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, a second surface comprising alternately arranged first regions and second regions; a first tunneling layer located on one side of the second surface and at least on the first regions; a first doped conductive layer located only on the first regions and on the side of the first tunneling layer away from the substrate; and a first passivation layer located on the side of the first doped conductive layer away from the substrate and on the first regions and the second regions. The first passivation layer directly contacts the surface of the covered second regions, which is a first sub-surface, and the first sub-surface has a plurality of microstructures, which are at least one of protrusions and recesses. At least part of the first sub-surface, the adjacent two microstructures are arranged at intervals, and the interval of the adjacent two microstructures in the direction parallel to the plane of the second surface is greater than 0. The application improves the performance of the solar cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell manufacturing, in particular to a solar cell, a manufacturing method thereof, a stacked cell and a photovoltaic module. BACKGROUND

[0002] Solar energy, as a new energy, has various advantages compared with traditional fossil fuels, such as inexhaustibility, cleanness and environmental protection. At present, a main way of solar energy utilization is to convert received light energy into electrical energy output through a solar cell module, which can be a large-area cell module formed by packaging and arranging in a square matrix after a plurality of solar cells (or photovoltaic cells, or photovoltaic modules) are connected in series. Among them, the solar cell absorbs light energy, and the accumulation of opposite charges appears at both ends of the cell, that is, a "photovoltaic effect" is generated. Under the action of the photovoltaic effect, an electromotive force is generated at both ends of the solar cell, thereby converting light energy into electrical energy.

[0003] However, the performance of the solar cell in the related art still needs to be improved. SUMMARY

[0004] Therefore, it is necessary to provide a solar cell, a manufacturing method thereof, a stacked cell and a photovoltaic module to solve the problem that the performance of the solar cell in the related art still needs to be improved.

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

[0006] a substrate having a first surface and a second surface arranged oppositely, wherein the second surface comprises first regions and second regions arranged alternately;

[0007] a first tunneling layer located on one side of the second surface and at least on the first regions;

[0008] a first doped conductive layer located only on the first regions and on a side of the first tunneling layer away from the substrate;

[0009] a first passivation layer located on a side of the first doped conductive layer away from the substrate and on the first regions and the second regions;

[0010] wherein the first passivation layer directly contacts a surface of the second regions, the surface is a first sub-surface, the first sub-surface has a plurality of microstructures, and the microstructures are at least one of protrusions and recesses; at least part of the first sub-surface, two adjacent microstructures are arranged at intervals, and the interval of the two adjacent microstructures in a direction parallel to the plane where the second surface is located is greater than 0.

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

[0012] The microstructure has a density of 5×10 4 cm-2-2×10 5 cm-2.

[0013] In some embodiments, the height of the protrusion or the depth of the recess is 1 μm-3 μm in a direction perpendicular to the plane in which the second surface lies;

[0014] The width of the protrusion or the recess is 2 μm-5 μm in a direction parallel to the plane in which the second surface lies.

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

[0016] The thickness of the first portion is greater than the thickness of the second portion in a direction perpendicular to the plane in which the second surface lies.

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

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

[0019] The height of the protrusion is 0.2 μm-0.5 μm in a direction perpendicular to the plane in which the second surface lies.

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

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

[0022] In a second aspect, based on the same inventive concept, the present application also provides a method for manufacturing a solar cell, the method for manufacturing a solar cell comprises:

[0023] A substrate is provided, the substrate has a first surface and a second surface arranged oppositely, the second surface comprises first regions and second regions arranged alternately;

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

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

[0026] The first doped conductive preset layer is removed at least on the second regions to form a first doped conductive layer to form a first sub-surface on the second regions, the first doped conductive layer is located only on the first regions;

[0027] The first sub-surface is roughened, the first sub-surface has a plurality of microstructures, the microstructures are at least one of protrusions and recesses; at least part of the first sub-surface, two adjacent microstructures are arranged at intervals, and the interval between the 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 the first doped conductive preset layer at least on the second regions to form the first doped conductive layer comprises: using a first laser to remove the first doped conductive preset layer at least on the second regions;

[0029] The step of roughening the first sub-surface comprises: using a second laser to roughen the first sub-surface;

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

[0031] In some embodiments, in the first laser, the energy density of the 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, in the second laser, the energy density of the 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, the roughness of the first sub-surface is less than 0.1 μm after the step of removing at least a first doped conductive pre-set layer to form a first doped conductive layer prior to the step of forming the second region.

[0034] The roughness of the first sub-surface is 0.2 μm-1.6 μm after the step of roughening the first sub-surface again.

[0035] In a third aspect, the present application provides a laminated battery, comprising a top battery, a bonding layer and a bottom battery which are sequentially stacked, wherein the bottom battery is the solar cell according to any one of the above.

[0036] In a fourth aspect, the present application provides a photovoltaic module, comprising:

[0037] A battery string connected by a plurality of solar cells according to any one of the above, or connected by a plurality of solar cells manufactured by the manufacturing method according to any one of the above, or connected by the laminated battery according to the above;

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

[0039] An encapsulation adhesive film for covering the surface of the battery string;

[0040] A cover plate for covering the surface of the encapsulation adhesive film away from the battery string.

[0041] In the embodiments of the present application, the surface of the second region covered by the first passivation layer is a first sub-surface, the first sub-surface has a plurality of microstructures, and the microstructures are at least one of protrusions and recesses; at least part of the first sub-surface, the adjacent two microstructures are arranged at intervals, and the distance between the adjacent two microstructures in the direction parallel to the plane of the second surface is greater than 0. In the first aspect, the first sub-surface is a rough surface, and the positions between the adjacent two microstructures are planar positions or flat positions (i.e., without protrusions or recesses) relative to the microstructures. The microstructures increase the contact area and mechanical interlocking effect of the first passivation layer with the first sub-surface, can provide stronger physical bonding, and significantly improve the adhesion of the first passivation layer on the first sub-surface. At the same time, the planar positions or flat positions (i.e., without protrusions or recesses) between the adjacent two microstructures provide a larger area of uniform chemical bonding (for example, Si-O-Al bond) position, which can be used as a stress buffer zone after stress is generated. The combination of the microstructures and the planar positions or flat positions between the adjacent two microstructures not only ensures strong adhesion, but also ensures good stress distribution and stress buffering, so that the problem of "blistering", "peeling" or "foaming" of the first passivation layer (especially the aluminum oxide layer) can be better prevented. In the second aspect, the rough surface can absorb and dissipate the thermal stress, intrinsic stress and additional stress caused by the release of H ions generated in the first passivation layer during the subsequent high-temperature sintering process, reduce stress concentration, and reduce the driving force for film peeling. That is, the rough surface provides good stress buffering. In the third aspect, the rough surface can microscopically extend the diffusion path of H ions from the inside of the first passivation layer to the substrate, increase the H diffusion resistance, and reduce the risk of H gathering in a local area and breaking through the first passivation layer. In the fourth aspect, in combination with the manufacturing method of the solar cell, the first laser is used to remove at least part of the first doped conductive preset layer in the second region, and the second laser is used to roughen the first sub-surface. The energy of the first laser is greater than that of the second laser, the energy of the second laser is small, and when the second laser manufactures the rough structure of 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 bonding between the precursors 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 "blistering", "peeling" or "foaming" of the first passivation layer (especially the aluminum oxide layer) are improved or avoided, thereby improving the continuity of the first passivation layer, improving its effective passivation ability to the carriers, reducing the recombination loss, and improving or avoiding the abnormal contact of the grid lines. Finally, the open-circuit voltage (Voc), the fill factor (FF) and the conversion efficiency of the solar cell are improved and thus the performance of the solar cell is improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments or the example embodiments of the present application, the drawings needed to be used in the description of the embodiments or the example embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A first cross-sectional structure schematic diagram of a solar cell provided by an embodiment of the present application.

[0044] Figure 2 A partial enlarged schematic diagram of the first cross-sectional structure of the solar cell provided by the embodiment of the present application.

[0045] Figure 3 A second cross-sectional structure schematic diagram of a solar cell provided by an embodiment of the present application.

[0046] Figure 4 A partial enlarged schematic diagram of the second cross-sectional structure of the solar cell provided by the embodiment of the present application.

[0047] Figure 5 A partial enlarged schematic diagram of the third cross-sectional structure of the solar cell provided by the embodiment of the present application.

[0048] Figure 6 A partial enlarged schematic diagram of the fourth cross-sectional structure of the solar cell provided by the embodiment of the present application.

[0049] Figure 7 A flow step schematic diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0050] Figure 8 A first intermediate process schematic diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0051] Figure 9 A second intermediate process schematic diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0052] Figure 10 A third intermediate process schematic diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0053] Figure 11 A fourth intermediate process schematic diagram of a manufacturing method of a solar cell provided by an embodiment of the present application.

[0054] Figure 12 A photo of a second surface of a solar cell provided by an embodiment of the present application under a 3D microscope.

[0055] Figure 13 A comparison diagram of various performances of the embodiment 1 and the comparative example 1 of the present application.

[0056] Figure 14 A structural diagram of a photovoltaic module provided by the embodiment of the present application.

[0057] Figures: 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 numerical 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; cell string 203; connecting component 204; encapsulating adhesive film 202; cover plate 201; microstructure W1. DETAILED DESCRIPTION

[0058] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways beyond the specific embodiments described herein without departing from the scope of the present application, and it is understood that similar modifications can be made by those skilled in the art in the light of the following disclosure, and therefore the present application is not limited to the following disclosed specific embodiments.

[0059] In the description of the present application, it should be understood that if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0060] In addition, the terms "first", "second", and the like, if any, are used herein for descriptive purposes only and should not be construed as indicating or implying relative importance or identifying the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0061] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be interpreted broadly. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0062] In the present application, unless otherwise explicitly specified and limited, if the first feature is described as "on" or "under" the second feature or similar, it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the second feature, or only indicate that the first feature is higher than the second feature in horizontal height. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the second feature, or only indicate that the first feature is lower than the second feature in horizontal height.

[0063] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are for illustrative purposes only and do not represent the only implementation.

[0064] Reference Figures 1 to 13 . Figure 1 A first cross-sectional structure of a solar cell provided in an embodiment of the present application is shown in a schematic diagram. Figure 2 A first cross-sectional structure of a solar cell provided in an embodiment of the present application is shown in a schematic diagram. Figure 2 A first cross-sectional structure of a solar cell provided in an embodiment of the present application is shown in a schematic diagram. Figure 1 A first cross-sectional structure of a solar cell provided in an embodiment of the present application is shown in a schematic diagram.

[0065] Figure 3 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 4 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 4 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 3 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2.

[0066] Figure 5 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 6 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 2 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 4 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 5 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 6 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2.

[0067] Figure 7 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 8 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 9 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 10 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 11 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2.

[0068] Figure 12 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2. Figure 13 A second cross-sectional structure of a solar cell according to an embodiment of the present application is shown in FIG. 2.

[0069] In a first aspect, the present application provides a solar cell 100, which comprises 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 arranged oppositely, and the second surface 112 comprises first regions 112a and second regions 112b arranged alternately; the first tunneling layer 21 is located on one side of the second surface 112 and at least on the first regions 112a; the first doped conductive layer 22 is located only on the first regions 112a and 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 on the first regions 112a and the second regions 112b; the first electrode 24 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 first passivation layer 23 directly contacts the surface of the second regions 112b, and the surface of the first passivation layer 23 located on the second regions 112b is a first sub-surface 112b1, and the first sub-surface 112b1 has a plurality of microstructures W1, and the microstructures W1 are at least one of protrusions and recesses; at least part of the first sub-surface 112b1, the adjacent two microstructures W1 are arranged at intervals, and the interval of the adjacent two microstructures W1 in the direction parallel to the plane of the second surface is greater than 0.

[0070] For example, the substrate 11 can have a doping element, and the doping element can be an N-type or a P-type. The N-type element can be a group V element such as a phosphorus (P) element, a bismuth (Bi) element, an antimony (Sb) element, or an arsenic (As) element. The P-type element can be a group III element such as a boron (B) element, an aluminum (Al) element, a gallium (Ga) element, or an indium (In) element. For example, when the substrate 11 is a P-type substrate, the internal doping element is a P-type. For another example, when the substrate 11 is an N-type substrate, the internal doping element is an N-type.

[0071] For example, the substrate 11 has a first surface 111 and a second surface 112 arranged oppositely. The first surface 111 and the second surface 112 are arranged oppositely 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 (for example, the first surface 111 is a front surface) is a main light-receiving surface, and the second surface 112 of the substrate 11 is a secondary light-receiving surface (for example, the second surface 112 is a back surface).

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

[0074] It can be understood that the light-receiving surface and the back surface are relative terms, and the light-receiving surface is specifically a surface on which sunlight mainly irradiates on the substrate 11 in the solar cell or in the photovoltaic module. With the development of solar cell technology, the back surface will also receive the energy of sunlight, mainly from the reflected light or scattered light in the surrounding environment.

[0075] For example, in some embodiments, the first doped conductive layer 22 has a first doped element, the substrate 11 has a second doped element, the first doped element and the second doped element are different in conductive type, one of the first doped element and the second doped element is a P-type conductive element, and the other is an N-type conductive element, but not limited thereto.

[0076] For example, the first tunneling layer 21 can be silicon oxide, and the first doped conductive layer 22 can be a doped polysilicon 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 thereto.

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

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

[0079] For example, in some other embodiments, as shown in Figure 3 and Figure 4 , the first passivation layer 23 directly contacts the covered surface of the second region 112b, which is a first sub-surface 112b1, and the first sub-surface 112b1 is a part of the surface of the substrate 11 away from the first surface 111.

[0080] In the related art, the first doped conductive layer 22 located at the second region 112b (e.g., the non-gate line region of the back surface) of the second surface 112 is removed, and the first doped conductive layer 22 of the first region 112a (e.g., the gate line region of the back surface) is retained as a local contact. However, after the first doped conductive layer 22 of the second region 112b is removed (e.g., by MAX laser processing) in the related art, the surface of the removal site is relatively flat and smooth. The relatively flat and smooth surface can cause insufficient adhesion of the subsequently deposited first passivation layer 23 (e.g., an aluminum oxide layer, such as a stack of aluminum oxide and silicon nitride). During the subsequent high-temperature sintering process of the solar cell 100, the stress within the first passivation layer 23 (especially the aluminum oxide layer) and the hydrogen ions (H + ) released by the breaking of Si-H, N-H, and other bonds can easily escape (H + effusion) through the weakly bonded interface. This H + effusion and insufficient adhesion can easily cause the first passivation layer 23 (especially the aluminum oxide layer) to "bubble", "peel", or "blister". These defects severely damage the continuity of the first passivation layer 23, reduce its effective passivation ability for carriers, increase the recombination loss, and can cause abnormal gate line contact, ultimately reducing the open-circuit voltage (Voc), fill factor (FF), and conversion efficiency of the solar cell 100. As a result, the current gain brought by the laser removal process (e.g., MAX laser processing) to reduce parasitic absorption is greatly offset and even turned into a negative effect. Therefore, the performance of the solar cell needs to be improved.

[0081] By way of example, a microstructure refers to a structure observed at a microscopic scale. In some embodiments, the microstructure can be observed by a scanning electron microscope (SEM) or a transmission electron microscope (TEM).

[0082] By way of example, the first sub-surface 112b1 is a rough surface, and the first sub-surface 112b1 has a plurality of microstructures W1, the microstructures W1 being at least one of protrusions and recesses. Figures 1 to 4 It is shown that the microstructures W1 are protrusions, Figure 5 It is shown that the microstructures W1 are recesses, Figure 6 It is shown that the microstructures W1 are protrusions and recesses (part of the microstructures W1 are protrusions, and part of the microstructures W1 are recesses). As Figures 1 to 6 shown, for example, the first sub-surface 112b1 can be a plane, and the microstructures W1 protrude in a direction away from the first surface 111 relative to the first sub-surface 112b1, or the microstructures W1 are recessed in a direction close 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 top flat area (or relatively flat area) of the trapezoid can provide a larger area of uniform chemical bonding (for example, Si-O-Al bond) sites, which can act as a stress buffer zone after stress generation, preventing "blistering", "peeling" or "bubbling" from expanding; the inclined edge of the trapezoid can increase the contact area and mechanical interlocking force (mechanical interlocking effect) of the first passivation layer 23 and the first sub-surface 112b1, and can provide stronger physical bonding. As shown in Figure 1 For example, the microstructure W1 is a protrusion, and the edge of the trapezoid away from the first surface 111 is the top flat area of the trapezoid. As shown in Figure 5 For example, the microstructure W1 is a protrusion, and the edge of the trapezoid away from the first surface 111 is the top flat area of the trapezoid. As shown in

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

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

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

[0087] For example, it is easy to understand that, relative to the microstructure W1, the site between the two adjacent microstructures W1 is a planar site or a flat site (i.e. without protrusions or depressions), the microstructure W1 increases the contact area and mechanical bite force (mechanical interlocking effect) of the first passivation layer 23 and the first sub-surface 112b1, which can provide stronger physical bonding and significantly improve the adhesion of the first passivation layer 23 on the first sub-surface 112b1; at the same time, the planar site or flat site (i.e. without protrusions or depressions) between the two adjacent microstructures W1 provides a larger area of uniform chemical bonding (e.g. Si-O-Al bond) site, which can serve as a stress buffer zone after stress is generated. The combination of the microstructure W1 and the planar site or flat site between the 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 aluminum oxide layer) from "blistering", "peeling" or "foaming".

[0088] In the embodiments of the present application, the first passivation layer 23 directly contacts the surface of the second region 112b, and the surface is a first sub-surface 112b1. The first sub-surface 112b1 has a plurality of microstructures W1, which are at least one of protrusions and recesses. At least some regions of the first sub-surface 112b1, two adjacent microstructures W1 are spaced apart, and the spacing between the two adjacent microstructures W1 in a direction parallel to the plane of the second surface is greater than 0. In a first aspect, the first sub-surface 112b1 is a rough surface. With respect to the microstructures W1, the positions between the two adjacent microstructures W1 are planar positions or flat positions (i.e., without protrusions or recesses). The microstructures W1 increase the contact area and mechanical interlocking force (mechanical interlocking effect) between the first passivation layer 23 and the first sub-surface 112b1, which can provide stronger physical bonding and significantly improve the adhesion of the first passivation layer 23 on the first sub-surface 112b1. At the same time, the planar positions or flat positions (i.e., without protrusions or recesses) between the two adjacent microstructures W1 provide a larger area of uniform chemical bonding (e.g., Si-O-Al bond) sites, which can act as a stress buffer zone after stress is generated. The combination of the microstructures W1 and the planar positions or flat positions between the two adjacent microstructures W1 ensures strong adhesion, good stress distribution, and stress buffering, thereby better preventing the first passivation layer 23 (especially the aluminum oxide layer) from "blistering", "peeling", or "foaming". In a second aspect, 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 subsequent high-temperature sintering, reducing stress concentration and the driving force for film peeling. That is, the rough surface provides good stress buffering. In a third aspect, the rough surface microscopically extends the diffusion path of H ions from the inside of the first passivation layer 23 to the substrate 11, increases the H diffusion resistance, and reduces the risk of H ions accumulating in a local area and breaking through the first passivation layer 23. In a fourth aspect, in combination with the method for manufacturing a solar cell of the present application, the first laser is used to remove at least the part of the first doped conductive pre-set layer in the second region, and the second laser is used for roughening the first sub-surface. The energy of the first laser is greater than that of the second laser. When the second laser is used to manufacture the rough structure of 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 (e.g., Si-O-Al bond) between the precursors of the first passivation layer 23 and the first sub-surface 112b1 in the subsequent ALD (atomic layer deposition) process. Figure 3 and Figure 4The part of the surface of the example substrate 11 can form stronger Si-O-Al bonds. From one or more of the above aspects, the problem of "bubbling", "peeling" or "blistering" of the first passivation layer 23 (especially the aluminum oxide layer) is improved or avoided, thereby improving the continuity of the first passivation layer 23, improving its effective passivation ability for carriers, reducing the loss of recombination, and improving or avoiding abnormal contact of the grid lines, ultimately improving and improving the open circuit voltage (Voc), the fill factor (FF) and the conversion efficiency of the solar cell 100, and therefore the performance of the solar cell is improved.

[0089] For example, in some embodiments, the first sub-surface 112b1 has a plurality of irregular microstructures W1, i.e. a plurality of irregular protrusions and / or recesses on the first sub-surface 112b1. Irregular protrusions and / or recesses refer to the size of the plurality of protrusions or the plurality of recesses in the first direction X being not uniform or uniform, and / or the size of the plurality of protrusions or the plurality of recesses in the second direction Y being not uniform or uniform, and / or the shape of the plurality of protrusions or the plurality of recesses being not the same. The first passivation layer 23 and the first sub-surface 112b1 can form a plurality of different sizes and a plurality of different directions of mechanical bite at different parts, and better improve the 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 4 cm²-2×10 5 cm².

[0091] For example, in combination with Figure 12 , a 3D microscope or a scanning electron microscope (SEM) can be used to measure the protrusion tq1 or the recess on the first sub-surface. Figure 12 The photo under the 3D microscope can be seen that the first sub-surface 112b1 has a plurality of irregular protrusions tq1.

[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, etc. After verification and analysis by the inventor, when 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 4 cm²-2×10 5 cm², the interface bonding performance of the first passivation layer 23 and the first sub-surface 112b1 can be better 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] As shown in Figure 2 and Figure 4 , the width of the protrusion or the recess in the direction parallel to the plane where the second surface 112 is located is a first width d2, the first width d2 is 2-5 microns, and the first width d2 can be any one of 2 microns, 2.5 microns, 3 microns, 3.5 microns, 4 microns, 4.5 microns, and 5 microns. The first width d2 and the number of microstructures W1 determine the area ratio of the microstructures W1 on the first sub-surface 112b1. The greater the area ratio of the microstructures W1 on the first sub-surface 112b1, the stronger the anchoring effect (the stronger the mechanical interlocking effect) of the first sub-surface 112b1, but the stress buffering effect of the planar or flat part between two adjacent microstructures W1 is reduced. The first width d2 of 2-5 microns can make the area ratio of the microstructures W1 be in an appropriate range, and can provide a strong anchoring effect and a good stress buffering effect at the same time.

[0099] As shown in Figure 2 and Figure 4 , by setting appropriate sizes of the protrusion and / or the recess, an appropriate surface roughness can be formed on the first sub-surface 112b1.

[0100] As an example, the first value d1 is 1-3 microns, and the first width d2 is 2-5 microns, which can provide a strong anchoring effect and a good stress buffering effect for the first passivation layer 23 and the first sub-surface 112b1, and can avoid aggravating carrier recombination and causing a loss of open-circuit voltage (Voc).

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

[0102] As shown in 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 0.5 nm-1.6 nm, and considering 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 protrusions and / or the bottom of the recesses on the first sub-surface 112b1 are the material of the first tunneling layer 21 (the second part 212 of the first tunneling layer 21 has a thickness greater than 0 in the second direction Y), so that the material of the first doped conductive layer 22 is completely removed at least at the bottom of the protrusions and / or the bottom of the recesses.

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

[0109] For example, as shown in 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, and considering the thickness of the first doped conductive layer 22 and the first tunneling layer 21, the height of the protrusions in the second direction Y is 0.2 microns-0.5 microns, for example, the height of the protrusions in the second direction Y can be any of 0.2 microns, 0.25 microns, 0.3 microns, 0.35 microns, 0.4 microns, 0.45 microns, 0.5 microns.

[0110] It should be noted that in other embodiments, Figure 3 and Figure 4 For example, the thickness of the first tunneling layer 21 in the second direction Y is small, and the top of the protrusions on the first sub-surface 112b1 can be the material of the first doped conductive layer 22, and the bottom of the protrusions can be the material of the first tunneling layer 21, in the direction away from the first surface 111 along the second surface 112.

[0111] In some embodiments, as shown in Figure 3 and Figure 4 As shown, the first sub-surface 112b1 is part of the surface 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.

[0112] For example, as shown in Figure 1 and Figure 2As shown, in the first region 112a, 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 a direction away from the first surface 111 along the second surface 112. In the second region 112b, the substrate 11 and the first passivation layer 23 are sequentially stacked in a direction away from the first surface 111 along the second surface 112, and the first sub-surface 112b1 is a partial 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 with the first distance h1, the first distance h3 is smaller, and the second distance h4 is larger. Figure 3 And Figure 4 For example, in the first region 112a, the first distance h3 is smaller than the first distance h1, and the second distance h4 is larger than the first distance h1. Figure 3 And Figure 4 For example, in the first region 112a, the first distance h3 is smaller than the first distance h1, and the second distance h4 is larger than the first distance h1.

[0114] In some embodiments, as shown in Figure 3 And Figure 4 As shown, in a direction perpendicular to the plane in which the second surface 112 lies, the distance from the second surface 112 to the first surface 111 at the first region 112a is a first distance h3, and the distance from the second surface 112 to the first surface 111 at the second region 112b is a second distance h4, and the difference between the first distance h3 and the second distance h4 is 1-3 microns.

[0115] For example, as shown in Figure 3 And Figure 4 As shown, the first sub-surface 112b1 has a plurality of microstructures W1; in a direction perpendicular to the plane in which the second surface 112 lies, the height of the protrusion is 1-3 microns, and the first distance d1 can be any one of 1 micron, 1.2 microns, 1.5 microns, 1.8 microns, 2 microns, 2.2 microns, 2.5 microns, 2.8 microns, and 3 microns.

[0116] It should be noted that, in Figures 1 to 4 And Figures 1 to 4In the example, the second region 112b does not reserve the second part 212 of the first tunnel layer 21, at this time, a larger surface roughness can be formed in the second region 112b, a stronger mechanical anchoring of the first passivation layer 23 and the first sub-surface 112b1 can be provided, and the “bubbling”, “peeling” or “blistering” of the first passivation layer 23 (especially the aluminum oxide layer) can be better avoided or improved, but the carrier recombination loss at the first sub-surface 112b1 needs to be controlled. For example, in the present application, the roughness of the first sub-surface 112b1 is strictly controlled, so that the carrier recombination loss at the first sub-surface 112b1 can be reduced or avoided; for example, in the present application, the difference between the first distance h3 and the second distance h4 is 1 μm-3 μm, so that the carrier recombination loss at the first sub-surface 112b1 can be reduced or avoided.

[0117] It should be noted that, as shown in Figure 1 , the solar cell 100 of the present application is exemplarily illustrated by taking a tunnel oxide passivated contact (TOPCon) solar cell as an example. With the development of solar cell technology, the first tunnel 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 shown in Figure 3 , the solar cell 100 further comprises 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 a side of the emitter layer 12 away from the substrate 11, and the second electrode 14 is located on a 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 performance and antireflection performance.

[0120] It should be noted that, in some embodiments, as shown in Figure 1 and Figure 2 , in the TOPCon solar cell, the first surface 111 of the substrate 11 is a front surface, and the first surface 111 can further have a plurality of textured structures R1. The textured structures R1 can be pyramid structures or inverted pyramid structures, which are not limited herein.

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

[0122] It should be noted that the second surface 112 includes the first regions 112a and the second regions 112b arranged alternately, the second surface 112 can include a plurality (at least two) of the second regions 112b, and the solar cell 100 can include a plurality (at least two) of the first sub-surfaces 112b1.1) The first sub-surface 112b1 is the surface of the second part 212 away from the substrate 11; in the direction perpendicular to the plane where the second surface 112 is located, the thickness of the first part 211 is greater than the thickness of the second part 212.2) The first sub-surface 112b1 is the surface of the substrate 11 away from the first surface 111. Figures 3 to 6 And Figures 7 to 11 An example arrangement is that the first tunneling layer 21 is located at the at least one second region 112b and the first regions 112a adjacent to the two sides of the second region 112b, at this time, the first tunneling layer 21 includes the first part 211 located at the first region 112a and the second part 212 located at the second region 112b, and the first sub-surface 112b1 is the surface of the second part 212 away from the substrate 11; in the direction perpendicular to the plane where the second surface 112 is located, the thickness of the first part 211 is greater than the thickness of the second part 212.2) The first sub-surface 112b1 is the surface of the substrate 11 away from the first surface 111. Figure 7 An example arrangement is that the first tunneling layer 21 is located at the at least one second region 112b and the first regions 112a adjacent to the two sides of the second region 112b, at this time, the first tunneling layer 21 includes the first part 211 located at the first region 112a and the second part 212 located at the second region 112b, and the first sub-surface 112b1 is the surface of the second part 212 away from the substrate 11; in the direction perpendicular to the plane where the second surface 112 is located, the thickness of the first part 211 is greater than the thickness of the second part 212.2) The first sub-surface 112b1 is the surface of the substrate 11 away from the first surface 111.

[0123] It should be noted that the second surface 112 includes the first regions 112a and the second regions 112b arranged alternately, the second surface 112 can include a plurality (at least two) of the second regions 112b, and the solar cell 100 can include a plurality (at least two) of the first sub-surfaces 112b1.1) The first sub-surface 112b1 is the surface of the second part 212 away from the substrate 11; in the direction perpendicular to the plane where the second surface 112 is located, the thickness of the first part 211 is greater than the thickness of the second part 212.2) The first sub-surface 112b1 is the surface of the substrate 11 away from the first surface 111.

[0124] In a second aspect, based on the same application concept, as Figure 8 It is shown that the application also provides a manufacturing method of a solar cell, and any one of the above-mentioned solar cells 100 can be manufactured by using the manufacturing method of the solar cell 100. As Figure 8 It is shown that the manufacturing method of the solar cell 100 includes the 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 9 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 10 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 10 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 1 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 2 As shown, in some embodiments, forming Figure 10 and Figure 3 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 4As shown, in some other embodiments, the forming Figure 11 and Figure 10 As shown, the first doped conductive preset layer and the first tunneling layer 21 located in the second region 112b are removed.

[0136] As shown, the first doped conductive preset layer located in the second region is removed to form the first doped conductive layer, which can ensure that the subsequent step S500 (for example, 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 hinders the combination of the first passivation layer 23 and the first sub-surface 112b1, and the difference in the thermal expansion coefficient of the material of the residual first doped conductive layer 22 easily causes bubbling, thereby avoiding the failure of the subsequent first passivation layer 23 to adhere to the first sub-surface 112b1 caused by the residual first doped conductive layer 22.

[0137] In step S500, the first sub-surface is roughened, the first sub-surface has a plurality of microstructures, the microstructures are at least one of protrusions and recesses, and at least part of the first sub-surface is provided with two adjacent microstructures spaced apart, and the distance between the two adjacent microstructures in the direction parallel to the plane of the second surface is greater than 0. Figure 11 As shown, the first sub-surface 112b1 is roughened, so that the first sub-surface 112b1 is a rough surface, the first sub-surface 112b1 has a plurality of microstructures W1, the microstructures W1 are at least one of protrusions and recesses, and at least part of the first sub-surface 112b1 is provided with two adjacent microstructures W1 spaced apart, and the distance between the 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 can 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; and 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 can further include: step S1001, texturing the first surface 111 to form a plurality of pyramid or inverted-pyramid textured structures R1; step S1002, forming an emitter layer 12 on the first surface; step S1003, forming a second passivation layer 13 on the side of 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, the second electrode 14 being 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 the solar cell can further include: step S506, cleaning the first region 112a and the second region 112b, for example, using chemical cleaning such as hydrofluoric acid to remove a small amount of splashes, loose debris and natural oxide layers generated by the roughening treatment of the first sub-surface 112b1, to expose the clean first sub-surface 112b1.

[0141] It should be noted that the method for manufacturing the solar cell of the present application has the same beneficial effects as the above-mentioned solar cell 100, which will not be repeated here.

[0142] In some embodiments, as shown in Figure 13 Before the step of removing at least the first doped conductive preset layer to form the first doped conductive layer 22 in the second region 112b (step S400), the method includes: using a first laser to remove at least the first doped conductive preset layer in the second region 112b. As shown in Figure 13 The step of roughening the first sub-surface 112b1 (step S500) includes: using a second laser to roughen the first sub-surface 112b1; 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, which can quickly remove the material and film layer of the first sub-surface 112b1 away from the first surface 111; the energy of the second laser is small, which can make the first sub-surface 112b1 a rough surface to form a plurality of microstructures W1; at the same time, it can avoid the second laser causing substantial damage to the film layer adjacent to the first laser processing boundary or 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 the infrared or ultraviolet laser is greater than that of the nanosecond or picosecond laser.

[0146] In some embodiments, in the first laser, the energy density of the 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, the first doped conductive layer 22 at the second region 112b can be completely vaporized, while avoiding over-damage to the film layer near the first surface 111 of the first sub-surface 112b1, balancing the processing efficiency and the control of the heat-affected zone, and ensuring the uniformity when removing the material of the second region 112b.

[0148] In some embodiments, in the second laser, the energy density of the 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, scanning speed, and other parameters of the second laser as described above, the first sub-surface 112b1 has a moderate roughness (micron-level protrusions / recesses), which is obviously higher than the surface roughness after the first laser treatment, but does not excessively damage the film layer near the first surface 111 of the first sub-surface 112b1 or destroy the flat boundary formed by the first laser. The second laser treatment also needs to avoid introducing deep cracks or causing excessive amorphization to affect the subsequent passivation effect, so as to control the roughness of the first sub-surface to be 0.2 μm-1.6 μm, and avoid the roughness of the first sub-surface being too large to affect the passivation quality of the first passivation layer 23.

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

[0151] For example, after the step (step S400) of removing at least the first doped conductive preset layer to form the first doped conductive layer 22 in the second region 112b, 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 (step S500) of roughening the first sub-surface 112b1 again, the first sub-surface 112b1 has a suitable roughness, and the roughness of the first sub-surface 112b1 is less than 0.1 μm.

[0153] Please refer to Figure 3 , Figure 4The performance parameters of Example 1 and Comparative Example 1 are compared. Example 1 is manufactured by using the manufacturing method of the solar cell of the embodiment of the present application, the wavelength of the first laser is 1064 nm, the second region 112b is part of the surface of the substrate 11 (as shown in Figure 13 and Figure 14 , the second laser is a 355 nm ultraviolet picosecond laser, the energy density is 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 only uses the first laser to remove the film layer of the second region 112b, without the second laser processing process. As can be seen from Figure 14 , 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 occurrence rate of the first passivation layer 23 in Example 1 is significantly reduced (from 15% to less than 5%), the short-circuit current Isc of Example 1 is slightly increased or has no loss (9.73 A is similar to 9.65 A), the open-circuit voltage Voc loss of Example 1 is significantly reduced (from 20 mV to less than 5 mV), the fill factor FF of Example 1 is increased by 0.8%, and the efficiency gain of Example 1 is 0.5%. Therefore, the embodiment of the present application can significantly reduce the bubble occurrence rate of the first passivation layer 23 and improve the performance of the solar cell.

[0154] In a third aspect, based on the same application concept, the present application also provides a laminated cell, which comprises a top cell, a bonding layer and a bottom cell arranged in sequence. The bottom cell is the solar cell 100 of any one of the above.

[0155] For example, in some embodiments, the top cell can be a perovskite solar cell 100, which comprises a laminated first transport layer, a perovskite substrate 11, a second transport layer, a transparent conductive layer and an anti-reflection layer. The first transport layer is opposite to the bottom cell. The first transport layer can be one of an electron transport layer or a hole transport layer, and the second transport layer can be the other one of the electron transport layer or the hole transport layer.

[0156] It should be noted that the laminated cell of the present application and the solar cell 100 of any one of the above are based on the same application concept, and have the same or similar effects as the solar cell 100 of any one of the above, which will not be repeated here.

[0157] Please refer to ​ , ​ for a structural schematic diagram of a photovoltaic module provided by the embodiment of the present application.

[0158] In a fourth aspect, based on the same inventive concept, the application further provides a photovoltaic module 200, comprising: a cell string 203 connected by a plurality of the solar cell 100 of any one of the above, or connected by a plurality of the solar cell 100 manufactured by the manufacturing method of any one of the above, or connected by the laminated cell of any one of the above; a connecting component 204 for electrically connecting two adjacent solar cells 100; an encapsulant film 202 for covering the surface of the cell string 203; and a cover plate 201 for covering the surface of the encapsulant film 202 away from the cell string 203.

[0159] For example, in some embodiments, the connecting component 204 can comprise a conductive strip, and the plurality of cell strings 203 can be electrically connected by the conductive strip. The encapsulant film 202 covers the front surface and the back surface of the solar cell 100 or the laminated solar cell 100.

[0160] For example, in some embodiments, the encapsulant film 202 can be an organic encapsulant film such as an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer elastomer (POE) film, or a 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 a cover plate having a light-transmitting function.

[0162] For example, in some embodiments, the surface of the cover plate 201 facing the encapsulant layer can be a concave-convex surface, thereby increasing the utilization rate of incident light.

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

[0164] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but it should be considered that any combination of the technical features is within the scope of the present application, as long as the combination does not result in contradictions.

[0165] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to 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 on one side of the second surface and at least in the first 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 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; Wherein, the surface directly contacted and covered by the first passivation layer and located in the second region is the first sub-surface, and the first sub-surface has a plurality of microstructures, wherein the microstructures are 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 the direction parallel to the plane of the second surface is greater than 0. 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. The first sub-surface is 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.

2. The solar cell according to claim 1, characterized in that, The roughness of the first sub-surface is 0.2 μm-1.6 μm; and / or, The density of the microstructure is 5 × 10⁻⁶. 4 pcs / cm² - 2×10 5 pcs / cm² 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; 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.

4. 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.

5. The solar cell according to claim 4, 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.

6. 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 5, 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, the first tunneling layer being at least located in the first region; 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; 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; 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.

7. The method for manufacturing a solar cell according to claim 6, 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.

8. The method for manufacturing a solar cell according to claim 7, characterized in that, In the first laser, the laser energy density is 5J / cm²-20J / cm²; the laser pulse width is 10ns-200ns; the laser scanning speed is 500-2000mm / s; the laser repetition frequency is 50kHz-300kHz; and the laser spot size is 20μm-50μm.

9. The method for manufacturing a solar cell according to claim 7, characterized in that, In the second laser, the laser energy density is 0.2 J / cm²-5 J / cm²; the laser pulse width is 10 ns-50 ns; the laser scanning speed is 1000-5000 mm / s; the laser repetition frequency is 50 kHz-100 kHz; and the laser spot size is 10 μm-30 μm.

10. The method for manufacturing a solar cell according to claim 6, characterized in that, 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; After the step of further roughening the first sub-surface, the roughness of the first sub-surface is 0.2 μm-1.6 μm.

11. 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 5.

12. 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 5, or by connecting multiple solar cells manufactured by the method of manufacturing solar cells as described in any one of claims 6 to 10, or by connecting tandem cells as described in claim 11. 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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