Solar cell and method of manufacturing the same, stacked cell, and photovoltaic module

Abstract

The application relates to a solar cell and a manufacturing method thereof, a laminated cell and a photovoltaic module. The solar cell comprises a substrate with a first surface and a second surface arranged oppositely, and the second surface comprises first regions and second regions arranged alternately; a first tunneling layer is arranged at the first regions and the second regions; a first doped conductive layer is arranged only at the first regions and is arranged at a side of the first tunneling layer away from the substrate; wherein the first tunneling layer comprises a first part arranged at the first regions and a second part arranged at the second regions; in a direction perpendicular to a plane where the second surface is located, the thickness of the first part is greater than the thickness of the second part; a surface of the second part away from the substrate is a first sub-surface; the first sub-surface is provided with a plurality of microstructures, and the microstructures are at least one of protrusions and recesses.

Description

Technical Field

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

[0002] Solar energy, as an emerging energy source, has advantages over traditional fossil fuels in many aspects, including inexhaustibility, cleanliness, and environmental friendliness. Currently, a major method of utilizing solar energy is through solar cell modules that convert received light energy into electrical energy. These modules can be large-area solar panels formed by connecting several solar cells (or photovoltaic cells, or photovoltaic modules) in series, encapsulating them, and arranging them in an array. When a solar cell absorbs light energy, opposite charges accumulate at its terminals, generating a "photovoltaic voltage," also known as the "photovoltaic effect." Under the influence of the photovoltaic effect, an electromotive force is generated at the terminals of the solar cell, thus converting light energy into electrical energy.

[0003] However, the performance of solar cells in related technologies still needs to be improved. Summary of the Invention

[0004] Therefore, it is necessary to address the issue of how to improve the performance of solar cells in related technologies by providing a solar cell, its manufacturing method, a tandem cell, and a photovoltaic module.

[0005] In a first aspect, this application provides a solar cell, comprising:

[0006] The substrate has a first surface and a second surface disposed opposite to each other, the second surface including an alternately disposed first region and a second region;

[0007] The first tunneling layer is located on one side of the second surface and at least in the first region;

[0008] The first doped conductive layer is located only in the first region and on the side of the first tunneling layer away from the substrate;

[0009] The first passivation layer is located on the side of the first doped conductive layer away from the substrate, and is located in both the first region and the second region;

[0010] Wherein, the surface directly contacted and covered by the first passivation layer and located in the second region is the first sub-surface, the first sub-surface has a plurality of microstructures, the microstructures being at least one of protrusions and depressions; in at least a portion of the first sub-surface, two adjacent microstructures are spaced apart, and the distance between two adjacent microstructures in a direction parallel to the plane of the second surface is greater than 0.

[0011] In some embodiments, the roughness of the first sub-surface is 0.2 μm-1.6 μm; and / or,

[0012] The density of the microstructure is 5 × 10⁻⁶. 4 pcs / cm²-2×10 5 pcs / cm²

[0013] In some embodiments, the height of the protrusion or the depth of the recess is 1 micrometer to 3 micrometers in a direction perpendicular to the plane containing the second surface;

[0014] In a direction parallel to the plane containing the second surface, the width of the protrusion or the depression is 2 micrometers to 5 micrometers.

[0015] In some embodiments, the first tunneling layer is located in the first region and the second region, the first tunneling layer includes a first portion located in the first region and a second portion located in the second region, and the first sub-surface is the surface of the second portion away from the substrate;

[0016] In a direction perpendicular to the plane containing the second surface, the thickness of the first portion is greater than the thickness of the second portion.

[0017] In some embodiments, the height difference between the first portion and the second portion is 0.5 nm to 1.6 nm in a direction perpendicular to the plane containing the second surface.

[0018] In some embodiments, the first sub-surface has a plurality of irregular protrusions;

[0019] The height of the protrusion is 0.2 micrometers to 0.5 micrometers in a direction perpendicular to the plane containing the second surface.

[0020] In some embodiments, the first sub-surface is a portion of the substrate that faces away from the first surface, and the first passivation layer covers the surface of the substrate in the second region.

[0021] In some embodiments, in a direction perpendicular to the plane containing the second surface, the distance from the second surface to the first surface in the first region is a first distance, and the distance from the second surface to the first surface in the second region is a second distance, the difference between the first distance and the second distance is 1μm-3μm.

[0022] Secondly, based on the same concept, this application also provides a method for manufacturing a solar cell, used to manufacture the solar cell described in any of the above-mentioned applications, the method comprising:

[0023] A substrate is provided, the substrate having a first surface and a second surface disposed opposite to each other, the second surface including alternating first regions and second regions;

[0024] A first tunneling layer is formed on the second surface, the first tunneling layer being at least located in the first region;

[0025] A first doped conductive preset layer is formed on the side of the first tunneling layer away from the substrate;

[0026] The first doped conductive preset layer is removed before the second region to form the first doped conductive layer, thereby forming a first sub-surface located in the second region, wherein the first doped conductive layer is located only in the first region;

[0027] The first sub-surface is then roughened, and the first sub-surface has a plurality of microstructures, the microstructures being at least one of protrusions and depressions; in at least a portion of the first sub-surface, two adjacent microstructures are spaced apart, and the distance between two adjacent microstructures in a direction parallel to the plane of the second surface is greater than 0.

[0028] In some embodiments, the step of removing at least the first doped conductive preset layer in the second region to form the first doped conductive layer includes: using a first laser to remove at least the portion of the first doped conductive preset layer in the second region;

[0029] The step of further roughening the first sub-surface includes: roughening the first sub-surface using a second laser;

[0030] The energy of the first laser is greater than the energy of the second laser.

[0031] In some embodiments, the energy density of the first laser is 5 J / cm²-20 J / cm²; the pulse width of the laser is 10 ns-200 ns; the scanning speed of the laser is 500-2000 mm / s; the repetition frequency of the laser is 50 kHz-300 kHz; and the spot size of the laser is 20 μm-50 μm.

[0032] In some embodiments, the energy density of the second laser is 0.2 J / cm²-5 J / cm²; the pulse width of the laser is 10 ns-50 ns; the scanning speed of the laser is 1000-5000 mm / s; the repetition frequency of the laser is 50 kHz-100 kHz; and the spot size of the laser is 10 μm-30 μm.

[0033] In some embodiments, after the step of removing at least the first doped conductive preset layer prior to the second region to form the first doped conductive layer, the roughness of the first sub-surface is less than 0.1 μm;

[0034] After the step of further roughening the first sub-surface, the roughness of the first sub-surface is 0.2 μm-1.6 μm.

[0035] Thirdly, this application provides a stacked battery, comprising a top battery, an adhesive layer, and a bottom battery stacked sequentially, wherein the bottom battery is a solar cell as described in any of the above-mentioned applications.

[0036] Fourthly, this application provides a photovoltaic module, comprising:

[0037] A battery string is formed by connecting multiple solar cells as described in any one of the above descriptions, or by connecting multiple solar cells manufactured by the manufacturing method of any one of the above descriptions, or by connecting the tandem cells described above.

[0038] A connecting component for electrically connecting two adjacent solar cells;

[0039] An encapsulating film is used to cover the surface of the battery string;

[0040] A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

[0041] In this embodiment, the surface directly contacted and covered by the first passivation layer and located in the second region is a first sub-surface. The first sub-surface has multiple microstructures, which are at least one of protrusions and depressions. In at least a portion of the first sub-surface, adjacent microstructures are spaced apart, and the distance between adjacent microstructures in the direction parallel to the plane of the second surface is greater than 0. In a first aspect, the first sub-surface is a rough surface. Relative to the microstructures, the portion between adjacent microstructures is a planar portion or a flat portion (i.e., without protrusions or depressions). The microstructures increase the contact area and mechanical interlocking force (mechanical interlocking effect) between the first passivation layer and the first sub-surface, which can provide a stronger physical bond and significantly improve the adhesion of the first passivation layer on the first sub-surface. At the same time, the planar portion or flat portion (i.e., without protrusions or depressions) between adjacent microstructures provides a large area of ​​uniform chemical bonding (e.g., Si-O-Al bonds), which can serve as a stress buffer zone after stress generation. The combination of microstructures with planar or flat portions between adjacent microstructures ensures both strong adhesion and good stress distribution and buffering, thus better preventing "bubbling," "peeling," or "blistering" of the first passivation layer (especially the alumina layer). Secondly, the rough surface absorbs and dissipates the thermal stress, intrinsic stress, and additional stress from H ion release generated within the first passivation layer during subsequent high-temperature sintering, reducing stress concentration and lowering the driving force for film peeling; in other words, the rough surface provides excellent stress buffering. Thirdly, the rough surface microscopically extends the diffusion path of H ions escaping from the first passivation layer to the substrate, increasing H diffusion resistance and reducing the risk of H ions accumulating in localized areas and breaking through the first passivation layer. Fourthly, in conjunction with the solar cell manufacturing method of this application, a first laser is used to remove at least the portion of the first doped conductive pre-defined layer in the second region, and a second laser is used to roughen the first sub-surface. The energy of the first laser is greater than that of the second laser, while the energy of the second laser is lower. When the second laser creates a roughened structure on the first sub-surface, more dangling bonds and unsaturated bonds are generated on the first sub-surface, which is more conducive to the formation of stronger chemical bonds between the precursor of the first passivation layer and the first sub-surface in the subsequent ALD (Atomic Layer Deposition) process. From one or more of the above aspects, the problems of "bubbling," "peeling," or "blistering" of the first passivation layer (especially the alumina layer) are improved or avoided, thereby improving the continuity of the first passivation layer, enhancing its effective passivation capability for charge carriers, reducing recombination losses, and improving or avoiding grid line contact anomalies. Ultimately, this improves the open-circuit voltage (Voc), fill factor (FF), and conversion efficiency of the solar cell, thus enhancing the performance of the solar cell. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the accompanying drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of a first cross-sectional structure of a solar cell provided in an embodiment of this application.

[0044] Figure 2 This is a partially enlarged schematic diagram of a first cross-sectional structure of a solar cell provided in an embodiment of this application.

[0045] Figure 3 This is a schematic diagram of a second cross-sectional structure of a solar cell provided in an embodiment of this application.

[0046] Figure 4 This is a partially enlarged schematic diagram of a second cross-sectional structure of a solar cell provided in an embodiment of this application.

[0047] Figure 5 This is a partially enlarged schematic diagram of a third cross-sectional structure of a solar cell provided in an embodiment of this application.

[0048] Figure 6 This is a partially enlarged schematic diagram of a fourth cross-sectional structure of a solar cell provided in an embodiment of this application.

[0049] Figure 7 This is a schematic diagram of the process steps for manufacturing a solar cell according to an embodiment of this application.

[0050] Figure 8 This is a schematic diagram of the first intermediate process of a method for manufacturing a solar cell provided in this application embodiment.

[0051] Figure 9 This is a schematic diagram of the second intermediate process of a method for manufacturing a solar cell provided in an embodiment of this application.

[0052] Figure 10 This is a schematic diagram of the third intermediate process of a method for manufacturing a solar cell provided in an embodiment of this application.

[0053] Figure 11 This is a schematic diagram of the fourth intermediate process of a method for manufacturing a solar cell provided in this application embodiment.

[0054] Figure 12 A photograph of the second surface of a solar cell provided in an embodiment of this application under a 3D microscope.

[0055] Figure 13 This is a schematic diagram comparing the performance of Embodiment 1 and Comparative Example 1 of this application.

[0056] Figure 14 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0057] Reference numerals: Photovoltaic module 200; Solar cell 100; Substrate 11; First tunneling layer 21; First doped conductive layer 22; First passivation layer 23; First electrode 24; First surface 111; Second surface 112; First region 112a; Second region 112b; First sub-surface 112b1; Protrusion tq1; First value d1; First width d2; First part 211; Second part 212; First thickness h1; Second thickness h2; First distance h3; Second distance h4; First doped conductive preset layer 22Y; Textured structure R1; Emitter layer 12; Second passivation layer 13; Second electrode 14; First direction X; Second direction Y; Battery string 203; Connecting component 204; Encapsulating film 202; Cover plate 201; Microstructure W1. Detailed Implementation

[0058] 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.

[0059] 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.

[0060] 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.

[0061] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to 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. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0062] 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.

[0063] 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.

[0064] See Figures 1 to 13 . Figure 1 This is a schematic diagram of a first cross-sectional structure of a solar cell provided in an embodiment of this application. Figure 2 This is a partially enlarged schematic diagram of a first cross-sectional structure of a solar cell provided in an embodiment of this application. Figure 2 for Figure 1 A magnified schematic diagram of the middle part of the membrane layer and structure.

[0065] Figure 3 This is a schematic diagram of a second cross-sectional structure of a solar cell provided in an embodiment of this application. Figure 4 This is a partially enlarged schematic diagram of a second cross-sectional structure of a solar cell provided in an embodiment of this application. Figure 4 for Figure 3 A magnified schematic diagram of the middle part of the membrane layer and structure.

[0066] Figure 5 This is a partially enlarged schematic diagram of a third cross-sectional structure of a solar cell provided in an embodiment of this application. Figure 6 This is a partially enlarged schematic diagram of a fourth cross-sectional structure of a solar cell provided in an embodiment of this application. Compared to Figure 2 and Figure 4 The diagram illustrates that the first sub-surface has protrusions. Figure 5 The diagram illustrates that the surface of the first element has a depression. Figure 6 The diagram illustrates that the first sub-surface has protrusions and depressions.

[0067] Figure 7 This is a schematic diagram of the process steps for manufacturing a solar cell according to an embodiment of this application. Figure 8 This is a schematic diagram of the first intermediate process of a method for manufacturing a solar cell provided in this application embodiment. Figure 9 This is a schematic diagram of the second intermediate process of a method for manufacturing a solar cell provided in an embodiment of this application. Figure 10 This is a schematic diagram of the third intermediate process of a method for manufacturing a solar cell provided in an embodiment of this application. Figure 11 This is a schematic diagram of the fourth intermediate process of a method for manufacturing a solar cell provided in this application embodiment.

[0068] Figure 12 A photograph of the second surface of a solar cell provided in an embodiment of this application under a 3D microscope. Figure 13 This is a schematic diagram comparing the performance of Embodiment 1 and Comparative Example 1 of this application.

[0069] In a first aspect, this application provides a solar cell 100, which includes a substrate 11, a first tunneling layer 21, a first doped conductive layer 22, a first passivation layer 23, and a first electrode 24. The substrate 11 has a first surface 111 and a second surface 112 disposed opposite to each other. The second surface 112 includes alternately disposed first regions 112a and second regions 112b. The first tunneling layer 21 is located on one side of the second surface 112 and is at least located in the first region 112a. The first doped conductive layer 22 is located only in the first region 112a and is located on the side of the first tunneling layer 21 away from the substrate 11. The first passivation layer 23 is located on the side of the first doped conductive layer 22 away from the substrate 11 and is located in the first region 112a and the second region 112b. The first electrode 24... 4 is located on the side of the first passivation layer 23 away from the substrate 11, and the first electrode 24 is in electrical contact with the first doped conductive layer 22; wherein, the surface directly covered by the first passivation layer 23 and located in the second region 112b is the first sub-surface 112b1, and the first sub-surface 112b1 has a plurality of microstructures W1, the microstructures W1 being at least one of protrusions and depressions; in at least a portion of the first sub-surface 112b1, two adjacent microstructures W1 are spaced apart, and the distance between two adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0.

[0070] For example, the substrate 11 may contain doped elements, which can be N-type or P-type. N-type elements can be Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As), while P-type elements can be Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In). For instance, when the substrate 11 is a P-type substrate, its internal doped element type is P-type. Similarly, when the substrate 11 is an N-type substrate, its internal doped element type is N-type.

[0071] For example, the substrate 11 has a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 and the second surface 112 are disposed opposite to each other along the thickness direction of the substrate 11. Both the first surface 111 and the second surface 112 can be used to receive incident light.

[0072] For example, in some embodiments, the first surface 111 of the substrate 11 (e.g., the first surface 111 is the front) is the main light-receiving surface, and the second surface 112 of the substrate 11 is the secondary light-receiving surface (e.g., the second surface 112 is the back).

[0073] For example, in some other embodiments, the second surface 112 of the substrate 11 (e.g., the second surface 112 is the front side) is the primary light-receiving surface, and the first surface 111 of the substrate 11 is the secondary light-receiving surface (e.g., the first surface 111 is the back side).

[0074] It is understandable that the terms "light-receiving surface" and "back-lighting surface" are relative. The light-receiving surface is specifically the surface on the substrate 11 of a solar cell or photovoltaic module that is primarily exposed to sunlight. With the development of solar cell technology, the back-lighting surface also receives energy from sunlight, mainly from reflected or scattered light from the surrounding environment.

[0075] For example, in some embodiments, the first doped conductive layer 22 has a first doped element, and the substrate 11 has a second doped element. The first doped element and the second doped element have different conductivity types. One of the first doped element and the second doped element is a P-type conductive element, and the other of the first doped element and the second doped element is an N-type conductive element, but it is not limited to this.

[0076] For example, the first tunneling layer 21 can be silicon oxide, and the first doped conductive layer 22 can be a doped polycrystalline silicon layer. With the development of solar cell technology, the materials of the first tunneling layer 21 and the first doped conductive layer 22 are not limited to these.

[0077] For example, the first region 112a is the region where the first electrode 24 is provided, and the second region 112b is the region where the first electrode 24 is not provided, or the region between two adjacent first electrodes 24. For example, the first region 112a is a grid line region, and the first electrode 24 is a grid line.

[0078] For example, in some implementations, such as Figure 1 and Figure 2 As shown, the surface of the first passivation layer 23 that is directly in contact with and covered and located in the second region 112b is the first sub-surface 112b1, which is the part of the first tunneling layer 21 that is away from the substrate 11.

[0079] For example, in some other implementations, such as Figure 3 and Figure 4 As shown, the surface of the first passivation layer 23 that is directly in contact with and covered and located in the second region 112b is the first sub-surface 112b1, and the first sub-surface 112b1 is the part of the substrate 11 that is away from the first surface 111.

[0080] In related technologies, the first doped conductive layer 22 in the second region 112b (e.g., the non-gateline region on the back side) located on the second surface 112 is removed, while the first doped conductive layer 22 in the first region 112a (e.g., the gateline region on the back side) is retained as a local contact. However, after removing (e.g., by MAX laser processing) the first doped conductive layer 22 in the second region 112b, the surface of the removed area is relatively flat and smooth. This relatively flat and smooth surface leads to insufficient adhesion of the subsequently deposited first passivation layer 23 (e.g., an alumina layer, or a stack formed by alumina and silicon nitride). In the high-temperature sintering process subsequently experienced by the solar cell 100, the stress inside the first passivation layer 23 (especially the alumina layer) and the hydrogen ions (H+) released by the breaking of Si-H, NH and other bonds... + It is easy to escape through weakly bounded interfaces (H) + Effusion), this H + The combined effects of escape and insufficient adhesion easily lead to "bubbling," "peeling," or "blistering" problems in the first passivation layer 23 (especially the alumina layer). These defects severely disrupt the continuity of the first passivation layer 23, reduce its effective passivation capability for charge carriers, increase recombination losses, and may cause abnormal grid line contacts. Ultimately, this reduces the open-circuit voltage (Voc), fill factor (FF), and conversion efficiency of the solar cell 100, significantly offsetting or even turning the current gain brought about by the laser removal process (e.g., MAX laser treatment) to reduce parasitic absorption into a negative effect. Therefore, the performance of the solar cell still needs to be improved.

[0081] For example, microstructure refers to a structure observed at a microscopic scale. In some embodiments, microstructures can be observed using a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0082] For example, the first sub-surface 112b1 is a rough surface, and the first sub-surface 112b1 has a plurality of microstructures W1, wherein the microstructures W1 are at least one of protrusions and depressions. Figures 1 to 4 The microstructure W1 is shown to be a protrusion. Figure 5 The microstructure W1 is shown to be concave. Figure 6 This illustrates that microstructure W1 can be convex or concave (a portion of microstructures W1 are convex, and a portion of microstructures W1 are concave). For example... Figures 1 to 6 As shown, for example, the first sub-surface 112b1 can be a plane, and the microstructure W1 protrudes in a direction away from the first surface 111 relative to the first sub-surface 112b1, or the microstructure W1 is recessed in a direction closer to the first surface 111 relative to the first sub-surface 112b1.

[0083] For example, the cross-sectional structure of the microstructure is trapezoidal. The flat (or relatively flat) top region of the trapezoid can provide a large area of ​​uniform chemical bonding (e.g., Si-O-Al bonds), which can act as a stress buffer zone after stress generation, preventing the expansion of "bubbling," "peeling," or "blistering." The inclined side of the trapezoid can increase the contact area and mechanical interlocking force (mechanical interlocking effect) between the first passivation layer 23 and the first sub-surface 112b1, providing a stronger physical bond. Figure 1 As shown, the microstructure W1 is a protrusion, and the side of the trapezoid furthest from the first surface 111 is the flat top region of the trapezoid. Figure 5 As shown, the microstructure W1 is concave, and the side of the trapezoid near the first surface 111 is the flat top region of the trapezoid.

[0084] For example, in at least a portion of the first sub-surface 112b1, two adjacent microstructures W1 are spaced apart, and the distance between two adjacent microstructures W1 in a direction parallel to the plane of the second surface is greater than 0. Figures 1 to 6 As shown, the first sub-surface 112b1 can be a plane, and the first sub-surface 112b1 has a plurality of microstructures W1 arranged at intervals. The distance between two adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0, that is, two adjacent microstructures W1 are not connected to each other. For example Figures 1 to 4 Adjacent protrusions are not connected to each other, for example... Figure 5 Adjacent depressions are not connected to each other, for example Figure 6 Adjacent protrusions and depressions are not connected to each other.

[0085] It should be noted that, in at least a portion of the first sub-surface 112b1, adjacent microstructures W1 are spaced apart, and the distance between adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0. This can be a large portion of the first sub-surface 112b1, for example, greater than 50%, 60%, 70%, 80%, or 90% of the area, where adjacent microstructures W1 are spaced apart. Alternatively, it can be a small portion of the first sub-surface 112b1, for example, less than 10% of the area, where adjacent microstructures W1 can be connected to each other.

[0086] It should be noted that in some other embodiments, adjacent microstructures W1 are spaced apart in the entire area of ​​the first sub-surface 112b1, and the distance between adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0, which will not be described in detail here.

[0087] For example, it is easy to understand that, relative to microstructure W1, the portion between two adjacent microstructures W1 is a planar or flat portion (i.e., without protrusions or depressions). Microstructure W1 increases the contact area and mechanical interlocking force (mechanical interlocking effect) between the first passivation layer 23 and the first sub-surface 112b1, providing a stronger physical bond and significantly improving the adhesion of the first passivation layer 23 on the first sub-surface 112b1. At the same time, the planar or flat portion (i.e., without protrusions or depressions) between two adjacent microstructures W1 provides a larger area of ​​uniform chemical bonding (e.g., Si-O-Al bonds), which can serve as a stress buffer zone after stress generation. The combination of microstructure W1 and the planar or flat portion between two adjacent microstructures W1 ensures both strong adhesion and good stress distribution and stress buffering, thereby better preventing the first passivation layer 23 (especially the alumina layer) from "bubbling," "peeling," or "blistering."

[0088] In this embodiment of the application, the surface directly contacted and covered by the first passivation layer 23 and located in the second region 112b is the first sub-surface 112b1. The first sub-surface 112b1 has a plurality of microstructures W1, and the microstructures W1 are at least one of protrusions and depressions. In at least a portion of the first sub-surface 112b1, two adjacent microstructures W1 are spaced apart, and the distance between two adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0. Firstly, the first sub-surface 112b1 is a rough surface. Relative to the microstructure W1, the regions between adjacent microstructures W1 are planar or flat (i.e., without protrusions or depressions). The microstructure W1 increases the contact area and mechanical interlocking force (mechanical interlocking effect) between the first passivation layer 23 and the first sub-surface 112b1, providing a stronger physical bond and significantly improving the adhesion of the first passivation layer 23 to the first sub-surface 112b1. Simultaneously, the planar or flat regions (i.e., without protrusions or depressions) between adjacent microstructures W1 provide a large area of ​​uniform chemical bonding (e.g., Si-O-Al bonds), which can serve as a stress buffer zone after stress generation. The combination of microstructure W1 and the planar or flat regions between adjacent microstructures W1 ensures both strong adhesion and good stress distribution and buffering, thereby better preventing "bubbling," "peeling," or "blistering" problems in the first passivation layer 23 (especially the alumina layer). Secondly, the rough surface can absorb and dissipate the thermal stress, intrinsic stress, and additional stress caused by the release of H ions generated inside the first passivation layer 23 during the subsequent high-temperature sintering process, reducing stress concentration and lowering the driving force for film peeling. In other words, the rough surface provides a good stress buffer. Thirdly, the rough surface can microscopically extend the diffusion path of H ions escaping from the inside of the first passivation layer 23 to the substrate 11, increasing the H diffusion resistance and reducing the risk of H accumulating in local areas and breaking through the first passivation layer 23. Fourthly, in conjunction with the solar cell manufacturing method of this application, a first laser is used to remove at least the first doped conductive preset layer in the second region, and a second laser is used to roughen the first sub-surface. The energy of the first laser is greater than that of the second laser, and the energy of the second laser is lower. When the second laser creates a rough structure on the first sub-surface 112b1, more dangling bonds and unsaturated bonds are generated on the first sub-surface 112b1, which is more conducive to the formation of stronger chemical bonds between the precursor of the first passivation layer 23 and the first sub-surface 112b1 in the subsequent ALD (atomic layer deposition) process (e.g., the first sub-surface is...). Figure 3 and Figure 4In the example, a portion of the surface of substrate 11 can form stronger Si-O-Al bonds. From one or more of the above aspects, the problems of "bubbling," "peeling," or "blistering" of the first passivation layer 23 (especially the alumina layer) are improved or avoided, thereby enhancing the continuity of the first passivation layer 23, improving its effective passivation capability for charge carriers, reducing recombination losses, and improving or avoiding grid contact anomalies. Ultimately, this improves the open-circuit voltage (Voc), fill factor (FF), and conversion efficiency of the solar cell 100, thus enhancing the performance of the solar cell.

[0089] For example, in some embodiments, the first sub-surface 112b1 has multiple irregular microstructures W1, that is, the first sub-surface 112b1 has multiple irregular protrusions and / or depressions. Irregular protrusions and / or depressions refer to the fact that the dimensions of multiple protrusions or multiple depressions are not uniform or consistent in the first direction X, and / or that the dimensions of multiple protrusions or multiple depressions are not uniform or consistent in the second direction Y, and / or that the shapes of multiple protrusions or multiple depressions are not the same. The first passivation layer 23 and the first sub-surface 112b1 can form multiple mechanical interlocking actions of different sizes and directions at different locations, thus better improving adhesion.

[0090] In some embodiments, the roughness of the first sub-surface 112b1 is 0.2 μm-1.6 μm; and / or, the density of the microstructure W1 is 5 × 10⁻⁶. 4 pcs / cm²-2×10 5 pcs / cm²

[0091] For example, combined Figure 12 As shown, the protrusions tq1 or depressions on the first sub-surface can be measured using a 3D microscope or a scanning electron microscope (SEM). Figure 12 The image is taken under a 3D microscope, showing multiple irregular protrusions tq1 on the first subsurface 112b1.

[0092] For example, the roughness of the first sub-surface 112b1 needs to match the thickness and / or material of the first passivation layer 23. Through verification and analysis by the inventors, the roughness of the first sub-surface 112b1 is 0.2 μm-1.6 μm, and / or the density of the microstructure W1 is 5 × 10⁻⁶. 4 pcs / cm²-2×10 5 When the number of cells / cm² is increased, the interfacial bonding performance between the first passivation layer 23 and the first sub-surface 112b1 can be improved.

[0093] For example, the roughness of the first sub-surface 112b1 is 0.2μm-1.6μm, and the roughness of the first sub-surface 112b1 can be any value among 0.2μm, 0.4μm, 0.5μm, 0.8μm, 1.0μm, 1.2μm, 1.3μm, 1.5μm, and 1.6μm.

[0094] For example, the density of microstructure W1 is 5 × 10⁻⁶. 4 pcs / cm² - 2×10 5 The density of microstructure W1 can be 5 × 10⁻⁶ units / cm². 4 pcs / cm², 4.5×10 4 Units / cm², 4×10 4 pcs / cm², 3.5×10 4 Units / cm², 3×10 4 pcs / cm², 2.5×10 4 Units / cm², 2×10 5 Any value in the range of units / cm².

[0095] In some implementations, such as Figure 2 and Figure 4 As shown, in the direction perpendicular to the plane of the second surface 112, the height of the protrusion or the depth of the depression is 1 micrometer to 3 micrometers; in the direction parallel to the plane of the second surface 112, the width of the protrusion or depression is 2 micrometers to 5 micrometers.

[0096] For example, such as Figure 2 and Figure 4 As shown, the direction perpendicular to the plane containing the second surface 112, or the thickness direction of the substrate 11, is the second direction Y. The direction parallel to the plane containing the first surface 111, or the plane containing the substrate, is the first direction X.

[0097] For example, such as Figure 2 and Figure 4 As shown, in the second direction Y, the height of the protrusion or the depth of the depression is a first value d1, which is 1 micrometer to 3 micrometers. The first value d1 can be any value among 1 micrometer, 1.2 micrometers, 1.5 micrometers, 1.8 micrometers, 2 micrometers, 2.2 micrometers, 2.5 micrometers, 2.8 micrometers, and 3 micrometers. The larger the first value d1, the stronger the anchoring effect (stronger mechanical interlocking effect) between the first passivation layer 23 and the first sub-surface 112b1. However, this will lead to an increase in the surface area of ​​the first sub-surface 112b1 and introduce lattice damage into the substrate 11, exacerbating carrier recombination and resulting in open-circuit voltage (Voc) loss. Therefore, setting the first value d1 to 1 micrometer to 3 micrometers can provide a strong anchoring effect between the first passivation layer 23 and the first sub-surface 112b1 while avoiding exacerbating carrier recombination and avoiding open-circuit voltage (Voc) loss.

[0098] For example, such as Figure 2 and Figure 4 As shown, in the direction parallel to the plane of the second surface 112, the width of the protrusion or depression is the first width d2, which is 2-5 micrometers. The first width d2 can be any value among 2 micrometers, 2.5 micrometers, 3 micrometers, 3.5 micrometers, 4 micrometers, 4.5 micrometers, and 5 micrometers. The first width d2 and the number of microstructures W1 determine the area ratio of microstructures W1 on the first sub-surface 112b1. The larger the area ratio of microstructures W1 on the first sub-surface 112b1, the stronger the anchoring effect (stronger the mechanical interlocking effect) of the first sub-surface 112b1, but it will reduce the stress buffering effect of the planar or flat parts between two adjacent microstructures W1. A first width d2 of 2-5 micrometers allows the area ratio of microstructures W1 to be within an appropriate range, which can simultaneously provide a strong anchoring effect and a good stress buffering effect.

[0099] For example, such as Figure 2 and Figure 4 As shown, by setting appropriate dimensions for the protrusions and / or recesses, a suitable surface roughness can be formed on the first sub-surface 112b1.

[0100] For example, the first value d1 is 1 micrometer to 3 micrometers and the first width d2 is 2 micrometers to 5 micrometers. This can provide a strong anchoring effect and a good stress buffering effect for the first passivation layer 23 and the first sub-surface 112b1, while avoiding the aggravation of carrier recombination and avoiding the loss of open circuit voltage (Voc).

[0101] In some implementations, such as Figure 1 and Figure 2 As shown, the first tunneling layer 21 is located in the first region 112a and the second region 112b. The first tunneling layer 21 includes a first portion 211 located in the first region 112a and a second portion 212 located in the second region 112b. The first sub-surface 112b1 is the surface of the second portion 212 away from the substrate 11. In the direction perpendicular to the plane of the second surface 112, the thickness of the first portion 211 is greater than the thickness of the second portion 212.

[0102] For example, such as Figure 1 and Figure 2As shown, in the first region 112a, along the direction of the second surface 112 away from the first surface 111, the substrate 11, the first portion 211 of the first tunneling layer 21, the first doped conductive layer 22, the first passivation layer 23, and the first electrode 24 are sequentially stacked. In the second region 112b, along the direction of the second surface 112 away from the first surface 111, the substrate 11, the second portion 212 of the first tunneling layer 21, and the first passivation layer 23 are sequentially stacked. The first sub-surface 112b1 is the surface of the second portion 212 away from the substrate 11, and the first passivation layer 23 directly contacts the first sub-surface 112b1.

[0103] For example, such as Figure 1 and Figure 2 As shown, in the direction perpendicular to the plane of the second surface 112 (second direction Y), the thickness of the first part 211 is the first thickness h1, and the thickness of the second part 212 is the second thickness h2. Since multiple irregular protrusions and / or depressions are provided on the first sub-surface 112b1, the first thickness h1 is greater than the second thickness h2.

[0104] It should be noted that, in Figure 1 and Figure 2 In the example, the second part 212 of the first tunneling layer 21 is retained in the second region 112b. At this time, the function of the first tunneling layer 21 is retained in the second region 112b, which can provide a certain stress buffering effect and can better avoid or improve the occurrence of "bubbling", "peeling" or "blistering" of the first passivation layer 23 (especially the alumina layer).

[0105] In some implementations, such as Figure 1 and Figure 2 As shown, in the direction perpendicular to the plane containing the second surface 112, the height difference between the first part 211 and the second part 212 is 0.5nm-1.6nm.

[0106] For example, such as Figure 1 and Figure 2 As shown, the difference between the first thickness h1 and the second thickness h2 is 0.5nm-1.6nm, and the difference between the first thickness h1 and the second thickness h2 can be any value among 0.5nm, 0.7nm, 0.8nm, 1nm, 1.2nm, 1.4nm, 1.5nm, and 1.6nm.

[0107] For example, such as Figure 1 and Figure 2As shown, the difference between the first thickness h1 and the second thickness h2 is 0.5nm-1.6nm. Taking into account process fluctuations and the thickness of the first tunneling layer 21 in the second direction Y, the part of the first sub-surface 112b1 closest to the first surface 111 can be the material of the first tunneling layer 21. For example, the bottom of the protrusion and / or the bottom of the depression on the first sub-surface 112b1 can be the material of the first tunneling layer 21 (the thickness of the second part 212 of the first tunneling layer 21 in the second direction Y is greater than 0), so that the material of the first doped conductive layer 22 is completely removed at least at the bottom of the protrusion and / or the bottom of the depression.

[0108] In some implementations, such as Figure 1 and Figure 2 As shown, the first sub-surface 112b1 has multiple irregular protrusions; in the direction perpendicular to the plane of the second surface 112, the height of the protrusions is 0.2 micrometers to 0.5 micrometers.

[0109] For example, such as Figure 1 and Figure 2 As shown, the first sub-surface 112b1 is the surface of the second part 212 of the first tunneling layer 21 away from the substrate 11. Considering the thickness of the first doped conductive layer 22 and the first tunneling layer 21, the height of the protrusion in the second direction Y is 0.2 micrometers to 0.5 micrometers. For example, the height of the protrusion in the second direction Y can be any value among 0.2 micrometers, 0.25 micrometers, 0.3 micrometers, 0.35 micrometers, 0.4 micrometers, 0.45 micrometers, and 0.5 micrometers.

[0110] It should be noted that in some other implementations, Figure 1 and Figure 2 In the example, the thickness of the first tunneling layer 21 is small in the second direction Y. Along the direction of the second surface 112 away from the first surface 111, the top of the protrusion on the first sub-surface 112b1 can be the material of the first doped conductive layer 22, and the bottom of the protrusion can be the material of the first tunneling layer 21.

[0111] In some implementations, such as Figure 3 and Figure 4 As shown, the first sub-surface 112b1 is a portion of the substrate 11 that is away from the first surface 111, and the first passivation layer 23 covers the surface of the substrate 11 in the second region 112b.

[0112] For example, such as Figure 3 and Figure 4As shown, in the first region 112a, along the direction of the second surface 112 away from the first surface 111, the substrate 11, the first portion 211 of the first tunneling layer 21, the first doped conductive layer 22, the first passivation layer 23, and the first electrode 24 are sequentially stacked. In the second region 112b, along the direction of the second surface 112 away from the first surface 111, the substrate 11 and the first passivation layer 23 are sequentially stacked, the first sub-surface 112b1 is a portion of the surface of the substrate 11, and the first passivation layer 23 covers (e.g., directly contacts and covers) the first sub-surface 112b1.

[0113] For example, compared to Figure 1 and Figure 2 Example, in Figure 3 and Figure 4 In the example, the thickness of the first tunneling layer 21 and the first doped conductive layer 22 in the second direction Y is small. The first sub-surface 112b1 can be set as part of the surface of the substrate 11, which can better tolerate process fluctuations and is also easier to set a larger first value d1 in the second direction Y.

[0114] In some implementations, such as Figure 3 and Figure 4 As shown, in the direction perpendicular to the plane where the second surface 112 is located, the distance from the second surface 112 at the first region 112a to the first surface 111 is the first distance h3, and the distance from the second surface 112 at the second region 112b to the first surface 111 is the second distance h4. The difference between the first distance h3 and the second distance h4 is 1μm-3μm.

[0115] For example, such as Figure 3 and Figure 4 As shown, the first sub-surface 112b1 has multiple microstructures W1; in the direction perpendicular to the plane of the second surface 112, the height of the protrusion is 1 micrometer to 3 micrometers, and the first value d1 can be any value among 1 micrometer, 1.2 micrometer, 1.5 micrometer, 1.8 micrometer, 2 micrometer, 2.2 micrometer, 2.5 micrometer, 2.8 micrometer, and 3 micrometer.

[0116] It should be noted that, in Figure 3 and Figure 4In the example, the second portion 212 of the first tunneling layer 21 is not retained in the second region 112b. In this case, a larger surface roughness can be formed in the second region 112b, providing stronger mechanical anchoring between the first passivation layer 23 and the first sub-surface 112b1. This can better prevent or improve the occurrence of "bubbling," "peeling," or "blistering" of the first passivation layer 23 (especially the alumina layer). However, it is necessary to control the carrier recombination loss at the first sub-surface 112b1. For example, in this application, by strictly controlling the roughness of the first sub-surface 112b1, the carrier recombination loss at the first sub-surface 112b1 can be reduced or avoided; for example, in this application, by setting the difference between the first distance h3 and the second distance h4 to 1μm-3μm, the carrier recombination loss at the first sub-surface 112b1 can be reduced or avoided.

[0117] It should be noted that, as Figures 1 to 4 As shown, the solar cell 100 of this application is illustrated using a tunnel oxide passivated contact (TOPCon) cell as an example. With the development of solar cell technology, the first tunneling layer 21, the first doped conductive layer 22, the first passivation layer 23, the first sub-surface 112b1, and the first electrode 24 can also be applied to other types of solar cells.

[0118] It should be noted that, as Figures 1 to 4 As shown, the solar cell 100 also includes an emitter layer 12, a second passivation layer 13, and a second electrode 14. The emitter layer 12 is located on one side of the first surface 111, the second passivation layer 13 is located on the side of the emitter layer 12 away from the substrate 11, and the second electrode 14 is located on the side of the second passivation layer 13 away from the substrate 11. The second electrode 14 is in electrical contact with the emitter layer 12.

[0119] For example, the material of the first passivation layer 23 includes at least one of silicon oxide, silicon nitride, and silicon oxynitride. Silicon oxide, silicon nitride, and silicon oxynitride have good passivation and antireflection properties.

[0120] It should be noted that in some implementation methods, such as Figure 1 and Figure 3 As shown, in the TOPCon battery, the first surface 111 of the substrate 11 is the front side, and the first surface 111 may also have multiple textured structures R1. The textured structure R1 can be a pyramid structure or an inverted pyramid structure, which is not limited here.

[0121] It should be noted that the orthographic projection of the first sub-surface 112b1 onto the plane of the substrate 11 is located between the orthographic projections of the two adjacent first electrodes 24 onto the plane of the substrate 11.

[0122] It should be noted that the second surface 112 includes alternately arranged first regions 112a and second regions 112b, and the second surface 112 may include multiple (at least two) second regions 112b. The solar cell 100 may include multiple (at least two) first sub-surfaces 112b1. At least one first sub-surface 112b1 is... Figure 1 and Figure 2 In an example configuration, the first tunneling layer 21 is located in at least one second region 112b and adjacent first regions 112a on both sides of the second region 112b. In this configuration, the first tunneling layer 21 includes a first portion 211 located in the first region 112a and a second portion 212 located in the second region 112b. A first sub-surface 112b1 is the surface of the second portion 212 away from the substrate 11. In a direction perpendicular to the plane of the second surface 112, the thickness of the first portion 211 is greater than the thickness of the second portion 212. 2) At least one first sub-surface 112b1 is... Figures 3 to 6 In an example setup, at least one first sub-surface 112b1 is a portion of the substrate 11 that is away from the first surface 111, and the first passivation layer 23 covers the surface of the substrate 11 in the second region 112b.

[0123] It should be noted that the second surface 112 includes alternating first regions 112a and second regions 112b, and the second surface 112 may include multiple (at least two) second regions 112b. The solar cell 100 may include multiple (at least two) first sub-surfaces 112b1. 1) At least one first sub-surface 112b1 is configured such that: a first tunneling layer 21 is located in the first region 112a and the second region 112b, the first tunneling layer 21 includes a first portion 211 located in the first region 112a and a second portion 212 located in the second region 112b, and the first sub-surface 112b1 is the surface of the second portion 212 away from the substrate 11; in the direction perpendicular to the plane of the second surface 112, the thickness of the first portion 211 is greater than the thickness of the second portion 212. 2) At least one first sub-surface 112b1 is configured such that: the first sub-surface 112b1 is a portion of the substrate 11 facing away from the first surface 111, and the first passivation layer 23 covers the surface of the substrate 11 in the second region 112b.

[0124] Secondly, based on the same application concept, such as Figures 7 to 11 As shown, this application also provides a method for manufacturing a solar cell, and any of the solar cells 100 described above can be manufactured using this method. Figure 7 As shown, the manufacturing method of solar cell 100 includes steps S100, S200, S300, S400, and S500.

[0125] Step S100: A substrate is provided, the substrate having a first surface and a second surface disposed opposite to each other, the second surface including an alternately disposed first region and a second region.

[0126] For example, such as Figure 8 As shown, a substrate 11 is provided, the substrate 11 having a first surface 111 and a second surface 112 disposed opposite to each other, the second surface 112 including an alternately disposed first region 112a and a second region 112b.

[0127] Step S200: A first tunneling layer is formed on the second surface, wherein the first tunneling layer is located at least in the first region.

[0128] For example, such as Figure 8 As shown, a first tunneling layer 21 is formed on the second surface 112, and the first tunneling layer 21 is located at least in the first region 112a.

[0129] For example, such as Figure 8 As shown, in some embodiments, the first tunneling layer 21 formed in step S200 is located in the first region 112a and the second region 112b.

[0130] Step S300: A first doped conductive preset layer is formed on the side of the first tunneling layer away from the substrate.

[0131] For example, such as Figure 9 As shown, a first doped conductive preset layer 22Y is formed on the side of the first tunneling layer 21 away from the substrate 11. At this time, the first doped conductive preset layer 22Y is located in the first region 112a and the second region 112b.

[0132] In step S400, at least the first doped conductive preset layer is removed in the second region to form a first doped conductive layer, thereby forming a first sub-surface located in the second region, wherein the first doped conductive layer is located only in the first region.

[0133] For example, such as Figure 10 As shown, at least the first doped conductive preset layer is removed before the second region 112b to form the first doped conductive layer 22, so as to form the first sub-surface 112b1 located in the second region 112b. The first doped conductive layer 22 is only located in the first region 112a.

[0134] For example, such as Figure 10 As shown, in some embodiments, forming Figure 1 and Figure 2 In the example, at least the first doped conductive preset layer is removed in the second region 112b to form the first doped conductive layer 22.

[0135] For example, such as Figure 10As shown, in some other embodiments, forming Figure 3 and Figure 4 In the example, the first doped conductive preset layer and the first tunneling layer 21 located in the second region 112b are removed.

[0136] For example, removing the first doped conductive preset layer located in the second region to form the first doped conductive layer can ensure that the subsequent step S500 (e.g., the second laser) directly acts on the first tunneling layer 21 or the substrate 11. The material of the residual first doped conductive layer 22 will hinder the bonding of the first passivation layer 23 to the first sub-surface 112b1, and the difference in the coefficient of thermal expansion of the material of the residual first doped conductive layer 22 is prone to blistering. This avoids the material of the residual first doped conductive layer 22 causing the subsequent first passivation layer 23 to fail to adhere to the first sub-surface 112b1.

[0137] Step S500: The first sub-surface is further roughened. The first sub-surface has multiple microstructures, which are at least one of protrusions and depressions. In at least a portion of the first sub-surface, adjacent microstructures are spaced apart, and the distance between adjacent microstructures in a direction parallel to the plane of the second surface is greater than 0. For example, as... Figure 11 As shown, the first sub-surface 112b1 is further roughened to make it a rough surface. The first sub-surface 112b1 has a plurality of microstructures W1, which are at least one of protrusions and depressions. In at least a portion of the first sub-surface 112b1, two adjacent microstructures W1 are spaced apart, and the distance between two adjacent microstructures W1 in the direction parallel to the plane of the second surface is greater than 0.

[0138] It should be noted that, in some embodiments, after step S500, the method for manufacturing a solar cell may further include: step S600, forming a first passivation layer 23 on the side of the first doped conductive layer 22 away from the substrate 11, the first passivation layer 23 directly contacting the first sub-surface 112b1; step S700, forming a first electrode 24 on the side of the first passivation layer 23 away from the substrate 11, the first electrode 24 being in electrical contact with the first doped conductive layer 22.

[0139] It should be noted that, in some embodiments, the method for manufacturing a solar cell may further include: step S1001, texturing the first surface 111 to form a textured surface structure R1 with multiple pyramid or inverted pyramid structures; step S1002, forming an emitter layer 12 on the first surface; step S1003, forming a second passivation layer 13 on the emitter layer 12 away from the substrate 11; and step S1004, forming a second electrode 14 on the side of the second passivation layer 13 away from the substrate, wherein the second electrode 14 is in electrical contact with the emitter layer 12.

[0140] It should be noted that, in some embodiments, after step S500 and before step S600, the method for manufacturing a solar cell may further include: step S506, cleaning the first region 112a and the second region 112b, for example by using chemical cleaning such as hydrofluoric acid, to remove a small amount of splashes, loose debris and natural oxide layer generated by the roughening treatment of the first sub-surface 112b1, thereby exposing a clean first sub-surface 112b1.

[0141] It should be noted that the manufacturing method of the solar cell in this application has the same beneficial effects as the solar cell 100 described above, and will not be repeated here.

[0142] In some implementations, such as Figure 10 As shown, the step of removing at least the first doped conductive preset layer in the second region 112b to form the first doped conductive layer 22 (step S400) includes: using a first laser to remove at least the portion of the first doped conductive preset layer in the second region 112b. Figure 11 As shown, the step of roughening the first sub-surface 112b1 (step S500) includes: roughening the first sub-surface 112b1 with a second laser; wherein the energy of the first laser is greater than the energy of the second laser.

[0143] For example, the energy of the first laser is greater than that of the second laser. The higher energy of the first laser allows for the rapid removal of material and film layers from the first sub-surface 112b1 that are far from the first surface 111. The lower energy of the second laser allows the first sub-surface 112b1 to become a rough surface, forming multiple microstructures W1. At the same time, it can prevent the second laser from causing substantial damage to the first laser processing boundary or the film layer below the first sub-surface 112b1.

[0144] For example, the first laser is an infrared or ultraviolet laser; and / or, the second laser is a nanosecond or picosecond laser.

[0145] For example, the energy of lasers in the infrared or ultraviolet bands is greater than that of nanosecond or picosecond lasers.

[0146] In some embodiments, the energy density of the first laser is 5 J / cm²-20 J / cm²; the pulse width of the laser is 10 ns-200 ns; the scanning speed of the laser is 500-2000 mm / s; the repetition frequency of the laser is 50 kHz-300 kHz; and the spot size of the laser is 20 μm-50 μm.

[0147] For example, by setting the parameters of the first laser, it is possible to ensure that the first doped conductive layer 22 at the second region 112b is completely vaporized, while avoiding excessive damage to the film layer near the first surface 111 on the first sub-surface 112b1. This balances processing efficiency with control of the heat-affected zone and ensures uniformity when removing material from the second region 112b.

[0148] In some embodiments, the energy density of the second laser is 0.2 J / cm²-5 J / cm²; the pulse width of the laser is 10 ns-50 ns; the scanning speed of the laser is 1000-5000 mm / s; the repetition frequency of the laser is 50 kHz-100 kHz; and the spot size of the laser is 10 μm-30 μm.

[0149] For example, by precisely controlling the energy density, pulse width, and scanning speed of the second laser as described above, the first sub-surface 112b1 is made to have a moderate roughness (micron-level protrusions / depressions). The goal is to form a surface roughness on the first sub-surface 112b1 that is significantly higher than that after the first laser treatment, without excessively damaging the film layer on the first sub-surface 112b1 close to the first surface 111 or destroying the smooth boundary formed by the first laser. The second laser treatment also needs to avoid introducing excessively deep cracks or causing excessive amorphization that affects the subsequent passivation effect, so as to control the roughness of the first sub-surface to be 0.2μm-1.6μm, and avoid the roughness of the first sub-surface being too large, which would affect the passivation quality of the first passivation layer 23.

[0150] In some embodiments, after the step of removing at least the first doped conductive preset layer prior to the second region 112b to form the first doped conductive layer 22 (step S400), the roughness of the first sub-surface 112b1 is less than 0.1 μm; after the step of further roughening the first sub-surface 112b1 (step S500), the roughness of the first sub-surface 112b1 is 0.2 μm-1.6 μm.

[0151] For example, after the step of removing at least the first doped conductive preset layer to form the first doped conductive layer 22 prior to the second region 112b (step S400), the first sub-surface 112b1 is a relatively flat and smooth surface, and the roughness of the first sub-surface 112b1 is less than 0.1 μm.

[0152] For example, after the step of roughening the first sub-surface 112b1 again (step S500), the first sub-surface 112b1 is made to have a suitable roughness, the roughness of the first sub-surface 112b1 being less than 0.1 μm.

[0153] Please see Figure 13 , Figure 13The performance parameters of Example 1 and Comparative Example 1 were compared. Example 1 was manufactured using the solar cell manufacturing method of the present application embodiment, the wavelength of the first laser was 1064 nm, and the second region 112b was a portion of the surface of the substrate 11 (e.g., Figure 3 and Figure 4 As shown), the second laser is a 355nm ultraviolet picosecond laser with an energy density of 0.5-1.0 J / cm², and the roughness Ra value of the first sub-surface 112b1 is 0.4±0.1 μm. Comparative Example 1 uses only the first laser to remove the film layer in the second region 112b, without the second laser processing. Figure 13 As can be seen, compared with Comparative Example 1, the adhesion of the first passivation layer 23 in Example 1 is significantly increased (from 10-15 MPa to 35-45 MPa), the bubble formation rate of the first passivation layer 23 in Example 1 is significantly reduced (from 15% to less than 5%), the short-circuit current Isc in Example 1 is slightly increased or has no loss (9.73A is similar to 9.65A), the open-circuit voltage Voc loss in Example 1 is significantly reduced (from 20mV to less than 5mV), the fill factor FF in Example 1 is increased by 0.8%, and the efficiency gain in Example 1 is 0.5%. Therefore, the embodiments of this application can significantly reduce the bubble formation rate of the first passivation layer 23 and improve various performance characteristics of the solar cell.

[0154] Thirdly, based on the same concept, this application also provides a stacked battery, which includes a top battery, an adhesive layer and a bottom battery stacked sequentially, wherein the bottom battery is a solar cell 100 of any of the above.

[0155] For example, in some embodiments, the top cell may be a perovskite solar cell 100, which includes: a first transport layer, a perovskite substrate 11, a second transport layer, a transparent conductive layer, and an antireflection layer stacked together. The first transport layer is directly opposite the bottom cell. The first transport layer may be either an electron transport layer or a hole transport layer, and the second transport layer may be either an electron transport layer or a hole transport layer.

[0156] It should be noted that the tandem cell of this application is based on the same concept as the solar cell 100 of any of the above claims, and the tandem cell has the same or similar effects as the solar cell 100 of any of the above claims, which will not be repeated here.

[0157] Please see Figure 14 , Figure 14 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0158] Fourthly, based on the same application concept, this application also provides a photovoltaic module 200, which includes: a battery string 203, which is formed by connecting a plurality of solar cells 100 as described above, or by connecting solar cells 100 manufactured by a method for manufacturing a plurality of solar cells as described above, or by connecting tandem cells as described above; a connecting member 204 for electrically connecting two adjacent solar cells 100; an encapsulating film 202 for covering the surface of the battery string 203; and a cover plate 201 for covering the surface of the encapsulating film 202 facing away from the surface of the battery string 203.

[0159] For example, in some embodiments, the connecting component 204 may include a conductive strip, through which multiple battery strings 203 can be electrically connected. The encapsulating film 202 covers both the front and back sides of the solar cell 100 or the tandem solar cell 100.

[0160] For example, in some embodiments, the encapsulating film 202 may be an organic encapsulating film such as ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene coelastomer (POE) film, or polyethylene terephthalate (PET) film.

[0161] For example, in some embodiments, the cover plate 201 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function.

[0162] For example, in some embodiments, the surface of the cover plate 201 facing the encapsulation layer can be an uneven surface, thereby increasing the utilization of incident light.

[0163] It should be noted that the photovoltaic module 200 of this application and the solar cell 100 of any of the above claims are based on the same application concept, and the photovoltaic module 200 and the solar cell 100 of any of the above claims have the same or similar effects, which will not be repeated here.

[0164] 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.

[0165] 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: The substrate has a first surface and a second surface disposed opposite to each other, the second surface including an alternately disposed first region and a second region; The first tunneling layer is located in the first region and the second region; The first doped conductive layer is located only in the first region and on the side of the first tunneling layer away from the substrate; The first tunneling layer includes a first portion located in the first region and a second portion located in the second region; in a direction perpendicular to the plane containing the second surface, the thickness of the first portion is greater than the thickness of the second portion. The second part, the surface away from the substrate, is a first sub-surface; the first sub-surface has a plurality of microstructures, the microstructures being at least one of protrusions and depressions.

2. The solar cell according to claim 1, characterized in that, In at least a portion of the first sub-surface, two adjacent microstructures are spaced apart, and the distance between two adjacent microstructures in a direction parallel to the plane containing the second surface is greater than 0.

3. The solar cell according to claim 1, characterized in that, In a direction perpendicular to the plane containing the second surface, the height of the protrusion or the depth of the depression is 1 micrometer to 3 micrometers.

4. The solar cell according to claim 1, characterized in that, In a direction parallel to the plane containing the second surface, the width of the protrusion or the depression is 2 micrometers to 5 micrometers.

5. The solar cell according to claim 1, characterized in that, The roughness of the first sub-surface is 0.2μm-1.6μm.

6. The solar cell according to claim 1, characterized in that, The density of the microstructure is 5 × 10⁻⁶. 4 pcs / cm²-2×10 5 pcs / cm² 7. The solar cell according to claim 2, characterized in that, In a region covering at least 70% of the area of ​​the first sub-surface, two adjacent microstructures are spaced apart.

8. The solar cell according to claim 1, characterized in that, In a direction perpendicular to the plane containing the second surface, the height difference between the first part and the second part is 0.5nm-1.6nm.

9. The solar cell according to claim 8, characterized in that, The first sub-surface has a plurality of irregular protrusions; The height of the protrusion is 0.2 micrometers to 0.5 micrometers in a direction perpendicular to the plane containing the second surface.

10. A method for manufacturing a solar cell, characterized in that, A method for manufacturing a solar cell as described in any one of claims 1 to 9, comprising: A substrate is provided, the substrate having a first surface and a second surface disposed opposite to each other, the second surface including alternating first regions and second regions; A first tunneling layer is formed on the second surface; A first doped conductive preset layer is formed on the side of the first tunneling layer away from the substrate; The first doped conductive preset layer is removed before the second region to form the first doped conductive layer, thereby forming a first sub-surface located in the second region, wherein the first doped conductive layer is located only in the first region; The first sub-surface is then roughened, and the first sub-surface has multiple microstructures, the microstructures being at least one of protrusions and depressions; the first tunneling layer is located in the first region and the second region, the first tunneling layer including a first portion located in the first region and a second portion located in the second region, the first sub-surface being the surface of the second portion away from the substrate; in a direction perpendicular to the plane of the second surface, the thickness of the first portion is greater than the thickness of the second portion.

11. The method for manufacturing a solar cell according to claim 10, characterized in that, The step of removing at least the first doped conductive preset layer in the second region to form the first doped conductive layer includes: using a first laser to remove at least the portion of the first doped conductive preset layer in the second region; The step of further roughening the first sub-surface includes: roughening the first sub-surface using a second laser; The energy of the first laser is greater than the energy of the second laser.

12. A stacked battery, characterized in that, It includes a top cell, an adhesive layer, and a bottom cell stacked in sequence, wherein the bottom cell is a solar cell as described in any one of claims 1 to 9.

13. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple solar cells as described in any one of claims 1 to 9, or by connecting multiple solar cells manufactured by the method of manufacturing solar cells as described in any one of claims 10 and 11, or by connecting tandem cells as described in claim 12. A connecting component for electrically connecting two adjacent solar cells; An encapsulating film is used to cover the surface of the battery string; and A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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