Solar cell and method of manufacturing the same, photovoltaic module

Abstract

The application relates to the technical field of solar cells, in particular to a solar cell, a manufacturing method thereof and a photovoltaic module. The solar cell comprises a cell substrate, a passivation layer and a plurality of first grid lines. The cell substrate has a first surface and a second surface arranged oppositely. The passivation layer is arranged on the first surface and / or the second surface. The plurality of first grid lines are arranged on the first surface and / or the second surface. The first grid line comprises a seed part, a transfer layer and a cover layer. The transfer layer and the cover layer are arranged on the side of the seed part away from the cell substrate and the side of the passivation layer away from the cell substrate, and the width of the cover layer is greater than the width of the seed part. Therefore, the electrical performance of the solar cell can be improved, and the reliability and service life of the solar cell can also be improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to solar cells and their manufacturing methods, and photovoltaic modules. Background Technology

[0002] A solar cell is a device that converts solar energy into electrical energy. Specifically, a solar cell uses the photovoltaic principle to generate charge carriers, and then uses electrodes to extract these carriers, thus facilitating the efficient use of electrical energy. However, the performance of solar cells needs further improvement. Summary of the Invention

[0003] Therefore, it is necessary to provide a solar cell and its manufacturing method, as well as a photovoltaic module, to improve the performance of solar cells.

[0004] According to one aspect of this application, an embodiment of this application provides a solar cell, including a cell substrate, a passivation layer, and a plurality of first grid lines. The cell substrate has a first surface and a second surface disposed opposite to each other. The passivation layer is disposed on the first surface and / or the second surface. The plurality of first grid lines are disposed on the first surface and / or the second surface. Each first grid line includes a seed portion, a transport layer, and a capping layer. Both the transport layer and the capping layer are disposed on the side of the seed portion away from the cell substrate and the side of the passivation layer away from the cell substrate, and the width of the capping layer is greater than the width of the seed portion.

[0005] In some embodiments, the first gate line is divided into a first region and a second region, with the second region located on both sides of the first region along the width direction of the first gate line. A transmission layer is located in the first region, a seed portion is located at least in the first region, and a cover layer is located in both the first and second regions.

[0006] In some embodiments, the width of the first region is smaller than the width of the second region; and / or, the thickness of the first region is greater than the thickness of the second region.

[0007] In some embodiments, the width of the first region is 5 μm to 100 μm, and the width of the second region is 10 μm to 495 μm; and / or, the thickness of the first region is 0.001 μm to 50 μm, and the thickness of the second region is 0.0001 μm to 30 μm.

[0008] In some embodiments, the width of the seed portion is s1, the width of the first region is s2, and the width of the second region is s3, where s1, s2, and s3 satisfy either a first condition or a second condition. The first condition includes: 2s3 > s1 - s2, 2 ≤ s1 / s2 ≤ 20; and / or, 10 μm ≤ s3 ≤ 495 μm. The second condition includes: 0.01 ≤ s1 / s2 ≤ 2; and / or, 10 μm ≤ s3 ≤ 495 μm.

[0009] In some embodiments, the first gate line has a center line, the extension direction of which is parallel to the extension direction of the first gate line. Along the width direction of the first gate line, the second region has two oppositely disposed first sides, the seed layer has two oppositely disposed second sides, and the first region has two oppositely disposed third sides. Along the width direction of the first gate line, the distance between the first side farther from the center line and the center line is w1, the distance between the second side and the center line is w2, and the distance between the third side and the center line is w3. Wherein, w1 > w2, w1 / w3 > 2; and / or, 10 μm ≤ w1 - w3 ≤ 495 μm.

[0010] In some embodiments, the first gate line includes a plurality of conductive particles in the capping layer. At least a portion of the conductive particles form a transport layer.

[0011] In some embodiments, the distribution density of conductive particles in the first region is greater than that in the second region.

[0012] In some embodiments, the width of the cover layer is 20 μm to 1000 μm, and the width of the seed portion is 5 μm to 200 μm. And / or, the ratio of the width of the cover layer to the width of the seed portion is 2 to 200.

[0013] In some embodiments, a plurality of pyramid-shaped structures are provided on the surfaces of the first and second surfaces where the first grid lines are provided.

[0014] In some embodiments, the surface on which the first grid line is provided in the first and second surfaces is defined as the grid line surface. At least one grid line surface is divided into a third region and a fourth region alternately arranged along the width direction of the first grid line, and the first grid line is provided at least in the third region. The plurality of pyramid-shaped structures include a plurality of first pyramid-shaped structures provided in the third region and a plurality of second pyramid-shaped structures provided in the fourth region. Wherein, the height of the first pyramid-shaped structure is less than the height of the second pyramid-shaped structure; and / or, the distance between the tips of two adjacent first pyramid-shaped structures is less than the distance between the tips of two adjacent second pyramid-shaped structures.

[0015] In some embodiments, the height of the first pyramidal structure is 100 nm to 530 nm, and the height of the second pyramidal structure is 350 nm to 1750 nm. And / or, the distance between the tips of two adjacent first pyramidal structures is 200 nm to 750 nm, and the distance between the tips of two adjacent second pyramidal structures is 750 nm to 2500 nm.

[0016] In some embodiments, the surface energy of the passivation layer is greater than the surface energy of the liquid capping layer.

[0017] In some embodiments, the surface energy of the passivation layer is 35 mJ / m². 2Up to 100mJ / m 2 The surface energy of the cross-linked layer in the liquid state is 15mN / m to 50mN / m.

[0018] In some embodiments, the material of the passivation layer includes one or more of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, silicon carbide, and silicon carbonitride.

[0019] In some embodiments, the edge region of the cover layer has a perforated structure.

[0020] In some embodiments, at least one sub-part includes a plurality of seed units spaced apart along the extension direction of the first gate line; and / or, at least one sub-part extends longitudinally along the extension direction of the first gate line.

[0021] In some embodiments, the material of the seed portion includes one or more of silver, aluminum, and nickel.

[0022] In some embodiments, the material of the transport layer includes one or more of silver, copper, and silver-clad copper.

[0023] In some embodiments, the material of the coating layer includes one or more of resin, fatty acid, paraffin, microcrystalline wax, and inorganic nanosol.

[0024] In some embodiments, the material of the cover layer includes one or more of epoxy resin, phenolic resin, polyurethane resin, acrylate resin, polyester resin, and vinyl chloride resin.

[0025] In some embodiments, the second side is the back side of the battery substrate, and the second side is provided with a first grid line.

[0026] According to another aspect of this application, an embodiment of this application provides a method for manufacturing a solar cell, comprising: providing a cell substrate having a first side and a second side disposed opposite to each other, and a passivation layer being provided on the first side and / or the second side; forming a seed portion on the first side and / or the second side; forming a transport layer and an initial capping layer on the side of the seed portion away from the cell substrate and the side of the passivation layer away from the cell substrate; and sequentially performing a static treatment and a curing treatment on the initial capping layer to form a capping layer, thereby forming a solar cell.

[0027] In some embodiments, the settling time is 10 seconds to 30 minutes; and / or the settling temperature is 5°C to 100°C.

[0028] According to another aspect of this application, embodiments of this application provide a photovoltaic module, including: a solar cell as described in any of the above embodiments; or a solar cell manufactured by the method for manufacturing a solar cell as described in any of the above embodiments.

[0029] In the aforementioned solar cells, manufacturing methods, and photovoltaic modules, by setting a first grid line, which includes a seed section, a transport layer, and a capping layer, and the width of the capping layer is greater than the width of the seed section, the contact area between the first grid line and the cell substrate and passivation layer can be increased through the capping layer, thereby improving the adhesion of the first grid line. This not only improves the electrical performance of the solar cell, but also enhances its reliability and lifespan.

[0030] 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

[0031] 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:

[0032] Figure 1 This is a cross-sectional view of a solar cell in some embodiments of this application;

[0033] Figure 2 This is a partial structural diagram of the battery substrate, passivation layer and first gate line in some embodiments of this application, viewed from one angle.

[0034] Figure 3 This is a partial structural diagram of the first grid line and the battery body cooperating in some embodiments of this application from another perspective;

[0035] Figure 4 This is a top-view SEM diagram of a portion of the structure of a solar cell in some embodiments of this application;

[0036] Figure 5 This is a schematic diagram of the pyramid-shaped structure in some embodiments of this application;

[0037] Figure 6 This is a schematic diagram of the spire identification point in some embodiments of this application;

[0038] Figure 7 This is a schematic diagram of the structure of the first gate line in some other embodiments of this application;

[0039] Figure 8 This is a cross-sectional view of a solar cell in some other embodiments of this application;

[0040] Figure 9 This is a schematic flowchart illustrating the method for manufacturing a solar cell in some embodiments of this application;

[0041] Figure 10 This is a schematic diagram of the structure of a photovoltaic module in some embodiments of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100 solar cells;

[0044] Battery substrate 110, substrate 111, tunneling layer 112, doped conductive layer 113, doped region 114, first surface m1, second surface m2, third region z3, fourth region z4, pyramid structure 1101, first pyramid structure 11011, second pyramid structure 11012, height H, tower tip spacing W, tower tip T.

[0045] Passivation layer 120, first passivation layer 121, second passivation layer 122;

[0046] First gate lines 130, 130a, seed sections 131, 131a, seed unit 1311, second side b2, width s1, transmission layers 132, 132a, cover layer 133, width d, conductive particle 1301, first region z1, third side b3, width s2, thickness h1, second region z2, first side b1, width s3, thickness h2, center line L, distances w1, w2, w3;

[0047] Anti-reflective layer 140;

[0048] Solar cell 100a, substrate 111a, first region m11, second region m12, spacer region m13, first passivation conductive structure T1, first tunneling layer T11, first doped conductive layer T12, second passivation conductive structure T2, second tunneling layer T21, second doped conductive layer T22, passivation layer 120a, first passivation layer 121a, second passivation layer 122a, passivation antireflection layer 102, grid lines E1, E2;

[0049] Photovoltaic module 10, cell string 11, encapsulation layer 12, cover plate 13, conductive strip 14;

[0050] First direction F1, second direction F2, third direction F3. Detailed Implementation

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] In addition, embodiments of the application are described with reference to cross-sectional views, which are schematic diagrams of some embodiments of the application, thus allowing for the expectation of variations in the illustrated shape due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the application should not be limited to the specific shape of the area shown herein, but should include shape deviations due to, for example, manufacturing techniques.

[0059] Furthermore, the use of terms such as "same," "equal," or "consistent" regarding dimensions in the description of the embodiments of this application does not require absolute mathematical or geometric precision. Given the actual manufacturing, measurement, and material factors, those skilled in the art should understand that the aforementioned dimensional terms include deviations within permissible limits or unavoidable deviations. As long as such deviations do not affect the realization of the corresponding dimensions' function and technical effect in this application, they should be considered to fall within the meaning of "same dimensions" as described in the embodiments of this application.

[0060] In solar cells, grid lines can be fabricated using high-temperature silver paste through screen printing and high-temperature sintering. The silver paste contains silver powder and glass powder. During the high-temperature sintering process, the glass powder melts, etches downwards into the passivation layer, and fills the space between the formed grid lines and the substrate. The grid lines and substrate form chemical bonds, while the silver powder within the grid lines melts and recrystallizes, forming metallic bonds. Therefore, the adhesion between the grid lines and the substrate is high, and they will not easily detach during subsequent processes. However, this method of fabricating grid lines consumes a relatively large amount of silver paste.

[0061] To address the issue of high silver paste consumption, low-temperature silver-coated copper paste or low-temperature copper paste can be used to fabricate grid lines via screen printing and low-temperature curing. Furthermore, to further reduce manufacturing costs, silver consumption can be decreased by printing finer or lattice-shaped seed sections and a transport layer formed by a low-temperature base metal. However, in this method, because the low-temperature paste does not contain glass powder, the adhesion between the grid lines and the substrate is relatively low, making them prone to detachment during subsequent processes due to friction or heat.

[0062] Based on this, in order to solve at least some of the above problems, embodiments of this application improve the structure of the grid lines to at least enhance the adhesion of the grid lines, thereby at least improving the performance of the solar cell.

[0063] Please refer to Figure 1 and Figure 2 , Figure 1 This is a cross-sectional view of the solar cell 100 in some embodiments of this application. Figure 2 This is a partial structural diagram from a certain perspective showing the interaction of the battery substrate 110, passivation layer 120, and first grid lines 130 in some embodiments of this application. Embodiments of this application provide a solar cell 100, including a battery substrate 110 and multiple first grid lines 130.

[0064] The battery substrate 110 includes a substrate 111 and functional layers and / or functional regions disposed on the substrate 111. Figure 1 For example, the first direction F1 is the thickness direction of the battery substrate 110, and the second direction F2 and the third direction F3 can be the length direction and width direction of the battery substrate 110, respectively. The first direction F1, the second direction F2, and the third direction F3 are all perpendicular to each other. It should be noted that the dimension of the battery substrate 110 along the length direction can be greater than or equal to the dimension along the width direction, and no specific restriction is imposed here.

[0065] The substrate 111 is used to receive incident light and generate photogenerated carriers. The substrate 111 can be selected according to actual needs. Exemplarily, the substrate 111 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 111 is not specifically limited. For example, the substrate 111 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 111 can be an N-type monocrystalline silicon wafer, which can improve the conversion efficiency of the solar cell 100 and reduce manufacturing costs.

[0066] The functional layer and / or functional region on the substrate 111 refers to a structure grown and / or fabricated on the surface of the substrate 111 to achieve optoelectronic functions such as conductivity, ohmic contact, and carrier collection. For example, it can be a passivated contact structure or a diffusion structure. No specific limitations are made here.

[0067] The battery substrate 110 has a first surface m1 and a second surface m2 disposed opposite to each other along the thickness direction of the battery substrate 110. For example, the first surface m1 is a backlight surface, and the second surface m2 is a light-receiving surface. Alternatively, the first surface m1 is a light-receiving surface, and the second surface m2 is a backlight surface. It can be understood that the terms "light-receiving surface" and "backlight surface" are relative, and the light-receiving surface specifically refers to the surface of the solar cell 100 that is primarily irradiated by sunlight. The light-receiving surface typically has a surface structure that can increase the light absorption area, improve the photocurrent, and help improve the efficiency of the battery.

[0068] The passivation layer 120 is disposed on the first surface m1 and / or the second surface m2. That is, the passivation layer 120 may be disposed on the first surface m1; the passivation layer 120 may be disposed on the second surface m2; or the passivation layer 120 may be disposed on both the first surface m1 and the second surface m2.

[0069] For example, refer to Figure 1 The passivation layer 120 is disposed on the first surface m1 and the second surface m2. The passivation layer 120 disposed on the first surface m1 is defined as the first passivation layer 121, and the passivation layer 120 located on the first surface side of the battery substrate 110 is defined as the second passivation layer 122.

[0070] For example, the passivation layer 120 can be deposited using plasma-enhanced chemical vapor deposition (PECVD). Other methods, such as organic chemical vapor deposition, can also be used to form the passivation layer 120. The passivation layer 120 can be a single-layer structure, a multilayer structure, or a combination of single-layer and multilayer structures, and the thickness of each layer can be designed accordingly, without limitation. Specifically, the passivation layer 120 can be any one or a combination of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide. Of course, other types of passivation layers can also be used for the passivation layer 120, without specific limitations.

[0071] The passivation layer 120 can effectively passivate the surface of the battery substrate 110, reduce the interface state density, reduce the recombination of minority carriers, thereby improving the carrier transport efficiency at the interface and improving the efficiency of the solar cell 100.

[0072] Multiple first grid lines 130 are disposed on the first surface m1 and / or the second surface m2. That is, multiple first grid lines 130 can be disposed on the first surface m1; multiple first grid lines 130 can be disposed on the second surface m2; or multiple first grid lines 130 can be disposed on both the first surface m1 and the second surface m2. Figure 1 In the illustrated embodiment, multiple first grid lines 130 are provided on both the first surface m1 and the second surface m2.

[0073] For example, when both a main gate line and a fine gate line are present, either the main gate line or the fine gate line can be the first gate line 130. When no main gate line is present, the fine gate line is the first gate line 130. Among multiple gate lines,

[0074] Combined with reference Figure 2 The first gate line 130 includes a seed section 131, a transmission layer 132, and a cover layer 133.

[0075] Seed portion 131 can be understood as a conductive transition layer deposited or printed on the first surface m1 and / or the second surface m2 of the battery substrate 110, used to achieve electrical connection. In the embodiments of this application, seed portion 131 is a structure used to achieve electrical connection between the first grid line 130 and the battery substrate 110, while improving the adhesion of the first grid line 130.

[0076] For example, the seed portion 131 is formed by a high-temperature paste, which includes at least one of silver paste and silver-nickel paste and a glass body. The glass body in the high-temperature paste penetrates the passivation layer 120 and contacts the battery substrate 110. The metal portion in the high-temperature paste contacts the glass body, the passivation layer 120, or the battery substrate 110.

[0077] The transport layer 132 and the cover layer 133 are both disposed on the side of the seed portion 131 away from the battery substrate 110 and the passivation layer 120 away from the battery substrate 110. That is, the structure formed by the transport layer 132 and the cover layer 133 is disposed on the side of the seed portion 131 away from the battery substrate 110 and the side of the passivation layer 120 away from the battery substrate 110.

[0078] For example, the transport layer 132 may be disposed on the side of the seed portion 131 away from the battery substrate 110, the cover layer 133 may be disposed on the side of the seed portion 131 away from the battery substrate 110, and the passivation layer 120 may be disposed on the side of the passivation layer 120 away from the battery substrate 110; alternatively, the transport layer 132 may be disposed on the side of the seed portion 131 away from the battery substrate 110, the passivation layer 120 may be disposed on the side of the passivation layer 120 away from the battery substrate 110, the cover layer 133 may be disposed on the side of the seed portion 131 away from the battery substrate 110, and the passivation layer 120 may be disposed on the side of the passivation layer 120 away from the battery substrate 110. No specific limitation is made here.

[0079] The transmission layer 132 is the main conductive structure in the first gate line 130, responsible for the long-distance conduction of photocurrent. The capping layer 133 is used to improve the mechanical stability, resistance to damp heat corrosion, and adhesion of the first gate line 130.

[0080] For example, the seed section 131 is made of a first conductive material, and the transport layer 132 is made of a second conductive material. The first conductive material and the second conductive material may be the same or different, and no specific limitation is made here.

[0081] For example, the capping layer 133 can serve as a matrix, constituting the framework structure of the transport layer 132. For instance, the capping layer 133 can be a cross-linked matrix formed by cross-linking curing, and the transport layer 132 can be composed of conductive structures within the cross-linked matrix. The conductive structure being within the cross-linked matrix can be understood as a portion of the conductive structure being within the cross-linked matrix, while another portion is outside the cross-linked matrix.

[0082] For example, after forming the transmission layer 132, a cover layer 133 can be provided to improve the adhesion performance of the first gate line 130.

[0083] The seed section 131 and the battery substrate 110 are electrically connected, and the transport layer 132 and the seed section 131 are electrically connected. The battery substrate 110, the seed section 131 and the transport layer 132 form a channel for carrier flow.

[0084] For example, the seed section 131 and the battery substrate 110 are physically contacted to form an electrical connection, enabling current collection and conduction. Since the seed section 131 is made of a first conductive material and the transport layer 132 is made of a second conductive material, the seed section 131 and the battery substrate 110 form a physical channel for carrier flow through physical contact, and the seed section 131 and the conductive particles 1301 also form a physical channel for carrier flow through physical contact. When the solar cell 100 is not in a power generation or power supply state, the carriers are not effectively separated and driven to flow, and the carriers do not flow through this physical channel. When the solar cell 100 is in a power generation or power supply state, the battery substrate 110 generates carriers, which are separated under the influence of its built-in electric field, and the carriers flow through this physical channel.

[0085] Combined with reference Figure 3 , Figure 3 This is a partial structural diagram from another view showing the interaction between the first grid line 130 and the battery substrate 110 in some embodiments of this application. The width of the cover layer 133 is greater than the width of the seed portion 131.

[0086] The first grid line 130 is a component with length and width. The length direction of the first grid line 130 refers to the direction in which a single first grid line 130 extends from beginning to end, that is, the direction along which the first grid line 130 is elongated. The width direction of the first grid line 130 can be roughly considered as the transverse direction perpendicular to its own length, that is, the direction in which two adjacent first grid lines 130 of the same type are arranged and separated from each other. Two first grid lines 130 of the same type mean that both first grid lines 130 are fine grids, or both first grid lines 130 are main grids.

[0087] For example, in Figures 1 to 3 In the illustrated embodiment, the width direction of the first gate line 130 is the second direction F2, the length direction of the first gate line 130 is the third direction F3, and the thickness direction of the first gate line 130 is the first direction F1. The width of the cover layer 133 is d, and the dimension of the cover layer 133 along the width direction of the first gate line 130 can be regarded as the width d of the cover layer 133. The width of the seed portion 131 is s1, and the dimension of the seed portion 131 along the width direction of the first gate line 130 can be regarded as the width s1 of the seed portion 131. That is, the width d is greater than the width s1.

[0088] Combined with reference Figure 4 , Figure 4 This is a top-view SEM diagram of a portion of the structure of the solar cell 100 in some embodiments of this application. From... Figure 4 As can be seen, due to the presence of a larger overlay layer 133, the area with the first gate line 130 exhibits a contrast difference compared to other areas.

[0089] By setting the first grid line 130, which includes a seed portion 131, a transport layer 132, and a cover layer 133, and making the width of the cover layer 133 greater than the width of the seed portion 131, the contact area between the first grid line 130 and the battery substrate 110 and the passivation layer 120 can be increased through the cover layer 133, thereby improving the adhesion of the first grid line 130. This not only improves the electrical performance of the solar cell 100, but also enhances the reliability and lifespan of the solar cell 100.

[0090] It should be noted that by using the first grid line 130 provided in this application embodiment, the adhesion of the first grid line 130 is improved by the cover layer 133, which not only reduces the amount of conductive paste used, thus helping to balance manufacturing costs, but also helps to ensure that the seed part 131 and the battery substrate 110 and passivation layer 120 have a certain contact area, thereby improving the efficiency of collecting photogenerated carriers.

[0091] Please continue to refer to Figures 1 to 3 According to some embodiments of this application, the first gate line 130 is divided into a first region z1 and a second region z2, and the second region z2 is disposed on both sides of the first region z1 along the width direction of the first gate line 130. The transmission layer 132 is in the first region z1, the seed part 131 is at least in the first region z1, and the cover layer 133 is in the first region z1 and the second region z2.

[0092] The first region z1 can be considered as the middle part of the first grid line 130, and the second region z2 can be considered as the edge part of the first grid line 130. The widths of the two second regions z2 can be the same or different. It should be noted that when the widths of the two second regions z2 are the same, due to factors such as actual manufacturing, measurement, and materials, if the widths of the two second regions z2 measured are different, it is considered a deviation within the allowable range or an unavoidable deviation.

[0093] It should be noted that the first region z1 and the second region z2 mentioned above are artificially divided into regions of the first gate line 130 for the purpose of describing the technical solution of the embodiments of this application. This division does not mean that the first region z1 and the second region z2 are physically separated or independent. Furthermore, there is not necessarily a clear boundary between the above regions.

[0094] The transmission layer 132 is located in the first region z1. That is, the transmission layer 132 constitutes a portion of the first region z1. Exemplarily, the transmission layer 132 and the first region z1 overlap in the thickness direction of the battery substrate 110. That is, from the perspective of the thickness direction of the battery substrate 110, the transmission layer 132 and the first region z1 overlap.

[0095] Since the transmission layer 132 is within the first region z1, that is, within the first region z1. For example, if the transmission layer 132 and the first region z1 completely overlap in the thickness direction of the battery substrate 110, then from the perspective of the thickness direction of the battery substrate 110, the transmission layer 132 can be used to divide the first region z1 and the second region z2. Alternatively, if the transmission layer 132 and the first region z1 do not completely overlap in the thickness direction of the battery substrate 110, then from the perspective of the thickness direction of the battery substrate 110, the transmission layer 132 is within the first region z1.

[0096] The seed portion 131 is at least in the first region z1. That is, the seed portion 131 may be in the first region z1, constituting a part of the first region z1; or the seed portion 131 may be in the first region z1 and the second region z2, constituting a part of the first region z1 and the second region z2. For example, with... Figure 3 For example, seed section 131 is in the first region z1 and the second region z2.

[0097] The cover layer 133 is in the first region z1 and the second region z2. That is, the cover layer 133 constitutes a part of the first region z1 and a part of the second region z2.

[0098] For example, from the perspective of the thickness direction of the battery substrate 110, the transmission layer 132 may cover a portion of the seed portion 131 of the first region z1 or it may cover the entire seed portion 131 of the first region z1, without any specific limitation.

[0099] For example, from the perspective of the thickness direction of the battery substrate 110, the cover layer 133 may cover at least a portion of the seed portion 131 in the first region z1 and at least a portion of the seed portion 131 in the second region z2, without specific limitation.

[0100] For example, with Figure 3 For example, from the perspective of the thickness direction of the battery substrate 110, the seed portion 131 in the first region z1 and the seed portion 131 in the second region z2 are both covered.

[0101] It should be noted that, in Figure 3 In the illustrated embodiment, the position of the seed section 131 is indicated by a dashed line to facilitate understanding of the relationship between the seed section 131, the transmission layer 132, and the cover layer 133.

[0102] By providing a cover layer 133 in the first region z1 and the second region z2, a cover layer 133 is provided on both sides of the seed part 131 along the width direction of the first gate line 130, and the width of the cover layer 133 is greater than the width of the seed part 131. That is, the cover layer 133 not only covers the seed part 131, but also adheres to and wraps around both sides of the seed part 131. In this way, on the one hand, it is beneficial to increase the bonding area between the seed part 131 and the cover layer 133, further improving the adhesion of the first gate line 130; on the other hand, it can seal the side gaps as much as possible, preventing water vapor, oxygen, etc. from invading the interior of the first gate line 130 from the side, inhibiting the oxidation of the internal transport layer 132, and improving the stability of the resistivity of the first gate line 130. In addition, the process window for manufacturing the seed part 131, the transport layer 132, and the cover layer 133 can be expanded.

[0103] Please continue to refer to Figure 2 and Figure 3 According to some embodiments of this application, the width of the first region z1 is smaller than the width of the second region z2. According to other embodiments of this application, the thickness of the first region z1 is greater than the thickness of the second region z2.

[0104] The width of the first region z1 is greater than the width of any second region z2, and the thickness of the first region z1 is greater than the thickness of any second region z2. The widths of the two second regions z2 can be the same or different. The thicknesses of the two second regions z2 can be the same or different.

[0105] by Figure 2 and Figure 3 For example, the width of the first region z1 is s2, and the dimension of the first region z1 along the width direction of the first grid line 130 can be regarded as the width s2 of the first region z1. The width of the second region z2 is s3, and the dimension of the second region z2 along the width direction of the first grid line 130 can be regarded as the width s3 of the second region z2. The thickness of the first region z1 is h1, and the dimension of the first region z1 along the thickness direction of the battery substrate 110 can be regarded as the thickness h1 of the first region z1. The thickness of the second region z2 is h2, and the dimension of the second region z2 along the thickness direction of the battery substrate 110 can be regarded as the thickness h2 of the second region z2.

[0106] For example, along the width direction of the first grid line 130, from the middle of the first grid line 130 to the edge of the first grid line 130, the thickness h1 of the first region z1 decreases, and the thickness h2 of the second region z2 decreases. That is, the size of the first grid line 130 along the thickness direction of the battery substrate 110 is larger in the middle and smaller towards the edge.

[0107] Since the width s2 of the first region z1 is smaller than the width s3 of the second region z2, the covering layer 133 of the second region z2 can be set in a relatively larger amount. This not only helps to more completely cover the side of the seed part 131, reducing the risk of water vapor and oxygen intruding into the interior of the first grid line 130, and further improving the reliability and stability of the first grid line 130, but also further reduces the risk of the first grid line 130 warping, delamination and falling off under stress.

[0108] Because the thickness h1 of the first region z1 is greater than the thickness h2 of the second region z2, the first gate line 130 exhibits a cross-sectional shape with a convex center and low sides. The higher first region z1 can increase the cross-sectional area of ​​the main current transmission channel, reduce the series resistance of the first gate line 130, and reduce power loss during photocurrent conduction. Furthermore, combined with the lower second region z2, it can disperse the internal stress caused by the difference in thermal expansion coefficients of different materials, reducing the risk of cracks and wire breakage caused by stress concentration.

[0109] By combining the fact that "the width s2 of the first region z1 is smaller than the width s3 of the second region z2" and "the thickness h1 of the first region z1 is greater than the thickness h2 of the second region z2," not only can the risk of cracking and interlayer delamination of the first grid line 130 be further reduced, but the second region z2 can also be used to extend the lateral penetration distance of water vapor, inhibiting the intrusion of water vapor and oxygen into the interior of the first grid line 130. Simultaneously, the first region z1 can be used to reduce current transmission losses while minimizing the overall shading area. Therefore, the conversion efficiency and long-term reliability of the solar cell 100 can be improved.

[0110] In some other embodiments, the width s2 of the first region z1 may be greater than the width s3 of the second region z2, which is not specifically limited here.

[0111] Please continue to refer to Figure 2 and Figure 3 According to some embodiments of this application, the width s2 of the first region z1 is 5 μm to 100 μm, and the width s3 of the second region z2 is 10 μm to 495 μm. According to other embodiments of this application, the thickness h1 of the first region z1 is 0.001 μm to 50 μm, and the thickness h2 of the second region z2 is 0.0001 μm to 30 μm.

[0112] For example, the width s2 of the first region z1 can be 5μm, 15μm, 30μm, 40μm, 50μm, 60μm, 70μm, 85μm, 95μm, or 100μm. The width s2 of the first region z1 can be any other value within the range of 5μm to 100μm, and no specific limitation is made here.

[0113] For example, the width s3 of the second region z2 can be 10μm, 50μm, 100μm, 250μm, 400μm, or 495μm. The width s3 of the second region z2 can be any other value within the range of 10μm to 495μm, and no specific limitation is made here.

[0114] For example, the thickness h1 of the first region z1 is 0.001 μm, 0.002 μm, 0.02 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, or 50 μm. The thickness h1 of the first region z1 can be any other value in the range of 0.001 μm to 50 μm, and no specific limitation is made here.

[0115] For example, the thickness h2 of the second region z2 is 0.0001 μm, 0.001 μm, 0.01 μm, 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 10 μm, 20 μm, or 30 μm. The thickness h2 of the second region z2 can be any other value in the range of 0.0001 μm to 30 μm, and no specific limitation is made here.

[0116] By controlling the width s2 of the first region z1, it is not only beneficial to make the current distribution more uniform and reduce the risk of local hot spots, but also to reserve space to form the second region z2.

[0117] By controlling the width s3 of the second region z2, it is not only beneficial to have a more sufficient lateral water vapor penetration distance, reducing the probability of inward erosion, but also to facilitate the manufacturing process and make it easier to cover the side of the seed part 131. Furthermore, the second region z2 can also be used to reduce the risk of side cracks in the first grid line 130 caused by thermal stress and mechanical stress, as well as the risk of the first grid line 130 falling off.

[0118] By controlling the thickness h1 of the first region z1, it is not only beneficial to have a certain conductive cross-sectional area and reduce the loss of photocurrent, but also to give the overall structure of the first grid line 130 a certain rigidity, strength and toughness, further reducing the risk of cracking and collapse under lamination and temperature alternation environments. Furthermore, it also makes the slurry consumption more controllable, balancing power generation efficiency and metallization cost.

[0119] By controlling the thickness h2 of the second region z2, it is not only beneficial to reduce the risk of water vapor penetration, but also to improve the adhesion of the first grid line 130, and also to facilitate manufacturing and improve manufacturing stability.

[0120] By controlling the width s2 and thickness h1 of the first region z1, and the width s3 and thickness h2 of the second region z2, the dimensions work together to not only reduce the risk of stress concentration, but also improve the resistance to damp heat and oxidation of the first grid line 130, and also help to balance battery power generation efficiency and manufacturing cost.

[0121] Please continue to refer to Figure 3 According to some embodiments of this application, the width s1 of the seed portion 131, the width s2 of the first region z1, and the width s3 of the second region z2 satisfy a first condition. The first condition includes: 2s3 > s1 - s2, 2 ≤ s1 / s2 ≤ 20; and / or, 10 μm ≤ s3 ≤ 495 μm.

[0122] For example, s1 / s2 can be 2, 3, 4, 6, 7, 9, 10, 12, 14, 16, 18 or 20, and s1 / s2 can also be any other value in the range of 2 to 20, without any specific restrictions.

[0123] For example, the width s3 can be 10μm, 20μm, 30μm, 50μm, 80μm, 100μm, 15μm, 200μm, 230μm, 250μm, 280μm, 300μm, 350μm, 400μm, or 495μm. The width s3 can be any other value within the range of 10μm to 495μm, and no specific limitation is made here.

[0124] By controlling 2s3 > s1 - s2 and 2 ≤ s1 / s2 ≤ 20, the size of the cover layer 133 in the second region z2 can be controlled to exceed the size of the seed portion 131 and the size of the transport layer 132 in the first region z1 relative to the seed portion 131 in the width direction of the first grid line 130. On the one hand, this allows the transport layer 132 in the first region z1 to make full contact with the seed portion 131, effectively reducing the interlayer contact resistance and improving the efficiency of current conduction. On the other hand, it also helps the cover layer 133 in the second region z2 to more completely cover both sides of the seed portion 131, enhancing the overall adhesion of the first grid line 130, reducing the internal stress caused by temperature alternation, and thus reducing the risk of delamination and warping of the first grid line 130. At the same time, by controlling the width s3 of the second region z2, the lateral water vapor penetration path can be extended, improving the stability and reliability of the first grid line 130. In addition, it is also beneficial to control the overall light-shielding area and the use of precious metal materials, and to facilitate manufacturing, thereby balancing the electrical performance and manufacturing cost of the battery.

[0125] By controlling the width s3 of the second region z2, as mentioned above, it is not only beneficial to have a more sufficient lateral water vapor penetration distance, reducing the probability of inward erosion, but also to facilitate the fabrication and make it easier to cover the side of the seed part 131. Furthermore, the second region z2 can also be used to reduce the risk of side cracks in the first grid line 130 caused by thermal stress and mechanical stress, as well as the risk of the first grid line 130 falling off.

[0126] By controlling "2s3>s1-s2", "2≤s1 / s2≤20", and "10μm≤s3≤495μm", these three factors work together to achieve the advantages mentioned above. On the one hand, this reduces the risk of the first grid line 130 detaching and cracking due to alternating temperature and stress, and also creates a more effective water and oxygen barrier structure. On the other hand, it not only facilitates manufacturing and results in a more stable morphology, but also, due to the mutual matching of the dimensions of the transmission layer 132 in the first region z1 and the cover layer 133 in the second region z2 relative to the seed portion 131, forms the main conductive and protective areas, thereby reducing the consumption of precious metal materials while optimizing current transmission and reducing light-shielding losses.

[0127] According to other embodiments of this application, the width s1 of the seed portion 131, the width s2 of the first region z1, and the width s3 of the second region z2 satisfy a second condition. The second condition includes: 0.01 ≤ s1 / s2 ≤ 2; and / or, 10 μm ≤ s3 ≤ 495 μm.

[0128] For example, s1 / s2 can be 0.01, 0.05, 0.1, 0.3, 0.5, 0.6, 0.75, 0.9, 1, 1.5, 1.8 or 2, and s1 / s2 can also be any other value in the range of 0.01 to 2, without any specific restrictions.

[0129] For example, the width s3 can be 10μm, 20μm, 30μm, 50μm, 80μm, 100μm, 15μm, 200μm, 230μm, 250μm, 280μm, 300μm, 350μm, 400μm, or 495μm. The width s3 can be any other value within the range of 10μm to 495μm, and no specific limitation is made here.

[0130] By controlling 0.01≤s1 / s2≤2, it is not only easier to manufacture, but also beneficial to improve the contact effect between the transmission layer 132 and the seed part 131 in the first region z1, thereby improving the efficiency of current conduction.

[0131] By controlling the width s3 of the second region z2, as mentioned above, it is not only beneficial to have a more sufficient lateral water vapor penetration distance, reducing the probability of inward erosion, but also to facilitate the fabrication and make it easier to cover the side of the seed part 131. Furthermore, the second region z2 can also be used to reduce the risk of side cracks in the first grid line 130 caused by thermal stress and mechanical stress, as well as the risk of the first grid line 130 falling off.

[0132] By controlling “0.01≤s1 / s2≤2” and “10μm≤s3≤495μm”, the aforementioned advantages can be achieved.

[0133] Please continue to refer to Figure 3According to some embodiments of this application, the first gate line 130 has a center line L, the extension direction of the center line L being parallel to the extension direction of the first gate line 130. Along the width direction of the first gate line 130, the second region z2 has two oppositely disposed first sides b1, the seed portion 131 has two oppositely disposed second sides b2, and the first region z1 has two oppositely disposed third sides b3. Along the width direction of the first gate line 130, the distance between the first side b1 farther from the center line L and the center line L is w1, the distance between the second side b2 and the center line L is w2, and the distance between the third side b3 and the center line L is w3. Wherein, w1 > w2, w2 / w3 > 2; and / or, 10μm ≤ w1 - w3 ≤ 495μm.

[0134] Combined with reference Figure 3 The center line L of the first gate line 130 is a virtual line; it is not a physical structure and does not consist of any actual material. The direction of this virtual center line L is parallel to the overall extension direction of the first gate line 130. In this embodiment, the center line L is located at the midpoint of the width direction of the first gate line 130 and can serve as a reference line to define dimensions at various points. It is understood that the center line L does not impose any limitations or constraints on the shape, size arrangement, or molding structure of the first gate line 130.

[0135] Using the center line L of the first grid line 130 as a reference, controlling the distances w1, w2 and w3 not only has the advantages of controlling the widths s1, s2 and s3 mentioned above, but also facilitates structural design and dimensional inspection.

[0136] Please continue to refer to Figure 2 and Figure 3 According to some embodiments of this application, the first gate line 130 includes a plurality of conductive particles 1301, which are located in the capping layer 133. At least a portion of the conductive particles 1301 form the transport layer 132.

[0137] Conductive particle 1301 is a structure with conductive properties.

[0138] For example, the material of the conductive particles 1301 includes at least one of metals, conductive metal oxides, and carbon-based materials, without specific limitations. For instance, the material of the conductive particles 1301 includes at least one of silver, copper, gold, nickel, aluminum, and their alloys. As another example, the material of the conductive particles 1301 includes one or more of silver-coated copper, silver-coated nickel, and graphene-coated copper.

[0139] For example, the shape of the conductive particle 1301 includes at least one of spherical, quasi-spherical, sheet-like, ellipsoidal, rod-like, and polyhedral (such as tetrahedron or dodecahedron). In some other embodiments, the shape of the conductive particle 1301 may also be irregular, and no specific limitation is made here.

[0140] For example, the particle size of the conductive particles 1301 can be from 0.05 μm to 10 μm, and no specific limitation is made here.

[0141] It should be noted that after the conductive particles 1301 form the transport layer 132, the conductive particles 1301 forming the transport layer 132 may stick together or fuse, which may cause changes in the particle size and shape of the conductive particles 1301.

[0142] For example, the capping layer 133 may be a cross-linked matrix formed by cross-linking curing, in which a plurality of conductive particles 1301 are contained. The cross-linked matrix is ​​used to form a skeleton structure to fix the conductive particles 1301 and improve the mechanical stability and resistance to damp heat corrosion of the first gate line 130.

[0143] Conductive particles 1301 are present in the capping layer 133, with at least a portion of the conductive particles 1301 overlapping to form a continuous conductive path, forming a transport layer 132. The presence of conductive particles 1301 in the capping layer 133 can be understood as some conductive particles 1301 being within the capping layer 133, and a portion of other conductive particles 1301 being within the capping layer 133, while another portion is outside the capping layer 133. The presence of multiple conductive particles 1301 in the capping layer 133 can also be understood as some conductive particles 1301 being within the capping layer 133, and a portion of other conductive particles 1301 being within the capping layer 133, while another portion is outside the capping layer 133.

[0144] Thus, forming the transport layer 132 through conductive particles 1301 not only helps to reduce interface contact loss and improve carrier transport capability, but also facilitates fabrication.

[0145] Please continue to refer to Figure 2 and Figure 3 According to some embodiments of this application, the distribution density of conductive particles 1301 in the first region z1 is greater than the distribution density of conductive particles 1301 in the second region z2.

[0146] At least a portion of the conductive particles 1301 in the first region z1 form a transport layer 132.

[0147] The distribution density of conductive particles 1301 is used to characterize the density of their distribution. A lower distribution density indicates a sparser distribution, and vice versa. The distribution density of conductive particles 1301 in the first region z1 is greater than that in the second region z2; that is, the distribution of conductive particles 1301 in the first region z1 is denser than that in the second region z2.

[0148] For example, taking the surface of the passivation layer 120 away from the battery substrate 110 as the reference plane, the first region z1 can be equivalently regarded as the area covered by the first region z1 on the reference plane, and the second region z2 can be equivalently regarded as the area covered by the second region z2 on the reference plane. The distribution density of conductive particles 1301 refers to the number of conductive particles 1301 per unit area within the planar coverage area of ​​the first grid line 130, without distinguishing the high or low position of the conductive particles 1301 in the thickness direction of the battery substrate 110. All conductive particles 1301 above and below the same planar position are uniformly included in the density statistics of that planar position.

[0149] The unit area region refers to the reference surface covered by the first gate line 130. It is related to the area of ​​the reference surface covered by the first gate line 130. The unit area region is a region selected from the reference surface covered by the transmission layer 132. The size and shape of the selected unit area region depend on different unit area size definitions. After the unit area size is defined, the size of the unit area region has a relative size and shape relative to the reference surface covered by the first gate line 130. For example, the size of the unit area region could be 100 μm. 2 (square micrometers), or 200 μm 2 The size of a unit area region, such as (square micrometers), can be determined based on the size of the selected surface and usage requirements; this application embodiment does not impose specific limitations on this. Similarly, the division of the unit area region can be customized according to the usage situation. For example, the reference surface covered by the first grid line 130 can be divided into N×M square regions of equal area, each region being a unit area region, where N and M are positive integers, and the selection of N and M is determined by the area size of the reference surface covered by the first grid line 130. Of course, the shape of each unit area region is not limited to a square. It is understood that each unit area region has the same shape and the same size.

[0150] In some embodiments, the shape of the unit area region can also be a rectangle or other shapes. The unit area region divided on the reference plane covered by the first grid line 130 may include an incomplete unit area region. For example, after dividing the unit area region according to the usage requirements, the remaining area is insufficient to divide a complete unit area region. The remaining area can be converted according to the actual situation.

[0151] The distribution density of conductive particles 1301 within a unit area of ​​the reference surface covered by the first gate line 130 is the ratio of the area occupied by conductive particles 1301 within that unit area to the area of ​​that unit area. The distribution density within a unit area characterizes the density of the conductive particles 1301. For example, the distribution density within a unit area refers to the proportion of area occupied by conductive particles 1301 within that unit area. The lower the distribution density of conductive particles 1301 within a unit area, the sparser the distribution of conductive particles 1301; conversely, the higher the density, the denser the distribution.

[0152] By configuring the distribution density of conductive particles 1301 in the first region z1 to be greater than that in the second region z2, on the one hand, the current flowing through the first grid line 130 is mainly conducted along the length direction through the first region z1. The denser distribution of conductive particles 1301 in the first region z1 is conducive to forming a continuous and lower-resistance conductive structure, thereby reducing the series resistance of the first grid line 130 and improving the photoelectric conversion efficiency of the battery. On the other hand, the sparser distribution of conductive particles 1301 in the second region z2, that is, the increased proportion of the capping layer 133, not only enhances the wrapping effect of the capping layer 133 on the side of the seed part 131, further improving the adhesion of the first grid line 130 and reducing the risk of cracking and peeling caused by stress such as temperature cycling, but also, with the denser capping layer 133 in the second region z2, prevents water vapor and oxygen from seeping into the interior of the first grid line 130 from the side, thereby improving the conductivity stability of the first grid line 130. In addition, the lower distribution density of conductive particles 1301 in the second region z2 is also beneficial to reduce the filling of precious metal conductive powder, further reducing the use of conductive materials while meeting the conductivity requirements, and further reducing the manufacturing cost of solar cell 100.

[0153] It should be noted that, in Figure 3 In the illustrated embodiment, since the distribution density of conductive particles 1301 in the first region z1 is greater than that in the second region z2, the boundary between the first region z1 and the second region z2 can be roughly determined by the boundary formed by the distribution of conductive particles 1301. In some other embodiments, the distribution of conductive particles 1301 may not form a boundary between the first region z1 and the second region z2. No specific limitations are imposed here.

[0154] It should also be noted that, in the embodiments of this application, the distribution density of conductive particles 1301 can be detected by any method known to those skilled in the art, and those skilled in the art can choose according to their needs. Those skilled in the art will understand that the distribution density of conductive particles 1301 can be the distribution density detection data of any unit area region on the reference surface covered by the first grid line 130, or it can be the average of the distribution density detection data of multiple unit area regions. Those skilled in the art can select any of the above-mentioned regions for detection based on the detection conditions and the instruments used, or they can detect multiple regions and calculate the average of the distribution densities of multiple regions as the distribution density of conductive particles 1301.

[0155] For example, in practice, a sample of the solar cell 100 can be prepared by selecting the portion including the first grid line 130 and creating a corresponding SEM image. For instance, taking the first surface m1 of the cell substrate 110 as an example where the first grid line 130 is located, a sample of the solar cell 100 containing the first grid line 130 is obtained. The first grid line 130 on the first surface m1 of the cell substrate 110 is photographed from above using an optical microscope or a scanning electron microscope to obtain a planar top-view image. On the planar top-view image, using the surface of the passivation layer 120 on the same side of the cell substrate 110 as the reference plane, which is away from the cell substrate 110, several square observation areas with a side length of 50 μm are delineated within the regions of the first region z1 and the second region z2 where the first grid line 130 is located. The area of ​​a single observation area is 2500 μm. 2 The area ratio of conductive particles 1301 within each square observation region was calculated using image analysis software. Comparison of the data showed that the distribution density of conductive particles 1301 in the first region z1 was greater than that in the second region z2.

[0156] In some detection methods, measuring the distribution density of the aforementioned conductive particles 1301 does not require individual testing of the first region z1 and the second region z2 where the transmission layer 132 is located; sampling testing is sufficient. It is understood that the design and layout of the regions on the aforementioned reference surface are regular. Those skilled in the art can reasonably infer and determine the distribution density of conductive particles 1301 in other regions based on the distribution density corresponding to the measured sample.

[0157] Please continue to refer to Figure 3 According to some embodiments of this application, the width d of the cover layer 133 is 20 μm to 1000 μm, and the width s1 of the seed portion 131 is 5 μm to 200 μm. According to other embodiments of this application, the ratio of the width d of the cover layer 133 to the width s1 of the seed portion 131 is 2 to 200.

[0158] For example, the width d of the cover layer 133 can be 20μm, 50μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, or 1000μm. The width d of the cover layer 133 can be any other value in the range of 20μm to 1000μm, and no specific limitation is made here.

[0159] For example, the width s1 of the seed portion 131 can be 5μm, 20μm, 50μm, 85μm, 90μm, 100μm, 120μm, 150μm, 180μm or 200μm. The width s1 of the seed portion 131 can be any other value in the range of 5μm to 200μm, and no specific limitation is made here.

[0160] For example, the ratio of the width d of the cover layer 133 to the width s1 of the seed portion 131 can be 2, 10, 30, 60, 70, 90, 110, 120, 140, 160, 180, 190, or 200. The ratio of the width d of the cover layer 133 to the width s1 of the seed portion 131 can be any other value in the range of 2 to 200, and no specific limitation is made here.

[0161] By controlling the width d of the cover layer 133, it is not only beneficial to improve the adhesion of the first grid line 130, but also to take into account the material cost.

[0162] By controlling the width s1 of the seed section 131, not only can the seed section 131 have a certain contact area to receive the photogenerated current, reducing the contact resistance between the seed section 131 and the battery substrate 110 and the transmission layer 132, but it can also reduce the risk of hot spots caused by excessive local current density while reducing material consumption.

[0163] By controlling the ratio of the width d of the cover layer 133 to the width s1 of the seed section 131, the coverage margin on both sides can always be maintained within a certain range, regardless of whether the size of the first gate line 130 is enlarged or reduced as required, thus taking into account the aforementioned advantages.

[0164] By controlling the width d of the cover layer 133, the width s1 of the seed part 131, and the ratio of the width d of the cover layer 133 to the width s1 of the seed part 131, in addition to having the advantages mentioned above, a dual constraint of numerical range and ratio range can be formed, thereby further reducing the dimensional fluctuations caused by the preparation process, which is conducive to taking into account interface conductivity, side water protection, stress release, and manufacturing cost.

[0165] It should be noted that the width d, width s1, width s2, width s3, distance w1, distance w2, distance w3, thickness h1, and thickness h2 mentioned above can be detected by any method known to those skilled in the art, and those skilled in the art can choose based on their needs.

[0166] For example, in practice, a sample of the solar cell 100 can be prepared, selecting the portion including the first grid line 130 and creating a corresponding SEM image. For instance, taking the first surface m1 of the cell substrate 110 as an example where the first grid line 130 is located, a sample of the solar cell 100 including the first grid line 130 is obtained. A planar top-view image is obtained by taking a top-view photograph of the first surface m1 of the cell substrate 110 using an optical microscope or a scanning electron microscope. On the planar top-view image, the width d, width s1, width s2, width s3, distance w1, distance w2, and distance w3 are calculated using image analysis software.

[0167] For example, in practice, a cross-section of the solar cell 100 can be prepared, selecting the portion including the first grid line 130 and creating a corresponding SEM image. The cross-sectional sample of the solar cell 100 is photographed using an optical microscope or scanning electron microscope to obtain a planar cross-sectional image. Thickness h1 and thickness h2 are calculated on the planar cross-sectional image using image analysis software.

[0168] In some detection methods, the measurement of the aforementioned widths d, s1, s2, s3, distances w1, w2, w3, thickness h1, and thickness h2 does not require individual testing of the first grid line 130; sampling testing is sufficient. It is understood that the design and layout of the first grid line 130 follow a regular pattern. Those skilled in the art can reasonably infer and determine the widths s1 of other first grid lines 130 based on the widths s1 of the first grid line 130 corresponding to the measured sample.

[0169] Please continue to refer to Figure 1 According to some embodiments of this application, the surface with the first grid line 130 in the first surface m1 and the second surface m2 is defined as the grid line surface, and at least one grid line surface is provided with a plurality of pyramid-shaped structures 1101.

[0170] The grid line surface refers to the surface between the first surface m1 and the second surface m2 where the first grid line 130 is arranged. The term "grid line surface" is only used for orientation and area definition, and is only used to distinguish between two surfaces with or without the first grid line 130. It is not a restriction on the shape, structure, or arrangement of the first grid line 130 of the battery.

[0171] For example, with Figure 1For example, the case where both the first surface m1 and the second surface m2 are grid lines is illustrated, and multiple pyramid-shaped structures 1101 are provided on one of the grid lines (i.e. the first surface m1).

[0172] On the one hand, the undulating texture formed by the pyramid-shaped structure 1101 can increase the adhesion contact surface of the cover layer 133 during the spreading process, improving the contact performance of the first grid line 130. On the other hand, since there are tiny grooves between two adjacent pyramid-shaped structures 1101, the slurry forming the first grid line 130 is constrained by capillary tension, and the flow spreading range is effectively restricted, which can limit the excessive outward spread and overflow of the cover layer 133, thereby helping to control the width d of the cover layer 133. Furthermore, by setting the pyramid-shaped structure 1101, it is also beneficial to improve the light utilization rate.

[0173] Please continue to refer to Figure 1 According to some embodiments of this application, at least one gate line surface is divided into a third region z3 and a fourth region z4, which are alternately arranged along the width direction of the first gate line 130, and the first gate line 130 is at least disposed on the third region z3. The plurality of pyramid-shaped structures 1101 include a plurality of first pyramid-shaped structures 11011 disposed on the third region z3, and a plurality of second pyramid-shaped structures 11012 disposed on the fourth region z4.

[0174] According to some embodiments of this application, the height of the first pyramid-shaped structure 11011 is less than the height of the second pyramid-shaped structure 11012. According to other embodiments of this application, the distance between the apex of two adjacent first pyramid-shaped structures 11011 is less than the distance between the apex of two adjacent second pyramid-shaped structures 11012.

[0175] It should be noted that the aforementioned third region z3 and fourth region z4 are artificially divided into regions of the transport layer 132 for the purpose of describing the technical solution of the embodiments of this application. This division does not mean that the third region z3 and the fourth region z4 are physically separated or independent. Furthermore, there are not necessarily obvious boundaries between the aforementioned regions.

[0176] The first gate line 130 is at least disposed on the third region z3. According to some embodiments of this application, the first gate line 130 is disposed on the third region z3. According to other embodiments of this application, a portion of the first gate line 130 is disposed on the third region z3, and another portion is disposed on the fourth region z4. Exemplarily, Figure 1 The illustration shows the case where the first gate line 130 is located on the third region z3. The width of the first gate line 130 and the width of the third region z3 can be the same or different. When the width of the first gate line 130 is greater than the width of the third region z3, a portion of the first gate line 130 is located on the fourth region z4.

[0177] Combined with reference Figure 5 , Figure 5 This is a schematic diagram of a pyramid-shaped structure 1101 in some embodiments of this application. According to some embodiments of this application, the height H of the pyramid-shaped structure 1101 is the distance from the bottom of the pyramid-shaped structure 1101 to the top T of the pyramid-shaped structure 1101, and the distance W between the tops of two adjacent pyramid-shaped structures 1101 is the distance between the tops T of the two pyramid-shaped structures 1101.

[0178] For example, the distance from the bottom to the top T of each of the multiple pyramid-shaped structures 1101 is measured, and the arithmetic mean of all the measurements is calculated. The result is the height of the pyramid-shaped structure 1101. The number of pyramid-shaped structures 1101 selected can be 5, 7, 8, 10, or 12, and there is no specific limitation here.

[0179] For example, multiple sets of two adjacent pyramid-shaped structures 1101 are selected, and the straight-line distance between the apex of each set is measured. The average value of all distance data is then calculated, which is the distance between the apex of the two adjacent pyramid-shaped structures 1101. The number of sets selected can be 4, 8, 12, 20, or 30 sets, and there is no specific limitation here.

[0180] By setting a first pyramidal structure 11011 on the third region z3 and a second pyramidal structure 11012 on the fourth region z4, since the height of the first pyramidal structure 11011 is smaller than the height of the second pyramidal structure 11012, and / or the distance between the apexes of two adjacent first pyramidal structures 11011 is smaller than the distance between the apexes of two adjacent second pyramidal structures 11012, the second pyramidal structure 11012 has a larger extended inclined fracture surface, and adjacent second pyramidal structures 11012 have more fine grooves, thus forming more capillary channels. During the curing stage, when the slurry forming the first grid line 130 is spread, there will be stronger capillary tension pulling the slurry, constraining the flow boundary of the slurry, which is more conducive to controlling the boundary of the cover layer 133 of the first grid line 130.

[0181] Therefore, the first pyramidal structure 11011 and the second pyramidal structure 11012 form a hierarchical constraint structure for slurry spread. The first pyramidal structure 11011 primarily uses physical boundary enclosure, supplemented by weak capillary control, to constrain slurry spread while simultaneously considering its characteristics. The second pyramidal structure 11012 primarily uses a larger physical boundary enclosure combined with greater capillary tension to further constrain slurry spread. This approach is beneficial for both forming a more uniform first grid line 130 and for controlling the boundary of the first grid line 130.

[0182] It should be noted that the height H of the pyramid-shaped structure 1101 and the distance W between the apex of two adjacent pyramid-shaped structures 1101 can be detected by any method known to those skilled in the art, and those skilled in the art can make the selection based on their needs.

[0183] For example, in practice, a cross-section of the solar cell 100 can be prepared, selecting the portion including the pyramidal structure 1101 and creating a corresponding SEM image. The cross-sectional sample of the solar cell 100 is photographed using an optical microscope or scanning electron microscope to obtain a planar cross-sectional image. On the planar cross-sectional image, image analysis software is used to calculate the height H of the pyramidal structure 1101 and the distance W between the apexes of two adjacent pyramidal structures 1101.

[0184] For example, in practice, a sample of the solar cell 100 can be prepared, selecting the portion including the pyramidal structure 1101 and creating a corresponding SEM image. The sample is then photographed from above using an optical microscope or scanning electron microscope to obtain a planar top-view image. This planar top-view image is then compared with a reference... Figure 6 , Figure 6 This is a schematic diagram of the pyramid tip identification point in some embodiments of this application. The distance between the tips of two adjacent pyramid-shaped structures 1101 can be obtained by identifying the pyramid tip of the pyramid-shaped structure 1101 through image analysis software and calculating the horizontal straight-line distance between two adjacent pyramid tips.

[0185] For example, when measuring the height of the pyramid-shaped structure 1101, multiple pyramid-shaped structures 1101 can be selected for measurement to obtain a height dataset. The arithmetic mean of all the height data in the height dataset is then used as the height of the pyramid-shaped structure 1101.

[0186] For example, when measuring the distance between the apex of two adjacent pyramid-shaped structures 1101, software can be used to automatically calculate the horizontal straight-line distance between each pair of adjacent apexes, generating a distance dataset. The arithmetic mean or median of the distance dataset is then calculated, which is the distance between the apex of two adjacent pyramid-shaped structures 1101.

[0187] In the process of calculating the distance between the apex of two adjacent pyramid-shaped structures 1101 using the above sampling method, to better reflect the accuracy of the data, the sampling area is greater than or equal to 400 μm. 2 For example, the sampling area can be 400 μm. 2 500μm 2 600μm 2 700μm 2 800μm 2 900μm 2 or 1000μm2 No specific restrictions are imposed here.

[0188] In some testing methods, measuring the height of the pyramid-shaped structure 1101 and the distance between the apexes of two adjacent pyramid-shaped structures 1101 does not require testing all pyramid-shaped structures 1101 individually; sampling testing is sufficient. It is understood that the design and layout of the pyramid-shaped structures 1101 follow a regular pattern. Those skilled in the art can reasonably infer and determine the dimensions of other pyramid-shaped structures 1101 based on the dimensions of the pyramid-shaped structure 1101 corresponding to the measured sample.

[0189] The height of the first pyramid-shaped structure 11011, the height of the second pyramid-shaped structure 11012, the distance between the apex of two adjacent first pyramid-shaped structures 11011, and the distance between the apex of two adjacent second pyramid-shaped structures 11012 can be measured in the manner described above.

[0190] According to some embodiments of this application, the height of the first pyramidal structure 11011 is 100nm to 530nm, and the height of the second pyramidal structure 11012 is 350nm to 1750nm. According to other embodiments of this application, the distance between the tips of two adjacent first pyramidal structures 11011 is 200nm to 750nm, and the distance between the tips of two adjacent second pyramidal structures 11012 is 750nm to 2500nm.

[0191] For example, the height of the first pyramid-shaped structure 11011 can be 100nm, 200nm, 300nm, 330nm, 400nm, 450nm, 500nm, or 530nm. The average height of the first pyramid-shaped structure 11011 can be any other value in the range of 100nm to 530nm, and no specific limitation is made here.

[0192] For example, the height of the second pyramidal structure 11012 can be 350nm, 450nm, 600nm, 650nm, 750nm, 900nm, 1350nm, 1600nm, or 1750nm. The average height of the second pyramidal structure 11012 can be any other value in the range of 350nm to 1750nm, and no specific limitation is made here.

[0193] For example, the distance between the tips of two adjacent first pyramidal structures 11011 can be 200nm, 300nm, 350nm, 400nm, 550nm, 600nm, 700nm, or 750nm. The distance between the tips of two adjacent first pyramidal structures 11011 can be any other value in the range of 200nm to 750nm, and no specific limitation is made here.

[0194] For example, the distance between the tips of two adjacent second pyramidal structures 11012 can be 750nm, 850nm, 1000nm, 1200nm, 1600nm, 1750nm, 1900nm, 2000nm, 2200nm, or 2500nm. The distance between the tips of two adjacent second pyramidal structures 11012 can be any other value within the range of 750nm to 2500nm, and no specific limitation is made here.

[0195] By controlling the height range of the first pyramid-shaped structure 11011, the slurry forming the first grid line 130 can be initially constrained while taking into account the shape of the first grid line 130.

[0196] By controlling the height range of the second pyramid-shaped structure 11012, the slope length and the number of surface micro-grooves of the second pyramid-shaped structure 11012 can be controlled, thereby making the magnitude of capillary force more stable and continuously constraining the spread of the cover layer 133.

[0197] By controlling the range of the distance between the tips of two adjacent first pyramid-shaped structures 11011, it is beneficial to balance the photocurrent collection capability with the shape control capability of the first grid line 130.

[0198] By controlling the range of the distance between the apex of two adjacent second pyramid-shaped structures 11012, it is beneficial to balance the constraint of the covering layer 133 and the anti-reflection effect.

[0199] By controlling the height range of the first pyramidal structure 11011, the height range of the second pyramidal structure 11012, the distance between the tips of two adjacent first pyramidal structures 11011, and the distance between the tips of two adjacent second pyramidal structures 11012, the second pyramidal structure 11012 can be used to control the overall spread and anti-reflection effect of the paste forming the first grid line 130, while the first pyramidal structure 11011 can be used to balance the shape of the first grid line 130 and its photocurrent collection capability. This creates a gradient confinement effect and optical effect, thereby improving the performance of the solar cell 100.

[0200] Please continue to refer to Figures 1 to 2 According to some embodiments of this application, the surface energy of the passivation layer 120 is greater than the surface energy of the liquid capping layer 133.

[0201] Surface energy is the excess free energy possessed by molecules on the surface of a material. The higher the surface energy of a solid, the stronger its wetting ability in liquid media. The surface energy of the passivation layer 120 can be calculated using a contact angle tester combined with various standard liquids, or it can be qualitatively determined using a dyne test device; no specific limitations are imposed here. The surface energy of the capping layer 133 in a liquid state can be determined using the pendant drop method or the platinum plate tensile method; no specific limitations are imposed here.

[0202] Since the surface energy of the passivation layer 120 is greater than that of the liquid capping layer 133, it is beneficial for the slurry forming the capping layer 133 to spread and wet the surface of the passivation layer 120, thereby facilitating the formation of the first gate line 130.

[0203] Please continue to refer to Figure 1 and Figure 2 According to some embodiments of this application, the surface energy of the passivation layer 120 is 35 mJ / m². 2 Up to 100mJ / m 2 The surface energy of the liquid capping layer 133 is 15 mN / m to 50 mN / m.

[0204] For example, the surface energy of the passivation layer 120 is 35 mJ / m². 2 40mJ / m 2 45mJ / m 2 50mJ / m 2 55mJ / m 2 58mJ / m 2 60mJ / m 2 70mJ / m 2 80mJ / m 2 90mJ / m 2 or 100mJ / m 2 The surface energy of passivation layer 120 is 35 mJ / m². 2 Up to 100mJ / m 2 Any other value within the range is not specifically restricted here.

[0205] For example, the surface energy of the liquid capping layer 133 is 15 mN / m, 20 mN / m, 22 mN / m, 30 mN / m, 35 mN / m, 40 mN / m, 45 mN / m, or 50 mN / m. Any other value in the range of 15 mN / m to 50 mN / m is not specifically limited herein.

[0206] By controlling the surface energy range of the passivation layer 120 and the surface energy range of the liquid capping layer 133, and ensuring that the surface energy of the passivation layer 120 is always higher than that of the liquid capping layer 133, it is beneficial to control the wetting and spreading state of the capping layer 133 during its molding process. Furthermore, the surface energy of the liquid capping layer 133 decreases after curing, further enhancing its hydrophobic and water-resistant properties and inhibiting capillary water vapor penetration, thereby improving overall reliability.

[0207] Please continue to refer to Figure 1 and Figure 2 According to some embodiments of this application, the material of the passivation layer 120 includes one or more of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, silicon carbide, and silicon carbonitride.

[0208] By controlling the material of the passivation layer 120, it is not only beneficial to form the capping layer 133, but also to reduce carrier recombination and improve photoelectric conversion efficiency.

[0209] Please continue to refer to Figure 1 and Figure 2 According to some embodiments of this application, the edge region of the cover layer 133 is provided with a perforated structure.

[0210] Combined with reference Figure 3 The edge region of the covering layer 133 can be understood as the edge region of the second region z2 on the side away from the first region z1 along the second direction F2.

[0211] The porous structure consists of voids, pores, micropores, and gap channels distributed within and on the surface of the capping layer 133. In other words, the porous structure includes open pores and closed pores.

[0212] Thus, the use of perforated structures helps to improve light transmittance, thereby increasing the utilization rate of light.

[0213] Please continue to refer to Figure 1 and Figure 2 According to some embodiments of this application, the material of the cover layer 133 includes at least one of resin, fatty acid, paraffin, microcrystalline wax, and inorganic nanosol.

[0214] For example, the resin includes at least one of thermosetting resin and thermoplastic resin.

[0215] Thus, by controlling the material of the capping layer 133 and the surface energy gradient change before and after crosslinking, not only can the adhesion of the first grid line 130 be improved by utilizing the propagation of the capping layer 133 during the molding stage, but it can also have light transmission and anti-reflection, interfacial bonding strength and UV and humid heat resistance.

[0216] Please continue to refer to Figure 1 and Figure 2According to some embodiments of this application, the material of the cover layer 133 includes one or more of epoxy resin, phenolic resin, polyurethane resin, acrylate resin, polyester resin, and vinyl chloride resin.

[0217] Thus, by controlling the material of the resin, different materials and shapes of the coating layer 133 can be formed more flexibly.

[0218] Please continue to refer to Figure 3 According to some embodiments of this application, at least one sub-part 131 includes a plurality of seed units 1311 spaced apart along the extension direction of the first gate line 130.

[0219] By configuring the seed section 131 to include multiple seed units 1311, it is not only beneficial to release the stress during the formation of the first grid line 130 and reduce the risk of warping and cracking of the first grid line 130, but also to improve the reliability of the first grid line 130 because the gap between the seed units 1311 can be filled by the cover layer 133, blocking the lateral erosion path of water vapor.

[0220] Please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of the first gate line 130a in some other embodiments of this application. According to some embodiments of this application, at least one sub-part 131a extends longitudinally along the extension direction of the first gate line 130a.

[0221] This not only facilitates the production of the seed section 131a, but also improves the uniformity of the covering layer covering the seed section 131a, thereby facilitating the formation of the first grid line 130a.

[0222] It should be noted that, in Figure 7 From this perspective, a portion of the seed section 131a is located on the back side of the transport layer 132a. This portion is indicated by a dashed line, but this is not intended to limit its structure. Figure 7 In the illustrated embodiment, the z2a and the seed portion 131a on both sides of the first region z1a along the first direction do not overlap.

[0223] It should also be noted that the relevant dimensions of each part in the first gate line 130a can satisfy the second condition in some of the aforementioned embodiments, thereby enabling the first gate line 130a to have the aforementioned advantages.

[0224] Furthermore, in some embodiments, the solar cell may include both the first grid line 130 and the first grid line 130a, enabling a more flexible manufacturing process. In other embodiments, the first grid line 130a may be formed in the middle region of the surface of the cell body, while the first grid line 130 may be formed in the edge region. This interaction between the first grid line 130 and the first grid line 130a not only improves power generation efficiency but also reduces the risk of cracking caused by stress at the edges.

[0225] Please continue to refer to Figures 1 to 3 According to some embodiments of this application, the seed section 131 is made of one or more of silver, aluminum, and nickel. According to other embodiments of this application, the transport layer 132 is made of one or more of silver, copper, and silver-clad copper.

[0226] Thus, by controlling the material of the seed section 131 and / or the material of the conductive particles 1301, both conductivity and production cost can be balanced, achieving overall conductivity, interface reliability, process compatibility, and damp heat durability.

[0227] Based on some embodiments of this application, please continue to refer to Figure 1 The second side m2 is the back side of the battery substrate 110, and the second side m2 is provided with the first grid line 130.

[0228] Thus, by setting the first grid line 130 on the back of the battery substrate 110, it is not only beneficial to reduce manufacturing costs, but also to improve light utilization.

[0229] According to some embodiments of this application, the solar cell is a tunneling oxide passivated contact cell; or, the solar cell is a back contact cell.

[0230] For example, Figure 1 This illustration shows the case of solar cell 100 as a tunnel oxide passivated contact cell.

[0231] For example, with Figure 1 Taking a solar cell 100 as an example, the cell substrate 111 includes a substrate 111, a tunneling layer 112, a doped conductive layer 113, and a doped region 114. The tunneling layer 112 is provided on one surface of the substrate 111 along the first direction F1, and the doped conductive layer 113 is provided on the side of the tunneling layer 112 opposite to the substrate 111. The doped region 114 is provided on one surface of the substrate 111 along the first direction F1.

[0232] The tunneling layer 112 is used to achieve interface passivation on one side surface of the substrate 111 along the first direction F1, achieving a chemical passivation effect. Specifically, by saturating the dangling bonds on one side surface of the substrate 111 along the first direction F1, the interface defect state density on that side surface is reduced, thereby reducing the recombination centers and lowering the carrier recombination rate. The material of the tunneling layer 112 can be a dielectric material. For example, the material of the tunneling layer 112 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 112 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 112; no specific limitations are imposed here. For example, the dimension of the tunneling layer 112 along the first direction F1, that is, the thickness of the tunneling layer 112, can be from 0.5 nm to 3 nm. By controlling the thickness of the tunneling layer 112, it is possible to suppress the reduction of the fill factor caused by contact resistance while having a certain passivation effect.

[0233] The dopant element of the conductive layer 113 is adapted to the conductivity type of the dopant element of the substrate 111. For example, if the substrate 111 is an N-type substrate, the dopant element of the substrate 111 can be phosphorus and / or antimony. The dopant element of the conductive layer 113 is phosphorus. As another example, if the substrate 111 is a P-type substrate, the dopant element of the conductive layer 113 is boron. In the embodiments of this application, the conductive layer 113 is formed by doping amorphous silicon, microcrystalline silicon, polycrystalline silicon, etc., with an N-type dopant element. Exemplarily, the conductive layer 113 is a phosphorus-doped polycrystalline silicon layer. In this case, the stacked tunneling layer 112 and the conductive layer 113 together form a passivation contact structure, which provides good surface passivation for one side surface of the substrate 111 along the first direction F1.

[0234] For example, the dimension of the doped conductive layer 113 along the first direction F1, that is, the thickness of the doped conductive layer 113, is 30 nm to 300 nm.

[0235] For example, with Figure 1 For example, a first passivation layer 121 is provided on the side of the doped conductive layer 113 away from the tunneling layer 112. The first passivation layer 121 can effectively passivate the surface of the doped conductive layer 113 away from the substrate 111, reduce the interface state density, reduce the recombination of minority carriers, thereby improving the carrier transport efficiency at the interface and improving the efficiency of the solar cell 100.

[0236] For example, with Figure 1 For example, the first passivation layer 121 has an anti-reflection layer 140 on the side opposite to the substrate 111, which mainly functions as an anti-reflection layer in the solar cell 100. Exemplarily, the material of the anti-reflection layer 140 may include SiN. x SiO x N y SiO x One or more combinations thereof, without specific limitations.

[0237] For example, a first grid line 130 is provided on the side of the doped conductive layer 113 opposite to the tunneling layer 112, and the first grid line 130 is electrically connected to the doped conductive layer 113. The electrical connection between the first grid line 130 and the doped conductive layer 113 means that, since both the materials of the first grid line 130 and the doped conductive layer 113 are conductive, the first grid line 130 and the doped conductive layer 113 form a physical channel for the flow of photogenerated carriers through physical contact. When the solar cell 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 solar cell is in a power generation or power supply state, the doped conductive layer 113 generates photogenerated carriers, which are separated under the influence of its built-in electric field, and the photogenerated carriers flow out through this physical channel.

[0238] The doped region 114 and the doped element in the substrate 111 have different conductivity types, allowing them to form a PN junction structure together. For example, when the substrate 111 is an N-type silicon substrate, the doped region 114 can be a P-type emitter. As another example, when the substrate 111 is a P-type silicon substrate, the doped region 114 can be an N-type emitter.

[0239] For example, the doped region 114 can be formed by diffusing a dopant element into the substrate 111 on the first surface m1 side of the substrate 111. When the substrate 111 is an N-type substrate, a P-type doped region 114 can be formed by boron diffusion into the substrate 111.

[0240] For example, the doped region 114 may also be made of doped polycrystalline silicon, microcrystalline silicon or amorphous silicon with a conductivity type opposite to that of the doped elements of the substrate 111. For example, when the substrate 111 is an N-type substrate, a tunneling layer and a polycrystalline silicon, microcrystalline silicon or amorphous silicon layer can be formed on the first surface m1 of the substrate 111 by means of low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition, and the doped region 114 is formed by doping the polycrystalline silicon, microcrystalline silicon or amorphous silicon layer with P-type doping elements. At this time, the doped region 114 can be regarded as a layer structure.

[0241] The second passivation layer 122 is disposed on the side surface of the doped region 114 facing away from the substrate 111. The first gate line 130 is disposed on the side of the doped region 114 facing away from the substrate 111, and the first gate line 130 is electrically connected to the doped region 114.

[0242] For example, with Figure 1 For example, solar cell 100 is a single-sided tunneling oxide passivated contact cell. In other embodiments, the solar cell can be a double-sided tunneling oxide passivated contact cell, and no specific limitation is made here. For example, both the light-receiving side and the back-lighting side of the solar cell are provided with tunneling oxide passivated contact structures, and when the solar cell is a double-sided tunneling oxide passivated contact cell, the film structure of its light-receiving side and back-lighting side can be the same. In addition, it should be noted that the tunneling oxide passivated contact structure on the solar cell can be provided in the area where the grid lines are provided, or it can be provided on the entire surface, and no specific limitation is made here. Figure 1 For example, it is shown that the entire surface of a solar cell along the first direction F1 is provided with a tunneling layer 112 and a doped conductive layer 113.

[0243] In some other embodiments, the solar cell is a BC cell (Back Contact cell).

[0244] For example, Figure 8 The illustration shows that solar cell 100a is a tunnel oxide passivated contact cell.

[0245] For example, refer to Figure 8 The substrate 111a has a first region m11, a second region m12, and a spacer region m13 on one side surface along the first direction F1. A first passivation conductive structure T1 is provided on the first region m11, and a second passivation conductive structure T2 is provided on the second region m12. The first passivation conductive structure T1 and the second passivation conductive structure T2 have different doping types. Passivation layers 120a are provided on the side of the first passivation conductive structure T1 away from the substrate 111a and the side of the second passivation conductive structure T2 away from the substrate 111a. The passivation layer 120a provided on the side of the first passivation conductive structure T1 away from the substrate 111a is the first passivation layer 121a. The passivation layer 120a provided on the side of the second passivation conductive structure T2 away from the substrate 111a is the second passivation layer 122a. A gate line E1 is provided on the first region m11 and is electrically connected to the first passivation conductive structure T1. The gate line E2 is disposed on the second region m12 and is electrically connected to the second passivated conductive structure T2. A passivated antireflection layer 102 is provided on one side surface of the substrate 111a along the first direction F1.

[0246] For example, the first passivated conductive structure T1 includes a first tunneling layer T11 and a first doped conductive layer T12 disposed on the side of the first tunneling layer T11 away from the substrate 111a.

[0247] For example, the second passivated conductive structure T2 includes a second tunneling layer T21 and a second doped conductive layer T22 disposed on the side of the second tunneling layer T21 away from the substrate 111a.

[0248] For example, at least one of the gate line E1 and gate line E2 is the first gate line mentioned above, and no specific limitation is made here. It should be noted that the pyramid-shaped structure shown in some of the foregoing embodiments can also be provided on the first region m11 and the second region m12 to improve light utilization and facilitate the formation of the first gate line.

[0249] Please refer to Figure 9 , Figure 9 This is a flowchart illustrating a method for manufacturing a solar cell according to some embodiments of this application. Embodiments of this application provide a method for manufacturing a solar cell, including:

[0250] Step S110: Provide a battery substrate; the battery substrate has a first side and a second side disposed opposite to each other, and a passivation layer is provided on the first side and / or the second side;

[0251] Step S120: Form a seed portion on the first surface and / or the second surface;

[0252] Step S130: A transport layer and an initial capping layer are formed on the side of the seed layer away from the battery substrate and on the side of the passivation layer away from the battery substrate; and

[0253] Step S140: The initial cover layer is subjected to static treatment and curing treatment in sequence to form a cover layer, thereby forming a solar cell.

[0254] In step S140, during the transport of the battery body with the seed section and the initial transport layer formed thereon, the time required for the resting process can be achieved by means of buffering, extending the transport path, or reducing the transport speed, etc., and no specific limitations are imposed here. During this process, the covering layer can fill between the conductive particles or coat the surface of the conductive particles.

[0255] Through static and curing processes, the initial capillary layer slowly diffuses and permeates due to capillary action, forming a structure where the dimension of the capillary layer along the width of the first grid line is larger than that of the seed portion along the width of the first grid line. This increases the contact area between the first grid line and the cell body, improving the adhesion of the first grid line. Consequently, this not only enhances the electrical performance of the solar cell but also improves its reliability and lifespan. Furthermore, because the static and curing processes are used, the minute irregularities and micro-grooves on the surface of the cell body are filled more thoroughly, which is beneficial for improving adhesion, reducing internal stress, and enhancing the reliability of the first grid line. It also facilitates manufacturing and reduces manufacturing costs.

[0256] According to some embodiments of this application, the settling time is 10 seconds to 30 minutes; and / or the settling temperature is 5°C to 100°C.

[0257] For example, the settling time can be 10s, 20s, 30s, 40s, 50s, 1min, 2min, 3min, 8min, 15min, 20min, 25min, or 30min. The settling time can be any other value within the range of 10s to 30min, and no specific limitation is made here.

[0258] For example, the settling temperature can be 5°C, 15°C, 25°C, 30°C, 50°C, 60°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C. The settling temperature can be any other value within the range of 5°C to 100°C, and no specific limitation is made here.

[0259] By controlling the settling time, the risks of insufficient low-temperature fluidity and poor wetting, premature pre-crosslinking, and excessively rapid solvent evaporation can be reduced, resulting in a more uniform coating layer. This also allows the initial coating layer to spread more fully, maximizing the interfacial contact area, releasing rheological stress, and improving interlayer adhesion after curing. Controlling the settling temperature allows for processing under different environmental conditions. For example, when the battery is transported near the sintering furnace, the temperature near the furnace can be used for settling. Alternatively, the battery can be settling at room temperature. This makes the manufacturing process more convenient. Therefore, controlling the settling time and temperature not only allows for more stable control of the viscosity, surface tension, and wetting and spreading rate of the initial coating layer but also improves the ease of manufacturing.

[0260] According to some embodiments of this application, the front grid lines of the solar cell include a front main grid and a front fine grid, and the back grid lines include a back main grid and a back fine grid, with the back fine grid being the first grid line. The front main grid, the front fine grid, the back main grid, and the back seed section are formed by a high-temperature silver paste printing and chain sintering process (peak temperature > 700°C). The back transport layer is formed by a low-temperature silver-coated copper paste printing process, a 15-second resting time, and a low-temperature curing process (peak temperature < 300°C). The back transport layer contains acrylic resin, and the capping layer formed by the acrylic resin has a width of 150 μm to 200 μm in the second region.

[0261] It should be noted that the above is merely an illustrative example. At least one of the aforementioned front main grid, front fine grid, and back main grid can also be the first grid line. Furthermore, the grid lines can be flexibly configured depending on the type of solar cell, and no specific limitations are imposed here.

[0262] Please refer to Figure 10 , Figure 10 This is a schematic diagram of the structure of a photovoltaic module in some embodiments of this application. Embodiments of this application provide a photovoltaic module, including: a solar cell as described in any of the above embodiments; or a solar cell manufactured by the method described in any of the above embodiments.

[0263] For example, refer to Figure 10 The photovoltaic module 10 includes a cell string 11, an encapsulation layer 12, and a cover plate 13. The encapsulation layer 12 covers the surface of the cell string 11, and the cover plate 13 covers the surface of the encapsulation layer 12 away from the cell string 11. The cell string 11 is formed by connecting multiple solar cells according to any of the embodiments; or, the cell string is formed by connecting multiple solar cells manufactured by any of the methods described in the embodiments.

[0264] Furthermore, the solar cells are electrically connected in the form of a whole or multiple segments to form multiple cell strings 11, and the multiple cell strings 11 are electrically connected in series and / or parallel.

[0265] In some embodiments, multiple cell strings 11 can be electrically connected via conductive strips 14. An encapsulation layer 12 covers both the front and back sides of the solar cell.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] The photovoltaic module 10 also possesses the advantages of the solar cells described above or the solar cells manufactured by the methods described above, and will not be elaborated further here.

[0270] 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.

[0271] 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 solar cell, characterized in that, include: A battery substrate having a first side and a second side disposed opposite to each other; A passivation layer is disposed on the first surface and / or the second surface; and Multiple first gate lines are disposed on the first surface and / or the second surface. Each first gate line includes a seed portion, a transport layer, and a cover layer. The transport layer and the cover layer are both disposed on the side of the seed portion away from the battery substrate and the side of the passivation layer away from the battery substrate. The width of the cover layer is greater than the width of the seed portion.

2. The solar cell according to claim 1, characterized in that, The first gate line is divided into a first region and a second region, and the second region is located on both sides of the first region along the width direction of the first gate line; The transport layer is in the first region, the seed portion is at least in the first region, and the overlay layer is in both the first and second regions.

3. The solar cell according to claim 2, characterized in that, The width of the first region is smaller than the width of the second region; and / or The thickness of the first region is greater than the thickness of the second region.

4. The solar cell according to claim 2, characterized in that, The width of the first region is 5 μm to 100 μm, and the width of the second region is 10 μm to 495 μm; and / or The thickness of the first region is 0.001 μm to 50 μm, and the thickness of the second region is 0.0001 μm to 30 μm.

5. The solar cell according to claim 2, characterized in that, The width of the seed section is s1, the width of the first region is s2, and the width of the second region is s3. s1, s2, and s3 satisfy either the first condition or the second condition. The first condition includes: 2s3>s1-s2, 2≤s1 / s2≤20; and / or, 10μm≤s3≤495μm; The second condition includes: 0.01≤s1 / s2≤2; and / or, 10μm≤s3≤495μm.

6. The solar cell according to claim 2, characterized in that, The first gate line includes a plurality of conductive particles, which are in the capping layer; At least a portion of the conductive particles form the transport layer.

7. The solar cell according to claim 6, characterized in that, The distribution density of the conductive particles in the first region is greater than that in the second region.

8. The solar cell according to any one of claims 1-7, characterized in that, The width of the covering layer is 20 μm to 1000 μm, and the width of the seed portion is 5 μm to 200 μm; and / or The ratio of the width of the covering layer to the width of the seed portion is between 2 and 200.

9. The solar cell according to any one of claims 1-7, characterized in that, The first and second surfaces, on which the first grid line is located, have multiple pyramid-shaped structures.

10. The solar cell according to any one of claims 1-7, characterized in that, The edge region of the covering layer has a perforated structure.

11. The solar cell according to any one of claims 1-7, characterized in that, At least one of the seed portions includes a plurality of seed units spaced apart along the extension direction of the first gate line; and / or At least one of the seed portions extends longitudinally along the extension direction of the first grid line.

12. The solar cell according to any one of claims 1-7, characterized in that, The seed section is made of one or more of silver, aluminum, and nickel; and / or The material of the transport layer includes one or more of silver, copper, and silver-clad copper; and / or The material of the coating layer includes one or more of resin, fatty acid, paraffin, microcrystalline wax, and inorganic nanosol.

13. The solar cell according to any one of claims 1-7, characterized in that, The second surface is the back side of the battery substrate, and the first grid line is provided on the second surface.

14. A method for manufacturing a solar cell, characterized in that, include: Provide battery substrate; The battery substrate has a first side and a second side disposed opposite to each other, and a passivation layer is provided on the first side and / or the second side. A seed portion is formed on the first surface and / or the second surface; A transport layer and an initial cover layer are formed on the side of the seed portion away from the battery substrate and on the side of the passivation layer away from the battery substrate; and The initial cover layer is subjected to static treatment and curing treatment in sequence to form a cover layer, thereby forming a solar cell.

15. A photovoltaic module, characterized in that, include: The solar cell as described in any one of claims 1-13; Alternatively, a solar cell manufactured by the method for manufacturing a solar cell as described in claim 14.

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