Solar cell, manufacturing method thereof and photovoltaic module

Abstract

The invention relates to a solar cell, a manufacturing method thereof and a photovoltaic module. The solar cell includes: a substrate including a first surface; the passivation contact structure is arranged on a part of the surface of the first surface; the first electrode is arranged on the side, away from the substrate, of the passivation contact structure and electrically connected with the passivation contact structure; wherein the surface of one side, deviating from the substrate, of a part of the passivation contact structure is provided with a marking part, the projection of the marking part and the projection of the first electrode on the first surface are not overlapped, and the marking part is configured to be used as a positioning reference in the forming process of the first electrode. According to the solar cell and the manufacturing method thereof, the reliability of grabbing the position of the marking part by the photovoltaic module is relatively high, and meanwhile, the manufacturing yield of the solar cell is relatively high.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a solar cell and a manufacturing method thereof, and a photovoltaic module. Background Art

[0002] In order to reduce the recombination rate, extend the minority carrier lifetime, and improve the photoelectric conversion efficiency of solar cells, the substrate is generally passivated in the relevant technology to form a passivation contact layer on the substrate surface to reduce the recombination of surface carriers, thereby reducing the impact caused by internal defects in the substrate.

[0003] However, most passivation contact structures will absorb incident light, resulting in a decrease in the photocurrent of the solar cell, affecting the efficiency of the solar cell. In order to solve this problem, a passivation contact structure is generally set up to reduce the absorption of incident light by reducing the area of ​​the passivation contact structure. Among them, the process flow of solar cells with passivation contact structures is relatively complex and requires higher precision. It is often necessary to set marking points on the surface of the cell as a positioning reference to ensure that the electrode slurry can be accurately printed on the passivation contact structure.

[0004] However, the prior art has the problem of low recognition accuracy of the marking points, which makes it impossible to accurately print the electrode paste onto the passivation contact structure, thereby reducing the yield of the solar cell. Summary of the invention

[0005] Based on this, it is necessary to provide a solar cell and a manufacturing method thereof, and a photovoltaic module with high reliability in grasping the position of the marking portion and high manufacturing yield.

[0006] A first aspect of an embodiment of the present application provides a solar cell, comprising:

[0007] a substrate, the substrate comprising a first surface;

[0008] A passivation contact structure, the passivation contact structure is disposed on a portion of the first surface; and

[0009] A first electrode, the first electrode is arranged on a side of the passivation contact structure away from the substrate and is electrically connected to the passivation contact structure;

[0010] A marking portion is provided on a surface of a portion of the passivation contact structure facing away from the substrate, the marking portion does not overlap with a projection of the first electrode on the first surface, and the marking portion is configured to serve as a positioning reference during the formation of the first electrode.

[0011] In one embodiment, the first electrode includes a plurality of first sub-electrodes and a plurality of second sub-electrodes, the plurality of first sub-electrodes are arranged at intervals along the first direction, and each first sub-electrode is connected to at least two second sub-electrodes arranged at intervals in the second direction;

[0012] The marking portion is located between two adjacent second sub-electrodes in the second direction, and the two adjacent second sub-electrodes are connected to the same first sub-electrode; the first direction and the second direction intersect and are both perpendicular to the thickness direction of the solar cell.

[0013] In one embodiment, the marking portion and two second sub-electrodes adjacent to the marking portion are arranged at intervals.

[0014] In one embodiment, the first surface includes a plurality of first regions and a plurality of passivation contact regions;

[0015] A first region is defined between adjacent passivation contact regions;

[0016] The passivation contact structure includes a plurality of first passivation contact structures and a plurality of second passivation contact structures;

[0017] The first passivation contact structure and the second passivation contact structure are respectively arranged in corresponding passivation contact regions, and projections of the second passivation contact structure and the first passivation contact structure on the first surface do not overlap;

[0018] The first electrode is arranged on a side of the first passivation contact structure away from the substrate; and the marking portion is arranged on a side of the second passivation contact structure away from the substrate.

[0019] In one embodiment, the contour edges of the plurality of first passivation contact structures respectively define a plurality of accommodation areas;

[0020] Each second passivation contact structure is located in a corresponding accommodation area.

[0021] In one embodiment, a plurality of first passivation contact structures are arranged spaced apart from each other;

[0022] Each first passivation contact structure includes a first contact region and a plurality of second contact regions extending from the first contact region in a direction away from the first contact region;

[0023] An accommodating area is formed between two adjacent second contact areas, and the two adjacent second contact areas are connected to the same first contact area.

[0024] In one embodiment, multiple first contact regions of multiple first passivation contact structures are arranged at intervals along a first direction, and multiple second contact regions connected to the same first contact region are arranged at intervals along a second direction. The first direction and the second direction intersect and are both perpendicular to the thickness direction of the solar cell.

[0025] In one embodiment, the first electrode includes a plurality of first sub-electrodes and a plurality of second sub-electrodes, each of the first sub-electrodes is connected to at least two second sub-electrodes spaced apart in the second direction; the plurality of first sub-electrodes are arranged one by one on a surface of the first contact region facing away from the substrate, and the plurality of second sub-electrodes are arranged one by one on a surface of the second contact region connected to the first contact region facing away from the substrate;

[0026] The second passivation contact structure is located between two adjacent second sub-electrodes in the second direction, and the two adjacent second sub-electrodes are connected to the same first sub-electrode.

[0027] In one embodiment, each first passivation contact structure includes a plurality of third contact regions arranged at intervals, and the accommodation region is disposed between two adjacent third contact regions;

[0028] The first electrode includes a plurality of third sub-electrodes, and the third sub-electrodes are arranged in the third contact region in a one-to-one correspondence.

[0029] In one embodiment, at least one of the first passivation contact structure and the second passivation contact structure includes a first tunneling oxide layer and a first polysilicon doped conductive layer stacked on each other, and the first tunneling oxide layer is disposed on the first surface.

[0030] In one embodiment, the first passivation contact structure and the second passivation contact structure are arranged spaced apart from each other.

[0031] In one embodiment, the marking portion is spaced apart from an edge of the corresponding second passivation contact structure.

[0032] In one embodiment, the number of the marking parts is plural;

[0033] The multiple marking portions are used to locate the geometric center of the solar cell.

[0034] In one embodiment, the marking portion includes a first groove;

[0035] The first groove extends deep into the second passivation contact structure; and / or

[0036] The first groove extends to a junction position between the second passivation contact structure and the passivation contact region along a thickness direction of the solar cell; and / or

[0037] The first groove goes deep into the interior of the substrate.

[0038] In one embodiment, when the first groove goes deep into the substrate, the maximum step difference D1 between the bottom wall of the first groove and the surface of the passivation contact region satisfies:

[0039] D1>1μm.

[0040] In one embodiment, the bottom wall of the first groove includes a central region and an over-etched region adjacent to an edge of the central region;

[0041] The height of the over-etched area relative to the second surface of the substrate is lower than the height of the central area relative to the second surface;

[0042] The second surface is arranged opposite to the first surface.

[0043] In one embodiment, the width dimension W1 of the first groove satisfies:

[0044] W1<100μm.

[0045] In one of the embodiments, the marking portion further includes a transition processing area between a notch edge of the first groove and an edge of an adjacent second passivation contact structure;

[0046] The reflectivity of a surface of the transitional processing region on a side facing away from the substrate is greater than the reflectivity of a surface of the second passivation contact structure on a side facing away from the substrate.

[0047] In one embodiment, a surface of the transitional processing zone facing away from the substrate is structured with a plurality of protrusions;

[0048] The heights of the tops of the plurality of protrusions relative to the second surface of the substrate gradually increase from the edge of the notch of the first groove to the edge of the adjacent second passivation contact structure.

[0049] In one embodiment, the roughness of a surface of the transitional treatment region facing away from the substrate is smaller than the roughness of a surface of the second passivation contact structure facing away from the substrate.

[0050] In one embodiment, the transition zone includes a melt of the first material and the second material;

[0051] The first material is the passivation contact material contained in the second passivation contact structure, and the second material is the substrate material contained in the substrate.

[0052] In one embodiment, a surface of the transitional treatment region facing away from the substrate is lower than a surface of the second passivation contact structure facing away from the substrate by D0, and D0 satisfies:

[0053] 50nm<D0<1μm.

[0054] In one embodiment, the dimension W2 of the marking portion along the width direction of the first groove satisfies:

[0055] W2<120μm.

[0056] In one of the embodiments, a third structure is further provided on a surface of the second passivation contact structure facing away from the substrate;

[0057] The third structure is arranged around the marking portion, and the reflectivity of a surface of the third structure facing away from the substrate is greater than the reflectivity of a surface of the second passivation contact structure facing away from the substrate.

[0058] In one embodiment, the reflectivity of the surface of the third structure facing away from the substrate, the reflectivity of the surface of the transitional treatment zone facing away from the substrate, and the reflectivity of the bottom wall of the first groove increase in sequence.

[0059] In one embodiment, the outer contour of the first groove is circular or annular; or,

[0060] The first groove includes at least two groove sections intersecting each other.

[0061] In one embodiment, the first surface includes a plurality of first regions and at least one passivation contact region;

[0062] Each of the at least some first regions is configured to be surrounded and bounded by the passivation contact region.

[0063] In one embodiment, the first region is closer to a second surface of the substrate than the passivation contact region, and the second surface is disposed opposite to the first surface.

[0064] In one embodiment, the height difference D2 between the surface of the first region and the surface of the passivation contact region satisfies:

[0065] D2>1μm.

[0066] In one embodiment, the marking portion includes a first groove, and the height differences D1 and D2 between the bottom wall of the first groove and the surface of the passivation contact area satisfy:

[0067] D2≤D1.

[0068] In one embodiment, the solar cell includes a plurality of side surfaces, and at least some of the side surfaces are cut surfaces.

[0069] A second aspect of an embodiment of the present application provides a method for manufacturing a solar cell, comprising:

[0070] Providing a substrate, the substrate comprising a substrate, a passivation contact material layer and a dielectric layer sequentially stacked on a first surface of the substrate, the first surface of the substrate comprising a first region and a passivation contact region;

[0071] Performing patterning on the portion of the dielectric layer covering the first region, forming a marking structure at a position where the dielectric layer covers the passivation contact region, wherein the marking structure at least extends to the passivation contact material layer;

[0072] Using the portion of the dielectric layer that has been patterned and formed with the marking structure and that covers the passivation contact region as a mask, removing the portion of the passivation contact material layer located in the first region, and removing the dielectric layer to form a marking portion with the marking structure;

[0073] A first passivation layer is formed on the side of the passivation contact material layer facing away from the substrate, and a first electrode is formed at a position where the first passivation layer covers the passivation contact area, using the marking portion as a positioning reference.

[0074] In one embodiment, the step of forming a marking structure at a position where the dielectric layer covers the passivation contact region specifically includes:

[0075] The first laser is used to locally scan the position where the dielectric layer covers the passivation contact area to form a marking structure.

[0076] In one embodiment, the step of patterning the portion of the dielectric layer covering the first region specifically includes:

[0077] Scanning the entire position of the dielectric layer covering the first area using a second laser;

[0078] The spot size of the second laser is larger than the spot size of the first laser, and the laser power of the second laser is larger than the laser power of the first laser.

[0079] In one embodiment, the spot diameter of the first laser is less than 120 μm, and the power is 10W-100W;

[0080] The spot diameter of the second laser is greater than 150 μm, and the power is 40W-200W.

[0081] In one embodiment, the step of locally scanning the position of the dielectric layer covering the passivation contact region using the first laser specifically includes:

[0082] Scanning the medium layer back and forth along a first path and scanning the medium layer back and forth along a second path using a first laser to form a marking structure with a cross-shaped outer contour on the medium layer, wherein the first path and the second path intersect and are both straight paths; or

[0083] Scanning the medium layer along a circular path using a first laser to form a marking structure with a circular outer contour; or

[0084] The medium layer is scanned along a circular area using a first laser to form a marking structure with a circular outer contour.

[0085] In one embodiment, the marking portion includes a first groove;

[0086] In the step of using a portion of the dielectric layer that has been patterned and formed with a marking structure and that covers the passivation contact area as a mask, removing a portion of the passivation contact material layer located in the first area, and removing the dielectric layer to form a marking portion from the marking structure:

[0087] The portion of the passivation contact material layer located in the first region is removed by wet etching, and the dielectric layer is removed to form a first groove in the passivation contact material layer covering the passivation contact region.

[0088] In one embodiment, the marking structure further includes a transition processing area located at the edge of the notch of the first groove; the energy intensity at the central local area of ​​the light spot of the first laser is greater than the energy intensity at the edge area of ​​the light spot;

[0089] After wet etching, in the passivation contact material layer, in the area processed by the central local area, a part of the position forms a first groove, and the other part of the position and the area processed by the edge area form a transition processing area, and the transition processing area includes the dielectric layer, the passivation contact material layer and the melt of the material included in the substrate.

[0090] In one embodiment, after wet etching, a third structure is formed around the mark structure, and the reflectivity of the surface of the third structure facing away from the substrate is greater than the reflectivity of the surface of the passivation contact material layer facing away from the substrate.

[0091] In one of the embodiments, a portion of the dielectric layer that has been patterned and formed with a marking structure and covers the passivation contact area is used as a mask, and in the step of removing the portion of the passivation contact material layer located in the first area, the first area of ​​the substrate is also etched partially inward in the thickness direction of the substrate.

[0092] In one embodiment, the step of patterning the portion of the dielectric layer covering the first region includes:

[0093] Modifying a portion of the dielectric layer covering the first region;

[0094] The step of using the portion of the dielectric layer that has been patterned and formed with the marking structure and that covers the passivation contact region as a mask to remove the portion of the passivation contact material layer located in the first region specifically includes:

[0095] By wet etching, the portion of the dielectric layer covering the first region is removed, and the portion of the passivation contact material layer located in the first region is removed.

[0096] In one embodiment, the step of patterning the portion of the dielectric layer covering the first region includes:

[0097] removing the portion of the dielectric layer covering the first region;

[0098] The step of using the portion of the dielectric layer that has been patterned and formed with the marking structure and that covers the passivation contact region as a mask to remove the portion of the passivation contact material layer located in the first region specifically includes:

[0099] The portion of the passivation contact material layer located in the first region is removed by wet etching.

[0100] In one embodiment, the step of cutting the solar cell into a plurality of solar cell substrates along the thickness is further included, wherein the number of marking portions in the partially cut solar cell substrates is 0, and the number of marking portions in the partially cut solar cell substrates is more than 1.

[0101] A third aspect of an embodiment of the present application provides a solar cell, which is manufactured using the above-mentioned method for manufacturing a solar cell.

[0102] A fourth aspect of an embodiment of the present application provides a photovoltaic assembly, comprising at least one battery string, wherein the battery string comprises at least two of the above-mentioned solar cells.

[0103] The above-mentioned solar cell and its manufacturing method, photovoltaic module have the following beneficial effects:

[0104] The passivation contact structure is provided on a part of the surface of the first surface, so that the passivation contact structure covers a part of the surface of the first surface, forming a local passivation contact structure. Since a marking portion is provided on a surface of a part of the passivation contact structure that is away from the substrate, the marking portion is configured to be used as a positioning reference in the process of forming the first electrode. In other words, the marking portion is provided on the passivation contact structure, and a passivation contact material is reserved around the marking portion. Compared with providing the marking portion outside the passivation contact structure, the difference in reflectivity between the marking portion and the surrounding background structure is large, making it easier and more accurate for an image capture mechanism, such as a camera, to capture the position of the marking portion, so that the position of the first electrode is more precise, and the yield of the solar cell is also improved. In addition, since the projections of the marking portion and the first electrode on the first surface do not overlap, the provision of the marking portion will not affect the first electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] Figure 1 A schematic diagram of the structure of a solar cell provided in an embodiment of the present application;

[0106] Figure 2 A partial top view of a solar cell provided in an embodiment of the present application;

[0107] Figure 3 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application;

[0108] Figure 4A schematic diagram of another structure of a solar cell provided in an embodiment of the present application;

[0109] Figure 5 A picture of a marking portion in a solar cell provided in an embodiment of the present application;

[0110] Figure 6 for Figure 5 A magnified view of the local structure;

[0111] Figure 7 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0112] Figure 8 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0113] Fig. 9 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0114] Fig.10 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0115] Fig.11 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0116] Fig.12 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application;

[0117] Fig.13 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application;

[0118] Fig.14 A schematic diagram of a process for manufacturing a solar cell provided in an embodiment of the present application;

[0119] Fig.15 A schematic diagram of the structure of a substrate in a method for manufacturing a solar cell provided in an embodiment of the present application;

[0120] Fig.16 A schematic diagram of forming a marking structure in a method for manufacturing a solar cell provided in an embodiment of the present application;

[0121] Fig.17 A schematic diagram of a structure for forming a marking portion in a method for manufacturing a solar cell provided in an embodiment of the present application;

[0122] Fig.18 A schematic diagram of the structure of forming a first passivation layer in the method for manufacturing a solar cell provided in an embodiment of the present application;

[0123] Fig.19 for Fig.16 Pictures of the labeled structures shown;

[0124] Fig. 20 for Fig.17 Pictures of the marked parts shown;

[0125] Fig.21 for Figure 5 Height curve diagram of each marked part shown.

[0126] Description of Figure Numbers:

[0127] 100. solar cell; 101. substrate;

[0128] 10. substrate; 200. passivation contact structure; 20. first passivation contact structure; 2011. first contact region; 2012. second contact region; 201. first tunneling oxide layer; 202. first polysilicon doped conductive layer; 21. passivation contact material layer; 211. tunneling oxide material layer; 212. polysilicon doped material layer; 22. dielectric layer; 30. second passivation contact structure; 40. marking structure; 50. marking part; 51. first groove; 510. groove section; 511. protruding structure; 52. transition processing region; 53. third structure; 60. first passivation layer; 70. second passivation layer; 81. first electrode; 810. first sub-electrode; 811. second sub-electrode; 82. second electrode; 90. doped conductive layer; 91. velvet structure; 92. third passivation contact structure;

[0129] Y, first surface; E, second surface; J, passivation contact area; F, first area; B, first direction; C, second direction; G, accommodation area. DETAILED DESCRIPTION

[0130] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0131] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0132] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0133] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0134] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0135] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0136] The solar cell of the embodiment of the present application is described below with reference to the accompanying drawings. It should be noted that the embodiment of the present application is applicable to a solar cell using a passivation contact structure. In the present application, the solar cell is described as a TOPCon cell. The solar cell may also be other types of cells using a passivation contact structure, such as TBC, etc. The case where the solar cell is of other types is similar to this and will not be described in detail here.

[0137] Figure 1 A schematic diagram of the structure of a solar cell provided in an embodiment of the present application; Figure 2 A partial top view of a solar cell provided in an embodiment of the present application; Figure 3 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application; Figure 4 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application; Figure 5 A picture of a marking portion in a solar cell provided in an embodiment of the present application; Figure 6 for Figure 5 A magnified view of the local structure; Figure 7 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application; Figure 8 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application; Fig. 9 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application;

[0138] Fig.10 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application; Fig.11 A schematic diagram of another structure of a marking portion in a solar cell provided in an embodiment of the present application; Fig.12 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application; Fig.13 A schematic diagram of another structure of a solar cell provided in an embodiment of the present application.

[0139] Reference Figure 1 , Figure 2 The solar cell 100 provided in the embodiment of the present application includes a substrate 10 , a passivation contact structure 200 and a first electrode 81 .

[0140] The substrate 10 includes a first surface Y. The passivation contact structure 200 is disposed on a portion of the first surface Y. The first electrode 81 is disposed on a side of the passivation contact structure 200 that is away from the substrate 10, and is electrically connected to the passivation contact structure 200. A marking portion 50 is disposed on a surface of a portion of the passivation contact structure 200 that is away from the substrate 10, and the marking portion 50 does not overlap with a projection of the first electrode 81 on the first surface Y, and the marking portion 50 is configured to be used as a positioning reference during the formation of the first electrode 81.

[0141] Since the passivation contact structure 200 is disposed on a portion of the surface of the first surface Y, the passivation contact structure 200 covers a portion of the surface of the first surface Y, forming a local passivation contact structure. Since a marking portion 50 is disposed on a surface of a portion of the passivation contact structure 200 that is away from the substrate 10, the marking portion 50 is configured to be used as a positioning reference during the formation of the first electrode 81. In other words, the marking portion 50 is disposed on the passivation contact structure 200, and a passivation contact material is reserved around the marking portion 50. Compared with disposing the marking portion 50 outside the passivation contact structure 200, the difference in reflectivity between the marking portion 50 and the surrounding background structure is large, making it easier and more accurate for an image capture mechanism, such as a camera, to capture the position of the marking portion 50, the position of the first electrode 81 is more accurate, and the yield of the solar cell 100 is also improved. In addition, since the projections of the marking portion 50 and the first electrode 81 on the first surface Y do not overlap, the provision of the marking portion 50 will not affect the first electrode 81.

[0142] In a specific implementation, the first surface Y may include a plurality of first regions F and a plurality of passivation contact regions J. A first region F is defined between adjacent passivation contact regions J. The passivation contact region J is an area on the first surface Y covered by the passivation contact structure 200, the first region F is an area on the first surface Y not covered by the passivation contact structure 200, and the area on the first surface Y other than the first region F is the passivation contact region J. The plurality of passivation contact regions J corresponding to this embodiment are spaced apart from each other, and adjacent passivation contact regions J may be spaced apart from each other by means of the first region F.

[0143] In other embodiments, the first surface Y may include a plurality of first regions F and at least one passivation contact region J; each of at least a portion of the first regions F is configured to be surrounded and defined by the passivation contact region J. In this embodiment, the passivation contact region J may be formed as a large whole, and a plurality of first regions F may be dispersedly arranged in the passivation contact region J, so that the entire first surface Y forms a large grid-like structure. Alternatively, a portion of the first surface Y may be formed as a grid-like structure, and a plurality of passivation contact regions J may be provided on another portion of the first surface Y, and the passivation contact regions J may be spaced apart from each other, and adjacent passivation contact regions J may be spaced apart from each other by means of the first regions F.

[0144] Of course, in the following description of the embodiment of the present application, the first surface Y includes a plurality of first regions F and a plurality of passivation contact regions J. The first region F is defined between adjacent passivation contact regions J. The scheme of "the first surface Y includes a plurality of first regions F and at least one passivation contact region J; each first region F in at least part of the first regions F is structured to be surrounded and defined by the passivation contact region J" is similar to this, and will not be repeated here.

[0145] The passivation contact structure 200 may include a plurality of first passivation contact structures 20 and a plurality of second passivation contact structures 30. Figure 1 In the figure, for the convenience of observation, the first passivation contact structure 20 and the second passivation contact structure 30 are divided by the dotted line. The first passivation contact structure 20 and the second passivation contact structure 30 are respectively arranged in the corresponding passivation contact area J, and the projections of the second passivation contact structure 30 and the first passivation contact structure 20 on the first surface Y do not overlap. The first electrode 81 is arranged on the side of the first passivation contact structure 20 away from the substrate 10, and is electrically connected to the first passivation contact structure 20. The marking portion 50 is arranged on the side of the second passivation contact structure 30 away from the substrate 10.

[0146] In the embodiment of the present application, the substrate 10 may further include a second surface E disposed opposite to the first surface Y.

[0147] By making the first surface Y of the substrate 10 include a passivation contact area J and a first area F, the first passivation contact structure 20 is arranged in the corresponding passivation contact area J, the second passivation contact structure 30 is arranged in the corresponding passivation contact area J, the marking portion 50 is arranged in the second passivation contact structure 30, and the second passivation contact structure 30 is arranged in the passivation contact area J, so that the marking portion 50 is located at a position corresponding to the passivation contact area J, and the passivation contact material in the second passivation contact structure 30 is reserved around the marking portion 50. The difference in reflectivity between the marking portion 50 and the surrounding background structure is large, making it easier and more accurate for an image capture mechanism, such as a camera, to capture the position of the marking portion 50.

[0148] In a specific implementation, the first electrodes 81 can be arranged one by one on the side of the first passivation contact structure 20 facing away from the substrate 10. In addition, the projections of the second passivation contact structure 30 and the first passivation contact structure 20 on the first surface Y do not overlap, which means that the first passivation contact structure 20 and the second passivation contact structure 30 are located in different areas on the passivation contact region J, wherein the adjacent second passivation contact structures 30 and the first passivation contact structures 20 can be connected as a whole or arranged at intervals.

[0149] The first passivation contact structure 20 is disposed in the corresponding passivation contact region J. For example, multiple first passivation contact structures 20 may be disposed in each passivation contact region J in a one-to-one correspondence. Alternatively, one passivation contact region J may be provided with more than one first passivation contact structure 20. In the embodiment of the present application, the example of multiple first passivation contact structures 20 being disposed in each passivation contact region J in a one-to-one correspondence is used for description, and other configurations are similar to this and are not described in detail herein.

[0150] The second passivation contact structure 30 is arranged in the corresponding passivation contact area J, which means that among all the passivation contact areas J, all, or only some of the passivation contact areas J are provided with the second passivation contact structure 30, and in the passivation contact area J provided with the second passivation contact structure 30, the second passivation contact structure 30 and the passivation contact area J can be in a one-to-one correspondence, or each passivation contact area J can be provided with two or more second passivation contact structures 30.

[0151] In a specific implementation, the first surface Y may be the light-receiving surface of the solar cell 100, and the second surface E may be the backlight surface of the solar cell 100, or the first surface Y may be the backlight surface of the solar cell 100, and the second surface E may be the light-receiving surface of the solar cell 100. Figure 1 In the example, the first surface Y is the backlight surface of the solar cell 100 .

[0152] In the present application, refer to Figure 1 and Figure 2 , the passivation contact regions J may be arranged at intervals along a preset direction, for example, a first direction B.

[0153] In addition, the first passivation contact structure 20 and the second passivation contact structure 30 have the same film structure, and at least one of the first passivation contact structure 20 and the second passivation contact structure 30 includes a first tunneling oxide layer 201 and a first polysilicon doped conductive layer 202 stacked on each other, and the first tunneling oxide layer 201 is disposed on the first surface Y. Of course, the first polysilicon doped conductive layer 202 in the first passivation contact structure 20 and the second passivation contact structure 30 has the same doping type, and can be the same N-type as the substrate 10, or the same P-type as the substrate 10. Figure 1 In the example shown in FIG. 1 , the types of the substrate 10 and the first polysilicon doped conductive layer 202 are both N-type.

[0154] The marking portion 50 is configured to be used as a positioning reference in the process of forming the first electrode 81, which means that in the process of forming the first electrode 81, it is necessary to use an image capture mechanism, such as a camera, to capture the marking portion 50, identify the position information, and then adjust the metallization equipment to achieve the positioning of the first electrode 81 and the first passivation contact structure 20. In the embodiment of the present application, it is precisely because of the improvement of the capture accuracy of the marking portion 50 that the metal paste can be accurately printed on the predetermined area on the first passivation contact structure 20.

[0155] In the present application, continue to refer to Figure 1 A first passivation layer 60 is further formed on the side of the first passivation contact structure 20 and the second passivation contact structure 30 facing away from the substrate 10. The first passivation layer 60 plays a role of passivation and anti-reflection. The first passivation layer 60 can be a single-layer or multi-layer structure, and its material can be aluminum oxide, silicon oxide, silicon nitride or silicon oxynitride. The first passivation layer 60 covers the first passivation contact structure 20, the second passivation contact structure 30 and each first region F.

[0156] Furthermore, the solar cell 100 further includes: a doped conductive layer 90 and a second passivation layer 70 sequentially stacked on the second surface E of the substrate 10, and a second electrode 82. The doped conductive layer 90 is used to form a PN junction with the substrate 10. In the embodiment of the present application, the substrate 10 is an N-type substrate as an example for explanation. At this time, the doped conductive layer 90 can be a P-type doped layer, for example, a boron-doped doped conductive layer 90 (also called a P+ type emitter).

[0157] The second passivation layer 70 may include, for example, a passivation layer and an anti-reflection layer (not shown) sequentially stacked on the doped conductive layer 90 . In addition, the second electrode 82 is disposed on the second passivation layer 70 and is electrically connected to the doped conductive layer 90 .

[0158] In the present application, refer to Figure 2 , the contour edges of the plurality of first passivation contact structures 20 respectively define a plurality of accommodation areas G. Each second passivation contact structure 30 is located in the corresponding accommodation area G. In this way, the second passivation contact structure 30 is equivalent to being embedded in the setting range of the first passivation contact structure 20, and will not occupy an additional effective area on the first surface Y, which is conducive to reducing the overall area of ​​the solar cell 100. Here, the accommodation area G is equivalent to the hollow area on the first passivation contact structure 20, and the first surface is exposed from the accommodation area G.

[0159] In the embodiment of the present application, Figure 2 Only one first passivation contact structure 20 is shown in the figure. When there are multiple first passivation contact structures 20, the multiple first passivation contact structures 20 are arranged at intervals from each other.

[0160] Each first passivation contact structure 20 includes a first contact region 2011 and a plurality of second contact regions 2012 extending from the first contact region 2011 in a direction away from the first contact region 2011. An accommodation region G is formed between two adjacent second contact regions 2012. Of course, the two adjacent second contact regions 2012 need to be connected to the same first contact region 2011. In this case, the accommodation region G formed is a semi-open region.

[0161] It is understandable that, in other embodiments, the two second contact regions 2012 forming the accommodation region G may also be connected to different first contact regions 2011 . Alternatively, the accommodation region G may also be defined by two adjacent first contact regions 2011 .

[0162] Furthermore, the second passivation contact structure 30 may also be disposed in a region between the first contact region 2011 and an edge of the solar cell 100 .

[0163] Further, the plurality of first contact regions 2011 of the plurality of first passivation contact structures 20 are arranged at intervals along the first direction B, and the plurality of second contact regions 2012 connected to the same first contact region 2011 are arranged at intervals along the second direction C, where the first direction B and the second direction C intersect and are both perpendicular to the thickness direction of the solar cell 100. Here, the first direction B and the second direction C may be perpendicular.

[0164] Further, the first electrode 81 includes a plurality of first sub-electrodes 810 and a plurality of second sub-electrodes 811, each first sub-electrode 810 is connected to at least two second sub-electrodes 811 spaced apart in the second direction C, the plurality of first sub-electrodes 810 are respectively arranged on a side surface of the first contact area 2011 facing away from the substrate 10, and the plurality of second sub-electrodes 811 are respectively arranged on a side surface of the second contact area 2012 connected to the first contact area 2011 facing away from the substrate 10.

[0165] The second passivation contact structure 30 is located between two adjacent second sub-electrodes 811 in the second direction C, and the two adjacent second sub-electrodes 811 are connected to the same first sub-electrode 810 .

[0166] In the embodiment of the present application, the first sub-electrode 810 may be a main gate, and the second sub-electrode 811 may be a fine gate.

[0167] Furthermore, in some other embodiments, each first passivation contact structure 20 may include a plurality of third contact regions (not shown) arranged at intervals, and the accommodation region G is disposed between two adjacent third contact regions. In this case, the first passivation contact structure 20 only includes the third contact region. Correspondingly, the first electrode 81 may include a plurality of third sub-electrodes, and the third sub-electrodes are disposed in the third contact region one by one. Of course, the third sub-electrode may be a fine grid, and in this case, the solar cell 100 may be a solar cell 100 without a main grid.

[0168] In addition, it can be understood that the marking portion 50 is located between two adjacent second sub-electrodes 811 in the second direction C, and the two adjacent second sub-electrodes 811 are connected to the same first sub-electrode 810 .

[0169] exist Figure 2 In the embodiment, the marking portion 50 and the two second sub-electrodes 811 adjacent to the marking portion 50 may be arranged at intervals, so as to avoid interference of the second sub-electrodes 811 on the marking portion 50 during the grasping process.

[0170] In the present application, continue to refer to Figure 1 , Figure 2 , the marking portion 50 includes a first groove 51 .

[0171] When implementing it specifically, you can Figure 1 As shown, the first groove 51 is made to penetrate into the interior of the substrate 10. This makes the appearance of the marking portion 50 more obvious and easier to be captured by a camera.

[0172] Alternatively, you can Figure 3 As shown, the first groove 51 penetrates into the passivation contact region J, that is, the first groove 51 extends to the boundary position between the second passivation contact structure 30 and the passivation contact region J along the thickness direction of the solar cell 100 .

[0173] Alternatively, the first groove 51 may also extend deep into the second passivation contact structure 30 (not shown).

[0174] Further, continue to refer to Figure 1 When the first groove 51 goes deep into the substrate 10, the maximum step difference D1 between the bottom wall of the first groove 51 and the surface of the passivation contact region J satisfies:

[0175] D1>1μm.

[0176] In a specific implementation, D1 may be 5.1 μm, 6 μm, 8 μm, etc. Such a configuration can make the first groove 51 in the marking portion 50 easier to grasp.

[0177] Further, refer to Figure 4In some other embodiments, a protruding structure 511 is provided in the central area of ​​the bottom wall of the first groove 51. In other words, the bottom wall of the first groove 51 includes a central area and an over-etched area adjacent to the edge of the central area, and the setting height of the over-etched area relative to the second surface E of the substrate 10 is lower than the setting height of the central area relative to the second surface E, thereby forming a protruding structure 511 in the central area of ​​the bottom wall. Of course, the bottom wall of the first groove 51 can be a plane, and of course, the present application is not limited thereto. The bottom wall of the first groove 51 can also be a curved surface, such as a concave surface, etc. It can also be an irregular curved surface shape, etc., which is related to parameters such as the energy and power of the laser.

[0178] Specifically, the marking portion 50 can be formed by laser processing. When the energy at the center of the laser spot is high, a melt-modified region appears on the bottom wall of the first groove 51, which is difficult to etch. Therefore, during the wet etching process, the etching speed of the center region of the bottom wall of the first groove 51 is lower than that of the remaining regions of the bottom wall, resulting in the formation of a protruding structure 511 with a height higher than that of the remaining regions in the center region of the bottom wall of the first groove 51. Compared with a flat bottom wall, such a setting can also make the first groove 51 in the marking portion 50 easier to grasp.

[0179] In the embodiment of the present application, the width dimension W1 of the first groove 51 satisfies: W1<100μm. It should be noted that, for the sake of convenience, the dimensions involved in the present application are marked as follows: Figure 4 In the embodiments of the present application, the above dimensions of the solar cells 100 of various structures are the same as Figure 4 Similarly, the following will not be repeated.

[0180] Furthermore, W1 satisfies: 5 μm ≤ W1 ≤ 50 μm. Such a setting can avoid excessive damage and affect efficiency.

[0181] In the present application embodiment, combined Figure 1 , Figure 4 , Figure 5 and Figure 6 The marking portion 50 further includes a transition processing area 52 located between the notch edge of the first groove 51 and the edge of the adjacent second passivation contact structure 30. The reflectivity of the surface of the transition processing area 52 facing away from the substrate 10 is greater than the reflectivity of the surface of the second passivation contact structure 30 facing away from the substrate 10.

[0182] The transition processing zone 52 includes a melt of a first material and a second material; wherein the first material is a passivation contact material contained in the second passivation contact structure 30, and the second material is a substrate material contained in the substrate 10. In other words, the transition processing zone 52 includes a melt of the passivation contact material contained in the second passivation contact structure 30 and the material contained in the substrate 10. In the process of laser forming the marking portion 50, when the laser spot is grooved at the position corresponding to the first groove 51, the area covered by the spot is the position of the first groove 51 and the transition processing zone 52. If the energy at the center of the spot is higher, the first groove 51 will be formed at the position corresponding to the higher energy. At the same time, the film layer passed by the laser, such as part of the passivation contact material in the second passivation contact structure 30 and part of the material contained in the substrate 10, will melt and form a melt around the first groove 51, so that the transition processing zone 52 is formed around the first groove 51.

[0183] In the embodiment of the present application, a plurality of protrusions are configured on the surface of the transitional processing area 52 facing away from the substrate 10. The height of the tops of the plurality of protrusions relative to the second surface E of the substrate 10 gradually increases from the notch edge side of the first groove 51 to the edge side of the adjacent second passivation contact structure 30.

[0184] Furthermore, the roughness of the surface of the transitional processed region 52 on the side facing away from the substrate 10 is smaller than the roughness of the surface of the second passivation contact structure 30 on the side facing away from the substrate 10 .

[0185] In the embodiment of the present application, the transition processing area 52 may be slightly lower than the surrounding second passivation contact structure 30 to increase identifiability.

[0186] Furthermore, the surface of the side of the transition processing area 52 facing away from the substrate 10 is lower than the surface of the side of the second passivation contact structure 30 facing away from the substrate 10 by D0, and D0 satisfies: 50nm<D0<1μm. In this way, it is more conducive to the obvious optical difference between the marking portion 50 and the surrounding area, which is convenient for camera capture. Of course, when the surface of the side of the transition processing area 52 facing away from the substrate 10 is compared with the surface of the side of the second passivation contact structure 30 facing away from the substrate 10, the comparison basis can be the second surface E.

[0187] In the embodiment of the present application, the dimension W2 of the marking portion 50 along the width direction of the first groove 51 satisfies:

[0188] W2<120μm.

[0189] In a specific implementation, the size W2 is less than 90 μm, for example, it can be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, or 80 μm.

[0190] Furthermore, a surface of the second passivation contact structure 30 facing away from the substrate 10 is also provided with a third structure 53, which is arranged around the marking portion 50, and the reflectivity of the surface of the third structure 53 facing away from the substrate 10 is greater than the reflectivity of the surface of the second passivation contact structure 30 facing away from the substrate 10.

[0191] The third structure 53 refers to a structure formed by the melt of each film layer being sputtered around the marking portion 50 during the laser film opening process. Specifically, during the process of laser forming the marking portion 50, when the laser spot is grooved at the position corresponding to the first groove 51, part of the passivation contact material in the second passivation contact structure 30 and part of the material included in the substrate 10 are melted and sputtered to the surface of the second passivation contact structure 30 around the transition processing area 52, so that the third structure 53 is formed around the transition processing area 52.

[0192] In the embodiment of the present application, the reflectivity of the surface of the third structure 53 facing away from the substrate 10, the reflectivity of the surface of the transition treatment zone 52 facing away from the substrate 10, and the reflectivity of the bottom wall of the first groove 51 increase successively. Among the surface of the third structure 53 facing away from the substrate 10, the surface of the transition treatment zone 52 facing away from the substrate 10, and the bottom wall of the first groove 51, the surface roughness decreases successively and the smoothness increases successively, so that the reflectivity increases successively. Such a setting can gradually increase the optical difference between the material contained in the marking portion 50, the transition treatment zone 52 and the third structure 53 and the surrounding second passivation contact structure 30. Compared with setting the reflectivity of these three to be the same, the optical difference between the transition treatment zone 52 and the third structure 53 and the surrounding materials becomes larger, so that the marking portion 50 is easier to be captured by the camera. Figure 5 , Figure 6 As shown in the picture, the formed third structure 53 is obviously different from the surrounding second passivation contact structure 30, and the third structure 53 and the transition processing area 52, as well as the transition processing area 52 and the first groove 51 are obviously different, which is convenient for camera capture.

[0193] Further, continue to refer to Figure 1 and Figure 4 , the first region F is closer to the second surface E of the substrate 10 than the passivation contact region J, that is, the setting position of the first region F is lower than the setting position of the passivation contact region J. During the formation of the first passivation contact structure 20 and the second passivation contact structure 30, a whole layer of polysilicon doping material layer is first formed, wherein an inner diffusion layer is formed in the first surface Y of the substrate 10 due to the diffusion of the doping elements, and the resulting recombination is relatively high. By setting as above, the inner diffusion layer of the first region F can be at least partially removed, which is beneficial to reducing recombination and improving the efficiency of the solar cell 100.

[0194] In the embodiment of the present application, the step D2 between the surface of the first region F and the surface of the passivation contact region J satisfies: D2>1 μm. In this way, the inner diffusion layer can be effectively removed to reduce recombination.

[0195] In the embodiment of the present application, the height difference D1 between the bottom wall of the first groove 51 and the surface of the passivation contact area J and D2 satisfy: D2≤D1.

[0196] In a specific implementation, D2 may be, for example, 5 μm. Alternatively, in some embodiments, D2 may be greater than D1.

[0197] In the present application, continue to refer to Figure 7 , Figure 8 The outer contour of the first groove 51 along the groove depth direction is circular or annular. Alternatively, the first groove 51 includes at least two groove sections 510 that intersect each other, and the outer contour of each groove section 510 along the groove depth direction can be a long strip. Figure 2 In the example, the number of the slot segments 510 is two. Of course, the number of the slot segments 510 is not limited thereto and can be set to other values ​​as needed.

[0198] It should be noted that, in the embodiments of the present application, the outer contour of a component refers to the outer edge of the component seen when the solar cell 100 is viewed from above. For example, the outer contour of the first groove 51 refers to the outer edge of the first groove 51 seen when the solar cell 100 is viewed from above, and the outer contour of the groove segment 510 refers to the outer edge of the groove segment 510 seen when the solar cell 100 is viewed from above.

[0199] In the present application embodiment, Figure 2 , Figure 7 , Figure 8 , Fig. 9 As shown, the first passivation contact structure 20 and the second passivation contact structure 30 may be connected to each other. Fig.10 , Fig.11 As shown, the first passivation contact structure 20 and the second passivation contact structure 30 are spaced apart from each other.

[0200] Furthermore, the number of the marking parts 50 can be multiple, and the multiple marking parts 50 are used to locate the geometric center of the solar cell. For example, when the number of the marking parts 50 is four, the four marking parts 50 can be set at the four corners of the square solar cell 100. Of course, the present application is not limited to this, and the number of the marking parts 50 can be set to other numbers as needed, and the number of the marking parts 50 set on each second passivation contact structure 30 can be one, or can be set to other numbers as needed.

[0201] In the embodiment of the present application, regardless of the number of marking portions 50 provided on each second passivation contact structure, the number of second passivation contact structures 30 can be set to an even number, and the even number of second passivation contact structures 30 can be divided into multiple groups of two, and the two second passivation contact structures 30 in each group are arranged opposite to each other with the geometric center of the solar cell 100 as a reference. When the number of the second passivation contact structures 30 is four, the four second passivation contact structures 30 can be provided at the four corners of the square solar cell 100. Of course, the present application is not limited thereto, and the number of the second passivation contact structures 30 can be set to other numbers as needed.

[0202] Further, in Figure 2 , Figure 7 , Figure 8 , Fig.11 In the described solution, the marking portion 50 is spaced apart from the two second sub-electrodes 811 to avoid the possible influence of the second sub-electrodes 811 on the grasping of the marking portion 50 .

[0203] In some embodiments, it is also possible to Fig. 9 , Fig.10 In this way, the first groove 51 included in the marking portion 50 extends beyond the range of the second passivation contact structure 30 and contacts the second sub-electrode 811 .

[0204] In addition, the marking portion 50 and the edge of the corresponding second passivation contact structure 30 may be spaced apart or may be continuous, as long as the grabbing center of the marking portion 50 is ensured to be within the range of the second passivation contact structure 30 .

[0205] In the present application, refer to Fig.12 On the basis of the above-mentioned embodiments, the transition processing zone 52 is also improved. For example, the transition processing zone 52 can also be flush with the surrounding second passivation contact structure 30, that is, the surface of the transition processing zone 52 facing away from the substrate 10 is flush with the surface of the second passivation contact structure 30 facing away from the substrate 10.

[0206] Reference Fig.13 On the basis of the above-mentioned embodiment, the embodiment of the present application also provides another structure of a solar cell 100, which is a double-sided TOPCon cell structure. Fig.13 In the solar cell 100 shown, the structures, shapes, and locations of the marking portion 50 , the first passivation contact structure 20 , the second passivation contact structure 30 , the first electrode 81 , and other parts are the same as those in the previous embodiment and will not be described in detail herein.

[0207] Fig.13The first surface Y of the solar cell 100 is a light-receiving surface, and the second surface E is a backlight surface. Each position on the first surface Y is provided with a velvet structure 91 , so the bottom wall and the side wall of the first groove 51 are formed with a velvet structure 91 .

[0208] A third passivation contact structure 92 and a second passivation layer 70 are sequentially stacked on the second surface E.

[0209] The third passivation contact structure 92 entirely covers the second surface E. The third passivation contact structure 92 includes a third tunneling oxide layer and a third polysilicon doped conductive layer (not shown) stacked on each other. The third tunneling oxide layer is disposed on the second surface E. Of course, the third polysilicon doped conductive layer in the third passivation contact structure 92 has a doping type opposite to that of the first polysilicon doped conductive layer 202 in the first passivation contact structure 20 and the second passivation contact structure 30.

[0210] In addition, in the embodiment of the present application, the solar cell 100 may include a plurality of side surfaces, and at least some of the side surfaces are cut surfaces, so that the solar cell 100 is a structure formed by cutting.

[0211] The second aspect of the present application provides a method for manufacturing a solar cell, which is used to manufacture the solar cell 100 of the above embodiment. That is, the solar cell 100 of all the above embodiments can be manufactured by the following method for manufacturing a solar cell.

[0212] Fig.14 A schematic diagram of a process for manufacturing a solar cell provided in an embodiment of the present application; Fig.15 A schematic diagram of the structure of a substrate in a method for manufacturing a solar cell provided in an embodiment of the present application; Fig.16 A schematic diagram of forming a marking structure in a method for manufacturing a solar cell provided in an embodiment of the present application; Fig.17 A schematic diagram of a structure for forming a marking portion in a method for manufacturing a solar cell provided in an embodiment of the present application; Fig.18 A schematic diagram of the structure of forming a first passivation layer in the method for manufacturing a solar cell provided in an embodiment of the present application; Fig.19 for Fig.16 Pictures of the labeled structures shown; Fig. 20 for Fig.17 Pictures of the marked parts shown; Fig.21 for Figure 5 The height curve diagram of each marked part is shown. Figure 5 , Figure 6 , Fig.19 , Fig. 20 , Fig.21 The pictures shown in the figure were all obtained using an optical microscope.

[0213] Reference Figure 14-Figure 21The method for manufacturing a solar cell provided in this embodiment includes:

[0214] S10. Provide a substrate, the substrate comprising a substrate, a passivation contact material layer and a dielectric layer sequentially stacked on a first surface of the substrate, the first surface of the substrate comprising a first region and a passivation contact region.

[0215] S20, patterning the portion of the dielectric layer covering the first region to form a marking structure at a position where the dielectric layer covers the passivation contact region, wherein the marking structure at least extends to the passivation contact material layer.

[0216] S30, using the portion of the dielectric layer that has been patterned and formed with a marking structure and that covers the passivation contact area as a mask, removing the portion of the passivation contact material layer located in the first area, and removing the dielectric layer to form a marking structure into a marking portion.

[0217] S40, forming a first passivation layer on the side of the passivation contact material layer facing away from the substrate, using the marking portion as a positioning reference, and forming a first electrode at a position where the first passivation layer covers the passivation contact area.

[0218] In the above solution, by patterning the portion of the dielectric layer 22 covering the first region F, the marking structure 40 is formed at the position where the dielectric layer 22 covers the passivation contact region J. The portion of the dielectric layer 22 covered with the passivation contact region J after the patterning process and formed with the marking structure 40 is used as a mask to remove the portion of the passivation contact material layer 21 located in the first region F. Therefore, the portion of the passivation contact material layer 21 covering the passivation contact area J will be retained, and the dielectric layer 22 will be removed later, and the marking structure 40 will be formed into a marking portion 50. Therefore, the marking portion 50 is finally formed on the portion of the passivation contact material layer 21 covering the passivation contact area J, which allows the passivation contact material to be reserved around the marking portion 50. Compared with the marking portion 50 being set in the first area F (without the passivation contact material), the reflection ability of the marking portion 50 and the surrounding background structure is greatly different. In the subsequent process of forming the first electrode 81 at the position where the first passivation layer 60 covers the passivation contact area J, the image capture mechanism, such as a camera, can capture the position of the marking portion 50 more easily and more accurately. The position of the first electrode 81 is more accurate, which also improves the yield of the solar cell 100.

[0219] It should be noted that in step S20, in the step of patterning the portion of the dielectric layer 22 covering the first region F and forming the marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J, the step of patterning the portion of the dielectric layer 22 covering the first region F may be performed first, and then the step of forming the marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J may be performed. Alternatively, the step of forming the marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J may be performed first, and then the step of patterning the portion of the dielectric layer 22 covering the first region F may be performed. Alternatively, the step of patterning the portion of the dielectric layer 22 covering the first region F and the step of forming the marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J may be performed simultaneously.

[0220] In the embodiment of the present application, in step S20, the step of forming the marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J specifically includes:

[0221] The first laser is used to locally scan the position of the dielectric layer 22 covering the passivation contact region J to form a marking structure 40 .

[0222] Furthermore, in step S20, the step of patterning the portion of the dielectric layer 22 covering the first region F specifically includes:

[0223] The second laser is used to scan the entire position of the dielectric layer 22 covering the first region F;

[0224] The spot size of the second laser is larger than that of the first laser, and the laser power of the second laser is larger than that of the first laser.

[0225] In the process of using laser to process the portion of the dielectric layer 22 covering the first region F and the passivation contact region J, because the laser processing area of ​​the dielectric layer 22 covering the first region F is large, a larger size and a larger power spot are required to meet the requirements. If the same laser is used to process the portion of the dielectric layer 22 covering the passivation contact region J to make the marking structure 40, the larger spot size will result in the obtained marking structure 40 having an excessively large area, which affects the passivation effect on the surface of the solar cell 100 and takes a longer time to process. In addition, in the process of opening the film over a large area, in order to make the opening of the film proceed smoothly and evenly, the spot needs to be shaped to ensure that the spot energy irradiated to the portion of the dielectric layer 22 covering the first region F is uniform. In this way, the laser required for laser processing of the dielectric layer 22 covering the first area F needs to have the characteristics of large spot size, high energy, and good uniformity (shaping is required). When a laser with these characteristics is used to laser process the portion of the dielectric layer 22 covering the passivation contact area J, the overall cost of the process is high due to the high cost of the laser, and the passivation performance at the position of the marking structure 40 will also be affected.

[0226] In the above technical solution, two sets of independent lasers, the second laser and the first laser, are used to laser process the portion of the dielectric layer 22 covering the first area F and the passivation contact area J respectively. The spot size of the second laser is larger than the spot size of the first laser, and the laser power of the second laser is larger than the laser power of the first laser. The spot size and laser power of the first laser are both smaller, which can not only reduce the cost, but also make the area of ​​the final mark 50 smaller due to the smaller spot size, thereby improving the passivation performance of the solar cell 100. In specific implementation, for example, the first laser can be an infrared laser, and the second laser can be a green light picosecond laser. The infrared laser is used as the first laser to laser process the portion of the dielectric layer 22 covering the passivation contact area J to form the marking structure 40, so as to avoid the problem that the green light picosecond has little damage to the film layer and needs to be repeatedly processed for many times, so as to further improve the production capacity. At the same time, the green light picosecond is used as the second laser to laser process the portion of the dielectric layer 22 covering the first area F. Thus, the processing of the two positions can be completed efficiently in steps, which is also conducive to improving the passivation performance of the solar cell 100.

[0227] In the embodiment of the present application, the spot diameter of the first laser is less than 120μm, and the power is 10W-100W, preferably, it can also be 10W-15W. It can be understood that the energy can also be increased by increasing the overlap rate. The spot diameter of the second laser is greater than 150μm, and the power is 40W-200W, preferably, it can also be 60W-80W. In specific implementation, the first laser can be a Gaussian beam. It can also be a shaped spot, such as a square spot. Since the first laser is used to form the marking structure 40, the requirements for the spot, especially the uniformity, are slightly lower than those of the second laser, and an unshaped Gaussian beam can be selected to reduce costs.

[0228] In the embodiment of the present application, the step of using the first laser to locally scan the position of the dielectric layer 22 covering the passivation contact area J specifically includes:

[0229] The medium layer 22 is scanned back and forth along a first path and a second path by a first laser to form a marking structure 40 with a cross-shaped outer contour on the medium layer 22 , wherein the first path and the second path intersect and are both straight paths.

[0230] Alternatively, in another embodiment, the medium layer 22 is scanned along a circular path using the first laser to form a marking structure 40 with a circular outer contour.

[0231] Alternatively, in other embodiments, the medium layer 22 is scanned along a circular area using the first laser to form a marking structure 40 with a circular outer contour.

[0232] In the present application embodiment, combined Figure 1 , Fig.16 , Fig.17 , the marking portion 50 includes a first groove 51 .

[0233] In step S30, the portion of the dielectric layer 22 which has been patterned and formed with the marking structure 40 and covers the passivation contact region J is used as a mask to remove the portion of the passivation contact material layer 21 located in the first region F; and the dielectric layer 22 is removed to form the marking structure 40 into the marking portion 50:

[0234] The portion of the passivation contact material layer 21 located in the first region F is removed by wet etching, and the patterned dielectric layer 22 is removed to form a first groove 51 in the passivation contact material layer 21 covering the passivation contact region J. After the portion of the passivation contact material layer 21 located in the first region F is removed, the remaining passivation contact material layer 21 forms a first passivation contact structure 20 covering the passivation contact region J, and a second passivation contact structure 30 covering the passivation contact region J.

[0235] Furthermore, the marking structure 40 further includes a transition processing area 52 located at the edge of the notch of the first groove 51; the energy intensity at the central local area of ​​the light spot of the first laser is greater than the energy intensity at the edge area of ​​the light spot;

[0236] After wet etching, in the passivation contact material layer 21, in the area processed by the central local area, a portion of the position forms a first groove 51, and another portion of the position and the area processed by the edge area form a transitional processing area 52, and the transitional processing area 52 includes a melt of the materials included in the dielectric layer 22, the passivation contact material layer 21, and the substrate 10. Alternatively, after wet etching, in the passivation contact material layer 21, in the area processed by the central local area, the position forms a first groove 51, and in the area processed by the edge area, the transitional processing area 52 is formed.

[0237] Of course, as an optional embodiment, the first laser may be a Gaussian beam, so that the energy intensity at the central local area of ​​the light spot of the first laser is greater than the energy intensity at the edge area of ​​the light spot. Of course, other types of beams may also be used, as long as the energy intensity at the central local area of ​​the light spot of the first laser is greater than the energy intensity at the edge area of ​​the light spot.

[0238] In the embodiment of the present application, further, after the above-mentioned wet etching, a third structure 53 is formed around the marking structure 40, and the reflectivity of the surface of the third structure 53 facing away from the substrate 10 is greater than the reflectivity of the surface of the passivation contact material layer 21 facing away from the substrate 10.

[0239] It is understandable that when the marking structure 40 is formed by using the first laser, Fig.16 As shown, the marking structure 40 may include a first groove 51 , a transition processing area 52 and a third structure 53 . When wet etching is subsequently performed, impurities on each part are removed, thereby forming a clearer marking portion 50 .

[0240] Alternatively, the first laser may only melt the film layers in the area where the first groove 51 is to be formed, and form a transition processing area 52 and a third structure 53. In the subsequent wet etching process, the melted part is removed to form the first groove 51 and finally the marking part 50.

[0241] like Fig.17 As shown, as mentioned above, the third structure 53 refers to the structure formed by the melt of each film layer sputtering around the marking structure 40 during the laser film opening process. After wet etching, its surface reflectivity is greater than the first passivation contact structure 20 and the second passivation contact structure 30, which is convenient for camera capture.

[0242] In the embodiment of the present application, the portion of the dielectric layer 22 that has been patterned and formed with the marking structure 40 and covers the passivation contact region J is used as a mask to remove the portion of the passivation contact material layer 21 located in the first region F, and the first region F of the substrate 10 is also etched inwardly in the thickness direction of the substrate 10 by a portion of the thickness to form a height difference D2. As described in the description of the solar cell 100 above, such a setting can remove the inner diffusion layer in the substrate 10 to a certain extent.

[0243] Furthermore, in step S20, the step of patterning the portion of the dielectric layer 22 covering the first region F includes:

[0244] Modifying the portion of the dielectric layer 22 covering the first region F;

[0245] The step of removing the portion of the passivation contact material layer 21 located in the first region F by using the portion of the dielectric layer 22 that has been patterned and formed with the marking structure 40 and covers the passivation contact region J as a mask specifically includes:

[0246] By wet etching, the portion of the dielectric layer 22 covering the first region F is removed, and the portion of the passivation contact material layer 21 located in the first region F is removed.

[0247] Alternatively, you can Fig.16 , 17 As shown, the step of patterning the portion of the dielectric layer 22 covering the first region includes:

[0248] The portion of the dielectric layer 22 covering the first region F is removed;

[0249] The step of removing the portion of the passivation contact material layer 21 located in the first region F by using the portion of the dielectric layer 22 that has been patterned and formed with the marking structure 40 and covers the passivation contact region J as a mask specifically includes:

[0250] The portion of the passivation contact material layer 21 located in the first region F is removed by wet etching.

[0251] In an embodiment of the present application, the method for manufacturing a solar cell also includes the step of cutting the solar cell 100 into multiple solar cell substrates along the thickness, the number of marking portions 50 in the partially cut solar cell substrates is 0, and the number of marking portions 50 in the partially cut solar cell substrates is more than 1.

[0252] The following is a specific example of a method for manufacturing a solar cell according to an embodiment of the present application. The method includes:

[0253] Step 1: Fig.15As shown, a passivation contact material layer 21 and a dielectric layer 22 are sequentially stacked on the first surface Y of the substrate 10, and the first surface Y of the substrate 10 includes a passivation contact region J and a first region F. At this time, the dielectric layer 22 may be, for example, naturally formed in the formation process of the passivation contact material layer 21, for example, when the passivation contact material layer 21 includes a phosphorus-doped polysilicon doping material layer 212, the dielectric layer 22 may be PSG.

[0254] Step 2: Fig.16 , Fig.19 As shown, the second laser is used to remove the portion of the dielectric layer 22 covering the first region F, and the first laser is used to form a marking structure 40 at the position where the dielectric layer 22 covers the passivation contact region J. The marking structure 40 at least extends to the passivation contact material layer 21.

[0255] Step 3: Fig.17 , Fig. 20 As shown, the patterned dielectric layer 22 is used as a mask, that is, the portion of the dielectric layer 22 that has been patterned and formed with the marking structure 40 and covers the passivation contact area J is used as a mask, and wet etching is performed to remove the portion of the passivation contact material layer 21 located in the first area F, and the portion located in the passivation contact area J is retained to form the first passivation contact structure 20 and the second passivation contact structure 30, and the patterned dielectric layer 22 is removed to form a first groove 51 in the passivation contact material layer 21 covering the passivation contact area J, and a transitional processing area 52 is formed around the first groove 51, and a third structure 53 is formed around the transitional processing area 52, thereby forming a marking portion 50. It should be noted that the first groove 51 can be a continuous or discontinuous groove structure in its extension direction.

[0256] Step 4: Figure 5 , Fig.18 , Fig.21 As shown, a first passivation layer 60 is formed on the side of the first passivation contact structure 20 and the second passivation contact structure 30 facing away from the substrate 10, and a first electrode 81 is formed at a position where the first passivation layer 60 covers the passivation contact region J using the marking portion 50 as a positioning reference.

[0257] exist Fig.21 The top of the figure is a schematic diagram of the thickness dimension of the marking portion 50 in a direction perpendicular to its extension direction R. Find a point on the side of the first groove 51 as the original point O, the horizontal axis L1 represents the distance from the original point O, and the vertical axis L2 represents the thickness dimension of each position in the thickness direction of the solar cell 100. Fig.21 It can be seen that a protruding structure 511 is formed in the first groove 51 , and the first groove 51 is more obviously recessed relative to the transition processing area 52 around it, so that it is easy to be captured by the camera.

[0258] It is understandable that in Figure 1 The steps for forming the solar cell 100 shown may also include, for example, a step of forming a doped conductive layer 90 on the second surface E of the substrate 10 before step 1, and after step 4, a step of forming a second passivation layer 70 on the surface of the doped conductive layer 90 facing away from the substrate 10, and a step of forming a second electrode 82 on the second passivation layer 70.

[0259] The embodiments of the present application also provide a photovoltaic module and a photovoltaic system. The photovoltaic module includes at least one battery string, and the battery string includes at least two solar cells 100 as described above, and the solar cells 100 can be connected together by serial welding.

[0260] The photovoltaic system includes the above-mentioned photovoltaic components. The photovoltaic system can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc. It can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid. After that, it is connected to the mains network to realize solar power supply.

[0261] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0262] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A solar cell, characterized in that: include: a substrate comprising a first surface; a passivation contact structure, the passivation contact structure being disposed on a portion of the first surface; as well as a first electrode, the first electrode being disposed on a side of the passivation contact structure away from the substrate and being electrically connected to the passivation contact structure; Wherein, a marking portion is provided on a surface of a part of the passivation contact structure which is away from the substrate; The first surface includes a plurality of passivation contact regions; The passivation contact structure comprises a plurality of first passivation contact structures and a plurality of second passivation contact structures, wherein the first passivation contact structures and the second passivation contact structures are respectively arranged in corresponding passivation contact regions; The first electrode is arranged on a side of the first passivation contact structure away from the substrate; and the marking portion is arranged on the second passivation contact structure.

2. The solar cell according to claim 1, characterized in that The marking portion does not overlap with a projection of the first electrode on the first surface.

3. The solar cell according to claim 1, characterized in that The marking portion partially overlaps with a projection of the first electrode on the first surface.

4. The solar cell according to claim 1, characterized in that The marking portion is configured to serve as a positioning reference during the formation of the first electrode.

5. The solar cell according to claim 1, characterized in that: The first electrode includes a plurality of first sub-electrodes and a plurality of second sub-electrodes, the plurality of first sub-electrodes are arranged at intervals along a first direction, and each of the first sub-electrodes is connected to at least two of the second sub-electrodes arranged at intervals in a second direction; The marking portion is at least partially located between two adjacent second sub-electrodes in the second direction, and the two adjacent second sub-electrodes are connected to the same first sub-electrode; the first direction and the second direction intersect and are both perpendicular to the thickness direction of the solar cell.

6. The solar cell according to claim 5, characterized in that: The marking portion is located between two second sub-electrodes adjacent to each other in the second direction.

7. The solar cell according to claim 6, characterized in that: The marking portion and two second sub-electrodes adjacent to the marking portion are arranged at intervals.

8. The solar cell according to claim 6, characterized in that: The marking portion and one of the two second sub-electrodes adjacent to the marking portion are spaced apart from each other and are in contact with the other second sub-electrode.

9. The solar cell according to claim 5, characterized in that: In the marking portion, a partial structure is located between two second sub-electrodes adjacent to each other in the second direction, and a partial structure extends to a side of one of the second sub-electrodes away from the other second sub-electrode.

10. The solar cell according to claim 1, characterized in that: The second passivation contact structure does not overlap with the projection of the first passivation contact structure on the first surface.

11. The solar cell according to claim 1, characterized in that: The contour edges of the plurality of first passivation contact structures respectively define a plurality of accommodation areas; Each of the second passivation contact structures is located in the corresponding accommodating area.

12. The solar cell according to claim 11, characterized in that: The plurality of first passivation contact structures are arranged spaced apart from each other; Each of the first passivation contact structures includes a first contact region and a plurality of second contact regions extending from the first contact region in a direction away from the first contact region; The accommodation area is formed between two adjacent second contact areas.

13. The solar cell according to claim 12, characterized in that: The two adjacent second contact regions are connected to the same first contact region.

14. The solar cell according to claim 12, characterized in that: The multiple first contact areas of the multiple first passivation contact structures are arranged at intervals along a first direction, and the multiple second contact areas connected to the same first contact area are arranged at intervals along a second direction. The first direction and the second direction intersect and are both perpendicular to the thickness direction of the solar cell.

15. The solar cell according to claim 14, characterized in that: The first electrode comprises a plurality of first sub-electrodes and a plurality of second sub-electrodes, each of the first sub-electrodes being connected to at least two second sub-electrodes spaced apart in the second direction; the plurality of first sub-electrodes being arranged one by one on a surface of the first contact region facing away from the substrate, and the plurality of second sub-electrodes being arranged one by one on a surface of the second contact region connected to the first contact region facing away from the substrate; The second passivation contact structure is located between two adjacent second sub-electrodes in the second direction, and the two adjacent second sub-electrodes are connected to the same first sub-electrode.

16. The solar cell according to claim 11, characterized in that: Each of the first passivation contact structures comprises a plurality of third contact regions arranged at intervals, and the accommodation region is provided between two adjacent third contact regions; The first electrode includes a plurality of third sub-electrodes, and the third sub-electrodes are arranged in the third contact region in a one-to-one correspondence.

17. The solar cell according to any one of claims 1 to 16, characterized in that: The first passivation contact structure and the second passivation contact structure are arranged spaced apart from each other; or The first passivation contact structure and the second passivation contact structure are connected to each other.

18. The solar cell according to any one of claims 1 to 16, characterized in that: A gripping center of the marking portion is within the range of the second passivation contact structure.

19. The solar cell according to claim 18, characterized in that The first passivation contact structure and the second passivation contact structure are arranged at an interval from each other, and the marking portion is spaced apart from an edge corresponding to the second passivation contact structure.

20. The solar cell according to claim 19, characterized in that The marking portion is located within a range corresponding to the second passivation contact structure; or The marking portion is located outside a range corresponding to the second passivation contact structure.

21. The solar cell according to claim 18, characterized in that The first passivation contact structure and the second passivation contact structure are connected to each other; The marking portion is located within a range corresponding to the second passivation contact structure; or The marking portion is located outside a range corresponding to the second passivation contact structure.

22. The solar cell according to any one of claims 1 to 16, characterized in that: The number of the marking parts is multiple; The multiple marking parts are used to locate the geometric center of the solar cell.

23. The solar cell according to any one of claims 1 to 16, characterized in that: The first surface further includes a plurality of first regions; the first regions are defined between adjacent passivation contact regions; or The first surface has at least one passivation contact region, and at least a portion of each of the first regions is configured to be surrounded and defined by the passivation contact region.

24. The solar cell according to claim 23, characterized in that The first region is closer to the second surface of the substrate than the passivation contact region, and the second surface is arranged opposite to the first surface.

25. The solar cell according to claim 24, characterized in that The height difference D2 between the surface of the first region and the surface of the region of the substrate where the second passivation contact structure is located satisfies: D2>1μm.

26. The solar cell according to any one of claims 1 to 16, characterized in that: The solar cell includes a plurality of side surfaces, at least some of which are cut surfaces.

27. The solar cell according to any one of claims 1 to 16, characterized in that: At least one of the first passivation contact structure and the second passivation contact structure includes a first tunneling oxide layer and a first polysilicon doped conductive layer stacked on each other, and the first tunneling oxide layer is disposed on the first surface.

28. A photovoltaic module, characterized in that: The method comprises at least one battery string, wherein the battery string comprises at least two solar cells according to any one of claims 1 to 27.

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