extending in a first direction and two grid line regions located at the two opposite sides of the isolation region; the grid line region comprises a first doped region and a second doped region which are spaced from each other, and a gap region located between the first doped region and the second doped region; the isolation region is located between the first doped region of one of the two adjacent grid line regions and the second doped region of the other of the two adjacent grid line regions, and the width of the isolation region is larger than that of the gap region in the second direction; the at least two main grid sections are located on the grid line area and are arranged at intervals in the first direction; the two adjacent main grid sections in the first direction are the first main grid section and the second main grid section respectively, and the two adjacent main grid sections in the second direction are the first main grid section and the second main grid section respectively. The embodiment of the invention is at least beneficial to improving the hot spot resistance of the back contact battery by means of the isolation region under the condition that the battery substrate is not divided.

Description

Technical Field

[0001] The present disclosure relates to the photovoltaic field, and in particular to a back-contact cell, a back-contact stacked cell, and a photovoltaic module. Background Art

[0002] With the gradual depletion of fossil energy, photovoltaic cells are becoming more and more widely used as a new energy alternative. Photovoltaic cells are devices that convert sunlight into electrical energy. Photovoltaic cells use the principle of photovoltaics to generate carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electrical energy. The grid lines of photovoltaic cells play an important role in collecting and transmitting electrons. When a photovoltaic module is assembled using multiple photovoltaic cells, the arrangement of the grid lines on the cell substrate will affect the efficiency of the photovoltaic cell in collecting carriers, and the difference in power generation performance of different areas on the cell substrate will also affect the efficiency of the photovoltaic cell in collecting carriers, thereby affecting the anti-hot spot performance of the photovoltaic cell.

[0003] In order to further avoid the grid lines blocking the front of photovoltaic cells, the research on BC cells (Back Contact) has become more and more in-depth. The arrangement of grid lines in BC cells and the anti-hot spot performance of BC cells also need further research. Summary of the Invention

[0004] The embodiments of the present disclosure provide a back-contact cell, a back-contact stacked cell, and a photovoltaic module, which are at least beneficial for improving the anti-hot spot performance of the back-contact cell by means of an isolation area without dividing the cell substrate.

[0005] According to some embodiments of the present disclosure, on the one hand, an embodiment of the present disclosure provides a back-contact battery, comprising: a battery substrate, the battery substrate comprising at least one isolation region extending along a first direction, and two gate line regions located on opposite sides of the isolation region along a second direction; wherein the gate line region comprises a first doping region and a second doping region spaced apart from each other, and a gap region located between the first doping region and the second doping region; the isolation region is located between the first doping region of one of the two gate line regions adjacent to each other along the second direction and the second doping region of the other, and along the second direction, the width of the isolation region is greater than the width of the isolation region. the width of the gap region; at least two main gate segments located on the gate line region and spaced apart along the first direction; wherein, one of the two main gate segments adjacent to each other along the first direction is a first main gate segment, and the other is a second main gate segment, and, one of the two main gate segments adjacent to each other along the second direction is the first main gate segment, and the other is the second main gate segment; first fine gates and second fine gates alternately arranged along the second direction, the first fine gate being located on the first doped region, the second fine gate being located on the second doped region, the first main gate segment being electrically connected to the first fine gate, and the second main gate segment being electrically connected to the second fine gate.

[0006] In some embodiments, the portion of the battery substrate located in the isolation area includes: a substrate; an anti-reflection layer located on the back side of the substrate; the portion of the battery substrate located in the gate line area includes: the substrate; a first tunneling layer and a first doped semiconductor layer located on the first doped area and stacked along a third direction; a second tunneling layer and a second doped semiconductor layer located on the second doped area and stacked along the third direction; the anti-reflection layer located on the side of both the first doped semiconductor layer and the second doped semiconductor layer away from the substrate.

[0007] In some embodiments, the anti-reflection layer includes a first anti-reflection layer and a second anti-reflection layer stacked along the third direction; along the third direction, the thickness of the first anti-reflection layer is 2nm to 10nm, and the thickness of the second anti-reflection layer is 40nm to 200nm.

[0008] In some embodiments, along the second direction, a width of the isolation region in the second direction is 100 μm to 5000 μm; and / or a width of the gap region in the second direction is 20 μm to 100 μm.

[0009] In some embodiments, the back-contact battery is divided into at least two sub-battery sheets by the isolation area, and the sub-battery sheets correspond one-to-one to the gate line area; in a single sub-battery sheet, a first main grid segment and a second main grid segment adjacent along the first direction are used as a lead-out group; wherein, the single lead-out group, the first fine grid electrically connected to the lead-out group, the second fine grid, and the battery substrate corresponding to the lead-out group together constitute a power generation unit; two power generation units adjacent along the second direction are connected in series.

[0010] In some embodiments, the sub-cell comprises at least two power generation units arranged along the first direction, and different power generation units belonging to the same sub-cell are connected in parallel.

[0011] In some embodiments, the three main gate segments adjacent along the second direction are taken as a group of main gate segment groups, and the first main gate segment in the main gate segment group along the second direction is a reference main gate segment; the back contact battery further includes: a connection structure, which contacts and connects two adjacent main gate segments in the main gate segment group, and the other two adjacent main gate segments in the main gate segment group are not contacted and connected with the connection structure; the reference main gate segment of one of the two main gate segment groups adjacent along the first direction is contacted and connected with the connection structure, and the reference main gate segment of the other one is not contacted and connected with the connection structure.

[0012] In some embodiments, the connecting structure is located between two adjacent main gate segments along the second direction, and the two main gate segments contacted and connected by the connecting structure are an integrally formed structure with the connecting structure.

[0013] In some embodiments, the two main gate segments contacted and connected by the connecting structure are a first main gate segment and a second main gate segment. Along the second direction, the first main gate segment has a first end face close to the second main gate segment, and the second main gate segment has a second end face close to the first main gate segment. The connecting structure is not only contacted and connected with the first end face, but also contacted and connected with the second end face.

[0014] In some embodiments, the two main gate segments contacted and connected by the connecting structure are a first main gate segment and a second main gate segment. Along the second direction, the first main gate segment has a first end close to the second main gate segment, and the second main gate segment has a second end close to the first main gate segment. The connecting structure includes: a connecting segment, at least one first welding point located on the first end, and at least one second welding point located on the second end. The connecting segment is not only in contact and connected with the first welding point, but also in contact and connected with the second welding point.

[0015] In some embodiments, the back-contact battery further includes: a first through-line and a second through-line respectively located at two opposite edges of the gate line area along the second direction, the first through-line and the second through-line both extend along the first direction, and the first through-line contacts and connects a plurality of first main gate segments arranged at intervals along the first direction, and the second through-line contacts and connects a plurality of second main gate segments arranged at intervals along the first direction; wherein, the first through-line corresponding to one of the two adjacent gate line areas along the second direction is close to the isolation area, and the second through-line corresponding to the other is close to the isolation area.

[0016] In some embodiments, the battery substrate is a half-cell battery, and the half-cell battery includes two edges opposite to each other along the second direction, the main gate segment close to the edge is an edge main gate segment, and the main gate segment located between two adjacent edge main gate segments along the second direction is an intermediate main gate segment; wherein, along the second direction, the extension length of the edge main gate segment is a first length, and the extension length of the intermediate main gate segment is a second length, and the second length is greater than the first length.

[0017] According to some embodiments of the present disclosure, on the other hand, embodiments of the present disclosure further provide a back-contact stack battery, comprising: a bottom battery, the bottom battery being the back-contact battery as described in any one of the above items; and a top battery, the top battery being located on one side of the bottom battery.

[0018] According to some embodiments of the present disclosure, another aspect of the embodiments of the present disclosure further provides a photovoltaic module, comprising: a plurality of back-contact cells as described in any one of the above items connected together, or a plurality of back-contact stacked cells as described above connected together; an encapsulation film for covering the surface of the cell string; and a cover plate for covering the surface of the encapsulation film facing away from the cell string.

[0019] In some embodiments, the two back contact cells adjacent along the second direction are respectively a first back contact cell and a second back contact cell, the main grid segment close to the second back contact cell in the first back contact cell is a first main grid segment to be welded, and the main grid segment close to the first back contact cell in the second back contact cell is a second main grid segment to be welded; the first main grid segment to be welded and the second main grid segment to be welded adjacent along the second direction are regarded as a group to be welded; the photovoltaic component also includes: a welding strip, the first main grid segment to be welded and the second main grid segment to be welded of one of the two adjacent groups to be welded along the first direction are respectively contacted and connected with the welding strip, and the first main grid segment to be welded and the second main grid segment to be welded of the other group are not contacted and connected with the welding strip.

[0020] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0021] Compared with designing a long main grid extending along the second direction, in the back contact battery provided by an embodiment of the present disclosure, a plurality of main grid segments are arranged at intervals along the second direction, and an isolation region is designed between two adjacent main grid segments along the second direction, so that the battery substrate can be divided into multiple power generation areas, i.e., multiple grid line areas, with the help of the isolation region. In this way, even if there is an obstacle to the collection of carriers in an individual power generation area, the collection of carriers in other power generation areas will not be affected, which is conducive to improving the anti-hot spot performance of the back contact battery. Moreover, whether the battery substrate is a whole cell or a sliced ​​cell, the battery substrate can be divided into multiple power generation areas with the help of the isolation region. Different power generation areas are separated by the isolation region to generate electricity separately. Subsequently, by adjusting the arrangement of the first main grid segment, the second main grid segment, the first fine grid and the second fine grid in the adjacent power generation area, the adjacent power generation areas can be flexibly designed to be connected in series or in parallel to flexibly control the overall working current and working voltage of the back contact battery. In addition, when the battery substrate is a whole cell, the battery substrate can be divided into multiple power generation areas without slicing the battery substrate, and the slicing damage to the battery substrate is not caused.

[0022] Furthermore, the width of the isolation region is designed to be larger than the width of the gap region, which is conducive to ensuring appropriate spacing between adjacent gate line regions, avoiding crosstalk between adjacent gate line regions, and facilitating the subsequent series or parallel connection of adjacent gate line regions in the isolation region with a larger width. At the same time, the width of the gap region is designed to be smaller, which is also conducive to making more areas in a single gate line region be used for the layout of the first doped region and the second doped region as much as possible, so as to increase the number of first fine gates and second fine gates that can be laid out in a single gate line region, thereby improving the carrier collection efficiency of the back contact battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic top view of a back-contact battery provided in one embodiment of the present disclosure;

[0025] Figure 2 A first partial top view schematic diagram of a back-contact battery provided by an embodiment of the present disclosure;

[0026] Figure 3 A partial cross-sectional schematic diagram of a back-contact battery provided in one embodiment of the present disclosure;

[0027] Figure 4 Another schematic top view of a back-contact battery provided in one embodiment of the present disclosure;

[0028] Figure 5 for Figure 4 An equivalent circuit diagram of the back contact battery shown;

[0029] Figure 6 A second partial top view schematic diagram of a back-contact battery provided by an embodiment of the present disclosure;

[0030] Figure 7 A third partial top view schematic diagram of a back-contact battery provided in one embodiment of the present disclosure;

[0031] Figure 8 A fourth partial top view schematic diagram of a back-contact battery provided by an embodiment of the present disclosure;

[0032] Figure 9 A fifth partial top view schematic diagram of a back-contact battery provided in one embodiment of the present disclosure;

[0033] Figure 10 A sixth partial top view schematic diagram of a back-contact battery provided in one embodiment of the present disclosure;

[0034] Figure 11 A seventh partial top view schematic diagram of a back-contact battery provided in one embodiment of the present disclosure;

[0035] Figure 12 A partial top view schematic diagram of a main grid segment on a battery substrate in a back-contact battery provided by an embodiment of the present disclosure;

[0036] Figure 13 A partial cross-sectional schematic diagram of a back-contact stacked battery provided by another embodiment of the present disclosure;

[0037] Figure 14 A first partial top view schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of the present disclosure;

[0038] Figure 15 A partial cross-sectional schematic diagram of a photovoltaic module provided by another embodiment of the present disclosure;

[0039] Figure 16 A second partial top view schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of the present disclosure;

[0040] Figure 17 A third partial top view schematic diagram of a cell string in a photovoltaic module provided by yet another embodiment of the present disclosure;

[0041] Figure 18 A fourth partial top view schematic diagram of a cell string in a photovoltaic module provided by yet another embodiment of the present disclosure;

[0042] Figure 19 A fifth partial top view schematic diagram of a cell string in a photovoltaic module provided by yet another embodiment of the present disclosure;

[0043] Figure 20 A sixth partial top view schematically illustrates a cell string in a photovoltaic assembly according to another embodiment of the present disclosure.

[0044] Description of reference numerals:

[0045] 100, battery substrate; 110, isolation region; 120, gate line region; 1201, first doped region; 1202, second doped region; 1203, gap region; 130, substrate; 140, anti-reflection layer; 1401, first anti-reflection layer; 1402, second anti-reflection layer; 150, first tunneling layer; 160, first doped semiconductor layer; 170, second tunneling layer; 180, second doped semiconductor layer; 101, main gate segment; 111, first main gate segment; 111a, first end face; 1111, first end portion; 121, second main gate segment; 121a, second end face; 1211, second end portion; 102, first fine gate; 103, second Fine grid; 104, lead-out group; 105, main grid segment group; 115, reference main grid segment; 125, edge main grid segment; 135, middle main grid segment; 106, connection structure; 116, connection segment; 126, first welding point; 136, second welding point; 10, sub-cell; 20, power generation unit; 50, series connection block; 117, first through-line; 127, second through-line; 108, bottom cell; 109, top cell; 40, back contact cell; 401, first back contact cell; 402, second back contact cell; 12a, first main grid segment to be welded; 12b, second main grid segment to be welded; 41, packaging film; 42, cover plate; 43, welding strip. DETAILED DESCRIPTION

[0046] As can be seen from the background technology, the anti-hot spot performance of back contact batteries needs to be improved.

[0047] The embodiments of the present disclosure provide a back-contact cell, a back-contact stacked cell, and a photovoltaic module. In the back-contact cell, compared with designing a long main grid extending along the second direction, the back-contact cell provided by an embodiment of the present disclosure is designed to have multiple main grid segments arranged at intervals along the second direction, and an isolation region is designed between two adjacent main grid segments along the second direction, so that the cell substrate can be divided into multiple power generation areas, i.e., multiple grid line areas, with the help of the isolation region. In this way, even if there is an obstacle to the collection of carriers in an individual power generation area, the collection of carriers in other power generation areas will not be affected, which is beneficial to improving the anti-hot spot performance of the back-contact cell. Moreover, regardless of whether the cell substrate is a whole cell or a sliced ​​cell, the cell substrate can be divided into multiple power generation areas with the help of the isolation region. Different power generation areas are separated by the isolation region to generate electricity separately. Subsequently, by adjusting the arrangement of the first main grid segment, the second main grid segment, the first fine grid and the second fine grid in the adjacent power generation area, the adjacent power generation areas can be flexibly designed to be connected in series or in parallel, so as to flexibly control the overall working current and working voltage of the back-contact cell. In addition, when the battery substrate is a whole battery, the battery substrate can be divided into multiple power generation areas without slicing the battery substrate, and the slicing will not cause damage to the battery substrate. Furthermore, the width of the isolation region is designed to be larger than the width of the gap region, which is conducive to ensuring that adjacent gate line regions have a suitable spacing, avoiding crosstalk between adjacent gate line regions, and also facilitating the subsequent series or parallel connection of adjacent gate line regions in the isolation region with a larger width. At the same time, the width of the gap region is designed to be smaller, which is also conducive to allowing more areas in a single gate line region to be used for the layout of the first doped region and the second doped region as much as possible, so as to increase the number of first fine gates and second fine gates that can be laid out in a single gate line region, thereby improving the carrier collection efficiency of the back contact battery.

[0048] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0049] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] In the description of the embodiments of the present disclosure, the term "and / or" is merely a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0051] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0052] In the description of the embodiments of the present disclosure, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", 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 embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0053] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and they can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0054] In the accompanying drawings corresponding to the embodiments of the present disclosure, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component can be "directly" located on the surface of the other component, or a third component can be present between the two components. Conversely, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0055] In the description of the embodiments of the disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can be further included. In addition, when a layer, film, region, plate, etc. component is referred to as "on / above" another component, it can be "directly on" another component (i.e. between another component surface and another component, no other component is present), or another component can be present therebetween. In addition, when a layer, film, region, plate, etc. component is "directly on" another component, or when a layer, film, region, plate, etc. component is on another component surface, it means that no other component is present therebetween.

[0056] The terms used in the description of various described embodiments herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of various embodiments and the appended claims herein, the phrase "the member" is also intended to include plural forms, unless the context clearly indicates otherwise. Among them, the components include layers, films, regions, or plates, etc.

[0057] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, those skilled in the art can understand that in the embodiments of the present disclosure, in order to enable the reader to better understand the embodiments of the present disclosure, many technical details are presented. However, even without these technical details and based on various changes and modifications of the following embodiments, the technical solutions claimed by the embodiments of the present disclosure can be implemented.

[0058] An embodiment of the present disclosure provides a back contact cell, and the back contact cell provided by the embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0059] Reference Figure 1 and Figure 2The back-contact battery includes: a battery substrate 100, the battery substrate 100 includes at least one isolation region 110 extending along a first direction X, and two gate line regions 120 located on opposite sides of the isolation region 110 along a second direction Y; wherein the gate line region 120 includes a first doped region 1201 and a second doped region 1202 spaced apart from each other, and a gap region 1203 located between the first doped region 1201 and the second doped region 1202; the isolation region 110 is located between the first doped region 1201 of one of the two gate line regions 120 adjacent to each other along the second direction Y and the second doped region 1202 of the other; along the second direction Y, the width of the isolation region 110 is greater than the width of the gap region 1203 ; at least two main gate segments 101 are located on the gate line region 120 and arranged at intervals along the first direction X; wherein, one of the two main gate segments 101 adjacent to each other along the first direction X is the first main gate segment 111, and the other is the second main gate segment 121, and, one of the two main gate segments 101 adjacent to each other along the second direction Y is the first main gate segment 111, and the other is the second main gate segment 121; first fine gates 102 and second fine gates 103 are alternately arranged along the second direction Y, the first fine gate 102 is located on the first doped region 1201, the second fine gate 103 is located on the second doped region 1202, the first main gate segment 111 is electrically connected to the first fine gate 102, and the second main gate segment 121 is electrically connected to the second fine gate 103.

[0060] It should be noted that Figure 1 A schematic top view of a back-contact battery provided in one embodiment of the present disclosure; Figure 2 This is a partial top view of a first embodiment of a back contact cell provided by the present disclosure. In addition, to facilitate the distinction between the first busbar segment 111 and the second busbar segment 121, Figure 1 and Figure 2 In the figure, the first main gate segment 111 and the second main gate segment 121 are drawn using different filling methods; in order to distinguish the first fine gate 102 and the second fine gate 103, Figure 1 In FIG. 1 , the first fine gate 102 is shown by a dotted line and the second fine gate 103 is shown by a solid line. Figure 2 In FIG. 1 , the first fine gate 102 is shown with a thicker solid line and the second fine gate 103 is shown with a thinner solid line.

[0061] It is worth noting that when the back-contact battery generates carriers based on the photovoltaic effect, the first fine gate 102 is used to collect the carriers generated in the first doped region 1201, and the first main gate segment 111 electrically connected to the first fine gate 102 is used to further collect the carriers collected in the first fine gate 102; the second fine gate 103 is used to collect the carriers generated in the second doped region 1202, and the second main gate segment 121 electrically connected to the second fine gate 103 is used to further collect the carriers collected in the second fine gate 103.

[0062] Based on this, compared to designing a long main grid extending along the second direction, the back-contact cell provided by one embodiment of the present disclosure is designed with multiple main grid segments 101 spaced apart along the second direction Y, and an isolation region 110 is designed between two adjacent main grid segments 101 along the second direction Y. This allows the cell substrate 100 to be divided into multiple power generation areas, i.e., multiple grid line areas 120, by means of the isolation region 110. Multiple main grid segments 101 belonging to the same row along the first direction X serve as multiple carrier collection ends for one power generation area. In this way, even if carrier collection in a particular power generation area is hindered, carrier collection in other power generation areas will not be affected, thereby improving the hot spot resistance of the back-contact cell. Moreover, even if the battery substrate 100 is a whole battery, the battery substrate 100 can be divided into multiple power generation areas with the help of the isolation area 110 without slicing the battery substrate 100. Different power generation areas are separated by the isolation area 110 to generate electricity independently. Subsequently, by adjusting the arrangement of the first main grid segment 111, the second main grid segment 121, the first fine grid 102 and the second fine grid 103 in adjacent power generation areas, the adjacent power generation areas can be flexibly designed to be connected in series or in parallel, so as to flexibly control the overall operating current and operating voltage of the back contact battery without causing slicing damage to the battery substrate 100.

[0063] Furthermore, the width of the isolation region 110 is designed to be greater than the width of the gap region 1203, which is conducive to ensuring appropriate spacing between adjacent gate line regions 120, avoiding crosstalk between adjacent gate line regions 120, and facilitating the subsequent series or parallel connection of adjacent gate line regions 120 in the isolation region 110 with a larger width. At the same time, the width of the gap region 1203 is designed to be smaller, which is also conducive to making more areas in a single gate line region 120 as possible for the layout of the first doped region 1201 and the second doped region 1202, so as to increase the number of first fine gates 102 and second fine gates 103 that can be laid out in a single gate line region 120, thereby improving the carrier collection efficiency of the back contact battery.

[0064] It should be noted that Figure 1 In the figure, the battery substrate 100 is taken as an example as a whole battery. In actual applications, the design of the isolation area and the main grid segment can also be applicable to the case where the battery substrate is a split battery, such as a half-cell battery. The half-cell battery can also be divided into multiple power generation areas with the help of the isolation area. Different power generation areas are separated by the isolation area to generate electricity separately. Subsequently, by adjusting the arrangement of the first main grid segment, the second main grid segment, the first fine grid and the second fine grid in adjacent power generation areas, the adjacent power generation areas can be flexibly designed to be connected in series or in parallel, so as to flexibly control the overall working current and working voltage of the back contact battery.

[0065] In some cases, the isolation region 110 is used to isolate two adjacent gate line regions 120, and the first main gate segment 111 in a single gate line region 120 is electrically connected to multiple first fine gates 102, and the second main gate segment 121 is electrically connected to multiple second fine gates 103; the gap region 1203 is used to isolate adjacent first doped regions 1201 and second doped regions 1202, then the gap region 1203 can be located between the first fine gate 102 and the second fine gate 103 adjacent to each other along the second direction Y in the same gate line region 120.

[0066] In some cases, a portion of the film layer in the first doping region 1201 is doped with one of a P-type doping element and an N-type doping element, and a portion of the film layer in the second doping region 1202 is doped with the other of the P-type doping element and the N-type doping element. In some examples, the N-type doping element may be at least one of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As); the P-type semiconductor substrate is doped with a P-type doping element, and the P-type doping element may be at least one of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In).

[0067] It is worth noting that due to the different types of doping elements doped in the first doping region 1201 and the second doping region 1202, the different polarities of the first fine gate 102 and the second fine gate 103, that is, the different types of carriers collected by the first fine gate 102 and the second fine gate 103, the main gate segment 101 is also divided into two types. Specifically, the main gate segment 101 is divided into a first main gate segment 111 that collects carriers from the first fine gate 102, and a second main gate segment 121 that collects carriers from the second fine gate 103.

[0068] The back contact battery provided by one embodiment of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0069] The isolation region 110 and the gate line region 120 of the battery substrate 100 are described in detail below.

[0070] In some embodiments, reference Figure 3 , Figure 3 A partial cross-sectional diagram of a back contact battery provided by an embodiment of the present disclosure, wherein the battery substrate 100 (refer to Figure 1) in the isolation region 110 includes: a substrate 130; an anti-reflection layer 140 located on the back side of the substrate 130; and a portion of the cell substrate 100 located in the gate line region 120 includes: a substrate 130; a first tunneling layer 150 and a first doped semiconductor layer 160 located on the first doped region 1201 and stacked along a third direction Z; a second tunneling layer 170 and a second doped semiconductor layer 180 located on the second doped region 1202 and stacked along the third direction Z; and the anti-reflection layer 140 located on the side of both the first doped semiconductor layer 160 and the second doped semiconductor layer 180 away from the substrate 130. The third direction Z is the thickness direction of the cell substrate 100.

[0071] It is worth noting that in the portion of the battery substrate 100 located in the isolation region 110, no other film layers are designed between the base 130 and the anti-reflection layer 140, for example, no semiconductor layer doped with doping elements is provided. In this way, the portion of the battery substrate 100 located in the isolation region 110 will not generate a strong electric field by itself, which is beneficial to strengthening the isolation effect of the isolation region 110 on the first doping region 1201 and the second doping region 1202 belonging to different gate line regions 120.

[0072] In addition, the first doped semiconductor layer 160 is doped with one of a P-type doping element and an N-type doping element, and the second doped semiconductor layer 180 is doped with the other of a P-type doping element and an N-type doping element; the first fine gate 102 is embedded in the anti-reflection layer 140 to contact and connect with the first doped semiconductor layer 160, and the second fine gate 103 is embedded in the anti-reflection layer 140 to contact and connect with the second doped semiconductor layer 180.

[0073] In some examples, the material of the first tunneling layer 150 and the material of the second tunneling layer 170 may both be silicon oxide, and the material of the first doped semiconductor layer 160 and the material of the second doped semiconductor layer 180 may both be polycrystalline silicon. In other examples, the material of the first tunneling layer 150 and the material of the second tunneling layer 170 may both be intrinsic amorphous silicon, the material of the first doped semiconductor layer 160 may be amorphous silicon doped with one of a P-type doping element and an N-type doping element, and the material of the second doped semiconductor layer 180 may be amorphous silicon doped with the other of the P-type doping element and the N-type doping element. In still other examples, the material of one of the first tunneling layer 150 and the second tunneling layer 170 may be silicon oxide, and the material of the other may be intrinsic amorphous silicon; the material of one of the first doped semiconductor layer 160 and the second doped semiconductor layer 180 may be polycrystalline silicon doped with one of a P-type doping element and an N-type doping element, and the material of the other may be amorphous silicon doped with the other of the P-type doping element and the N-type doping element.

[0074] In some cases, the anti-reflection layer 140 may have a single-layer structure or a stacked-layer structure, and the material of the anti-reflection layer 140 may include at least one of aluminum oxide, silicon nitride, silicon oxide, or silicon oxynitride.

[0075] In some cases, continue to refer to Figure 3 The anti-reflection layer 140 may include a first anti-reflection layer 1401 and a second anti-reflection layer 1402 stacked along a third direction Z; along the third direction Z, the thickness of the first anti-reflection layer 1401 may be 2nm~10nm, for example, it may be 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm, 5nm, 5.5nm, 6nm, 6.5nm, 7nm, 7.5nm, 8nm, 8.5nm, 9nm or 9.5nm; the thickness of the second anti-reflection layer 1402 may be 40nm~200nm, for example, it may be 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm or 190nm, etc.

[0076] In some examples, the material of the first anti-reflection layer 1401 may be aluminum oxide, and the material of the second anti-reflection layer 1402 may be silicon nitride.

[0077] In some cases, along the third direction Z, the thickness of the first tunneling layer 150 and the thickness of the second tunneling layer 170 can both be 1.5nm~2.5nm, for example, 1.6nm, 1.7nm, 1.8nm, 1.9nm, 2nm, 2.1nm, 2.2nm, 2.3nm or 2.4nm, etc.; the thickness of the first doped semiconductor layer 160 and the thickness of the second doped semiconductor layer 180 can both be 50nm~300nm, for example, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm or 290nm, etc.

[0078] In some embodiments, reference Figure 2, along the second direction Y, the width W1 of the isolation region 110 in the second direction Y can be 100μm to 5000μm, for example, it can be 300μm, 500μm, 800μm, 1000μm, 1300μm, 1500μm, 1800μm, 2000μm, 2200μm, 2500μm, 2700μm, 3000μm, 3300μm, 3500μm, 3600μm, 4000μm, 4200μm, 4500μm or 4800μm, etc.

[0079] It is worth noting that, on the one hand, the size of the width W1 of the isolation region 110 will affect the spacing between the first main gate segment 111 and the second main gate segment 121 adjacent to each other along the second direction Y, thereby affecting the width of the layout area of ​​the connection structure 106; on the other hand, the size of the width W1 of the isolation region 110 will affect the layout ratio of the gate line region 120 on the limited layout area on the battery substrate 100. Based on this, the width W1 of the isolation region 110 is designed to be 100μm to 5000μm. On the one hand, it is helpful to avoid the width W1 of the isolation region 110 being too small, and ensure that the connection structure 106 has a layout area of ​​appropriate size, so as to reduce the difficulty of the connection structure 106 contacting and connecting the first main gate segment 111 and the second main gate segment 121, so as to ensure good contact performance between the connection structure 106 and the first main gate segment 111 and the second main gate segment 121; on the other hand, it is helpful to avoid the width W1 of the isolation region 110 being too large, so as to ensure that the layout ratio of the gate line region 120 on the battery substrate 100 is high, thereby increasing the number of the first fine grids 102 and the second fine grids 103 that can be laid out on the battery substrate 100, so as to improve the carrier collection efficiency of the back contact battery.

[0080] In some embodiments, reference Figure 2 Along the second direction Y, the width W2 of the gap area 1203 in the second direction Y can be 20μm to 100μm, for example, it can be 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm or 95μm, etc.

[0081] It is worth noting that, based on the limitations of the current preparation process of the first doping region 1201 and the second doping region 1202, in order to avoid mutual interference between the doping process for preparing the first doping region 1201 and the doping process for preparing the second doping region 1202, the width of the gap region 1203 between the first doping region 1201 and the second doping region 1202 in the same gate line region 120 should not be too small.

[0082] Based on this, the width W2 of the gap region 1203 is designed to be greater than or equal to 20 μm, which is beneficial to avoiding the mutual diffusion of doping elements in the first doping region 1201 and the second doping region 1202, thereby ensuring the good electrical properties of the first doping region 1201 and the second doping region 1202; the width W2 of the gap region 1203 is designed to be less than or equal to 100 μm, which is beneficial to improving the layout ratio of the first doping region 1201 and the second doping region 1202 in the gate line region 120, that is, making as much area as possible in a single gate line region 120 for the layout of the first doping region 1201 and the second doping region 1202, so as to increase the number of first fine gates 102 and second fine gates 103 that can be laid out in a single gate line region 120, thereby improving the carrier collection efficiency of the back contact battery.

[0083] In some embodiments, reference Figure 2 On the basis that the first fine gate 102 is located on the first doped region 1201 and the second fine gate 103 is located on the second doped region 1202, the positional relationship between the first main gate segment 111 and the first doped region 1201, and the positional relationship between the second main gate segment 121 and the second doped region 1202 include at least the following two examples:

[0084] In some cases, continue to refer to Figure 2 , the orthographic projections of the first fine gate 102 and the first main gate segment 111 on the cell substrate 100 are both located in the first doped region 1201, and a first doped region 1201 is further provided in the gap between two adjacent first fine gates 102. Thus, if at least a portion of the first main gate segment 111 is designed to be in contact with the first doped region 1201 located in the gap between two adjacent first fine gates 102, this facilitates direct collection of carriers in the first doped region 1201 located in the gap between two adjacent first fine gates 102 by the first main gate segment 111, without first having to pass through the first fine gate 102 and then be collected by the first main gate segment 111. This facilitates shortening the transmission distance of carriers from the first doped region 1201 to the first main gate segment 111, thereby reducing carrier transmission losses and improving the carrier collection efficiency of the first main gate segment 111, thereby improving the photoelectric conversion efficiency of the back-contact cell.

[0085] Similarly, the orthographic projections of the second fine gate 103 and the second main gate segment 121 on the cell substrate 100 are both located in the second doped region 1202, and a second doped region 1202 is also present in the gap between two adjacent second fine gates 103. Thus, if at least a portion of the second main gate segment 121 is designed to be in contact with the second doped region 1202 located in the gap between two adjacent second fine gates 103, this facilitates direct collection of carriers in the second doped region 1202 located in the gap between two adjacent second fine gates 103 by the second main gate segment 121, without first having to pass through the second fine gate 103 and then be collected by the second main gate segment 121. This helps shorten the transmission distance of carriers from the second doped region 1202 to the second main gate segment 121, thereby reducing carrier transmission losses and improving the carrier collection efficiency of the second main gate segment 121, thereby improving the photoelectric conversion efficiency of the back-contact cell.

[0086] In other cases, the orthographic projection of the first fine gate on the battery substrate is located in the first doped region, and the orthographic projection of only the portion of the first main gate segment that intersects with the first fine gate on the battery substrate is located in the first doped region. In this way, the orthographic projection of the first main gate segment on the battery substrate only overlaps with the first doped region in multiple places.

[0087] Similarly, the orthographic projection of the second fine gate on the battery substrate is located in the second doped region, and the orthographic projection of only the portion of the second main gate segment that intersects with the second fine gate on the battery substrate is located in the second doped region. In this way, the orthographic projection of the second main gate segment on the battery substrate overlaps with the second doped region only in a few places.

[0088] The following describes in detail the electrical connection relationship between the multiple power generation areas divided by the isolation area 110 of the battery substrate 100, that is, the multiple gate line areas 120.

[0089] In some embodiments, in conjunction with reference Figures 4 to 6 The back contact cell is divided into at least two sub-cells 10 by the isolation area 110, and the sub-cells 10 correspond to the gate line areas 120 one by one; in a single sub-cell 10, a first main grid segment 111 and a second main grid segment 121 adjacent along the first direction X are used as a lead-out group 104; wherein, the single lead-out group 104, the first fine grid 102 and the second fine grid 103 electrically connected to the lead-out group 104, and the cell substrate 100 corresponding to the lead-out group 104 together constitute a power generation unit 20; two power generation units 20 adjacent to each other along the second direction Y are connected in series.

[0090] in, Figure 4 Another schematic top view of a back-contact battery provided in one embodiment of the present disclosure; Figure 5 for Figure 4 An equivalent circuit diagram of the back contact battery shown; Figure 6A second partial top view schematic diagram of a back-contact battery provided in one embodiment of the present disclosure.

[0091] It is worth noting that a single power generation unit 20 includes a single lead group 104, a first fine grid 102 and a second fine grid 103 electrically connected to the lead group 104, and a cell substrate 100 corresponding to the lead group 104. In this way, multiple lead groups 104 can be designed along the first direction X on a single gate line region 120, that is, multiple power generation units 20 can be designed on a single gate line region 120.

[0092] Therefore, the first busbar segments 111 and the second busbar segments 121 are designed to be arranged alternately along the first direction X and the second direction Y, so that the back-contact cell can be divided into multiple power generation units 20 based on the multiple first busbar segments 111 and the multiple second busbar segments 121, and the multiple power generation units 20 are arranged along both the first direction X and the second direction Y. In this way, even if carrier collection in an individual power generation unit 20 is hindered, the carrier collection in other power generation units 20 will not be affected, thereby improving the hot spot resistance of the back-contact cell.

[0093] Furthermore, if two adjacent power generation units 20 along the second direction Y are designed to be connected in series, then on a single battery substrate 100, multiple power generation units 20 in the same column along the second direction Y can be connected in series in sequence to form a series block 50, and the adjacent power generation units 20 along the first direction X belong to different series blocks 50 respectively.

[0094] In some cases, in conjunction with reference Figure 4 and Figure 5 The sub-cell 10 includes at least two power generation units 20 arranged along the first direction X, and different power generation units 20 belonging to the same sub-cell 10 are connected in parallel.

[0095] It is worth noting that, based on the design of connecting two adjacent power generation units 20 in series along the second direction Y, different power generation units 20 belonging to the same sub-cell 10 are designed to be connected in parallel. This facilitates the parallel connection of adjacent power generation units 20 along the first direction X, that is, different power generation units 20 belonging to the same sub-cell 10. In this way, based on the fact that multiple power generation units 20 in the same column along the second direction Y can be sequentially connected in series to form a series block 50, the back-contact battery can be divided into multiple parallel series blocks 50, thereby reducing the current in a single carrier transmission path, as well as reducing the operating voltage and operating current of the back-contact battery, thereby further improving the hot spot resistance of the back-contact battery. In other words, it is conducive to constructing a new carrier transmission path on the battery substrate 100 by means of the electrical connection design of the power generation unit 20.

[0096] The specific structure for connecting two adjacent power generation units 20 in series along the second direction Y will be described in detail below.

[0097] In some cases, in conjunction with reference Figure 1 and Figure 7 , Figure 7 A third partial top view schematic diagram of a back-contact battery provided in an embodiment of the present disclosure, in which three main gate segments 101 adjacent along the second direction Y are grouped as a main gate segment group 105, and the first main gate segment 101 in the main gate segment 101 group along the second direction Y is a reference main gate segment 115; the back-contact battery may further include: a connecting structure 106, which contacts and connects two adjacent main gate segments 101 in the main gate segment 101 group, and the other two adjacent main gate segments 101 in the main gate segment 101 group are not contacted and connected with the connecting structure 106; the reference main gate segment 115 of one of the two main gate segment 101 groups adjacent along the first direction X is contacted and connected with the connecting structure 106, and the reference main gate segment 115 of the other one is not contacted and connected with the connecting structure 106.

[0098] In this way, based on the alternating arrangement of the first main gate segment 111 and the second main gate segment 121, with the help of the design of the connection structure 106, two main gate segment groups 105 adjacent to each other along the first direction X form an "S"-shaped carrier transmission path. Moreover, multiple main gate segment groups 105 are arranged along the second direction Y. Multiple "S"-shaped carrier transmission paths are connected in series to form a "wave"-shaped carrier transmission path extending along the second direction Y, and multiple "wave"-shaped carrier transmission paths arranged along the first direction X are connected in parallel to each other to output from the total positive electrode + and the total negative electrode -. It is worth noting that a single "wave"-shaped carrier transmission path extending along the second direction Y can be regarded as a series block 50 (refer to Figure 5 ), the back contact battery is designed to include multiple series blocks 50 connected in parallel, so as to reduce the overall operating voltage and operating current of the back contact battery with a certain back area.

[0099] In other words, based on the design of alternating arrangement of the first main grid segment 111 and the second main grid segment 121, the middle part of the battery substrate 100 is formed to realize series connection, so as to improve the transmission path of carriers in the back contact battery, that is, to improve the transmission path of current in the back contact battery, thereby achieving the purpose of reducing the operating current of the back contact battery, so as to facilitate the subsequent improvement of the CTM value of the photovoltaic module formed by the electrical connection of the back contact battery; in addition, based on the design of the connection structure 106, it is beneficial to improve the anti-hot spot performance of the back contact battery.

[0100] It should be noted that the CTM value is generally the percentage of the output power of the photovoltaic module and the total power of the back contact cell. The CTM value can indicate the degree of power loss of the photovoltaic module. The higher the CTM value, the smaller the degree of power loss of the photovoltaic module packaging.

[0101] It is worth noting that, combined with reference Figure 7 and Figure 3 , the connection structure 106 will not corrode the anti-reflection layer 140 . In other words, the connection structure 106 is located on the side of the anti-reflection layer 140 away from the substrate 130 , so as to avoid the connection structure 106 causing adverse effects on the photoelectric conversion efficiency of the cell substrate 100 .

[0102] The arrangement of the plurality of first busbar segments 111 and the plurality of second busbar segments 121 on a single cell substrate 100 is described in detail below.

[0103] refer to Figure 1 or Figure 4 , the first main gate segments 111 and the second main gate segments 121 that are alternately arranged along the first direction X and the second direction Y can be understood as follows: one of the two main gate segments 101 adjacent to each other along the first direction X is the first main gate segment 111, and the other is the second main gate segment 121, and one of the two main gate segments 101 adjacent to each other along the second direction Y is the first main gate segment 111, and the other is the second main gate segment 121. In other words, for a single first main gate segment 111, the two opposite sides of the first main gate segment 111 along the first direction X can each be adjacent to a second main gate segment 121, and the two opposite sides of the first main gate segment 111 along the second direction Y can also each be adjacent to a second main gate segment 121, that is, a single first main gate segment 111 can be surrounded by four second main gate segments 121. Similarly, a single second main gate segment 121 can be surrounded by four first main gate segments 111.

[0104] It should be noted that Figure 1 and Figure 4 In the example, only 10 main gate segments 101 are sequentially arranged along the first direction X on a single battery substrate 100, and 6 main gate segments 101 are sequentially arranged along the second direction Y on a single battery substrate 100 are taken. In practical applications, the number of main gate segments sequentially arranged along the first direction on a single battery substrate can be flexibly designed, for example, it can be 2 to 30, such as 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or 28, etc.; the number of main gate segments sequentially arranged along the second direction on a single battery substrate can also be flexibly designed, for example, it can be 2 to 8, such as 3, 4, 5, 6 or 7, etc. In addition, Figure 5 Only the corresponding Figure 4 In the figure, there are four power generation units 20 arranged along the first direction X. In actual applications, based on the different numbers of main grid segments arranged in sequence along the first direction, the number of power generation units arranged along the first direction will also be different.

[0105] The connection structure 106 in the battery substrate 100 is described in detail below.

[0106] Combined with reference Figure 4 and Figure 7 , the reference bus gate segment 115 of one of two adjacent bus gate segment groups 105 along the first direction X is designed to be in contact with and connected to the connection structure 106, while the reference bus gate segment 115 of the other bus gate segment 115 is not in contact with and connected to the connection structure 106. In this way, for two bus gate segment groups 105 that are in the same row along the first direction X, only two connection structures 106 are required to complete the electrical connection design between the two bus gate segment groups 105, and the two connection structures 106 are not directly opposite each other along the first direction X.

[0107] The following at least three examples are provided for the positional relationship between the connecting structure 106 and the busbar segment 101 :

[0108] In some examples, reference Figure 8 The connecting structure 106 can be located between two adjacent bus gate segments 101 along the second direction Y, and the two bus gate segments 101 contacted and connected by the connecting structure 106 are integrally formed with the connecting structure 106. In other words, the integrally formed structure can be considered as an extension strip extending along the second direction Y. The extension strip is electrically connected not only to the first fine gate 102 but also to the second fine gate 103. The portion of the extension strip contacting the first fine gate 102 can serve as the first bus gate segment 111, and the portion of the extension strip contacting the second fine gate 103 can serve as the second bus gate segment 121.

[0109] It should be noted that Figure 8 This is a fourth partial top view of a back-contact cell provided by an embodiment of the present disclosure, showing that the two main grid segments 101 contacted and connected by the connecting structure 106 and the connecting structure 106 are an integrally formed structure. Figure 8 The connection structure 106 , the first busbar segment 111 , and the second busbar segment 121 shown in the figure are all drawn using the same filling method, and the thicker dotted lines divide the connection structure 106 , the first busbar segment 111 , and the second busbar segment 121 in the extension strip.

[0110] It is worth noting that the two main grid segments 101 in the same extension strip belong to two different power generation units 20 (refer to Figure 5), the other ends of the two power generation units 20 will not be electrically connected together, so as to realize the series connection of the two adjacent power generation units 20 with the help of the extension bars. In addition, for the two main grid segment groups 105 adjacent to each other along the first direction X, on the basis that the two connecting structures 106 are not directly opposite to each other along the second direction Y, the two extension bars adjacent to each other along the first direction X are staggered. Among them, the main grid segments 101 in the main grid segment group 105 are divided into the first-level main grid segment, the second-level main grid segment and the third-level main grid segment in sequence along the second direction Y, then one of the two extension bars adjacent to each other along the first direction X includes the first-level main grid segment and the second-level main grid segment in one main grid segment group 105, and the other of the two extension bars adjacent to each other along the first direction X includes the second-level main grid segment and the third-level main grid segment in another main grid segment group 105, thereby realizing the series connection between the three levels of main grid segments 101.

[0111] In other examples, reference Figure 9 or Figure 10 The two main gate segments 101 contacted and connected by the connecting structure 106 are a first main gate segment 111 and a second main gate segment 121. Along the second direction Y, the first main gate segment 111 has a first end face 111a close to the second main gate segment 121, and the second main gate segment 121 has a second end face 121a close to the first main gate segment 111. The connecting structure 106 is not only contacted and connected with the first end face 111a, but also contacted and connected with the second end face 121a.

[0112] It should be noted that Figure 9 This is a fifth partial top view of a back contact battery provided by an embodiment of the present disclosure. Figure 10 This is a sixth partial top view of a back-contact cell according to an embodiment of the present disclosure; to illustrate that the first busbar segment 111 and the second busbar segment 121 contact-connected by the connecting structure 106 are separate structures, Figure 9 and Figure 10 In the figure, the first busbar segment 111 and the second busbar segment 121 are drawn using different filling methods.

[0113] It is worth noting that the first bus gate segment 111, the second bus gate segment 121, and the connecting structure 106 are all separate structures. The connecting structure 106 is in contact with and connected to not only the first end surface 111a but also the second end surface 121a, which facilitates the series connection of the first bus gate segment 111 and the second bus gate segment 121 adjacent to each other along the second direction Y by means of the connecting structure 106.

[0114] It should be noted that the connection structure 106 is not only in contact with the first end surface 111 a but also in contact with the second end surface 121 a, including at least the following two examples:

[0115] In one example, refer to Figure 9Taking the battery substrate 100 as the base reference, the first main grid segment 111, the second main grid segment 121 and the connecting structure 106 are almost in the same layer, and the connecting structure 106 is only in contact and connected with the first end face 111a and the second end face 121a, which is conducive to achieving the series connection between the first main grid segment 111 and the second main grid segment 121 adjacent to each other in the second direction Y while reducing the length of the connecting structure 106 along the second direction Y as much as possible, so as to reduce the material cost of the connecting structure 106.

[0116] In other examples, refer to Figure 10 , the connecting structure 106 is in addition to the first end surface 111a (reference Figure 9 ) and the second end surface 121a (reference Figure 9 ) contact connection, and can also be located on a portion of the top surface of the first main grid segment 111 away from the battery substrate 100, and / or, on a portion of the top surface of the second main grid segment 121 away from the battery substrate 100. In this way, it is beneficial to increase the contact area between the connection structure 106 and the first main grid segment 111 to reduce the transmission resistance between the connection structure 106 and the first main grid segment 111, and / or, increase the contact area between the connection structure 106 and the second main grid segment 121 to reduce the transmission resistance between the connection structure 106 and the second main grid segment 121, thereby helping to reduce the transmission loss of carriers when transmitting in the main grid segment 101 and the connection structure 106, so as to improve the collection efficiency of carriers by the back contact battery.

[0117] It should be noted that Figure 10 In the example, the connection structure 106 is located not only on the portion of the top surface of the first busbar segment 111 away from the battery substrate 100, but also on the portion of the top surface of the second busbar segment 121 away from the battery substrate 100. In actual applications, on the basis of the connection structure being in contact with the first end surface and the second end surface, the connection structure may be located only on the portion of the top surface of the first busbar segment away from the battery substrate, or only on the portion of the top surface of the second busbar segment away from the battery substrate.

[0118] In some other examples, reference Figure 11 The two main gate segments 101 contacted and connected by the connecting structure 106 are a first main gate segment 111 and a second main gate segment 121. Along the second direction Y, the first main gate segment 111 has a first end 1111 close to the second main gate segment 121, and the second main gate segment 121 has a second end 1211 close to the first main gate segment 111; the connecting structure 106 includes: a connecting segment 116, at least one first welding point 126 located on the first end 1111, and at least one second welding point 136 located on the second end 1211. The connecting segment 116 is not only contacted and connected with the first welding point 126, but also contacted and connected with the second welding point 136.

[0119] It should be noted that Figure 11 This is a seventh partial top view of a back-contact cell provided in one embodiment of the present disclosure, showing that the first busbar segment 111 and the second busbar segment 121 contact-connected by the connecting structure 106 are separate structures. Figure 11 The first main gate segment 111 and the second main gate segment 121 are drawn using different filling methods, and Figure 11 In the figure, a thicker dotted line divides the first end portion 1111 in the first busbar segment 111 , and a thicker dotted line divides the second end portion 1211 in the second busbar segment 121 .

[0120] It is worth noting that the connecting segment 116 can be considered a welding strip extending along the second direction Y for a relatively short length, and the entirety of the welding strip is located on the battery substrate 100. On this basis, at least one first welding spot 126 is designed at the first end 1111 of the first busbar segment 111, and at least one second welding spot 136 is designed at the second end 1211 of the second busbar segment 121. This facilitates increasing the probability that the connecting segment 116 will electrically connect to the first busbar segment 111 and the second busbar segment 121 via the first welding spot 126 and the second welding spot 136. In other words, the design of the first welding spot 126 and the second welding spot 136 facilitates reducing the alignment accuracy requirements between the connecting segment 116 and the first and second busbar segments 111 and 121. This allows the connecting segment 116 to achieve electrical connection to the first and second busbar segments 111 and 121 even when there is a certain offset relative to the first and second busbar segments 111 and 121.

[0121] It should be noted that the difference between the first end face 111a and the first end portion 1111 is that the first end face 111a is a face on the first main gate segment 111, and the first end portion 1111 is a region in the first main gate segment 111 where at least one first welding point 126 is provided and is close to the second main gate segment 121 along the second direction Y; similarly, the difference between the second end face 121a and the second end portion 1211 is that the second end face 121a is a face on the second main gate segment 121, and the second end portion 1211 is a region in the second main gate segment 121 where at least one second welding point 136 is provided and is close to the first main gate segment 111 along the second direction Y.

[0122] In some cases, along the first direction X, the width of the first welding spot 126 is greater than the width of the first bus gate segment 111 , and the width of the second welding spot 136 is greater than the width of the second bus gate segment 121 .

[0123] In some cases, the first welding point 126 is not only located on the first end portion 1111 , but also the orthographic projection of the first welding point 126 on the battery substrate 100 coincides with the orthographic projection of the first fine grid 102 on the battery substrate 100 .

[0124] In some cases, the second welding point 136 is not only located on the second end portion 1211 , but also the orthographic projection of the second welding point 136 on the battery substrate 100 coincides with the orthographic projection of the second fine grid 103 on the battery substrate 100 .

[0125] In the various embodiments described above, whether part of the first main gate segment 111 and the second main gate segment 121 are included in the same extension strip, or the first main gate segment 111 and the second main gate segment 121 are spaced apart from each other, when designing the alternating arrangement of the first main gate segment 111 and the second main gate segment 121 on the battery substrate 100, the main gate segments 101 can be arranged in an array along the first direction X and the second direction Y, and two adjacent main gate segments 101 are electrically connected to the first fine grid 102 and the second fine grid 103, respectively. Based on the design of the array arrangement of the main gate segments 101, Dividing the battery substrate 100 into multiple small areas of similar size is beneficial for the carriers generated in the battery substrate 100 to be evenly collected by each main gate segment 101. In other words, it promotes the uniform flow of carriers on multiple main gate segments 101 to improve the overall electrical performance of the back contact battery, such as the uniformity of current density, which is beneficial to improving the uniformity of the overall photoelectric conversion efficiency of the back contact battery, and avoiding local heating problems caused by excessive differences in carriers in different areas on the back contact battery, thereby improving the anti-hot spot performance of the back contact battery.

[0126] In some embodiments, reference Figure 4 The back-contact battery may further include: a first through-line 117 and a second through-line 127 respectively located at two opposite edges of the gate line region 120 along the second direction Y, the first through-line 117 and the second through-line 127 both extending along the first direction X, and the first through-line 117 contacts and connects a plurality of first main gate segments 111 arranged at intervals along the first direction X, and the second through-line 127 contacts and connects a plurality of second main gate segments 121 arranged at intervals along the first direction X; wherein, the first through-line 117 corresponding to one of the two adjacent gate line regions 120 along the second direction Y is close to the isolation region 110, and the second through-line 127 corresponding to the other is close to the isolation region 110.

[0127] It should be noted that, in order to distinguish the first fine gate 102 from the second fine gate 103, Figure 4 In the figure, the first fine grid 102 is indicated by a thinner dotted line, and the second fine grid 103 is indicated by a thinner solid line; in order to distinguish the first through-line 117 from the second through-line 127, Figure 4 The first penetration line 117 is indicated by a thicker dotted line, and the second penetration line 127 is indicated by a thicker solid line.

[0128] It is worth noting that, based on the different polarities of the two adjacent main gate segments 101 along the first direction X, i.e., one is the first main gate segment 111 and the other is the second main gate segment 121, the types of the two through-lines used to bring together the two adjacent main gate segments 101 along the first direction X will also be different, i.e., one contact connects the first through-line 117 of multiple first main gate segments 111 belonging to one gate line region 120 along the first direction X, and the other contact connects the second through-line 127 of multiple second main gate segments 121 belonging to another gate line region 120 along the first direction X. In addition, the design of the first through-line 117 and the second through-line 127 relative to each other along the second direction Y in the gate line region 120 is conducive to producing a good current sharing effect on the gate line region 120, thereby producing a good current sharing effect on the back contact battery as a whole, thereby improving the electrical performance of the back contact battery.

[0129] The following describes in detail how the first through-line 117 and the second through-line 127 produce a good current sharing effect on the gate line region 120 .

[0130] The first through-line 117 can simultaneously contact and connect multiple first main gate segments 111 in the same gate line region 120 along the first direction X, so that the multiple first main gate segments 111 are electrically connected to each other. Then, the carriers in the multiple first main gate segments 111 can have multiple flow paths based on the first through-line 117. Moreover, the multiple first main gate segments 111 in the same gate line region 120 along the first direction X belong to different series blocks 50 (refer to Figure 5 ), in other words, different first main gate segments 111 in the multiple first main gate segments 111 in the same gate line area 120 along the first direction X correspond to sub-components of different series blocks 50. In this way, the multiple first main gate segments 111 in the same gate line area 120 along the first direction X are electrically connected at the same time by means of the first through-line 117, so that the multiple series blocks 50 arranged at intervals along the first direction X can be connected in parallel to each other to form a denser carrier transmission path, and the first through-line 117 is used to make the various first main gate segments 111 in the same gate line area 120 along the first direction X at the same potential, that is, effectively avoid the potential difference between the various first main gate segments 111 in the same gate line area 120 along the first direction X.

[0131] In addition, in the same series block 50, different first main gate segments 111 belonging to different gate line regions 120 are respectively contacted and connected with different first through-lines 117. When the connection structure 106 contacts and connects two adjacent main gate segments 101 in the main gate segment group 105, the first through-line 117 can also be electrically connected to the connection structure 106, further forming a denser carrier transmission path.

[0132] Similarly, the second through line 127 can contact and connect multiple second main grid segments 121 in the same grid line area 120 along the first direction X at the same time, so that the multiple second main grid segments 121 are electrically connected to each other, and the carriers in the multiple second main grid segments 121 can have multiple flow paths based on the second through line 127. Moreover, the multiple second main grid segments 121 in the same grid line area 120 along the first direction X belong to different series blocks 50 respectively, in other words, different second main grid segments 121 in the multiple second main grid segments 121 in the same grid line area 120 along the first direction X each correspond to a sub-component of a different series block 50, and thus, the multiple series blocks 50 arranged at intervals along the first direction X can be connected in parallel to each other by means of the second through line 127 to simultaneously electrically connect the multiple second main grid segments 121 in the same grid line area 120 along the first direction X, so as to form a more dense carrier transmission path, and the multiple second main grid segments 121 in the same grid line area 120 along the first direction X are at the same potential by means of the second through line 127, that is, the potential difference between the multiple second main grid segments 121 in the same grid line area 120 along the first direction X is effectively avoided.

[0133] In addition, in the same series block 50, different second main grid segments 121 belonging to different grid line areas 120 are respectively connected with different second through lines 127, and the second through line 127 can be electrically connected with the connection structure 106 when the connection structure 106 connects two adjacent main grid segments 101 in the main grid segment group 105, so as to further form a more dense carrier transmission path.

[0134] It should be noted that the first through line 117 and the first fine grid 102 can be formed by the same preparation process, and the second through line 127 and the second fine grid 103 can be formed by the same preparation process, so that the first through line 117 can be connected with the first doped area 1201 for directly collecting carriers from the battery substrate 100, and the second through line 117 can be connected with the second doped area 1202 for directly collecting carriers from the battery substrate 100. In practical applications, the first through line can also be formed by the same preparation process as the first main grid segment, and the second through line can also be formed by the same preparation process as the second main grid segment.

[0135] Therefore, the design of the same gate line area 120 including the first through line 117 and the second through line 127 relative to each other along the second direction Y is beneficial for interconnecting the multiple first main gate segments 111 in the same gate line area 120 into a whole, and is also beneficial for interconnecting the multiple second main gate segments 121 in the same gate line area 120 into a whole. In this way, even if a local area of ​​the back contact battery fails and current cannot be effectively collected, resulting in the actual current collected in the local area where the failure occurs being smaller than the ideal state, based on the effects of the first through line 117 and the second through line 127, the current can be uniformly circulated on the multiple first main gate segments 111 and the multiple second main gate segments 121 respectively, so as to improve the overall electrical performance of the back contact battery, such as the uniformity of the current density, thereby improving the uniformity of the overall photoelectric conversion efficiency of the back contact battery, and avoiding the problem of local heating caused by excessive current differences in different areas on the back contact battery sheet, so as to improve the anti-hot spot performance of the back contact battery.

[0136] In some embodiments, reference Figure 12 , the battery substrate 100 is a half-cell battery, and the half-cell battery may include two edges opposite to each other along the second direction Y, the main grid segment 101 close to the edge is the edge main grid segment 125, and the main grid segment 101 located between the two adjacent edge main grid segments along the second direction Y is the middle main grid segment 135; wherein, along the second direction Y, reference Figure 12 The extending length of the edge busbar segment 125 is a first length, and the extending length of the middle busbar segment 135 is a second length, which is greater than the first length.

[0137] It should be noted that Figure 12 A partial top view of a busbar segment on a battery substrate in a back-contact battery provided in one embodiment of the present disclosure is provided. To facilitate the distinction between the first busbar segment 111 and the second busbar segment 121, Figure 12 In the figure, the first busbar segment 111 and the second busbar segment 121 are drawn using different filling methods.

[0138] It is worth noting that the edge of the half-cell battery is more susceptible to greater external forces, which may lead to damage to the generation or collection of carriers. As the edge main grid segment 125 located at the edge of the half-cell battery, its extension length along the second direction Y is designed to be smaller, which is beneficial to avoid the impact of the damage to the carrier collection efficiency from spreading to the main grid segment 101 at a longer distance, thereby balancing the current difference between the edge main grid segments 125 and the middle main grid segment 135.

[0139] In summary, compared to designing a long main grid extending along the second direction, the back-contact cell provided by one embodiment of the present disclosure is designed with multiple main grid segments 101 spaced apart along the second direction Y, and an isolation region 110 is designed between two adjacent main grid segments 101 along the second direction Y. This allows the cell substrate 100 to be divided into multiple power generation areas, i.e., multiple grid line areas 120, by means of the isolation region 110. In this way, even if carrier collection in a particular power generation area is hindered, carrier collection in other power generation areas will not be affected, thereby facilitating the improvement of the hot spot resistance of the back-contact cell. Moreover, regardless of whether the cell substrate 100 is a whole cell or a sliced ​​cell, the isolation region 110 can be used to divide the cell substrate 100 into multiple power generation areas. Different power generation areas are separated by the isolation region 110 to independently generate electricity. Subsequently, by adjusting the arrangement of the first main grid segment 111, the second main grid segment 121, the first fine grid 102, and the second fine grid 103 in adjacent power generation areas, adjacent power generation areas can be flexibly designed to be connected in series or in parallel, thereby flexibly controlling the overall operating current and operating voltage of the back-contact cell. In addition, when the cell substrate 100 is a whole cell, the cell substrate 100 can be divided into multiple power generation areas without slicing the cell substrate 100 and without causing any damage to the cell substrate 100.

[0140] Another embodiment of the present disclosure provides a back-contact tandem battery, which includes the back-contact battery provided by the aforementioned embodiment. The following describes the back-contact tandem battery provided by another embodiment of the present disclosure in detail with reference to the accompanying drawings. It should be noted that parts that are identical or corresponding to the aforementioned embodiments will not be repeated here.

[0141] refer to Figure 13 , Figure 13 A partial cross-sectional schematic diagram of a back-contact stack battery provided in another embodiment of the present disclosure, the back-contact stack battery includes: a bottom battery 108, which is the back-contact battery provided in the aforementioned embodiment; and a top battery 109, which is located on one side of the bottom battery 108.

[0142] In some embodiments, the top cell 109 may be one of a perovskite solar cell, a donor-acceptor cell, a cadmium telluride (CdTe) solar cell, a copper indium gallium selenide (CIGS) solar cell, or a gallium arsenide (GaAs) solar cell.

[0143] In some cases, the top cell 109 may include: a stacked first transmission layer, a perovskite substrate, a second transmission layer, a transparent conductive layer, and an anti-reflection layer, wherein the first transmission layer is directly opposite to the bottom cell 108 .

[0144] In some examples, the first transport layer may be one of an electron transport layer and a hole transport layer, and the second transport layer may be the other of the electron transport layer and the hole transport layer.

[0145] In some embodiments, the band gap width of the top cell 109 can be wider than that of the bottom cell 108. Therefore, stacking the top cell 109 on the bottom cell 108 can enable the back-contact stack cell to have a wider spectral response range, thereby maximizing the use of solar energy and improving the efficiency of the back-contact stack cell.

[0146] In some embodiments, the back-contact stacked battery may further include an intermediate connection layer (not shown in the figure), which is connected between the bottom battery 108 and the top battery 109 .

[0147] In some cases, the intermediate connecting layer is typically a tunnel junction or a very thin metal or transparent electrode composite layer. Alternatively, the intermediate connecting layer can be a transparent conductive oxide, which has excellent optoelectronic properties, high photon transmittance and high conductivity, thereby maintaining good ohmic contact between the top cell 109 and the bottom cell 108.

[0148] In other cases, the grid lines in the back contact cell serving as the bottom cell 108 may also serve as an intermediate connection layer for achieving electrical connection with the top cell 109 .

[0149] In some embodiments, the battery substrate 100 in the back-contact battery serving as the bottom battery 108 has opposite front and back sides, and the top battery 109 can be located on the side of the front side away from the back side, or on the side of the back side away from the front side.

[0150] Another embodiment of the present disclosure provides a photovoltaic module, comprising a plurality of back-contact cells provided in the preceding embodiments, or a plurality of back-contact stacked cells provided in the preceding embodiments. The photovoltaic module provided in this further embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that portions identical or corresponding to the preceding embodiments are not described in detail here.

[0151] Combined with reference Figures 14 to 20 ,as well as Figures 1 to 13 The photovoltaic module includes: a plurality of back-contact cells 40 provided by the aforementioned embodiments connected together, or a plurality of back-contact laminated cells provided by the aforementioned embodiments connected together; an encapsulation film 41 for covering the surface of the cell string; and a cover plate 42 for covering the surface of the encapsulation film 41 facing away from the cell string.

[0152] It should be noted that the back-contact cell 40 is electrically connected in the form of a whole cell or multiple slices to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. The back-contact cell 40 can be a whole cell or a sliced ​​cell. A sliced ​​cell refers to a cell formed by cutting a complete whole cell.

[0153] also, Figure 14 A first partial top view schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure is provided. Figure 15 A partial cross-sectional schematic diagram of a photovoltaic module provided by another embodiment of the present disclosure is provided to clearly illustrate the positional relationship between the connecting structure 106 and the main grid segment 101, as well as the positional relationship between the welding ribbon 43 and the main grid segment 101. Figure 14 、 Figure 16 as well as Figures 18 to 20 In the figure, the connection structure 106 and the main grid segment 101 are drawn in perspective.

[0154] It is worth noting that based on the back contact cell 40 provided in the aforementioned embodiment, or including the back contact laminated cell including the back contact cell 40 provided in the aforementioned embodiment, even if a single cell substrate 100 is a whole cell, by means of a layout in which the first main grid segment 111 and the second main grid segment 121 are alternately arranged along the first direction X and the second direction Y, and by flexibly designing the series or parallel connection of adjacent grid line areas 120, the current in a single carrier transmission path can be reduced without slicing the entire cell, and the operating voltage and operating current of the back contact cell can be reduced. On this basis, after constructing a cell string in a photovoltaic module with the help of the back contact cell 40, it is beneficial to reduce the operating current in the cell string, thereby reducing thermal damage to the photovoltaic module and increasing the power of the photovoltaic module.

[0155] In some embodiments, reference Figure 12 , the two back contact cells 40 adjacent along the second direction Y are respectively the first back contact cell 401 and the second back contact cell 402, the main grid segment 101 close to the second back contact cell 402 in the first back contact cell 401 is the first main grid segment 12a to be welded, and the main grid segment 101 close to the first back contact cell 401 in the second back contact cell 402 is the second main grid segment 12b to be welded; the first main grid segment 12a to be welded and the second main grid segment 12b to be welded adjacent along the second direction Y are regarded as a group to be welded; the photovoltaic component may also include: a welding strip 43, the first main grid segment 12a to be welded and the second main grid segment 12b to be welded of one of the two adjacent groups to be welded along the first direction X are respectively contacted and connected with the welding strip 43, and the first main grid segment 12a to be welded and the second main grid segment 12b to be welded of the other group are not contacted and connected with the welding strip 43.

[0156] It is worth noting that, based on the design of the connection structure 106 in the back-contact cell 40, the soldering ribbon 43 does not need to pass through the entire back-contact cell 40 along the second direction Y. The soldering ribbon 43 only needs to contact and connect the first main grid segment 12a to be welded and the second main grid segment 12b to be welded of one of two adjacent groups to be welded along the first direction X. This helps to significantly shorten the extension length of the soldering ribbon 43 along the second direction Y, thereby reducing the usage cost of the soldering ribbon 43. In addition, for a single back-contact cell 40, the area welded to the single soldering ribbon 43 is relatively small. Therefore, in the process of achieving electrical connection between the single soldering ribbon 43 and the single back-contact cell 40, only a portion of the edge area of ​​the back-contact cell 40 is affected by high temperature, which helps to significantly reduce the high-temperature warping effect caused by the slow-release soldering ribbon 43.

[0157] It should be noted that the welding strip 43, like the connecting structure 106, can be located only between two adjacent main grid segments 101 along the second direction Y. The difference is that the two main grid segments 101 contacted and connected by the welding strip 43 are respectively located on different battery substrates 100. In other words, the two main grid segments 101 contacted and connected by the welding strip 43 belong to different back-contact batteries 40, and the two main grid segments 101 contacted and connected by the connecting structure 106 are located on the same battery substrate 100, and the two main grid segments 101 contacted and connected by the connecting structure 106 belong to different gate line areas 120.

[0158] The following describes in detail the relationship between the number of main grid segments 101 arranged along the first direction X on a single battery substrate 100, the number of main grid segments 101 arranged along the second direction Y on a single battery substrate 100, and the arrangement of two adjacent battery substrates 100 when realizing the series connection between two adjacent back-contact batteries 40.

[0159] In some cases, reference Figure 16 or Figure 17 When the number of main grid segments 101 arranged along the first direction X on a single battery substrate 100 is an even number and the number of main grid segments 101 arranged along the second direction Y on a single battery substrate 100 is an odd number, if the arrangement of the first main grid segments 111 and the second main grid segments 121 on two adjacent battery substrates 100 is consistent, one of the two adjacent battery substrates 100 is rotated 180°, so that the first main grid segment 111 on one of the two adjacent half-cell batteries can be adjacent to the second main grid segment 121 on the other, so that the series connection of the two adjacent back-contact batteries 40 can be achieved with the help of the welding strip 43.

[0160] in, Figure 16 A second partial top view schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure is provided. Figure 17 A third partial top view schematically illustrates a cell string in a photovoltaic assembly according to another embodiment of the present disclosure.

[0161] In some cases, referring to Figure 14 , the number of main grid segments 101 arranged along the first direction X on a single cell substrate 100 is even, and the number of main grid segments 101 arranged along the second direction Y on a single cell substrate 100 is also even, if the arrangement of the first main grid segment 111 and the second main grid segment 121 on two adjacent cell substrates 100 is consistent, the first main grid segment 111 on one of the two adjacent half-cell substrates and the second main grid segment 121 on the other half-cell substrate are adjacent without rotating the cell substrate 100, and thus the series connection of the two adjacent back contact cells 40 can be achieved by means of the solder ribbon 43.

[0162] In some other cases, referring to Figure 18 or Figure 19 , the number of main grid segments 101 arranged along the first direction X on a single cell substrate 100 is odd, and the number of main grid segments 101 arranged along the second direction Y on a single cell substrate 100 is also odd.

[0163] Referring to Figure 18 , Figure 18 is a fourth partial top view schematic diagram of a cell string in a photovoltaic module according to another embodiment of the present disclosure, if the arrangement of the first main grid segment 111 and the second main grid segment 121 on two adjacent cell substrates 100 is consistent, the first main grid segment 111 on one of the two adjacent half-cell substrates and the first main grid segment 111 on the other half-cell substrate are adjacent, regardless of whether the cell substrate 100 is rotated, and thus the parallel connection of the two adjacent back contact cells 40 can be achieved by means of the solder ribbon 43.

[0164] Referring to Figure 19 , Figure 19 is a fifth partial top view schematic diagram of a cell string in a photovoltaic module according to another embodiment of the present disclosure, if the arrangement of the first main grid segment 111 and the second main grid segment 121 on two adjacent cell substrates 100 is inconsistent, the first main grid segment 111 on one of the two adjacent half-cell substrates and the second main grid segment 121 on the other half-cell substrate are adjacent without rotating the cell substrate 100, and thus the series connection of the two adjacent back contact cells 40 can be achieved by means of the solder ribbon 43.

[0165] In some other cases, referring to Figure 20 , Figure 20A sixth partial top view schematic of a cell string in a photovoltaic module according to yet another embodiment of the present disclosure is provided. The number of main grid segments 101 arranged along the first direction X on a single cell substrate 100 is odd, and the number of main grid segments 101 arranged along the second direction Y on a single cell substrate 100 is even. If the arrangement of the first main grid segment 111 and the second main grid segment 121 on two adjacent cell substrates 100 is consistent, the first main grid segment 111 on one of the two adjacent half-cell substrates and the second main grid segment 121 on the other half-cell substrate can be adjacent to each other without rotating the cell substrate 100, so that the series connection of the two adjacent back contact cells 40 can be achieved by means of the solder ribbon 43.

[0166] It should be noted that based on the adjustment of the arrangement of the first main grid segment 111 and the second main grid segment 121 on two adjacent cell substrates 100, or the rotation of the cell substrate 100, the series or parallel connection of the two adjacent back contact cells 40 can be flexibly designed, and the present disclosure does not exhaustively list the series or parallel connection of the two adjacent back contact cells 40.

[0167] In addition, in order to distinguish the first main grid segment 111 and the second main grid segment 121, Figure 14 、 Figures 16 to 20 In the above-mentioned figures, different filling methods are used to draw the first main grid segment 111 and the second main grid segment 121.

[0168] In some embodiments, the back contact cell 40 is a BC cell (Back Contact), which includes but is not limited to an IBC cell (Interdigitated Back Contact), an HBC cell (Heterojunction Back Contact), a TBC cell (TOPCon Back Contact), or an HPBC cell (Hybrid Passivated Back Contact), etc.

[0169] In some embodiments, the encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer, wherein the first encapsulation layer covers one of the front side and the back side of the back-contact cell 40, and the second encapsulation layer covers the other of the front side and the back side of the back-contact cell 40. Specifically, at least one of the first encapsulation layer and the second encapsulation layer can be an organic encapsulation film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first encapsulation layer and the second encapsulation layer can also be an EP film, an EPE film, or a PVP film. EP film refers to a coextruded film composed of stacked EVA film and POE film, EPE film refers to a coextruded film formed by stacking EVA film, POE film, and EVA film, and PVP film refers to a coextruded film formed by stacking POE film, EVA film, and POE film. Coextruded films can be produced by sequentially extruding one or more raw materials onto another pre-existing film during the film processing process, or by bonding different pre-existing films together.

[0170] In some cases, there is a boundary line between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0171] In some embodiments, the cover plate 42 may be a light-transmitting cover plate such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may have a concave-convex surface or a velvet surface including multiple raised structures, thereby increasing the utilization of incident light. The cover plate 42 includes a first cover plate and a second cover plate. The first cover plate faces the first encapsulation layer, and the second cover plate faces the second encapsulation layer.

[0172] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the scope of protection of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A back contact battery, characterized in that: include: A battery substrate comprising at least one isolation region extending along a first direction, and two gate line regions located on opposite sides of the isolation region along a second direction; The gate line region includes a first doped region and a second doped region spaced apart from each other, and a gap region located between the first doped region and the second doped region; the isolation region is located between the first doped region of one of two gate line regions adjacent to each other along the second direction and the second doped region of the other, and along the second direction, the width of the isolation region is greater than the width of the gap region; At least two main gate segments are located on the gate line area and arranged at intervals along the first direction; wherein, one of the two main gate segments adjacent to each other along the first direction is a first main gate segment, and the other is a second main gate segment, and, one of the two main gate segments adjacent to each other along the second direction is the first main gate segment, and the other is the second main gate segment; a first fine gate and a second fine gate are alternately arranged along the second direction, the first fine gate is located on the first doped region, the second fine gate is located on the second doped region, the first main gate segment is electrically connected to the first fine gate, and the second main gate segment is electrically connected to the second fine gate.

2. The back contact battery according to claim 1, characterized in that The portion of the battery substrate located in the isolation area includes: a substrate; an anti-reflection layer located on the back side of the substrate; The portion of the battery substrate located in the gate line area includes: the base; a first tunneling layer and a first doped semiconductor layer located on the first doped area and stacked along a third direction; a second tunneling layer and a second doped semiconductor layer located on the second doped area and stacked along the third direction; and the anti-reflection layer located on a side of both the first doped semiconductor layer and the second doped semiconductor layer away from the base.

3. The back contact battery according to claim 2, characterized in that The anti-reflection layer includes a first anti-reflection layer and a second anti-reflection layer stacked along the third direction; along the third direction, the thickness of the first anti-reflection layer is 2nm-10nm, and the thickness of the second anti-reflection layer is 40nm-200nm.

4. The back contact battery according to claim 1, characterized in that Along the second direction, the width of the isolation region in the second direction is 100 μm to 5000 μm; and / or the width of the gap region in the second direction is 20 μm to 100 μm.

5. The back contact battery according to claim 1, characterized in that The back contact cell is divided into at least two sub-cells by the isolation region, and the sub-cells correspond to the gate line regions one by one; In a single sub-cell, a first busbar segment and a second busbar segment adjacent to each other along the first direction are used as a lead-out group; The single lead-out group, the first fine grid electrically connected to the lead-out group, the second fine grid, and the battery substrate corresponding to the lead-out group together constitute a power generation unit; two adjacent power generation units along the second direction are connected in series.

6. The back contact battery according to claim 5, characterized in that The sub-cell includes at least two power generation units arranged along the first direction, and different power generation units belonging to the same sub-cell are connected in parallel.

7. The back contact battery according to claim 5, characterized in that The three adjacent bus gate segments along the second direction are grouped as a bus gate segment group, wherein the first bus gate segment in the bus gate segment group along the second direction is a reference bus gate segment; The back-contact battery also includes: a connecting structure that contacts and connects two adjacent main gate segments in the main gate segment group, and the other two adjacent main gate segments in the main gate segment group are not contacted and connected to the connecting structure; the reference main gate segment of one of the two adjacent main gate segment groups along the first direction is contacted and connected to the connecting structure, and the reference main gate segment of the other one is not contacted and connected to the connecting structure.

8. The back contact battery according to claim 7, characterized in that The connecting structure is located between two adjacent main grid segments along the second direction, and the two main grid segments contacted and connected by the connecting structure are an integrally formed structure with the connecting structure.

9. The back contact battery according to claim 7, characterized in that The two main gate segments contacted and connected by the connecting structure are a first main gate segment and a second main gate segment. Along the second direction, the first main gate segment has a first end face close to the second main gate segment, and the second main gate segment has a second end face close to the first main gate segment. The connecting structure is not only contacted and connected with the first end face, but also contacted and connected with the second end face.

10. The back contact battery according to claim 7, characterized in that The two main gate segments contacted and connected by the connecting structure are a first main gate segment and a second main gate segment. Along the second direction, the first main gate segment has a first end close to the second main gate segment, and the second main gate segment has a second end close to the first main gate segment. The connection structure includes: a connection section, at least one first welding point located on the first end, and at least one second welding point located on the second end. The connection section is in contact with not only the first welding point but also the second welding point.

11. The back contact battery according to claim 1, characterized in that Also includes: a first through-line and a second through-line respectively located at two opposite edges of the gate line region along the second direction, wherein both the first through-line and the second through-line extend along the first direction, and the first through-line contacts and connects a plurality of first main gate segments arranged at intervals along the first direction, and the second through-line contacts and connects a plurality of second main gate segments arranged at intervals along the first direction; The first penetration line corresponding to one of the two gate line regions adjacent to each other along the second direction is close to the isolation region, and the second penetration line corresponding to the other gate line region is close to the isolation region.

12. The back contact battery according to claim 1, characterized in that The battery substrate is a half-cell battery, the half-cell battery includes two edges opposite to each other along the second direction, the main grid segment close to the edges is an edge main grid segment, and the main grid segment located between two adjacent edge main grid segments along the second direction is an intermediate main grid segment; Wherein, along the second direction, the extension length of the edge main gate segment is a first length, the extension length of the middle main gate segment is a second length, and the second length is greater than the first length.

13. A back contact stacked battery, characterized in that: include: A bottom cell, the bottom cell being a back contact cell according to any one of claims 1 to 12; A top cell is located on one side of the bottom cell.

14. A photovoltaic module, characterized in that: include: A plurality of back-contact cells according to any one of claims 1 to 12 connected together, or a plurality of back-contact stacked cells according to claim 13 connected together; A packaging film, used to cover the surface of the battery string; A cover plate is used to cover the surface of the packaging film facing away from the battery string.

15. The photovoltaic module according to claim 14, characterized in that: The two back-contact cells adjacent to each other along the second direction are respectively a first back-contact cell and a second back-contact cell, the busbar segment close to the second back-contact cell in the first back-contact cell is a first busbar segment to be welded, and the busbar segment close to the first back-contact cell in the second back-contact cell is a second busbar segment to be welded; the first busbar segment to be welded and the second busbar segment to be welded adjacent to each other along the second direction are regarded as a group to be welded; The photovoltaic component also includes: a welding strip, wherein the first main grid segment to be welded and the second main grid segment to be welded of one of the two adjacent groups to be welded along the first direction are respectively in contact with the welding strip, and the first main grid segment to be welded and the second main grid segment to be welded of the other group are not in contact with the welding strip.

Images