Back contact cells and photovoltaic modules

Abstract

The application relates to the technical field of back contact cells, in particular to a back contact cell and a photovoltaic module. In the embodiment of the application, by adjusting the size of the first passivation contact layer along the arrangement direction of the first area and the second area, the size of the second passivation contact layer located on the second area along the arrangement direction of the first area and the second area, and the difference between the size of the first passivation contact layer along the arrangement direction of the first area and the second area and the size of the second passivation contact layer located on the second area along the arrangement direction of the first area and the second area, the photoelectric conversion efficiency of the back contact cell can be considered, and the light energy can be used to the maximum extent, so that the performance of the back contact cell is improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to back-contact solar cells and photovoltaic modules. Background Technology

[0002] Back-contact (BC) cells are devices that convert solar energy into electrical energy. Specifically, BC cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy. However, the performance of BC cells needs further improvement. Summary of the Invention

[0003] Therefore, it is necessary to provide a back-contact battery and photovoltaic module to improve the performance of the back-contact battery.

[0004] According to one aspect of this application, an embodiment of this application provides a back-contact battery, including a substrate, a first passivation contact layer, and a second passivation contact layer. The substrate has a first surface, which includes alternating first and second regions. The first passivation contact layer includes a tunneling layer and a first doped layer, wherein the tunneling layer is disposed on the first region, and the first doped layer is disposed on the side of the tunneling layer facing away from the substrate. The second passivation contact layer includes an amorphous material layer and a second doped layer, wherein the amorphous material layer is disposed at least on the second region, and the second doped layer is disposed on the side of the amorphous material layer facing away from the substrate. Wherein, along the arrangement direction of the first and second regions, the edge regions of the first surface are located on both sides of the middle region of the first surface; a portion of the first and second regions are located in the middle region, and another portion of the first and second regions are located in the edge regions; on at least one edge region, along the arrangement direction of the first and second regions, the total size of the first passivation contact layer is larger than the total size of the second passivation contact layer located on the second region.

[0005] In some embodiments, along the arrangement direction of the first and second regions, the ratio of the size of the edge region to the size of the middle region is 0.2 to 1; and / or, along the arrangement direction of the first and second regions, the size of the edge region is 0.3 mm to 20 mm, and the size of the middle region is 65 mm to 190 mm; and / or, on the same edge region, along the arrangement direction of the first and second regions, the ratio q1 of the total size of the first passivation contact layer to the total size of the second passivation contact layer located on the second region satisfies: 1 < q1 ≤ 2.

[0006] In some embodiments, on the same edge region, along the arrangement direction of the first region and the second region, the ratio q2 of the size of the first passivation contact layer to the size of the second passivation contact layer located on the second region satisfies: 1≤q2≤2; and / or, on the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is 200μm to 1000μm, and the size of the second passivation contact layer located on the second region is 100μm to 500μm.

[0007] In some embodiments, on at least one edge region, along the arrangement direction of the first and second regions, the size of the first passivation contact layer is larger than the size of the second passivation contact layer located on the second region.

[0008] In some embodiments, on at least one edge region, along the arrangement direction of the first and second regions, the size of the first passivation contact layer is smaller than the size of the second passivation contact layer located on the second region.

[0009] In some embodiments, the edge region has a first side connecting to the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer tends to increase.

[0010] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the preceding first passivation contact layer is smaller than the size of the subsequent first passivation contact layer.

[0011] In some embodiments, the back contact battery further includes a first electrode, which is disposed on the side of the first doped layer away from the tunneling layer and is electrically connected to the first doped layer; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first electrode tends to increase.

[0012] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first electrode located on the first region is smaller than the size of the first electrode located on the second region; and / or, on the same edge region, along the arrangement direction of the first region and the second region, the size of the first electrode ranges from 30 μm to 70 μm.

[0013] In some embodiments, the edge region has a first side connecting to the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer tends to decrease.

[0014] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the preceding first passivation contact layer is larger than the size of the subsequent first passivation contact layer.

[0015] In some embodiments, the back contact battery further includes a first electrode, which is disposed on the side of the first doped layer away from the tunneling layer and is electrically connected to the first doped layer; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first electrode tends to decrease.

[0016] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the first electrode located on the first region is larger than the size of the first electrode located on the second region; and / or, on the same edge region, along the arrangement direction of the first and second regions, the size of the first electrode ranges from 30 μm to 70 μm.

[0017] In some embodiments, the size of the first passivation contact layer is the same along the arrangement direction of the first and second regions in the same edge region.

[0018] In some embodiments, on the same edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer has multiple specifications, and the size of two adjacent first passivation contact layers is different.

[0019] In some embodiments, the edge region has a first side connecting to the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located on the second region tends to increase.

[0020] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second passivation contact layer located on the second region is smaller than the size of the second passivation contact layer located on the second region.

[0021] In some embodiments, the back contact battery further includes a second electrode, which is disposed on the side of the second doped layer away from the amorphous material layer and is electrically connected to the second doped layer; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second electrode tends to increase.

[0022] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second electrode located on the second region is smaller than the size of the second electrode located on the second region; and / or, on the same edge region, along the arrangement direction of the first and second regions, the size of the second electrode ranges from 30 μm to 70 μm.

[0023] In some embodiments, the edge region has a first side connecting to the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located on the second region tends to decrease.

[0024] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second passivation contact layer located on the first region is larger than the size of the second passivation contact layer located on the second region.

[0025] In some embodiments, the back contact battery further includes a second electrode, which is disposed on the side of the second doped layer away from the amorphous material layer and is electrically connected to the second doped layer; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second electrode tends to decrease.

[0026] In some embodiments, on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second electrode located on the second region is larger than the size of the second electrode located on the second region; and / or, on the same edge region, along the arrangement direction of the first and second regions, the size of the second electrode ranges from 30 μm to 70 μm.

[0027] In some embodiments, on the same edge region, along the arrangement direction of the first and second regions, the second passivation contact layer located on the second region has the same size.

[0028] In some embodiments, on the same edge region, along the arrangement direction of the first and second regions, the size of the second passivation contact layer located on the second region has various specifications, and the sizes of two adjacent second passivation contact layers located on the second region are different.

[0029] In some embodiments, the region furthest from the middle region on at least one edge region is the first region.

[0030] In some embodiments, at least one edge region includes a gap region; the area on the at least one edge region that is furthest from the middle region is the gap region.

[0031] In some embodiments, the size of the spacing region is 100 μm to 300 μm along the arrangement direction of the first and second regions.

[0032] In some embodiments, in the intermediate region, along the arrangement direction of the first and second regions, the size of the first passivation contact layer and the size of the second passivation contact layer located in the second region are equal.

[0033] In some embodiments, the first surface includes a plurality of unit regions; each unit region includes at least one first region and at least one second region; on the same unit region, along the arrangement direction of the first and second regions, the size of the first passivation contact layer and the size of the second passivation contact layer located on the second region are equal; along the arrangement direction of the first and second regions, two adjacent unit regions are spaced apart.

[0034] According to another aspect of this application, embodiments of this application provide a photovoltaic module, including a cell string, an encapsulation layer, and a cover plate. The encapsulation layer is used to cover the surface of the cell string. The cover plate is used to cover the surface of the encapsulation layer away from the cell string. The cell string is formed by connecting multiple back-contact cells as described in any of the embodiments above.

[0035] In the aforementioned back-contact solar cells and photovoltaic modules, because the total size of the first passivation contact layer is larger than the total size of the second passivation contact layer located in the second region along the arrangement direction of the first and second regions on at least one edge region of the first surface of the substrate, there is a difference between the total size of the first passivation contact layer along the arrangement direction of the first and second regions on at least one edge region and the total size of the second passivation contact layer along the arrangement direction of the first and second regions on the second region. With this structure, by adjusting the size of the first passivation contact layer along the arrangement direction of the first and second regions, the size of the second passivation contact layer along the arrangement direction of the first and second regions on the second region, and utilizing the difference between the size of the first passivation contact layer along the arrangement direction of the first and second regions and the size of the second passivation contact layer along the arrangement direction of the first and second regions on the second region, it is possible to maximize the utilization of light energy while maintaining the photoelectric conversion efficiency of the back-contact solar cell, thereby improving the performance of the back-contact solar cell.

[0036] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments described below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0038] Figure 1 This is a partial structural schematic diagram of the back contact battery in some embodiments of this application from a cross-sectional perspective.

[0039] Figure 2 This is a schematic diagram of the edge region and the middle region of the first surface in some embodiments of this application;

[0040] Figure 3 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some embodiments of this application;

[0041] Figure 4 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in other embodiments of this application;

[0042] Figure 5 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some embodiments of this application;

[0043] Figure 6 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some embodiments of this application;

[0044] Figure 7 This is a schematic diagram of a first passivation contact layer on an edge region, a second passivation contact layer on a second region, and a first electrode in some embodiments of this application;

[0045] Figure 8 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some other embodiments of this application;

[0046] Figure 9 This is a schematic diagram of a first passivation contact layer on an edge region, a second passivation contact layer on a second region, and a first electrode in some other embodiments of this application;

[0047] Figure 10 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer on a second region in some other embodiments of this application;

[0048] Figure 11This is a schematic diagram of a first passivation contact layer on an edge region, a second passivation contact layer on a second region, and a second electrode in some other embodiments of this application;

[0049] Figure 12 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some other embodiments of this application;

[0050] Figure 13 This is a schematic diagram of a first passivation contact layer on an edge region, a second passivation contact layer on a second region, and a second electrode in some other embodiments of this application;

[0051] Figure 14 This is a schematic diagram of a first passivated contact layer on an edge region and a second passivated contact layer located on a second region in some other embodiments of this application;

[0052] Figure 15 This is a schematic diagram of a first passivation contact layer on an edge region, a second passivation contact layer on a second region, a first electrode, and a second electrode in some other embodiments of this application;

[0053] Figure 16 This application also provides schematic diagrams of a first passivation contact layer on an edge region and a second passivation contact layer located on a second region in some embodiments;

[0054] Figure 17 This application also provides schematic diagrams of a first passivation contact layer on an edge region and a second passivation contact layer located on a second region in some embodiments;

[0055] Figure 18 This is a schematic diagram of a first passivated contact layer on the intermediate region and a second passivated contact layer on the second region in some embodiments of this application;

[0056] Figure 19 This is a schematic diagram of a first passivated contact layer on the intermediate region and a second passivated contact layer on the second region in some other embodiments of this application;

[0057] Figure 20 This is a schematic diagram of a first passivation contact layer on the intermediate region and a second passivation contact layer on the second region in some embodiments of this application;

[0058] Figure 21 This is a schematic diagram of a first passivation contact layer on the intermediate region and a second passivation contact layer on the second region in some embodiments of this application;

[0059] Figure 22 This is a schematic diagram of a first passivation contact layer on the intermediate region and a second passivation contact layer on the second region in some other embodiments of this application;

[0060] Figure 23 This is a schematic diagram of a first passivated contact layer on the intermediate region and a second passivated contact layer on the second region in some other embodiments of this application;

[0061] Figure 24 This is a schematic diagram of a first passivation contact layer on a unit region and a second passivation contact layer located on a second region in some embodiments of this application;

[0062] Figure 25 This is a schematic diagram of a first passivation contact layer on a unit region and a second passivation contact layer located on a second region in some other embodiments of this application;

[0063] Figure 26 This is a schematic diagram illustrating the interaction between unit regions and non-unit regions in other embodiments of this application;

[0064] Figure 27 This is a schematic diagram showing the arrangement of the first electrodes in some embodiments of this application;

[0065] Figure 28 This is a schematic diagram showing the arrangement of the second electrodes in some embodiments of this application;

[0066] Figure 29 This is a schematic diagram of the structure of a photovoltaic module in some embodiments of this application.

[0067] Explanation of reference numerals in the attached figures:

[0068] Back contact battery 100;

[0069] Base 110, first surface m1, first region m11, second region m12, edge region mb, third dimension h3, middle region mz, ​​fourth dimension h4, interval region mj, seventh dimension h7, unit regions mu, mu1, second surface m2;

[0070] First passivation contact layers 120, 120a, 120b, 120c, 120d, 120e, 120f, 120g, 120h, 120i, 120j, 120k, 120m, 120n, 120p, 120q, 120r, 120s, 120t; tunneling layer 121; first doped layer 122; first dimensions h1, h1a, h1b, h1c, h1d, h1e, ​​h1f, h1g, h1h, h1i, h1j, h1k, h1m, h1n, h1p, h1q, h1r, h1s;

[0071] The second passivation contact layer 130, the amorphous material layer 131, the second doped layer 132, the second passivation contact layers 1301, 1301a, 1301b, 1301c, 1301d, 1301e, 1301f, 1301g, 1301h, 1301i, 1301j, 1301k, 1301m, 1301n, 1301p, 1301q, 1301r, 1301s, 1301t located on the second region, and the second dimensions h2, h2a, h2b, h2c, h2d, h2e, h2f, h2g, h2h, h2i, h2j, h2k, h2m, h2n, h2p, h2q, h2r, h2s;

[0072] First electrodes 140, 140a, 140b, 140c, 140d; fifth dimensions h5a, h5b, h5c; first height d1;

[0073] First transparent conductive layer 150;

[0074] Second electrodes 160, 160a, 160b, 160c, 160d; sixth dimensions h6a, h6b, h6c; second height d2;

[0075] Second transparent conductive layer 170;

[0076] Passivation antireflection layer 180;

[0077] Photovoltaic module 10, cell string 11, encapsulation layer 12, cover plate 13, conductive strip 14;

[0078] First direction F1, second direction F2, third direction F3. Detailed Implementation

[0079] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0080] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0081] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. It is worth noting that in the following description and the appended claims, "electrical connection" between one feature and another not only includes direct contact between the two features to form an electrical energy transmission or current transmission channel, but also includes an intermediate feature between the two features, which, along with the intermediate feature, forms an electrical energy transmission or current transmission channel to achieve electrical energy transmission or transmission. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0083] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0084] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0085] In the accompanying drawings, the thicknesses of layers, films, regions, substrates, etc., are exaggerated for clarity. Throughout the specification, the same reference numerals refer to the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it may be directly on the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0086] According to some embodiments of this application, please refer to Figure 1 , Figure 1 This is a partial structural schematic diagram of the back contact battery 100 in some embodiments of this application from a cross-sectional perspective. The embodiments of this application provide a back contact battery 100, including a substrate 110, a first passivation contact layer 120 and a second passivation contact layer 130.

[0087] The substrate 110 is used to receive incident light and generate photogenerated carriers. The substrate 110 can be selected according to actual needs. Exemplarily, the substrate 110 can be a silicon substrate, which may include one or more of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. The doping type of the substrate 110 is not specifically limited. For example, the substrate 110 can be an N-type doped silicon substrate, or it can be a P-type doped silicon substrate; there is no specific limitation in this regard. The N-type doping element can be a group V element such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As), and the P-type doping element can be a group III element such as boron (B), aluminum (Al), gallium (Ga), or indium (In). In the embodiments of this application, the substrate 110 can be an N-type monocrystalline silicon wafer, which can improve the conversion efficiency of the back contact cell 100 and reduce manufacturing costs.

[0088] The substrate 110 has a first surface m1, which includes alternating first regions m11 and second regions m12.

[0089] For example, in conjunction with reference Figure 1 The substrate 110 has a first surface m1 and a second surface m2 disposed opposite to each other. The first surface m1 and the second surface m2 are disposed opposite to each other along the thickness direction of the substrate 110. The thickness direction of the substrate 110 is... Figure 1 The first direction F1 is shown in the diagram. For example, with... Figure 1 For example, the first surface m1 is the backlight surface, and the second surface m2 is the light-receiving surface. It can be understood that the light-receiving surface and the backlight surface are relative terms. The light-receiving surface specifically refers to the surface on the substrate of the back contact cell 100 or the surface that is primarily exposed to sunlight. The light-receiving surface typically has a surface structure that can increase the light absorption area, improve the photocurrent, and help improve the cell efficiency.

[0090] The first zone m11 and the second zone m12 are arranged alternately. That is, along the arrangement direction of the first zone m11 and the second zone m12, an arrangement pattern of "first zone m11, second zone m12, first zone m11, second zone m12, first zone m11..." or "second zone m12, first zone m11, second zone m12, first zone m11..." is formed. In other words, along the arrangement direction of the first zone m11 and the second zone m12, the zone adjacent to the first zone m11 is the second zone m12, not another first zone m11; the zone adjacent to the second zone m12 is the first zone m11, not another second zone m12. It can be understood that the first zone can be either the first zone m11 or the second zone m12, and the last zone can be either the first zone m11 or the second zone m12; no specific restrictions are made here. For example, using... Figure 1 For example, the arrangement direction of the first zone m11 and the second zone m12 is the second direction F2, and, in Figure 1The diagram only shows one first zone m11 and one second zone m12, and does not limit the number of both first zone m11 and second zone m12.

[0091] The first passivation contact layer 120 includes a tunneling layer 121 and a first doped layer 122. The tunneling layer 121 is disposed on the first region m11, and the first doped layer 122 is disposed on the side of the tunneling layer 121 away from the substrate 110.

[0092] The tunneling layer 121 serves to passivate the interface of the first region m11 of the first surface m1 of the substrate 110, reduce the interface state density, and decrease carrier recombination, thus achieving a chemical passivation effect. Specifically, by saturating the dangling bonds of the first region m11 of the first surface m1 of the substrate 110, the interface defect state density of the first region m11 of the first surface m1 of the substrate 110 is reduced, thereby reducing the recombination centers of the first region m11 of the first surface m1 of the substrate 110 and lowering the carrier recombination rate. The tunneling layer 121 can be a dielectric material layer. For example, the material of the tunneling layer 121 can be at least one of silicon oxide, magnesium fluoride, silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, or titanium oxide. In this embodiment, the tunneling layer 121 can be formed using low-pressure chemical vapor deposition (LPCVD). Of course, other processes such as thermal oxidation, plasma oxidation, or nitric acid oxidation can also be used to fabricate the tunneling layer 121; no specific limitations are imposed here.

[0093] The doping element of the first doped layer 122 is compatible with the conductivity type of the doping element of the substrate 110. For example, if the substrate 110 is an N-type substrate, the doping element of the substrate 110 can be phosphorus and / or antimony. The doping element of the first doped layer 122 is phosphorus. As another example, if the substrate 110 is a P-type substrate, the doping element of the first doped layer 122 is boron. In the embodiments of this application, the first doped layer 122 is formed by doping amorphous silicon, microcrystalline silicon, polycrystalline silicon, etc., with an N-type doping element. Exemplarily, the first doped layer 122 is a phosphorus-doped polycrystalline silicon layer. In this case, the stacked tunneling layer 121 and the first doped layer 122 together form a passivation contact structure (i.e., the first passivation contact layer 120), which provides good surface passivation for the first region m11 of the first surface m1 of the substrate 110.

[0094] The second passivation contact layer 130 includes an amorphous material layer 131 and a second doped layer 132. The amorphous material layer 131 is at least disposed on the second region m12, and the second doped layer 132 is disposed on the side of the amorphous material layer 131 away from the substrate 110.

[0095] The amorphous material layer 131 serves as a passivation and barrier layer, and is at least disposed on the second region m12 to achieve interface passivation. The amorphous material layer 131 is at least disposed on the second region m12; that is, the amorphous material layer 131 can be disposed entirely on the second region m12, or a portion of the amorphous material layer 131 can be disposed on the second region m12 and another portion on the first region m11. For example, using... Figure 1 For example, a portion of the amorphous material layer 131 is disposed on the second region m12, and another portion is disposed on the side of the first doped layer 122 opposite to the tunneling layer 121. The amorphous material layer 131 can be a non-dielectric material layer. For example, non-dielectric materials include amorphous silicon, microcrystalline silicon, or nanocrystalline silicon. Exemplarily, the amorphous material layer 131 can be an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, an intrinsic silicon oxide layer, etc., without specific limitations.

[0096] The doping type of the second doped layer 132 is different from that of the first doped layer 122. For example, the doping element of the first doped layer 122 is an N-type doping element, while the doping element of the second doped layer 132 is a P-type doping element. For instance, in this embodiment, the second doped layer 132 is formed by doping amorphous silicon, microcrystalline silicon, polycrystalline silicon, etc., with a P-type doping element. For example, the second doped layer 132 is a boron-doped amorphous silicon layer.

[0097] For example, the amorphous material layer 131 can be an intrinsic amorphous silicon layer, and the second doped layer 132 can be a doped amorphous silicon layer. The intrinsic amorphous silicon layer has good surface passivation properties, which can reduce surface recombination at the interface between the second doped layer 132 and the substrate 110, thereby improving the lifetime of charge carriers. In addition, the intrinsic amorphous silicon layer can also serve as a transport medium for electrons and holes, promoting their separation and directional movement near the PN junction, and improving the charge collection efficiency. When the second doped layer 132 is a P-type doped layer, the intrinsic amorphous silicon layer can be used as a barrier for electrons to allow holes to pass through. When the second doped layer 132 is an N-type doped layer, the intrinsic amorphous silicon layer can be used as a barrier for holes to allow electrons to pass through.

[0098] It should be noted that, taking the amorphous material layer 131 as an intrinsic amorphous material layer as an example, during the process of preparing the second doped layer 132, a small amount of the same doping element as the second doped layer 132 may diffuse or be incorporated into the amorphous material layer 131, resulting in a lower doping concentration. In this case, the amorphous material layer 131 is not an intrinsic amorphous material layer in a strict chemical sense, but a lightly doped amorphous material layer, which can also be called a near-intrinsic amorphous material layer. That is to say, the "intrinsic" mentioned in the embodiments of this application is a concept relative to the second doped layer, rather than a definition of absolutely no doping. The "intrinsic" in the embodiments of this application is used to refer to the situation where no doping is intentionally performed, no doping is performed, or the actual doping amount is extremely low (or very small) and the impact on the conductivity type and conductivity performance is negligible. Its connotation covers intrinsic amorphous material layers, lightly doped amorphous layers, and near-intrinsic amorphous layers.

[0099] In some possible embodiments, with Figure 1 For example, the substrate 110 can be an N-type doped substrate, and the tunneling layer 121 can be made of silicon oxide (SiO2). x The first doped layer 122 can be an N-type doped layer, the amorphous material layer 131 can be an intrinsic amorphous silicon layer, and the second doped layer 132 can be a P-type doped layer. In this structure, the tunneling layer 121 is used for electrons to pass through, and the second doped layer 132 is used to block electrons while allowing holes to pass through. Thus, by combining the high conductivity of the N-type polycrystalline silicon doped layer and the good passivation capability of the P-type amorphous silicon doped layer, the embodiment of this application can balance the transport of charge carriers and improve the photoelectric conversion efficiency of the back contact cell 100.

[0100] Of course, in practical applications, the design of each film layer in the back contact battery 100 is not limited to the above-described cases. For example, the substrate 110 can be a P-type doped substrate, the first doped layer 122 can be a P-type doped layer, and the second doped layer 132 can be an N-type doped layer. In this case, the tunneling layer 121 is used to allow holes to pass through, and the second doped layer 132 is used to block holes while allowing electrons to pass through. No specific limitations are imposed here.

[0101] Combined with reference Figure 2 , Figure 2This diagram illustrates the edge region mb and the middle region mz of the first surface m1 in some embodiments of this application. Along the arrangement direction of the first region m11 and the second region m12, the edge region mb of the first surface m1 is located on both sides of the middle region mz of the first surface m1. That is, with reference to the arrangement direction of the first region m11 and the second region m12, the first surface m1 is divided into a middle region mz and an edge region mb. The middle region mz is located in the center of the first surface m1, and the edge regions mb are distributed on both sides of the middle region mz along this arrangement direction, i.e., the edge regions mb are located on opposite sides of the middle region mz, ​​forming a layout where the middle region mz is in the center and the edge regions mb are on both sides. In other words, the two sides of the middle region mz of the first surface m1 along the second direction F2 are the edge regions mb. It should be noted that there may or may not be a boundary between the middle region mz and the edge regions mb; no specific limitation is made here. Figure 2 For example, the dashed line indicates the boundary between the middle region mz and the edge region mb of the first surface m1. This only represents the division between the middle region mz and the edge region mb, and is not a limitation on the structure of the first surface m1. Figure 2 The viewpoint shown can be seen as Figure 1 The view shown is a top-down perspective.

[0102] A portion of the first regions m11 and the second regions m12 are located in the middle region mz, ​​while another portion of the first regions m11 and the second regions m12 are located in the edge region mb. That is, a portion of all the first regions m11 are located in the middle region mz, ​​and another portion are located in the edge region mb. Similarly, a portion of all the second regions m12 are located in the middle region mz, ​​and another portion are located in the edge region mb. In other words, there are multiple first regions m11 located in the edge region mb, and multiple second regions m12 located in the edge region mb. For example, with... Figure 3 For example, Figure 3 This is a schematic diagram of the first passivated contact layer 120 on the edge region m12 and the second passivated contact layer 1301 on the second region m12 in some embodiments of this application. Figure 3 The viewpoint shown can be seen as Figure 1 From the top-down view shown, the first passivation contact layer 120 is disposed on the first region m11, and the location of the first passivation contact layer 120 can be roughly regarded as the location of the first region m11. The second passivation contact layer 130 is disposed on at least the second region m12, that is, the location of the second passivation contact layer 1301 on the second region m12 can be roughly regarded as the location of the second region m12.

[0103] Understandable, Figure 3To more clearly illustrate the relationship between the first region m11 and the second region m12, only the second passivation contact layer 1301 located on the second region m12 is shown. Furthermore, Figure 3 Indicate Figure 2 The left edge region mb is shown from the perspective of [viewer name]. The diagrams of the edge region mb and the middle region mz mentioned later can be found in [reference to the diagram]. Figure 3 I will not elaborate further on this understanding.

[0104] Based on some embodiments of this application, please continue to refer to Figures 1 to 3 On at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120 is larger than the total size of the second passivation contact layer 1301 located on the second region m12. That is, the size control mentioned above can be applied to at least one of the two edge regions mb, without specific limitations here.

[0105] by Figure 3 For example, in the edge region mb, the total dimension of the first passivation contact layer 120 along the arrangement direction of the first region m11 and the second region m12 is, in other words, the sum of the dimensions of all the first passivation contact layers 120 along the second direction F2 in the edge region mb. The dimension of the first passivation contact layer 120 along the second direction F2 is the first dimension h1, which can be considered as the width of the first passivation contact layer 120. Similarly, in the edge region mb, the total dimension of the second passivation contact layer 1301 located in the second region m12 along the arrangement direction of the first region m11 and the second region m12 is, in other words, the sum of the dimensions of all the second passivation contact layers 1301 located in the second region m12 along the second direction F2 in the edge region mb. The dimension of the second passivation contact layer 1301 located in the second region m12 along the second direction F2 is the second dimension h2, which can be considered as the width of the second passivation contact layer 1301 located in the second region m12. In other words, on at least one edge region mb, the total width of the first passivation contact layer 120 is greater than the total width of the second passivation contact layer 1301 located on the second region m12.

[0106] For example, continue with Figure 3 For example, and in conjunction with reference Figure 1Since both the first region m11 and the second region m12 extend longitudinally along the third direction F3, both the first region m11 and the second region m12 can be regarded as rectangular regions. The dimension of the first passivation contact layer 120 along the third direction F3 can be regarded as the length of the first passivation contact layer 120. The dimension of the second passivation contact layer 1301 located on the second region m12 along the third direction F3 can be regarded as the length of the second passivation contact layer 1301 located on the second region m12. The length of the first passivation contact layer 120 and the length of the second passivation contact layer 1301 located on the second region m12 are approximately the same. In the case mentioned above, where "on at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120 is greater than the total size of the second passivation contact layer 1301 located on the second region m12", it can also be seen that on at least one edge region mb, the area ratio of the first passivation contact layer 120 is greater than the area ratio of the second passivation contact layer 1301 located on the second region m12.

[0107] For example, the first direction F1, the second direction F2, and the third direction F3 intersect each other. For instance, in this embodiment, the first direction F1, the second direction F2, and the third direction F3 are perpendicular to each other. For example, the second direction F2 can be the length direction of the base 110, and the third direction F3 can be the width direction of the base 110; alternatively, the second direction F2 can be the width direction of the base 110, and the third direction F3 can be the length direction of the base 110. No specific limitations are imposed here. Of course, the length dimension of the base 110 can be greater than or equal to the width dimension of the base 110.

[0108] During the fabrication of the back contact cell 100, the edge region mb may contain structural and interface defects such as crystal damage, lattice distortion, dangling bonds, microcracks, notches, impurity accumulation, and surface roughness. These defects can form numerous recombination centers, exacerbating carrier recombination, reducing the minority carrier lifetime of the edge region mb, and easily causing leakage, current shunting, or even edge breakdown, thereby reducing the photoelectric conversion efficiency, parallel resistance, and operational stability of the back contact cell 100. However, by controlling the width difference between the first passivation contact layer 120 on at least one edge region mb and the second passivation contact layer 1301 located on the second region m12, the amount of the second passivation contact layer 130 can be reduced, while the amount of the first passivation contact layer 120 can be increased. Since the first passivation contact layer 120 does not involve the collection and separation of charge carriers, while the second passivation contact layer 130 does, the field passivation effect at the corresponding edge region mb can be improved by increasing the first passivation contact layer 120, and the recombination loss of charge carriers at the corresponding edge region mb can be reduced by reducing the second passivation contact layer 130. This is more conducive to reducing the risk of the efficiency at the corresponding edge region mb being reduced due to the aforementioned defects, and is beneficial to improving the performance of the back contact battery 100.

[0109] Furthermore, since a portion of the first region m11 and a portion of the second region m12 are located in the edge region mb, it is beneficial to expand the adjustment window for the dimensions of the first passivation contact layer 120 along the arrangement direction of the first region m11 and the second region m12, as well as the dimensions of the second passivation contact layer 1301 located on the second region m12 along the arrangement direction of the first region m11 and the second region m12. This makes it easier to control the dimensions of the first passivation contact layer 120 along the arrangement direction of the first region m11 and the second region m12 and the dimensions of the second passivation contact layer 1301 located on the second region m12 along the arrangement direction of the first region m11 and the second region m12 in a more flexible manner, thereby further improving the performance of the back contact battery 100.

[0110] Therefore, since the total size of the first passivation contact layer 120 on at least one edge region mb of the first surface m1 of the substrate 110, along the arrangement direction of the first region m11 and the second region m12, is greater than the total size of the second passivation contact layer 1301 located on the second region m12, there is a difference between the total size of the first passivation contact layer 120 on at least one edge region mb along the arrangement direction of the first region m11 and the second region m12 and the total size of the second passivation contact layer 1301 located on the second region m12 along the arrangement direction of the first region m11 and the second region m12. With this structure, by adjusting the dimensions of the first passivation contact layer 120 along the arrangement direction of the first region m11 and the second region m12, the dimensions of the second passivation contact layer 1301 located on the second region m12 along the arrangement direction of the first region m11 and the second region m12, and by utilizing the difference between the dimensions of the first passivation contact layer 120 along the arrangement direction of the first region m11 and the second region m12 and the dimensions of the second passivation contact layer 1301 located on the second region m12 along the arrangement direction of the first region m11 and the second region m12, it is possible to maximize the utilization of light energy while taking into account the photoelectric conversion efficiency of the back contact battery 100, thereby improving the performance of the back contact battery 100.

[0111] It should be noted that in some possible embodiments, the thickness of the first passivation contact layer 120 is greater than the thickness of the second passivation contact layer 130. For example, the thickness of the tunneling layer 121 is 1 nm to 5 nm, the thickness of the first doped layer 122 is 30 nm to 200 nm, the thickness of the amorphous material layer 131 on the second region m12 is 3 nm to 20 nm, and the thickness of the second doped layer 132 on the second region m12 is 10 nm to 50 nm. For instance, the thickness of the tunneling layer 121 is 1 nm, the thickness of the first doped layer 122 is 30 nm, the thickness of the amorphous material layer on the second region m12 is 3 nm, and the thickness of the second doped layer 132 on the second region m12 is 10 nm. For example, the tunneling layer 121 has a thickness of 5 nm, the first doped layer 122 has a thickness of 200 nm, the amorphous material layer 131 on the second region m12 has a thickness of 20 nm, and the second doped layer 132 on the second region m12 has a thickness of 50 nm. Thus, based on the thickness difference, the width boundaries of the first passivation contact layer 120 and the second passivation contact layer 1301 on the second region m12 can be determined using optical or electronic imaging testing equipment, ellipsometers, or reflectance spectroscopy measurement methods. Specifically, taking an ellipsometer as an example, when scanning along the area to be measured using an ellipsometer, the ellipsometric spectral signals corresponding to different passivation contact layers will change significantly with different thicknesses. Based on the signal abrupt change points caused by the thickness difference, the boundary position between the first passivation contact layer 120 and the second passivation contact layer 1301 on the second region m12 can be determined, thereby obtaining the width information of the first passivation contact layer 120 and the width information of the second passivation contact layer 1301 on the second region m12.

[0112] In some possible embodiments, based on the fabrication method of the back contact battery 100, a height difference exists between the first region m11 and the second region m12 of the first surface m1 of the substrate 110. Exemplarily, firstly, an initial first passivation contact layer is formed on the first surface of the initial substrate; secondly, the initial first passivation contact layer on the second region of the first surface of the initial substrate is removed to form a first passivation contact layer 120; subsequently, at least a second passivation contact layer 1301 is formed on the second region m12. During this process, for example... Figure 1 The schematic diagram shows a structure with a height difference at the first region m11 and the second region m12 of the first surface m1 of the substrate 110. For example, the height difference at the first region m11 and the second region m12 of the first surface m1 of the substrate 110 can be from 3 μm to 10 μm. Thus, the aforementioned height difference can be used to determine the width boundary of the first passivation contact layer 120 and the width boundary of the second passivation contact layer 1301 located on the second region m12. In this process, instruments such as an ellipsometer can also be used to determine the first passivation contact layer 120 and the second passivation contact layer 130.

[0113] It should also be noted that when there is a height difference between the first region m11 and the second region m12 on the first surface m1 of the substrate 110, the second region m12 includes an edge region for connecting the first region m11, and the edge region can be a sloping surface. When measuring the thickness of the second passivation contact layer located on the edge region of the second region m12, the obtained value fluctuates within a range that can be approximated as the thickness of the second passivation contact layer located on the middle region of the second region m12, and the specific fluctuation range can be determined according to the specific shape of the edge region.

[0114] The total size of the first passivation contact layer 120 on the edge region mb mentioned above can be obtained by determining the width of each first passivation contact layer 120 on the edge region mb, thereby obtaining the total size of the first passivation contact layer 120 on the edge region mb. The total size of the second passivation contact layer 1301 located on the second region m12 on the edge region mb can be understood by referring to the measurement of the total size of the first passivation contact layer 120 on the edge region mb, and will not be elaborated further.

[0115] Furthermore, in some testing methods, it is not necessary to test every area individually for the aforementioned total dimension; only sampling testing is required. Those skilled in the art can reasonably infer and determine the corresponding total dimension based on the measured sample dimensions.

[0116] It is understandable that the design and layout of the aforementioned passivation contact layer patterns follow a regular pattern. For example, the design parameters on the middle region mz are largely the same, and the design parameters on the edge region mb are also largely the same. Those skilled in the art only need to measure the dimensions of the edge region sample to deduce the overall dimensions of the corresponding region. Similarly, by measuring the dimensions of the middle region sample, the overall dimensions of the corresponding region can also be deduced.

[0117] It should also be noted that when the back contact battery 100 also includes other film layers located on the side of the corresponding passivation contact layer that are away from the substrate 110, the aforementioned other film layers can be removed first, and then the width of the corresponding passivation contact layer can be determined.

[0118] Based on some embodiments of this application, please continue to refer to Figure 1 The back contact battery 100 also includes a first electrode 140, which is disposed on the side of the first doped layer 122 away from the tunneling layer 121 and is electrically connected to the first doped layer 122.

[0119] The first electrode 140 is used to collect and summarize the current from the back contact battery 100. The first electrode 140 and the first doped layer 122 can be in contact directly or indirectly to form an electrical connection. Exemplarily, the first electrode 140 can be prepared by screen printing and sintering. Exemplarily, the metal paste used to make the first electrode 140 can be one or more of aluminum, silver, gold, nickel, molybdenum or copper, without specific limitations.

[0120] The electrical connection between the first electrode 140 and the first doped layer 122 means that, since both the materials of the first electrode 140 and the first doped layer 122 are conductive, they form a physical channel for the flow of photogenerated carriers through direct or indirect physical contact. When the back contact battery 100 is not in a power generation or power supply state, the photogenerated carriers are not effectively separated and driven to flow, and the photogenerated carriers do not flow through this physical channel. When the back contact battery 100 is in a power generation or power supply state, the first doped layer 122 generates photogenerated carriers, which are separated under the action of its built-in electric field, and the photogenerated carriers flow out through this physical channel.

[0121] Based on some embodiments of this application, please continue to refer to Figure 1 The back contact battery 100 also includes a first transparent conductive layer 150, which is disposed on the side of the first doped layer 122 opposite to the tunneling layer 121 and is electrically connected to the first doped layer 122. The first electrode 140 is located on the first transparent conductive layer 150.

[0122] For example, the material of the first transparent conductive layer 150 may be one or more of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), indium tungsten oxide (IWO), indium cerium oxide (ICO), and indium zinc oxide (IZO), without any specific limitation.

[0123] By setting the first transparent conductive layer 150, it helps to reduce the transfer loss of charge directly from the passivated contact structure to the electrode, improve the output power of the battery, thereby improving the photoelectric conversion efficiency, and also improve the weather resistance of the battery and extend its service life.

[0124] Based on some embodiments of this application, please continue to refer to Figure 1 The back contact battery 100 also includes a second electrode 160, which is disposed on the side of the second doped layer 132 opposite to the amorphous material layer 131 and is electrically connected to the second doped layer 132. The understanding and implementation of the second electrode 160 can be referred to the first electrode 140, and will not be repeated here.

[0125] Based on some embodiments of this application, please continue to refer to Figure 1The back contact battery 100 also includes a second transparent conductive layer 170, which is disposed on the side of the second doped layer 132 opposite to the amorphous material layer 131 and is electrically connected to the second doped layer 132. A second electrode 160 is located on the second transparent conductive layer 170. The material and advantages of the second transparent conductive layer 170 can be understood and implemented with reference to the first transparent conductive layer 150, and will not be elaborated here.

[0126] Based on some embodiments of this application, please continue to refer to Figure 1 The back contact battery 100 also includes a passivation antireflection layer 180, which is disposed on the second surface m2 of the substrate 110. The passivation antireflection layer 180 can be a single-layer or multi-layer structure. In a multi-layer passivation antireflection layer 180, each layer can be made of materials such as silicon oxide, silicon nitride, or silicon oxynitride. No specific limitations are imposed here.

[0127] Based on some embodiments of this application, please continue to refer to Figure 1 The first surface m1 has a pyramid-shaped structure on its second section m12. Of course, the second surface m2 can also have a pyramid-shaped structure. This improves light utilization.

[0128] Based on some embodiments of this application, please continue to refer to Figure 2 Along the arrangement direction of the first region m11 and the second region m12, the ratio of the size of the edge region mb to the size of the middle region mz is 0.2 to 1.

[0129] For example, with Figure 2 For example, the dimension of the edge region mb along the arrangement direction of the first region m11 and the second region m12 is also the dimension of the edge region mb along the second direction F2. The dimension of the edge region mb along the second direction F2 is the third dimension h3. The dimension of the middle region mz along the arrangement direction of the first region m11 and the second region m12 is also the dimension of the middle region mz along the second direction F2. The dimension of the middle region mz along the second direction F2 is the fourth dimension h4. The ratio of the third dimension h3 to the fourth dimension h4 is between 0.2 and 1. For example, the ratio of the third dimension h3 to the fourth dimension h4 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1. Of course, the ratio of the third dimension h3 to the fourth dimension h4 can also be any other value within the range of 0.2 to 1, without specific restrictions.

[0130] Thus, by controlling the size ratio of the edge region mb to the middle region mz, ​​the proportion of the photoelectric conversion area can be increased while suppressing edge leakage and recombination, thereby improving the area utilization of the back contact cell 100. Furthermore, with this area ratio, the carrier collection path can be improved, reducing the risk of insufficient effective area or exacerbated edge defects, thereby improving photoelectric conversion efficiency, parallel resistance, and cell performance stability.

[0131] Based on some embodiments of this application, please continue to refer to Figure 2 Along the arrangement direction of the first zone m11 and the second zone m12, the size of the edge region mb is 0.3mm to 20mm, and the size of the middle region mz is 65mm to 190mm.

[0132] For example, with Figure 2 For example, the third dimension h3 can be 0.3mm, 1mm, 2mm, 5mm, 8mm, 10mm, 12mm, 17mm, or 20mm, and the fourth dimension h4 can be 65mm, 70mm, 80mm, 90mm, 100mm, 120mm, 150mm, 170mm, or 190mm. Of course, the third dimension h3 can also be any other value within the range of 0.3mm to 20mm, and the fourth dimension h4 can also be any other value within the range of 65mm to 190mm; no specific restrictions are imposed here.

[0133] Thus, by controlling the size range of the edge region mb along the arrangement direction of the first region m11 and the second region m12, and the size range of the middle region mz along the arrangement direction of the first region m11 and the second region m12, not only can the middle region mz be made larger, which is beneficial to improving the overall light absorption and carrier generation, but it is also beneficial to control the size ratio of the edge region mb. This reduces the risk of leakage, current shunting, and increased recombination at the edge region mb while taking into account the effective power generation area. At the same time, by matching the sizes of the middle region mz and the edge region mb, the impact of edge defects on battery performance can be reduced while fully collecting the carriers generated by the edge region mb, thereby improving the performance of the back contact battery 100.

[0134] Based on some embodiments of this application, please continue to refer to Figures 1 to 3 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the ratio q1 of the total size of the first passivation contact layer 120 to the total size of the second passivation contact layer 1301 located on the second region m12 satisfies: 1 < q1 ≤ 2.

[0135] For example, q1 can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2. Of course, q1 can be any other value within the above range, and no specific restriction is imposed here.

[0136] Thus, since there are multiple first regions m11 located on the edge region mb and multiple second regions m12 located on the edge region mb, by controlling the ratio of the total size of the first passivation contact layer 120 to the total size of the second passivation contact layer 1301 located on the second region m12, it is beneficial to improve the overall passivation and carrier collection capability of the corresponding edge region mb more uniformly and efficiently.

[0137] Furthermore, by controlling the size ratio of the edge region mb to the middle region mz, ​​controlling the size range of the edge region mb along the arrangement direction of the first region m11 and the second region m12 and the size range of the middle region mz along the arrangement direction of the first region m11 and the second region m12, and controlling the ratio of the total size of the first passivation contact layer 120 to the total size of the second passivation contact layer 1301 located on the second region m12, in addition to the advantages mentioned above, synergistic control can be achieved in terms of both region allocation and functional layer ratio. This increases the effective photoelectric conversion area while strengthening edge field effect passivation or carrier extraction capabilities, balancing area utilization, edge protection, and carrier collection, thereby simultaneously improving battery efficiency, stability, and yield. Moreover, the control of the aforementioned ratios and sizes also facilitates fabrication.

[0138] Based on some embodiments of this application, please continue to refer to Figures 1 to 3 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the ratio q2 of the size of the first passivation contact layer 120 to the size of the second passivation contact layer 1301 located on the second region m12 satisfies: 1≤q2≤2. That is, the ratio of the first size h1 to the second size h2 is 1 to 2.

[0139] For example, q2 can be 1, 1.2, 1.4, 1.5, 1.7, 1.9, or 2. Of course, q2 can be any other value within the above range, and no specific restriction is imposed here.

[0140] Thus, given that there are multiple first regions m11 and multiple second regions m12 located on the edge region mb, by controlling the ratio of the size of the first passivation contact layer 120 to the size of the second passivation contact layer 1301 located on the second region m12, more refined and uniform control of the local performance of the edge region mb can be achieved at the cell structure level. This is beneficial for improving battery performance and yield.

[0141] Based on some embodiments of this application, please continue to refer to Figures 1 to 3 On the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120 is 200μm to 1000μm, and the size of the second passivation contact layer 1301 located on the second region m12 is 100μm to 500μm.

[0142] For example, in conjunction with reference Figure 3 The first dimension h1 can be 200μm, 300μm, 400μm, 500μm, 700μm, 800μm, 900μm, or 1000μm, and the second dimension h2 can be 100μm, 150μm, 200μm, 300μm, 400μm, 450μm, or 500μm. Of course, the first dimension h1 can also be any other value in the range of 200μm to 1000μm, and the second dimension h2 can also be any other value in the range of 100μm to 500μm; no specific restrictions are imposed here.

[0143] Thus, by controlling the size range of a single first passivation contact layer 120 and the size range of a single second passivation contact layer 1301 located on the second region m12, more precise control can be achieved at the cell-level structure. This is beneficial for improving battery performance and yield.

[0144] Furthermore, by controlling the ratio of the size of the first passivation contact layer 120 to the size of the second passivation contact layer 1301 located on the second region m12, and by controlling the size range of a single first passivation contact layer 120 and the size range of a single second passivation contact layer 1301 located on the second region m12, in addition to the advantages mentioned above, it is also beneficial to enhance the tolerance of the corresponding edge region mb to process deviations, improve the process window, and facilitate manufacturing.

[0145] According to some embodiments of this application, please refer to Figure 4 , Figure 4 This is a schematic diagram illustrating a first passivated contact layer 120a on an edge region mb and a second passivated contact layer 1301a on a second region m12 in some other embodiments of this application. On at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivated contact layer 120a is larger than the size of the second passivated contact layer 1301a on the second region m12. That is, the first size h1a is larger than the second size h2a.

[0146] Thus, since the first size h1a is larger than the second size h2a, it not only makes the sum of the first size h1a greater than the sum of the second size h2a in the corresponding edge region mb, but also gives the first passivation contact layer 120a a larger manufacturing process window.

[0147] According to some embodiments of this application, please refer to Figure 5 , Figure 5 This is a schematic diagram of a first passivated contact layer 120b on an edge region mb and a second passivated contact layer 1301b on a second region m12 in some embodiments of this application. On at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivated contact layer 120b is smaller than the size of the second passivated contact layer 1301b on the second region m12. That is, the first size h1b is smaller than the second size h2b.

[0148] Thus, since the first size h1b is smaller than the second size h2b, it not only helps to reduce the parasitic absorption of the first doped layer 122 located in the first region m11 on the corresponding edge region mb, but also helps to provide a larger working space for the second passivation contact layer 1301b located in the second region m12 on the corresponding edge region mb.

[0149] Of course, in other embodiments of this application, please continue to refer to Figure 3 On at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120 is equal to the size of the second passivation contact layer 1301 located on the second region m12. That is, the first size h1 is equal to the second size h2. No specific limitations are imposed here.

[0150] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 6 , Figure 6 This is a schematic diagram of a first passivated contact layer 120c on an edge region mb and a second passivated contact layer 1301c on a second region m12 in some embodiments of this application. The edge region mb has a first side connecting to the intermediate region mz and a second side disposed opposite to the first side. On the same edge region mb, from the first side to the second side, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivated contact layer 120c tends to increase. That is, on the same edge region mb, from the first side to the second side, the first dimension h1c tends to increase.

[0151] Combined with reference Figure 6The increasing trend refers to the fact that, within the same edge region mb, from the first side of mb to the second side, the first dimension h1c generally increases. The first dimension h1c can remain constant before increasing, increase first, remain constant again, increase again, or continuously increase; no specific restrictions are imposed here. In other words, the increasing trend is a general, generally observed trend.

[0152] In this way, the field-effect passivation intensity at the corresponding edge region mb can be gradually enhanced, better suppressing carrier recombination, leakage, and shunting phenomena caused by edge defects, and improving the parallel resistance and electrical performance stability of the edge region mb. At the same time, this design can also reduce the risk of interface stress concentration or uncontrollable process caused by the size change of the first passivation contact layer 120c, achieving a smoother transition of passivation capability, and further improving the overall photoelectric conversion efficiency, yield, and reliability of the battery.

[0153] It should be noted that during actual measurement, due to factors such as instrument measurement accuracy, local differences in sampling points, test noise, or individual abnormal sampling points, a small number of test points may exhibit temporary fluctuations or local errors in size. As long as the overall direction of change is increasing and the overall distribution conforms to the increasing law, it is considered to meet the requirement that the size shows an increasing trend.

[0154] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 6 On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the preceding first passivation contact layer 120c is smaller than the size of the following first passivation contact layer 120c. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the preceding first dimension h1c is smaller than the following first dimension h1c. On the same edge region mb, from the first side to the second side of the edge region mb, the size of the first passivation contact layer 120c increases sequentially along the second direction F2.

[0155] This approach gradually enhances the field-effect passivation strength and interface protection capability of the edge region mb, more effectively suppressing carrier recombination, leakage, and shunting phenomena at the edge, and improving the parallel resistance and electrical performance stability of the edge region mb. Simultaneously, this step-by-step, continuous transition method further reduces the difficulty of process control and interface stress problems caused by abrupt size changes, further improving photoelectric conversion efficiency, performance uniformity, and mass production yield.

[0156] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 6 and in conjunction with reference Figure 7 , Figure 7 This is a schematic diagram of the first passivation contact layer 120c on the edge region mb, the second passivation contact layer 1301c on the second region m12 and the first electrode 140a in some embodiments of this application. On the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140a tends to increase.

[0157] The dimension of the first electrode 140a along the second direction F2 is the fifth dimension h5a. That is, on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, the fifth dimension h5a tends to increase. The dimension of the first electrode 140a along the second direction F2 can be regarded as the width of the first electrode 140a.

[0158] The understanding and implementation of the increasing trend can be referred to the above illustrations, and will not be repeated here.

[0159] In this way, the lateral conductivity can be gradually enhanced, edge carrier recombination, shunting, and leakage can be suppressed more efficiently, and the parallel resistance and electrical performance stability of the battery can be improved. Simultaneously, by controlling the dimensions of the first electrode 140a, not only can the uniformity of current collection in the edge region be improved, but the local series resistance can also be reduced, mitigating the risk of stress concentration and the difficulty of process control caused by abrupt changes in electrode dimensions. Furthermore, since the dimensional variation trend of the first electrode 140a along the second direction F2 is the same as that of the first passivation contact layer 120c along the second direction F2, the dimensional variation trend of the first passivation contact layer 120c along the second direction F2 can be used to expand the fabrication window of the first electrode 140a.

[0160] It is understandable that when the back contact battery 100 includes a first transparent conductive layer 150, it is also beneficial to increase the size of the first transparent conductive layer 150 on the edge region mb on the first region m11, thereby helping to further reduce the transfer loss of charge directly from the passivated contact structure to the electrode.

[0161] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 6 and Figure 7Within the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140a located in the first region m11 is smaller than the size of the second electrode 140a located in the first region m11. That is, within the same edge region mb, from the first side to the second side of the edge region mb, the size of the first electrode 140a increases sequentially along the second direction F2.

[0162] Thus, by progressively increasing the conductive area of ​​the first electrode 140a and utilizing the field-effect passivation effect, carrier recombination, shunting, and leakage in the edge region mb can be further suppressed, improving the parallel resistance and electrical performance stability of the battery. Simultaneously, the sequentially increasing size of the first electrode 140a along the second direction F2 can further enhance the lateral transport and collection efficiency of the current in the edge region mb, reduce local series resistance, and improve current output uniformity.

[0163] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 6 and Figure 7 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140a ranges from 30μm to 70μm.

[0164] For example, the fifth dimension h5a can be 30μm, 40μm, 50μm, 60μm, 65μm, or 70μm. Of course, the fifth dimension h5a can also be any other value in the range of 30μm to 70μm, and no specific limitation is made here.

[0165] Thus, by controlling the size range of the first electrode 140a along the second direction F2, the light-shielding area of ​​the first electrode 140a can be taken into account while achieving good lateral conductivity and current collection effect.

[0166] Furthermore, by controlling the dimensional change trend of the first electrode 140a along the second direction F2 and the dimensional range of the first electrode 140a along the second direction F2, the aforementioned advantages can be combined.

[0167] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 8 , Figure 8This is a schematic diagram of a first passivation contact layer 120d on an edge region m12 and a second passivation contact layer 1301d on a second region m12 in some other embodiments of this application. On the same edge region m12, from the first side to the second side of the edge region m12, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120d decreases. That is, on the same edge region m12, from the first side to the second side of the edge region m12, the first dimension h1d decreases.

[0168] Combined with reference Figure 8 The decreasing trend refers to the fact that, within the same edge region mb, from the first side of mb to the second side, the first dimension h1d generally decreases. The first dimension h1d can first remain constant and then decrease, or it can decrease first, then remain constant, and then decrease again, or it can decrease continuously; no specific restrictions are imposed here. In other words, the decreasing trend is a general trend.

[0169] In this way, with a structural layout where the overall area occupied by the edge region mb is relatively larger, the local proportion of the field passivation region can be reduced, thereby providing a larger working space for the carrier separation and collection region. This can improve the passivation effect at the edge region mb, while also enhancing the carrier extraction, separation, and transport capabilities at the edge region mb, thereby improving the collection efficiency and effective area utilization of photogenerated carriers at the edge region mb.

[0170] It should be noted that during actual measurement, due to factors such as instrument measurement accuracy, local differences in sampling points, test noise, or individual abnormal sampling points, a small number of test points may exhibit temporary fluctuations or local errors in size. As long as the overall direction of change is decreasing and the overall distribution conforms to a decreasing pattern, it is considered to meet the requirement that the size shows a decreasing trend.

[0171] Based on some embodiments of this application, please continue to refer to 2 and Figure 8 On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the preceding first passivation contact layer 120d is larger than the size of the subsequent first passivation contact layer 120d. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the preceding first dimension h1d is larger than the subsequent first dimension h1d. On the same edge region mb, from the first side to the second side of the edge region mb, the size of the first passivation contact layer 120d decreases sequentially along the second direction F2.

[0172] In this way, with a relatively large overall area occupied by the edge region (mb), the proportion of the field passivation region can be gradually reduced, thereby increasing the size proportion of the carrier separation and collection region. While ensuring sufficient field passivation effect and suppressing edge recombination and leakage, the carrier extraction, separation, and transport capabilities of the edge region mb can be improved, enhancing the collection efficiency of photogenerated carriers and the effective area utilization. Furthermore, through a progressively decreasing size arrangement, a smooth transition and reasonable distribution of field passivation and carrier collection effects can be achieved, reducing the difficulty of process control and the risk of performance fluctuations caused by sudden changes in local dimensions, further improving the uniformity of current output and photoelectric conversion efficiency of the battery.

[0173] Based on some embodiments of this application, please continue to refer to 2 and Figure 8 and in conjunction with reference Figure 9 , Figure 9 This is a schematic diagram of the first passivation contact layer 120d on the edge region mb, the second passivation contact layer 1301d on the second region m12, and the first electrode 140b in some other embodiments of this application. On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140b decreases. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the fifth dimension h5b decreases.

[0174] The understanding and implementation of the reduction trend can be referred to the above illustrations, and will not be repeated here.

[0175] Thus, since the dimensional change trend of the first electrode 140b along the second direction F2 is the same as that of the first passivation contact layer 120d along the second direction F2, the first electrode 140b and the first passivation contact layer 120d can achieve synchronous matching of size, function and working area in the edge region mb. This is beneficial to make field passivation, electrode conductivity and carrier collection work together, further improving the photoelectric conversion efficiency, current uniformity and structural stability of the battery.

[0176] Based on some embodiments of this application, please continue to refer to 2. Figure 8 and Figure 9Within the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140b located in the first region m11 is larger than the size of the second electrode 140b located in the first region m11. That is, within the same edge region mb, from the first side to the second side of the edge region mb, the size of the first electrode 140b decreases sequentially along the second direction F2.

[0177] In this way, the gradually decreasing setting can achieve a smooth transition and reasonable allocation of field passivation function and carrier collection function, reduce the risks of poor contact, stress concentration and difficulty in process control caused by abrupt size changes, make the current output of the edge region mb more uniform, and further improve the photoelectric conversion efficiency, electrical performance stability and mass production yield of the battery.

[0178] It should be noted that, in the case where "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140b located on the first region m11 is larger than the size of the second electrode 140b located on the first region m11", the size of the first electrode 140b along the second direction F2 (i.e., the fifth size h5b) can also be 30μm to 70μm as shown in some of the foregoing embodiments. The relevant implementation methods and advantages can be referred to the content illustrated in some of the foregoing embodiments, and will not be repeated here.

[0179] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 3 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the dimensions of the first passivation contact layer 120 are the same. That is, the corresponding first dimension h1 on the same edge region mb are all the same. Of course, in Figure 4 , Figure 5 In the illustrated case, the dimensions of the first passivation contact layer 120a (i.e., the first dimension h1a) are the same, and the dimensions of the first passivation contact layer 120b (i.e., the first dimension h1b) are the same.

[0180] This allows for a more uniform distribution of the first passivation contact layer 120 on the edge region mb, thereby reducing the risk of insufficient passivation. Furthermore, the uniform size structure facilitates better process control.

[0181] Based on some implementations of this application, please continue to refer to Figure 2 , Figure 6 and Figure 7 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120c has various specifications, and the size of two adjacent first passivation contact layers 120c is different. That is, the first dimension h1c corresponding to two adjacent first passivation contact layers 120c along the second direction F2 is different. Figure 8 and Figure 9 The diagram also illustrates that the first dimensions h1d corresponding to the two adjacent first passivation contact layers 120d along the second direction F2 are different.

[0182] In this way, the size of the field passivation region can be precisely and differentiated according to the defect distribution, recombination degree, and carrier transport requirements at different locations on the edge region mb. At the same time, this diverse size specification also enhances the flexibility and adaptability of the structural design.

[0183] In some possible implementations, on the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140 has various specifications, and the sizes of two adjacent first electrodes 140 are different. Thus, the size variation trend of the first electrode 140 is the same as the size variation trend of the first passivation contact layer 120. This is advantageous for utilizing the size variation trend of the first electrode 140 to improve the structural reliability of the battery.

[0184] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 10 , Figure 10 This is a schematic diagram of a first passivation contact layer 120e on an edge region mb and a second passivation contact layer 1301e on a second region m12 in some other embodiments of this application. On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301e on the second region m12 tends to increase. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the second dimension h2e tends to increase.

[0185] The understanding of the increasing trend and the implementation of the measurement process can be referred to the above-described scenario, and will not be repeated here.

[0186] In this way, on the one hand, the carrier separation, extraction and transport capabilities of the edge region mb can be gradually improved, and the photogenerated carriers of the edge region mb can be collected more fully, thereby improving the photoelectric conversion efficiency and current uniformity. On the other hand, from the perspective of force and stress distribution, the size of the second passivation contact layer 1301e located on the second region m12 tends to increase, which can make the stress area of ​​the film layer and the interface bonding area increase steadily from the inside to the outside. This is conducive to dispersing and releasing the stress concentration of the edge region mb, reducing the shear stress and local stress mutation between the film layer interfaces, reducing the risk of film warping, cracking, detachment or poor contact during the preparation and use of the battery, and improving the mechanical stability and structural reliability of the edge region mb.

[0187] Furthermore, it is understandable that with a structural layout where the overall area occupied by the edge region mb is relatively larger, the size of the second passivation contact layer 1301e located on the second region m12 can be adjusted more flexibly under the aforementioned increasing trend.

[0188] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 10 On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301e located on the second region m12 is smaller than the size of the second passivation contact layer 1301e located on the second region m12. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the size of the second passivation contact layer 1301e located on the second region m12 increases sequentially along the second direction F2.

[0189] In this way, photogenerated carriers in the edge region mb can be extracted and transmitted more fully, improving the current collection efficiency and photoelectric conversion utilization rate of the edge region mb.

[0190] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 10 and in conjunction with reference Figure 11 , Figure 11 The diagram shows a first passivation contact layer 120e on an edge region mb, a second passivation contact layer 1301e on a second region m12, and a second electrode 160a in some other embodiments of this application. On the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160a tends to increase.

[0191] The dimension of the second electrode 160a along the second direction F2 is the sixth dimension h6a. That is, on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, the sixth dimension h6a tends to increase. The dimension of the second electrode 160a along the second direction F2 can be regarded as the width of the second electrode 160a.

[0192] The understanding and implementation of the increasing trend can be referred to the above illustrations, and will not be repeated here.

[0193] In this way, not only can the carrier collection and lateral conductivity be enhanced step by step, but the risk of stress concentration at the edge region mb can also be reduced. Furthermore, since the dimensional variation trend of the second electrode 160a along the second direction F2 is the same as that of the second passivation contact layer 1301e located on the second region m12 along the second direction F2, the dimensional variation trend of the second passivation contact layer 1301e located on the second region m12 along the second direction F2 can be utilized to expand the fabrication window of the second electrode 160a.

[0194] It is understandable that when the back contact battery 100 includes a second transparent conductive layer 170, it is also beneficial to increase the size of the second transparent conductive layer 170 on the edge region m12, thereby helping to further reduce the transfer loss of charge directly from the passivated contact structure to the electrode.

[0195] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 10 and Figure 11 Within the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160a located in the previous region m12 is smaller than the size of the second electrode 160a located in the next region m12. That is, within the same edge region mb, from the first side to the second side of the edge region mb, the size of the second electrode 160a increases sequentially along the second direction F2.

[0196] In this way, not only can the carrier collection and lateral conductivity be improved step by step, but the photogenerated carriers in the edge region mb can be extracted more smoothly, reducing the series resistance, improving the current output uniformity and photoelectric conversion efficiency, but also the contact area of ​​the second electrode 160a can be increased step by step, thereby reducing the risk of stress concentration at the edge region mb and improving the mechanical stability and long-term reliability of the structure.

[0197] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 10 and Figure 11 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160a ranges from 30μm to 70μm.

[0198] For example, the sixth dimension h6a can be 30μm, 40μm, 50μm, 60μm, 65μm, or 70μm. Of course, the sixth dimension h6a can also be any other value in the range of 30μm to 70μm, and no specific limitation is made here.

[0199] Thus, by controlling the size range of the second electrode 160a along the second direction F2, the light-shielding area of ​​the second electrode 160a can be taken into account while achieving good lateral conductivity and current collection effect.

[0200] Furthermore, by controlling the dimensional change trend of the second electrode 160a along the second direction F2 and the dimensional range of the second electrode 160a along the second direction F2, the aforementioned advantages can be combined.

[0201] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 12 , Figure 12 This is a schematic diagram of a first passivation contact layer 120f on an edge region m12 and a second passivation contact layer 1301f on a second region m12 in some embodiments of this application. On the same edge region m12, from the first side to the second side of the edge region m12, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301f on the second region m12 decreases. That is, the second size h2f decreases.

[0202] The understanding of the decreasing trend and related implementation methods can be referred to the decreasing trend illustrated in some of the foregoing embodiments, and will not be repeated here.

[0203] In this way, on the one hand, the area occupied by the carrier separation and collection region can be gradually reduced, thereby freeing up more space for the field passivation region on the first region m11. This improves the field effect passivation, leakage current suppression, and interface protection capabilities of the edge region mb, and enhances the parallel resistance and electrical performance stability of the battery. On the other hand, it allows the stress-bearing region of the film layer to transition smoothly from the inside to the outside, reducing the risk of stress concentration and thus improving the mechanical stability and long-term reliability of the battery.

[0204] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 12On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301f located on the second region m12 is larger than the size of the second passivation contact layer 1301f located on the second region m12. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the size of the second passivation contact layer 1301f located on the second region m12 decreases sequentially along the second direction F2.

[0205] In this way, the space occupied by the carrier collection region can be gradually reduced along the edge extension direction, which is conducive to increasing the proportion of the field passivation region. This gradually enhances the field effect passivation, leakage current suppression, and recombination protection capabilities of the edge region mb, and improves the parallel resistance and electrical performance stability of the battery. At the same time, since the size of the second passivation contact layer 1301f located on the second region m12 decreases sequentially along the second direction F2, the stress area of ​​the film interface can change smoothly step by step, resulting in a more uniform stress distribution at the edge region mb, and improving the mechanical stability and structural reliability of the battery.

[0206] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 12 and in conjunction with reference Figure 13 , Figure 13 This is a schematic diagram of the first passivation contact layer 120f on the edge region m12, the second passivation contact layer 1301f on the second region m12, and the second electrode 160b in some further embodiments of this application. On the same edge region m12, from the first side to the second side of the edge region m12, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160b decreases. That is, on the same edge region m12, from the first side to the second side of the edge region m12, the sixth dimension h6b decreases.

[0207] The understanding and implementation of the reduction trend can be referred to the above illustrations, and will not be repeated here.

[0208] Thus, since the dimensional change trend of the second electrode 160b along the second direction F2 is the same as the dimensional change trend of the second passivation contact layer 1301f located on the second region m12 along the second direction F2, the second electrode 160b and the second passivation contact layer 1301f located on the second region m12 can achieve synchronous matching of size, function and working area on the edge region mb, which is beneficial to further improve the photoelectric conversion efficiency, current uniformity and structural stability of the battery.

[0209] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 12 and Figure 13 Within the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160b located in the previous region m12 is larger than the size of the second electrode 160b located in the next region m12. That is, within the same edge region mb, from the first side to the second side of the edge region mb, the size of the first sixth dimension h6b is larger than the second sixth dimension h6b. Within the same edge region mb, from the first side to the second side of the edge region mb, the size of the second electrode 160b decreases sequentially along the second direction F2.

[0210] In this way, the area occupied by the second electrode 160b in the edge region mb can be gradually reduced, leaving more space for the field passivation region and the light-transmitting region. Under the premise of being able to conduct the basic current, the field passivation effect, leakage current suppression capability, and light absorption utilization rate on the edge region mb can be improved, thereby increasing the parallel resistance and photoelectric conversion efficiency of the battery. At the same time, the stress distribution at the edge region mb can also be made more uniform, improving the mechanical stability and structural reliability of the battery.

[0211] It should be noted that, in the case where "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160b located on the second region m12 is larger than the size of the second electrode 160b located on the second region m12", the size of the second electrode 160b along the second direction F2 (i.e., the sixth size h6b) can also be 30μm to 70μm as shown in some of the foregoing embodiments. The relevant implementation methods and advantages can be referred to the content illustrated in some of the foregoing embodiments, and will not be repeated here.

[0212] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 3 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the dimensions of the second passivation contact layer 1301 located on the second region m12 are the same. That is, the second dimension h2 corresponding to the second passivation contact layer 1301 located on the second region m12 on the same edge region mb are all the same. Of course, in Figures 4 to 9In the illustrated case, the dimensions (i.e., the second dimension h2a) of the second passivation contact layer 1301a located on the second region m12 are the same, the dimensions (i.e., the second dimension h2b) of the second passivation contact layer 1301b located on the second region m12 are the same, the dimensions (i.e., the second dimension h2c) of the second passivation contact layer 1301c located on the second region m12 are the same, and the dimensions (i.e., the second dimension h2d) of the second passivation contact layer 1301d located on the second region m12 are the same.

[0213] This allows for a more uniform distribution of the second passivation contact layer 1301 located on the second region m12 in the edge region mb, thereby improving the current uniformity and photoelectric conversion stability of the battery. Simultaneously, the uniform size structure also facilitates better process control.

[0214] Of course, in some implementations, in conjunction with the situations illustrated in the foregoing embodiments, in Figures 10 to 13 In the illustrated scenario, on the same edge region mb, the dimensions of the first passivation contact layer 120e (i.e., the first dimension h1e) are the same, and the dimensions of the first passivation contact layer 120f (i.e., the first dimension h1f) are the same. Related advantages can be seen in the foregoing illustration, and will not be elaborated upon here.

[0215] Based on some embodiments of this application, please continue to refer to Figure 2 , Figure 10 and Figure 11 On the same edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301e located on the second region m12 has various specifications, and the sizes of two adjacent second passivation contact layers 1301e located on the second region m12 are different. That is, the second size h2e corresponding to two adjacent second passivation contact layers 1301e located on the second region m12 along the second direction F2 is different. Figure 12 and Figure 13 The diagram also illustrates that the second dimensions h2f corresponding to the two adjacent second passivation contact layers 1301f located on the second region m12 along the second direction F2 are different.

[0216] In this way, the dimensions of the second passivation contact layer 1301e located on the second region m12 can be finely and differentially adjusted according to the defect distribution, recombination intensity, light transmission requirements and carrier transport capacity at different locations on the edge region mb. This allows for flexible matching of local electrical characteristics, achieving the local optimal allocation of carrier collection, passivation protection and light transmission area, and improving the overall electrical performance uniformity and photoelectric conversion efficiency at the edge region mb.

[0217] In some possible implementations, the second electrode 160 has various dimensions along the arrangement direction of the first region m11 and the second region m12 on the same edge region m12, and the dimensions of two adjacent second electrodes 160 are different. Thus, the dimensional variation trend of the second electrode 160 is the same as the dimensional variation trend of the second passivation contact layer located on the second region m12. This is advantageous for utilizing the dimensional variation trend of the second electrode 160 to improve the structural reliability of the battery.

[0218] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 14 , Figure 14 This is a schematic diagram of a first passivation contact layer 120g on an edge region m11 and a second passivation contact layer 1301g on a second region m12 in some other embodiments of this application. On the same edge region m11, from the first side to the second side of the edge region m11, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120g tends to increase, while the size of the second passivation contact layer 1301g on the second region m12 tends to decrease. That is, on the same edge region m11, from the first side to the second side of the edge region m11, the first dimension h1g tends to increase, and the second dimension h2g tends to decrease.

[0219] The implementation and related advantages of "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120g tends to increase" can be understood with reference to the situation illustrated in some of the foregoing embodiments. The implementation and related advantages of "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301g located on the second region m12 tends to decrease" can be understood with reference to the situation illustrated in some of the foregoing embodiments, and will not be repeated here.

[0220] In this way, by controlling the dimensions of the first passivation contact layer 120g on the edge region mb and the second passivation contact layer 1301g on the second region m12, a complementary distribution of the field passivation region and the carrier collection region can be achieved, which is beneficial to further improving battery performance.

[0221] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 14 and in conjunction with reference Figure 15 , Figure 15This is a schematic diagram of the first passivation contact layer 120g on the edge region mb, the second passivation contact layer 1301g on the second region m12, the first electrode 140c, and the second electrode 160c in some other embodiments of this application. On the same edge region mb, from the first side to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140c tends to increase, and the size of the second electrode 160c tends to decrease. That is, on the same edge region mb, from the first side to the second side of the edge region mb, the fifth dimension h5c tends to increase, and the sixth dimension h6c tends to decrease.

[0222] The implementation and related advantages of "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the first electrode 140c tends to increase" can be understood with reference to the situation illustrated in some of the foregoing embodiments. The implementation and related advantages of "on the same edge region mb, from the first side of the edge region mb to the second side of the edge region mb, along the arrangement direction of the first region m11 and the second region m12, the size of the second electrode 160c tends to decrease" can be understood with reference to the situation illustrated in some of the foregoing embodiments, and will not be repeated here.

[0223] In this way, on the one hand, it can coordinate with the size variation trends of the first passivation contact layer 120g and the second passivation contact layer 1301g located on the second region m12, which can not only enhance the conductivity and contact stability of the field passivation region, better suppress edge leakage and recombination, and improve parallel resistance and edge reliability, but also reserve more layout space for the field passivation region and the first electrode 140c, further improving the edge protection effect. At the same time, since the size variation trends of the first electrode 140c and the second electrode 160c are opposite, it helps to disperse stress concentration at the edge region mb, thereby improving the mechanical stability and long-term reliability of the battery structure.

[0224] It should be noted that, compared to the case where both the first electrode and the second electrode have the same dimensions along the second direction F2, the aforementioned control over the dimensional variation trends of the first electrode 140c and the second electrode 160c helps reduce the material used in both electrodes, thereby lowering manufacturing costs. Furthermore, the use of electrodes with different widths helps reduce overall circuit resistance, thus reducing power loss and increasing output power. Moreover, electrodes of different widths can help disperse heat generated in the battery, reducing the risk of overheating and improving stability and lifespan.

[0225] In some other embodiments, the first passivation contact layers 120 on the two edge regions m12 are symmetrically arranged about the middle region m2, and the second passivation contact layers 1301 on the second region m12 on the two edge regions m12 are symmetrically arranged about the middle region m2. This further improves the overall stress resistance of the battery.

[0226] In some other embodiments, the dimensions of the first passivation contact layer 120 along the second direction F2 can alternate on at least one edge region mb, and the dimensions of the second passivation contact layer 1301 on the second region m12 can also alternate along the second direction F2. Alternating variation means that the first passivation contact layer 120 has two different dimensions along the second direction F2, with two adjacent first passivation contact layers 120 having different dimensions along the second direction F2; and the second passivation contact layer 1301 on the second region m12 has two different dimensions along the second direction F2, with two adjacent second passivation contact layers 1301 on the second region m12 having different dimensions along the second direction F2.

[0227] In this way, the first passivation contact layer 120 and the second passivation contact layer 1301 located on the second region m12 are arranged in two alternating configurations, which enables the field passivation region and the carrier collection region to form a periodic and complementary distribution in the edge region mb, thereby achieving a dynamic balance between passivation protection and carrier collection, and effectively improving the uniformity of electrical performance, parallel resistance and photoelectric conversion efficiency of the edge region mb.

[0228] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 3 At least one edge region mb, the region furthest from the middle region mz, ​​is the first region m11. At this point, it can be seen that the layer furthest from the middle region mz on at least one edge region mb is the first passivation contact layer 120. Of course, in Figures 4 to 15 In the illustrated scenarios, the layer furthest from the middle region mz on the edge region mb is shown to be the first passivation contact layer.

[0229] In this way, the outermost part of the edge region mb can be directly protected, further improving the effect of suppressing edge leakage, surface recombination and bypass leakage current, thereby further improving battery performance.

[0230] Of course, in some other embodiments, the region furthest from the middle region mz on at least one edge region mb can also be the second region m12, and no specific limitation is made here.

[0231] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 16 , Figure 16The present application also provides schematic diagrams of a first passivation contact layer 120h on an edge region mb and a second passivation contact layer 1301h on a second region m12 in some embodiments. At least one edge region mb includes a spacer region mj. The region furthest from the middle region mz on the at least one edge region mb is the spacer region mj.

[0232] The spacer region mj refers to the outermost region located on the edge region mb of the back contact battery 100, furthest from the middle region mz. No functional film layer is provided on the spacer region mj; it is a blank isolation area.

[0233] In this way, not only can the leakage path of the edge surface be directly blocked, reducing the risk of surface composite and bypass leakage caused by edge defects, impurities, scratches, etc., but also the process difficulty can be reduced, and problems such as edge film residue, over-etching, and peeling can be reduced, which is conducive to improving mass production yield and product consistency.

[0234] It should be noted that, with Figure 16 For example, with a spacer region mj, the dimensions of the first passivation contact layer 120h along the second direction F2 (i.e., the first dimension h1h) and the dimensions of the second passivation contact layer 1301h located on the second region m12 along the second direction F2 (i.e., the second dimension h2h) can be the same. Figure 17 For example, Figure 17 This application also provides schematic diagrams of a first passivated contact layer 120i on the edge region m12 and a second passivated contact layer 1301i on the second region m12 in some embodiments. When a spacer region mj is provided, the dimensions of the first passivated contact layer 120i along the second direction F2 (i.e., the first dimension h1i) and the dimensions of the second passivated contact layer 1301i on the second region m12 along the second direction F2 (i.e., the second dimension h2i) may be different, and no specific limitations are imposed here. It is understood that other implementations of the dimensions of the first passivated contact layer 120i along the second direction F2 and the dimensions of the second passivated contact layer 1301i on the second region m12 along the second direction F2 can also be implemented with reference to the situations illustrated in the foregoing embodiments, and will not be elaborated upon here.

[0235] Based on some embodiments of this application, please continue to refer to Figure 16 and Figure 17 Along the arrangement direction of the first region m11 and the second region m12, the size of the spacer region mj is 100μm to 300μm. That is, the size of the spacer region mj along the second direction F2 is the seventh size h7, which is 100μm to 300μm.

[0236] For example, the seventh dimension h7 can be 100μm, 110μm, 130μm, 150μm, 180μm, 200μm, 220μm, 280μm, or 300μm. Of course, the seventh dimension h7 can also be any other value in the range of 100μm to 300μm, and no specific limitation is made here.

[0237] In this way, it is possible to achieve both electrical isolation and reduced edge stress while also ensuring an effective power generation area and ease of manufacturing.

[0238] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 18 , Figure 18 This is a schematic diagram of a first passivated contact layer 120j on the intermediate region mz and a second passivated contact layer 1301j on the second region m12 in some embodiments of this application. On the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the first passivated contact layer 120j and the size of the second passivated contact layer 1301j on the second region m12 are equal. That is, the first size h1j and the second size h2j are equal.

[0239] This not only makes manufacturing easier, but also helps to distribute the force more evenly across the battery.

[0240] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 19 , Figure 19 This is a schematic diagram of a first passivation contact layer 120k on the intermediate region mz and a second passivation contact layer 1301k on the second region m12 in some other embodiments of this application. On the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120k is smaller than the total size of the second passivation contact layer 1301k on the second region m12.

[0241] by Figure 19For example, in the intermediate region mz, ​​the total dimension of the first passivation contact layer 120k along the arrangement direction of the first region m11 and the second region m12 is, in other words, the sum of the dimensions of all the first passivation contact layers 120k along the second direction F2 in the intermediate region mz. The dimension of the first passivation contact layer 120k along the second direction F2 is the first dimension h1k. Similarly, in the intermediate region mz, ​​the total dimension of the second passivation contact layer 1301k located in the second region m12 along the arrangement direction of the first region m11 and the second region m12 is, in other words, the sum of the dimensions of all the second passivation contact layers 1301k located in the second region m12 along the second direction F2 in the intermediate region mz. The dimension of the second passivation contact layer 1301k located in the second region m12 along the second direction F2 is the second dimension h2k. That is to say, in the intermediate region mz, ​​the total width of the first passivation contact layer 120k is less than the total width of the second passivation contact layer 1301k located in the second region m12.

[0242] For example, continue with Figure 19 For example, and in conjunction with reference Figure 2 Since both the first region m11 and the second region m12 extend longitudinally along the third direction F3, both the first region m11 and the second region m12 can be regarded as rectangular regions. The dimension of the first passivation contact layer 120k along the third direction F3 can be regarded as the length of the first passivation contact layer 120k. The dimension of the second passivation contact layer 1301k on the second region m12 along the third direction F3 can be regarded as the length of the second passivation contact layer 1301k on the second region m12. The length of the first passivation contact layer 120k and the length of the second passivation contact layer 1301k on the second region m12 are approximately the same. In the case mentioned above, where "in the middle region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120k is smaller than the total size of the second passivation contact layer 1301k located in the second region m12", it can also be seen that in the middle region mz, ​​the area ratio of the first passivation contact layer 120k is smaller than the area ratio of the second passivation contact layer 1301k located in the second region m12.

[0243] Since the central region mz is the main area of ​​the battery where light is fully received and photogenerated carriers are concentrated, the defect density is low, and surface recombination and edge leakage are weak, but the requirements for carrier separation, collection, and transport are higher. Therefore, the total size of the first passivation contact layer 120k on the central region mz is set to be smaller than the total size of the second passivation contact layer 1301k located on the second region m12. This maximizes the area of ​​the carrier separation and collection region while meeting basic passivation protection requirements, improves the carrier collection efficiency and photoelectric conversion efficiency of the central region mz, ​​reduces the crowding of the effective power generation area due to the excessively large field passivation region area, and improves the current output and conversion efficiency in the main area of ​​the battery.

[0244] Furthermore, since a portion of the first region m11 and a portion of the second region m12 are located in the intermediate region mz, ​​it is beneficial to expand the adjustment window for the dimensions of the first passivation contact layer 120k along the arrangement direction of the first region m11 and the second region m12, as well as the dimensions of the second passivation contact layer 1301k located on the second region m12 along the arrangement direction of the first region m11 and the second region m12. This makes it easier to control the dimensions of the first passivation contact layer 120k along the arrangement direction of the first region m11 and the second region m12 and the dimensions of the second passivation contact layer 1301k located on the second region m12 along the arrangement direction of the first region m11 and the second region m12 in a more flexible manner, thereby further improving the performance of the back contact battery 100.

[0245] Therefore, since the total size of the first passivation contact layer 120k on the middle region mz of the first surface m1 of the substrate 110, along the arrangement direction of the first region m11 and the second region m12, is smaller than the total size of the second passivation contact layer 1301k on the second region m12, there is a difference between the total size of the first passivation contact layer 120k on the middle region mz along the arrangement direction of the first region m11 and the second region m12 and the total size of the second passivation contact layer 1301k on the second region m12 along the arrangement direction of the first region m11 and the second region m12. In this structure, by adjusting the dimensions of the first passivation contact layer 120k along the arrangement direction of the first region m11 and the second region m12, the dimensions of the second passivation contact layer 1301k located on the second region m12 along the arrangement direction of the first region m11 and the second region m12, and by utilizing the difference between the dimensions of the first passivation contact layer 120k along the arrangement direction of the first region m11 and the second region m12 and the dimensions of the second passivation contact layer 1301k located on the second region m12 along the arrangement direction of the first region m11 and the second region m12, it is possible to maximize the utilization of light energy while taking into account the photoelectric conversion efficiency of the back contact battery 100, thereby improving the performance of the back contact battery 100.

[0246] It should be noted that, in the case that "in the middle region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120k is smaller than the total size of the second passivation contact layer 1301k located on the second region m12" and "in at least one edge region mb, along the arrangement direction of the first region m11 and the second region m12, the total size of the first passivation contact layer 120k is larger than the total size of the second passivation contact layer 1301k located on the second region m12", not only are the aforementioned advantages present, but the middle region mz and the edge region mb can also complement each other. This further balances the photoelectric conversion efficiency of the back contact battery 100 as a whole while maximizing the utilization of light energy, thereby further improving the performance of the back contact battery 100.

[0247] Based on some embodiments of this application, please continue to refer to Figure 1 , Figure 2 and Figure 19 In the middle region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the ratio q3 of the total size of the second passivation contact layer 1301k located on the second region m12 to the total size of the first passivation contact layer 120k satisfies: 1 < q3 ≤ 2.

[0248] For example, q3 can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2. Of course, q3 can be any other value within the above range, and no specific restriction is imposed here.

[0249] Thus, since there are multiple first regions m11 and multiple second regions m12 located in the middle region mz, ​​by controlling the ratio of the total size of the first passivation contact layer 120k to the total size of the second passivation contact layer 1301k located in the second region m12, it is beneficial to improve the overall passivation and carrier collection capability of the corresponding middle region mz more uniformly and efficiently.

[0250] Furthermore, by controlling the size ratio of the edge region mb to the middle region mz, ​​controlling the size range of the middle region mz along the arrangement direction of the first region m11 and the second region m12, and controlling the size range of the middle region mz along the arrangement direction of the first region m11 and the second region m12, and controlling the ratio of the total size of the first passivation contact layer 120k to the total size of the second passivation contact layer 1301k located on the second region m12, in addition to the advantages mentioned above, synergistic control can be achieved in terms of both region allocation and functional layer ratio. This increases the effective photoelectric conversion area while strengthening edge field effect passivation or carrier extraction capabilities, balancing area utilization, edge protection, and carrier collection, thus simultaneously improving battery efficiency, stability, and yield. Moreover, the control of the aforementioned ratios and sizes also facilitates fabrication.

[0251] Based on some embodiments of this application, please continue to refer to Figure 1 , Figure 2 and Figure 19 In the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the ratio q4 of the size of the second passivation contact layer 1301k on the second region m12 to the size of the first passivation contact layer 120k satisfies: 1≤q4≤2. That is, the ratio of the second size h2k to the first size h1k is 1 to 2.

[0252] For example, q4 can be 1, 1.2, 1.4, 1.5, 1.7, 1.9, or 2. Of course, q4 can be any other value within the above range, and no specific restriction is imposed here.

[0253] Thus, given that there are multiple first regions m11 and multiple second regions m12 located on the intermediate region mz, ​​by controlling the ratio of the size of the first passivation contact layer 120k to the size of the second passivation contact layer 1301k located on the second region m12, more refined and uniform control of the local performance of the intermediate region mz can be achieved at the cell structure level. This is beneficial for improving battery performance and yield.

[0254] Based on some embodiments of this application, please continue to refer to Figure 1 , Figure 2 and Figure 19 Along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120k is 100μm to 500μm, and the size of the second passivation contact layer 1301k located on the second region m12 is 200μm to 1000μm.

[0255] For example, in conjunction with reference Figure 19The first dimension h1k can be 100μm, 150μm, 200μm, 300μm, 400μm, 450μm, or 500μm, and the second dimension h2k can be 200μm, 300μm, 400μm, 500μm, 700μm, 800μm, 900μm, or 1000μm. Of course, the first dimension h1k can also be any other value in the range of 100μm to 500μm, and the second dimension h2k can also be any other value in the range of 200μm to 1000μm; no specific restrictions are imposed here.

[0256] Thus, by controlling the size range of a single first passivation contact layer 120k and the size range of a single second passivation contact layer 1301k located on the second region m12, more precise control can be achieved at the cell-level structure. This is beneficial for improving battery performance and yield.

[0257] Furthermore, by controlling the ratio of the size of the first passivation contact layer 120k to the size of the second passivation contact layer 1301k located on the second region m12, and by controlling the size range of a single first passivation contact layer 120k and the size range of a single second passivation contact layer 1301k located on the second region m12, in addition to the advantages mentioned above, it is also beneficial to enhance the tolerance for process deviations, increase the process window, and facilitate manufacturing.

[0258] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 20 , Figure 20 This is a schematic diagram of a first passivation contact layer 120m on the intermediate region mz and a second passivation contact layer 1301m on the second region m12 in some embodiments of this application. On the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120m increases. The direction from the center of the intermediate region mz to the edge of the intermediate region mz is parallel to the arrangement direction of the first region m11 and the second region m12. That is, from the center to the edge of the intermediate region mz, ​​the first dimension h1m increases.

[0259] Combined with reference Figure 20 The increasing trend means that from the center of the intermediate region mz to its edge, the first dimension h1m generally increases. The first dimension h1m can remain unchanged first and then increase, or it can increase first, remain unchanged, and then increase again, or it can increase continuously; no specific restrictions are imposed here.

[0260] Because the center of the intermediate region (mz) receives ample light, has fewer defects, and concentrates carrier generation, the smaller size of the first passivation contact layer (120m) maximizes the area for carrier separation and collection, thereby improving the photoelectric conversion efficiency of the main region. As the transition from the center to the edge of the intermediate region (mz) occurs, defect density, surface recombination, and stress levels may gradually increase. Consequently, the size of the first passivation contact layer (120m) gradually increases, progressively enhancing passivation protection, suppressing recombination and leakage, and improving the electrical performance stability of the edge of the intermediate region (mz). This allows for a gradient and synergistic optimization of passivation protection and carrier collection within the intermediate region (mz).

[0261] It should be noted that during actual measurement, due to factors such as instrument measurement accuracy, local differences in sampling points, test noise, or individual abnormal sampling points, a small number of test points may exhibit temporary fluctuations or local errors in size. As long as the overall direction of change is increasing and the overall distribution conforms to the increasing law, it is considered to meet the requirement that the size shows an increasing trend.

[0262] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 20 In the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the preceding first passivation contact layer 120m is smaller than the size of the following first passivation contact layer 120m. That is, from the center to the edge of the intermediate region mz, ​​the preceding first dimension h1m is smaller than the following first dimension h1m. From the center to the edge of the intermediate region mz, ​​the size of the first passivation contact layer 120m increases sequentially along the second direction F2.

[0263] In this way, the gradually increasing size of the structure makes the overall structure transition more smoothly and the process controllability better. This allows for more efficient power generation in the middle region mz while improving protection capabilities, thereby enhancing battery performance.

[0264] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 21 , Figure 21 This is a schematic diagram of a first passivation contact layer 120n on the intermediate region mz and a second passivation contact layer 1301n on the second region m12 in some embodiments of this application. On the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120n decreases. The direction from the center of the intermediate region mz to the edge of the intermediate region mz is parallel to the arrangement direction of the first region m11 and the second region m12. That is, from the center to the edge of the intermediate region mz, ​​the first dimension h1n decreases.

[0265] Combined with reference Figure 21 The decreasing trend means that from the center of the intermediate region mz to its edge, the first dimension h1n generally decreases. The first dimension h1n can remain constant first and then decrease, or it can decrease first, remain constant, and then decrease again, or it can decrease continuously; no specific restrictions are imposed here.

[0266] In this way, the carrier collection capability at the center of the intermediate region mz can be further improved, while more layout space for the second passivation contact layer 1301n on the second region m12 is reserved at the edge of the intermediate region mz, ​​thereby improving the carrier separation and export efficiency at the edge of the intermediate region mz.

[0267] It should be noted that in the actual measurement process, the aforementioned explanation of the increasing trend can be used to understand the decreasing trend. As long as the overall direction of change is decreasing and the overall distribution conforms to the decreasing law, it is considered to meet the limitation that the size is decreasing. This will not be elaborated on here.

[0268] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 21 In the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the preceding first passivation contact layer 120n is larger than the size of the subsequent first passivation contact layer 120n. That is, in the same edge region mb, from the first side to the second side of the edge region mb, the preceding first dimension h1 is larger than the subsequent first dimension h1. In the same edge region mb, from the first side to the second side of the edge region mb, the size of the first passivation contact layer 120n decreases sequentially along the second direction F2.

[0269] In this way, the size of the first passivation contact layer 120n gradually decreases from the center towards the edge of the middle region mz, ​​which can gradually increase the layout space of the second passivation contact layer 1301n located on the second region m12, further improving the carrier separation and collection capabilities at the edge. Furthermore, through the progressively decreasing size arrangement, a smooth transition and reasonable distribution of field passivation and carrier collection effects can be achieved, reducing the difficulty of process control and the risk of performance fluctuations caused by sudden changes in local dimensions, and further improving the uniformity of current output and photoelectric conversion efficiency of the battery.

[0270] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 19In the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the dimensions of the first passivation contact layer 120k are the same. That is, the first dimension h1k corresponding to the first passivation contact layer 120k in the intermediate region mz is the same.

[0271] This allows for a more uniform distribution of the first passivation contact layer 120k on the edge region mb, thereby reducing the risk of insufficient passivation. Furthermore, the uniform size structure facilitates better process control.

[0272] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 20 In the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the first passivation contact layer 120m has various specifications, and the size of two adjacent first passivation contact layers 120m is different. That is, the first dimension h1m corresponding to two adjacent first passivation contact layers 120m along the second direction F2 is different. Figure 21 The diagram also illustrates that the first dimensions h1m corresponding to the two adjacent first passivation contact layers 120m along the second direction F2 are different.

[0273] In this way, the size of the field passivation region can be precisely and differentiated according to the defect distribution, recombination degree, and carrier transport requirements at different locations on the intermediate region mz. At the same time, this diverse size specification also enhances the flexibility and adaptability of the structural design.

[0274] In some possible implementations, the dimensions of the first electrode 140 in the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, are of various specifications, and the dimensions of two adjacent first electrodes 140 are different. Thus, the dimensional variation trend of the first electrode 140 is the same as the dimensional variation trend of the first passivation contact layer. This is advantageous for utilizing the dimensional variation trend of the first electrode 140 to improve the structural reliability of the battery.

[0275] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 22 , Figure 22This is a schematic diagram of a first passivation contact layer 120p on the intermediate region mz and a second passivation contact layer 1301p on the second region m12 in some other embodiments of this application. In the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301p on the second region m12 increases. The direction from the center to the edge of the intermediate region mz is parallel to the arrangement direction of the first region m11 and the second region m12. That is, in the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​the second dimension h2p increases.

[0276] The understanding of the increasing trend and the implementation of the measurement process can be referred to the above-described scenario, and will not be repeated here.

[0277] Thus, on the one hand, by gradually increasing the size of the second passivation contact layer 1301p on the second region m12 from the center of the middle region mz to the edge of the middle region mz, ​​the carrier separation, collection and lateral conductivity can be improved step by step, the series resistance can be reduced, the current output uniformity at the edge of the middle region mz can be improved, and the overall electrical performance can be improved; on the other hand, the size of the second passivation contact layer 1301p on the second region m12 can change more smoothly, thereby alleviating local stress concentration, reducing the risk of film warping, cracking or peeling, and improving the reliability of interface bonding.

[0278] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 22 In the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301p located in the previous region m12 is smaller than the size of the second passivation contact layer 1301p located in the next region m12. That is, from the center to the edge of the intermediate region mz, ​​the size of the second passivation contact layer 1301p located in the second region m12 increases sequentially along the second direction F2.

[0279] In this way, photogenerated carriers in the edge region mb can be extracted and transmitted more fully, improving the current collection efficiency and photoelectric conversion utilization rate of the middle region mz.

[0280] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 23 , Figure 23This is a schematic diagram of a first passivation contact layer 120q on the intermediate region mz and a second passivation contact layer 1301q on the second region m12 in some other embodiments of this application. On the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301q on the second region m12 decreases. The direction from the center of the intermediate region mz to the edge of the intermediate region mz is parallel to the arrangement direction of the first region m11 and the second region m12.

[0281] The understanding of the decreasing trend and related implementation methods can be referred to the decreasing trend illustrated in some of the foregoing embodiments, and will not be repeated here.

[0282] In this way, on the one hand, the area occupied by the carrier separation and collection region can be gradually reduced, thereby freeing up more space for the field passivation region on the first region m11. This improves the field effect passivation, leakage current suppression, and interface protection capabilities at the edge of the middle region mz, ​​and enhances the parallel resistance and electrical performance stability of the battery. On the other hand, it allows the stress-bearing region of the film layer to transition smoothly from the inside to the outside, reducing the risk of stress concentration and thus improving the mechanical stability and long-term reliability of the battery.

[0283] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 23 In the intermediate region mz, ​​from the center to the edge of the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the size of the second passivation contact layer 1301q located in the previous region m12 is larger than the size of the second passivation contact layer 1301q located in the next region m12. That is, from the center to the edge of the intermediate region mz, ​​the size of the second passivation contact layer 1301q located in the previous region m12 is larger than the size of the second passivation contact layer h2q. From the first side to the second side of the edge region mb, the size of the second passivation contact layer 1301q located in the second region m12 decreases sequentially along the second direction F2.

[0284] In this way, the space occupied by the carrier collection region can be gradually reduced along the edge extension direction, which is conducive to increasing the proportion of the field passivation region. This gradually enhances the field effect passivation, leakage current suppression, and recombination protection capabilities of the edge region mb, and improves the parallel resistance and electrical performance stability of the battery. At the same time, since the size of the second passivation contact layer 1301q on the second region m12 decreases sequentially along the second direction F2, the stress area of ​​the film interface can change smoothly step by step, resulting in a more uniform stress distribution at the edge region mb, and improving the mechanical stability and structural reliability of the battery.

[0285] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 19In the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the dimensions of the second passivation contact layer 1301k on the second region m12 are the same. That is, the second dimension h2k corresponding to the second passivation contact layer 1301k on the second region m12 in the intermediate region mz are all the same. Of course, in Figure 20 and Figure 21 In the illustrated case, the dimensions (i.e., the second dimension h2m) of the second passivation contact layer 1301m located on the second region m12 are the same, and the dimensions (i.e., the second dimension h2n) of the second passivation contact layer 1301n located on the second region m12 are the same.

[0286] This allows for a more uniform distribution of the second passivation contact layer 1301k located on the second region m12 in the middle region mz, ​​thereby improving the current uniformity and photoelectric conversion stability of the battery. Simultaneously, the uniform size structure also facilitates better process control.

[0287] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 22 In the intermediate region mz, ​​along the arrangement direction of the first region m11 and the second region m12, the second passivation contact layer 1301p located on the second region m12 has various dimensions, and the dimensions of two adjacent second passivation contact layers 1301p located on the second region m12 are different. That is, the second dimension h2p corresponding to two adjacent second passivation contact layers 1301p located on the second region m12 along the second direction F2 are different. Figure 7 The diagram also illustrates that the second dimensions h2p of the two adjacent second passivation contact layers 1301p located on the second region m12 along the second direction F2 are different.

[0288] In this way, the dimensions of the second passivation contact layer 1301p on the second region m12 can be finely and differentially adjusted according to the defect distribution, recombination intensity, light transmission requirements and carrier transport capacity at different locations on the middle region mz. This allows for flexible matching of local electrical characteristics, achieving optimal local allocation of carrier collection, passivation protection and light transmission area, and improving the overall electrical performance uniformity and photoelectric conversion efficiency at the middle region mz.

[0289] It should be noted that in the above-illustrated embodiment of the dimensional variation trend of the second passivation contact layer located on the second region m12 in the intermediate region mz along the second direction F2, the dimensional variation trend of the first passivation contact layer in the intermediate region mz along the second direction F2 can also be implemented with reference to the dimensional variation trend of the first passivation contact layer in the edge region mb along the second direction F2, which will not be elaborated here. For example, Figure 22This illustrates that the first passivation contact layer 120p on the intermediate region mz has the same dimensions (i.e., the first dimension h1p) along the second direction F2. Figure 23 This illustrates that the first passivation contact layer 120q on the intermediate region mz has the same dimensions (i.e., the first dimension h1q) along the second direction F2. Of course, it can also be as follows... Figure 20 The dimensions (i.e., the first dimension h1m) of the first passivation contact layer 120m on the middle region mz along the second direction F2, as shown in the diagram, have a corresponding trend of change.

[0290] In some possible implementations, the dimensions of the first electrode along the second direction F2 in the intermediate region mz and the second electrode along the second direction F2 can be implemented and understood with reference to the dimensions of the first electrode along the second direction F2 in the edge region mb. For example, the dimension variation trend of the first electrode along the second direction F2 in the intermediate region mz can be the same as the dimension variation trend of the first passivation contact layer along the second direction F2 in the intermediate region mz; the dimension variation trend of the second electrode along the second direction F2 in the intermediate region mz can be the same as the dimension variation trend of the second passivation contact layer located on the second region m12 in the intermediate region mz along the second direction F2. As another example, the dimension of the first electrode along the second direction F2 in the intermediate region mz can be the same as the dimension of the first electrode along the second direction F2 in the edge region mb; the dimension of the second electrode along the second direction F2 in the intermediate region mz can be the same as the dimension of the second electrode along the second direction F2 in the edge region mb. Further details are omitted here.

[0291] According to some embodiments of this application, please refer to Figure 24 , Figure 24 This is a schematic diagram of a first passivated contact layer 120r on a unit region m11 and a second passivated contact layer 1301r on a second region m12 in some embodiments of this application. The first surface m1 includes multiple unit regions m11. Each unit region m11 includes at least one first region m11 and at least one second region m12. On the same unit region m11, along the arrangement direction of the first region m11 and the second region m12, the size of the first passivated contact layer 120r and the size of the second passivated contact layer 1301r on the second region m12 are equal.

[0292] A cell region mu refers to a basic functional unit in a battery structure that is composed of at least one first region m11 and at least one second region m12.

[0293] For example, Figure 24 This illustration depicts a unit region mu comprising two first regions m11 and two second regions m12, where the first dimension h1r and the second dimension h2r are equal. Furthermore, by way of example... Figure 25 For example, Figure 25 This is a schematic diagram illustrating the first passivation contact layer 120s on the unit region mu1 and the second passivation contact layer 1301s on the second region m12 in other embodiments of this application. It shows the case where the unit region mu1 includes a first region m11 and a second region m12, with the first dimension h1s and the second dimension h2s being equal. Of course, the unit region may also include other numbers of first regions m11 and other numbers of second regions m12, which is not specifically limited here.

[0294] Continue to refer to Figure 24 and in conjunction with reference Figure 26 , Figure 26 This is a schematic diagram of the combination of unit regions mu and non-unit regions in some other embodiments of this application. Along the arrangement direction of the first region m11 and the second region m12, two adjacent unit regions mu are arranged at intervals.

[0295] This not only ensures a more balanced distribution of passivation protection and carrier collection functions within the unit region mu, improving battery output stability, but also allows each unit region mu to be independent and non-overlapping through spacing between adjacent unit regions mu. Furthermore, the spacing between adjacent unit regions mu provides space for other first passivation contact layers 120t with different sizes and other second passivation contact layers 1301t located on the second region m12. Simultaneously, setting multiple unit regions mu helps improve the uniformity of stress at the film interface, reducing the risk of localized stress concentration, thereby improving the battery's mechanical stability and long-term reliability.

[0296] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 27 , Figure 27 This is a schematic diagram of the arrangement of the first electrode 140d in some embodiments of this application. From the middle region mz to the edge region mb, the height of the first electrode 140d increases.

[0297] The height of the first electrode 140d is also the dimension of the first electrode 140d along the third direction F3, which is the first height d1. The increasing trend can be understood by referring to the situation illustrated in some of the aforementioned embodiments, and will not be repeated here.

[0298] This not only improves conductivity and contact reliability in areas closer to the edge, but also enhances strength and stability in areas closer to the edge.

[0299] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 27From the middle region mz to the edge region mb, the height of the preceding first electrode 140d is less than the height of the following first electrode 140d. That is, from the middle region mz to the edge region mb, the height of the first electrode 140d increases sequentially.

[0300] In this way, not only can the conductivity of the electrodes be improved step by step, but the risk of battery damage caused by greater mb stress in the edge region can also be reduced.

[0301] Based on some embodiments of this application, please continue to refer to Figure 27 The height of the first electrode 140d ranges from 8 μm to 15 μm.

[0302] For example, the first height d1 can be 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm. Of course, the first height d1 can also be any other value in the range of 8μm to 15μm, and no specific limitation is made here.

[0303] In this way, not only can the first electrode 140d have a certain conductivity, but it is also beneficial to improve the mechanical strength of the first electrode 140d, thereby improving the reliability of the edge region mb.

[0304] Based on some embodiments of this application, please continue to refer to Figure 2 and in conjunction with reference Figure 28 , Figure 28 This is a schematic diagram of the arrangement of the second electrode 160d in some embodiments of this application. From the middle region mz to the edge region mb, the height of the second electrode 160d increases.

[0305] The height of the second electrode 160d is also the dimension of the second electrode 160d along the third direction F3, which is the second height d2. The increasing trend can be understood by referring to the situation illustrated in some of the aforementioned embodiments, and will not be repeated here.

[0306] This not only improves conductivity and contact reliability in areas closer to the edge, but also enhances strength and stability in areas closer to the edge.

[0307] Based on some embodiments of this application, please continue to refer to Figure 2 and Figure 28 From the middle region mz to the edge region mb, the height of the preceding second electrode 160d is less than the height of the following second electrode 160d. That is, from the middle region mz to the edge region mb, the height of the second electrode 160d increases sequentially.

[0308] In this way, not only can the conductivity of the electrodes be improved step by step, but the risk of battery damage caused by greater mb stress in the edge region can also be reduced.

[0309] Based on some embodiments of this application, please continue to refer to Figure 28 The height of the second electrode 160d ranges from 8 μm to 15 μm.

[0310] For example, the second height d2 can be 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm. Of course, the second height d2 can also be any other value in the range of 8μm to 15μm, and no specific limitation is made here.

[0311] In this way, not only can the second electrode 160d have a certain conductivity, but it is also beneficial to improve the mechanical strength of the second electrode 160d, thereby improving the reliability of the edge region mb.

[0312] According to some embodiments of this application, please refer to Figure 29 , Figure 29 This is a schematic diagram of the structure of a photovoltaic module 10 provided in some embodiments of this application. The embodiments of this application provide a photovoltaic module 10, including a battery string 11, an encapsulation layer 12, and a cover plate 13. The encapsulation layer 12 is used to cover the surface of the battery string 11, and the cover plate 13 is used to cover the surface of the encapsulation layer 12 away from the battery string 11. The battery string 11 is formed by connecting multiple back-contact batteries as described in any of the embodiments above.

[0313] Furthermore, the back contact batteries are electrically connected in the form of a whole piece or multiple pieces to form multiple battery strings 11, and the multiple battery strings 11 are electrically connected in series and / or parallel.

[0314] In some embodiments, multiple battery strings 11 can be electrically connected via conductive strips 14. Encapsulation layer 12 covers both the front and back sides of the back-contact battery.

[0315] In some embodiments, the encapsulation layer 12 may be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene coelastomer (POE) film, or polyethylene terephthalate (PET) film.

[0316] In some embodiments, the cover plate 13 can be a glass cover plate, a plastic cover plate, or other cover plate with light transmission function.

[0317] In some embodiments, the surface of the cover plate 13 facing the encapsulation layer 12 can be an uneven surface, thereby increasing the utilization rate of incident light.

[0318] The photovoltaic module 10 also possesses the advantages of the back-contact battery mentioned above, and will not be elaborated further here.

[0319] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0320] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A back-contact battery, characterized in that, include: A substrate having a first surface, the first surface comprising alternating first and second regions; The first passivation contact layer includes a tunneling layer and a first doped layer, wherein the tunneling layer is disposed on the first region and the first doped layer is disposed on the side of the tunneling layer opposite to the substrate. and The second passivation contact layer includes an amorphous material layer and a second doped layer, wherein the amorphous material layer is at least disposed on the second region, and the second doped layer is disposed on the side of the amorphous material layer opposite to the substrate. Wherein, along the arrangement direction of the first region and the second region, the edge region of the first surface is located on both sides of the middle region of the first surface; a portion of the first region and the second region are located in the middle region, and another portion of the first region and the second region are located in the edge region; on at least one of the edge regions, along the arrangement direction of the first region and the second region, the total size of the first passivation contact layer is greater than the total size of the second passivation contact layer located on the second region; on the middle region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer and the size of the second passivation contact layer located on the second region are equal.

2. The back contact battery according to claim 1, characterized in that, Along the arrangement direction of the first and second regions, the ratio of the size of the edge region to the size of the middle region is 0.2 to 1; and / or Along the arrangement direction of the first and second regions, the size of the edge region is 0.3 mm to 20 mm, and the size of the middle region is 65 mm to 190 mm; and / or On the same edge region, along the arrangement direction of the first region and the second region, the ratio q1 of the total size of the first passivation contact layer to the total size of the second passivation contact layer located on the second region satisfies: 1 < q1 ≤ 2.

3. The back contact battery according to claim 1, characterized in that, On the same edge region, along the arrangement direction of the first region and the second region, the ratio q2 of the size of the first passivation contact layer to the size of the second passivation contact layer located on the second region satisfies: 1 ≤ q2 ≤ 2; and / or On the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is 200 μm to 1000 μm, and the size of the second passivation contact layer located on the second region is 100 μm to 500 μm.

4. The back contact battery according to claim 1, characterized in that, In at least one of the said edge regions, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is larger than the size of the second passivation contact layer located on the second region.

5. The back contact battery according to claim 1, characterized in that, In at least one of the said edge regions, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is smaller than the size of the second passivation contact layer located on the second region.

6. The back contact battery according to any one of claims 1-5, characterized in that, The edge region has a first side connecting the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer tends to increase.

7. The back contact battery according to claim 6, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is smaller than the size of the second passivation contact layer.

8. The back contact battery according to claim 6, characterized in that, The back contact battery further includes a first electrode, which is disposed on the side of the first doped layer away from the tunneling layer and is electrically connected to the first doped layer. On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first electrode tends to increase.

9. The back contact battery according to claim 8, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the first electrode located in the first region is smaller than the size of the first electrode located in the second region; and / or On the same edge region, along the arrangement direction of the first region and the second region, the size of the first electrode ranges from 30 μm to 70 μm.

10. The back contact battery according to any one of claims 1-5, characterized in that, The edge region has a first side connecting the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer decreases.

11. The back contact battery according to claim 10, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is larger than the size of the second passivation contact layer.

12. The back contact battery according to claim 10, characterized in that, The back contact battery further includes a first electrode, which is disposed on the side of the first doped layer away from the tunneling layer and is electrically connected to the first doped layer. On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the first electrode tends to decrease.

13. The back contact battery according to claim 12, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the first electrode located in the first region is larger than the size of the first electrode located in the second region; and / or On the same edge region, along the arrangement direction of the first region and the second region, the size of the first electrode ranges from 30 μm to 70 μm.

14. The back contact battery according to any one of claims 1-5, characterized in that, On the same edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer is the same.

15. The back contact battery according to any one of claims 1-5, characterized in that, On the same edge region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer has various specifications, and the size of two adjacent first passivation contact layers is different.

16. The back contact battery according to any one of claims 1-5, characterized in that, The edge region has a first side connecting the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located on the second region tends to increase.

17. The back contact battery according to claim 16, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located in the first region is smaller than the size of the second passivation contact layer located in the second region.

18. The back contact battery according to claim 16, characterized in that, The back contact battery further includes a second electrode, which is disposed on the side of the second doped layer opposite to the amorphous material layer and is electrically connected to the second doped layer. On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second electrode tends to increase.

19. The back contact battery according to claim 18, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second electrode located in the previous second region is smaller than the size of the second electrode located in the subsequent second region; and / or On the same edge region, along the arrangement direction of the first region and the second region, the size of the second electrode ranges from 30 μm to 70 μm.

20. The back contact battery according to any one of claims 1-5, characterized in that, The edge region has a first side connecting the middle region and a second side disposed opposite to the first side; on the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located on the second region tends to decrease.

21. The back contact battery according to claim 20, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located in the first region is larger than the size of the second passivation contact layer located in the second region.

22. The back contact battery according to claim 20, characterized in that, The back contact battery further includes a second electrode, which is disposed on the side of the second doped layer opposite to the amorphous material layer and is electrically connected to the second doped layer. On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first region and the second region, the size of the second electrode tends to decrease.

23. The back contact battery according to claim 22, characterized in that, On the same edge region, from the first side of the edge region to the second side of the edge region, along the arrangement direction of the first and second regions, the size of the second electrode located in the previous second region is larger than the size of the second electrode located in the subsequent second region; and / or On the same edge region, along the arrangement direction of the first region and the second region, the size of the second electrode ranges from 30 μm to 70 μm.

24. The back contact battery according to any one of claims 1-5, characterized in that, On the same edge region, along the arrangement direction of the first region and the second region, the second passivation contact layer located on the second region has the same size.

25. The back contact battery according to any one of claims 1-5, characterized in that, On the same edge region, along the arrangement direction of the first region and the second region, the size of the second passivation contact layer located on the second region has various specifications, and the size of two adjacent second passivation contact layers located on the second region is different.

26. The back contact battery according to any one of claims 1-5, characterized in that, The region furthest from the middle region on at least one of the edge regions is the first region.

27. The back contact battery according to any one of claims 1-5, characterized in that, At least one of the edge regions includes a gap region; The region furthest from the middle region on at least one of the said edge regions is the interval region.

28. The back contact battery according to claim 27, characterized in that, Along the arrangement direction of the first and second regions, the size of the interval region is 100μm to 300μm.

29. The back contact battery according to any one of claims 1-5, characterized in that, The first surface includes multiple unit regions; The unit region includes at least one first region and at least one second region; in the same unit region, along the arrangement direction of the first region and the second region, the size of the first passivation contact layer and the size of the second passivation contact layer located on the second region are equal; Along the arrangement direction of the first and second zones, two adjacent unit zones are spaced apart.

30. A photovoltaic module, characterized in that, include: Battery string; An encapsulation layer is used to cover the surface of the battery string; and A cover plate, the cover plate being used to cover the surface of the encapsulation layer away from the battery string; The battery string is formed by connecting multiple back-contact batteries as described in any one of claims 1-29.

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