Solar cells and photovoltaic modules

Abstract

The present application provides a solar cell and a photovoltaic module, which relate to the field of photovoltaic technology, wherein the solar cell includes a silicon substrate, the light-receiving surface of the silicon substrate includes a first velvet structure and a second velvet structure, the first velvet structure includes a plurality of prism-shaped protrusions, and the second velvet structure includes a plurality of pyramid-shaped protrusions; the solar cell also includes a grid line and a passivation structure, the grid line and the passivation structure are at least located on one side of the light-receiving surface of the silicon substrate, and the passivation structure is located between the grid line and the first velvet structure; the passivation structure includes a first aluminum oxide layer and a silicon nitride layer, the first aluminum oxide layer is located on one side of the silicon substrate, and the silicon nitride layer is located on the side of the first aluminum oxide layer away from the silicon substrate. The first aluminum oxide layer in the passivation structure of the present application is formed on a flat surface, which is conducive to improving the passivation effect of the solar cell, thereby helping to reduce the recombination loss on the surface of the solar cell, and further helping to improve the conversion efficiency of the solar cell.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, and more specifically, to a solar cell and a photovoltaic component. Background Art

[0002] With the rapid development of the photovoltaic industry, the requirements for the performance of solar cells are getting higher and higher. In solar cells, passivation is a very important process. Passivation can be achieved by forming a passivation layer on the surface of the cell. Passivation is beneficial to reduce the recombination loss on the surface of the cell and improve the conversion efficiency of the cell.

[0003] Therefore, how to improve the passivation effect has become one of the technical problems that need to be solved urgently at this stage. Utility Model Content

[0004] In view of this, the utility model provides a solar cell and a photovoltaic module, which improve the passivation effect of the solar cell surface through a differentiated velvet design.

[0005] In a first aspect, the present application provides a solar cell, comprising a silicon substrate, wherein a light-receiving surface of the silicon substrate comprises a first velvet structure and a second velvet structure, wherein the first velvet structure and the second velvet structure do not overlap, the first velvet structure comprises a plurality of prism-shaped protrusions, and the second velvet structure comprises a plurality of pyramid-shaped protrusions;

[0006] The solar cell further comprises a grid line and a passivation structure, wherein the grid line and the passivation structure are at least located on one side of the light-receiving surface of the silicon substrate, and the passivation structure is located between the grid line and the first velvet structure;

[0007] The orthographic projection of the gate line on the silicon substrate along a first direction and the orthographic projection of the passivation structure on the silicon substrate along the first direction both overlap with the orthographic projection of the first velvet structure on the silicon substrate along the first direction, and both do not overlap with the orthographic projection of the second velvet structure on the silicon substrate along the first direction, and the first direction is the thickness direction of the silicon substrate;

[0008] The passivation structure includes a first aluminum oxide layer and a silicon nitride layer. The first aluminum oxide layer is located on one side of the silicon substrate, and the silicon nitride layer is located on a side of the first aluminum oxide layer away from the silicon substrate.

[0009] Optionally, where:

[0010] The height of the prism-shaped protrusion along the first direction is H1, H1<1 μm; the height of the pyramid-shaped protrusion along the first direction is H2, 1 μm≤H2≤2 μm.

[0011] Optionally, where:

[0012] The passivation structure further includes a polysilicon layer located between the first aluminum oxide layer and the silicon nitride layer.

[0013] Optionally, where:

[0014] The passivation structure further includes a second aluminum oxide layer located between the polysilicon layer and the silicon nitride layer.

[0015] Optionally, where:

[0016] The thickness of the first aluminum oxide layer along the first direction is L1, 2nm≤L1≤8nm.

[0017] Optionally, where:

[0018] The thickness of the second aluminum oxide layer along the first direction is L2, 1nm≤L2≤4nm.

[0019] Optionally, where:

[0020] The backlight surface of the silicon substrate also includes the first velvet structure and the second velvet structure;

[0021] The gate line and the passivation structure are also located on the backlight side of the silicon substrate.

[0022] Optionally, where:

[0023] The passivation structure further includes a polysilicon layer located between the first aluminum oxide layer and the silicon nitride layer.

[0024] Optionally, where:

[0025] The passivation structure further includes a second aluminum oxide layer located between the polysilicon layer and the silicon nitride layer.

[0026] In a second aspect, the present application provides a photovoltaic module, comprising the solar cell described in the first aspect.

[0027] Compared with the prior art, the solar cell and photovoltaic module provided by the utility model achieve at least the following beneficial effects:

[0028] The present application provides a solar cell and a photovoltaic module, wherein the solar cell includes a silicon substrate, the light-receiving surface of the silicon substrate includes a first velvet structure and a second velvet structure, the first velvet structure includes a plurality of prism-shaped protrusions, and the second velvet structure includes a plurality of pyramid-shaped protrusions; the solar cell also includes a grid line and a passivation structure, the grid line and the passivation structure are at least located on one side of the light-receiving surface of the silicon substrate, and the passivation structure is located between the grid line and the first velvet structure; the passivation structure includes a first aluminum oxide layer and a silicon nitride layer, the first aluminum oxide layer is located on one side of the silicon substrate, and the silicon nitride layer is located on the side of the first aluminum oxide layer away from the silicon substrate. The solar cell provided by the present application has a grid line located on the first velvet structure, a passivation structure is included between the grid line and the first velvet structure, the first velvet structure includes a prism-shaped protrusion, the first velvet structure is relatively flat compared to the pyramid-shaped protrusion of the second velvet structure, and when the first aluminum oxide layer in the passivation structure is formed on a flat surface, the passivation effect is better, therefore, the present application is conducive to improving the passivation effect of the solar cell, thereby being conducive to reducing the recombination loss on the surface of the solar cell, and further conducive to improving the conversion efficiency of the solar cell.

[0029] Of course, any product implementing the present utility model does not necessarily need to achieve all of the above-mentioned technical effects at the same time.

[0030] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0032] Figure 1 Shown is a schematic diagram of a solar cell provided in an embodiment of the present application;

[0033] Figure 2 Shown is a schematic diagram of another solar cell provided in an embodiment of the present application;

[0034] Figure 3 Shown is a schematic diagram of another solar cell provided in an embodiment of the present application;

[0035] Figure 4 Shown is a schematic diagram of another solar cell provided in an embodiment of the present application;

[0036] Figure 5 Shown is a schematic diagram of another solar cell provided in an embodiment of the present application;

[0037] Figure 6 Shown is a schematic diagram of another solar cell provided in an embodiment of the present application;

[0038] Figure 7 Shown is a schematic diagram of a photovoltaic module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0041] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0042] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0043] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] The inventors found in their research that texturing is a very important process in the production of solar cells. Texturing is the process of preparing a textured surface on the surface of a silicon wafer, thereby increasing the silicon wafer surface's absorption rate of sunlight and thus improving the photoelectric conversion efficiency. After texturing of monocrystalline silicon, a pyramid structure will form on the surface of the silicon substrate. The pyramid structure is locally sharp and has a large difference between the top and the bottom. A passivation film layer is deposited on this structure, and the passivation effect is poor. After screen printing and high-temperature sintering in this area, the overall compounding is more serious, affecting the performance of the solar cell.

[0045] Therefore, how to improve the passivation effect has become one of the technical problems that need to be solved urgently at this stage.

[0046] In view of this, the utility model provides a solar cell and a photovoltaic module, which improve the passivation effect of the solar cell surface through a differentiated velvet design.

[0047] The following is a detailed description with reference to the accompanying drawings and specific embodiments.

[0048] Figure 1 FIG. 1 is a schematic diagram of a solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 1The present application provides a solar cell 100, comprising a silicon substrate 10, wherein a light-receiving surface 101 of the silicon substrate 10 comprises a first velvet structure 21 and a second velvet structure 22, wherein the first velvet structure 21 and the second velvet structure 22 do not overlap, wherein the first velvet structure 21 comprises a plurality of prism-shaped protrusions 210, and the second velvet structure 22 comprises a plurality of pyramid-shaped protrusions 220;

[0049] The solar cell 100 further includes a grid line 30 and a passivation structure 40a-1, the grid line 30 and the passivation structure 40a-1 are at least located on one side of the light receiving surface 101 of the silicon substrate 10, and the passivation structure 40a-1 is located between the grid line 30 and the first velvet structure 21;

[0050] The orthographic projection of the gate line 30 on the silicon substrate 10 along the first direction D1 and the orthographic projection of the passivation structure 40a-1 on the silicon substrate 10 along the first direction D1 both overlap with the orthographic projection of the first velvet structure 21 on the silicon substrate 10 along the first direction D1, and do not overlap with the orthographic projection of the second velvet structure 22 on the silicon substrate 10 along the first direction D1, and the first direction D1 is the thickness direction of the silicon substrate 10;

[0051] The passivation structure 40a - 1 includes a first aluminum oxide layer 41a - 1 and a silicon nitride layer 42a - 1 . The first aluminum oxide layer 41a - 1 is located on one side of the silicon substrate 10 , and the silicon nitride layer 42a - 1 is located on a side of the first aluminum oxide layer 41a - 1 away from the silicon substrate 10 .

[0052] It should be noted that the drawings in this application are for illustration only and do not represent their actual size, quantity and actual structure.

[0053] Specifically, the present application provides a solar cell 100, which includes a silicon substrate 10, a gate line 30 and a passivation structure 40a-1. The silicon substrate 10 includes a light-receiving surface 101 and a backlight surface 102. The light-receiving surface 101 of the silicon substrate 10 includes a first velvet structure 21 and a second velvet structure 22. The gate line 30 and the passivation structure 40a-1 are correspondingly arranged at the first velvet structure 21. The passivation structure 40a-1 includes a first aluminum oxide layer 41a-1 and a silicon nitride layer 42a-1. The first aluminum oxide layer 41a-1 is located on one side of the first velvet structure 21, the silicon nitride layer 42a-1 is located on the side of the first aluminum oxide layer 41a-1 away from the first velvet structure 21, and the gate line 30 is located on the side of the silicon nitride layer 42a-1 away from the first velvet structure 21. It can be understood that the first velvet structure 21 includes a prism-shaped protrusion 210, and the second velvet structure 22 includes a pyramid-shaped protrusion 220. The first velvet structure 21 is relatively flat compared to the second velvet structure 22. When the first aluminum oxide layer 41a-1 is formed on a relatively flat surface, its passivation effect is better. Therefore, the present application is beneficial to improving the passivation effect of the solar cell 100, thereby helping to reduce the recombination loss on the surface of the solar cell 100, and further helping to improve the conversion efficiency of the solar cell 100.

[0054] It should be noted that the second velvet structure 22 can be corroded on the surface of the silicon substrate 10 by an alkaline solution to form a pyramid-shaped protrusion 220, and the first velvet structure 21 is based on the pyramid-shaped protrusion 220, and the corresponding area is processed by laser or mechanical polishing to form a prism-shaped protrusion 210. The first velvet structure 21 is arranged in the corresponding area of ​​the gate line 30, and the other areas can retain the pyramid-shaped protrusion 220 in order to reduce the influence on the light absorption effect, but the present application is not limited to this. After the first velvet structure 21 is polished, a prism-shaped protrusion is formed, which becomes a relatively flat structure. The first aluminum oxide layer 41a-1 is formed on the first velvet structure 21, and the passivation effect of aluminum oxide is better. In order to improve the adhesion of aluminum oxide, when making the first aluminum oxide layer 41a-1, electroplating can be used. Similarly, in order to improve the adhesion of the gate line 30, the gate line 30 can be formed by electroplating, but the present application is not limited to this, and can be selected according to actual conditions.

[0055] It should also be noted that the side of the second velvet structure 22 facing away from the silicon substrate 10 also includes a passivation layer, and the passivation layer also includes aluminum oxide and silicon nitride. The aluminum oxide is located on one side of the second velvet structure 22, and the silicon nitride is located on the side of the aluminum oxide facing away from the second velvet structure 22. This application is only used as an example for illustration and is not limited to this. It can be selected according to actual conditions.

[0056] Please continue to refer to Figure 1Optionally, the height of the prism-shaped protrusion 210 along the first direction D1 is H1, H1<1 μm; the height of the pyramid-shaped protrusion 220 along the first direction D1 is H2, 1 μm≤H2≤2 μm.

[0057] Specifically, the first velvet structure 21 includes a prism-shaped protrusion 210, and the second velvet structure 22 includes a pyramid-shaped protrusion 220. The first velvet structure 21 is formed by laser or mechanically polishing the pyramid-shaped protrusion 220 on the basis of the second velvet structure 22. Therefore, the height H1 of the prism-shaped protrusion 210 along the first direction D1 is less than the height H2 of the pyramid-shaped protrusion 220 along the first direction D1. In order to better improve the passivation effect, the present application sets the height H1 of the prism-shaped protrusion 210 along the first direction D1 to H1<1μm, and the pyramid-shaped protrusion 220 forms a relatively flat first velvet structure 21 after polishing. When the first aluminum oxide layer 41a-1 is prepared on the first velvet structure 21, the passivation effect of the first aluminum oxide layer 41a-1 is better, which is beneficial to improving the passivation effect of the solar cell 100, thereby helping to reduce the recombination loss on the surface of the solar cell 100, and further helping to improve the conversion efficiency of the solar cell 100; the present application provides an optional implementation manner that the height H1 of the prism-shaped protrusion 210 along the first direction D1 is H1=0.2μm; the present application provides another optional implementation manner that the height H1 of the prism-shaped protrusion 210 along the first direction D1 is H1=0.4μm; the present application provides another optional implementation manner that the height of the prism-shaped protrusion 210 along the first direction D1 is set to H1≤0.8μm.

[0058] In order to reduce the impact on the light absorption rate of the surface of the solar cell 100, the second velvet structure 22 includes a pyramid-shaped protrusion 220, which is conducive to increasing the absorption rate of the light on the surface of the solar cell 100. In the present application, the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is set to 1μm≤H2≤2μm. When the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is <1μm, the height of the pyramid-shaped protrusion 220 is low and the absorption rate of light is poor; when the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is >2μm, the height of the pyramid-shaped protrusion 220 is too high, which is not conducive to the attachment of the subsequent film structure. Therefore, in the present application, the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is set to 1μm≤H2≤2μm. It is set to 1μm≤H2≤2μm, which is beneficial to improving the absorption rate of light on the surface of the solar cell 100, and is also beneficial to improving the adhesion of other film layers on the surface of the solar cell 100; the present application provides an optional implementation manner that the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is H2=1.2μm; the present application provides another optional implementation manner that the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is H2=1.5μm; the present application provides another optional implementation manner that the height H2 of the pyramid-shaped protrusion 220 along the first direction D1 is H2=1.6μm; the present application provides another optional implementation manner that the height 1.1μm≤H2≤1.8μm of the pyramid-shaped protrusion 220 along the first direction D1.

[0059] It should be noted that the first velvet structure 21 is relatively flat compared to the second velvet structure 22, but this does not mean that the first velvet structure 21 is a planar structure. The first velvet structure 21 has tiny protrusions. With this arrangement, when the slurry is subsequently printed, the slurry has resistance, and the contact area between the slurry and the surface of the solar cell 100 is larger. Compared with a completely planar structure, the adhesion of the slurry is better.

[0060] It should also be noted that since the first velvet structure 21 is polished on the basis of the pyramid-shaped protrusion 220 of the second velvet structure 22 to form the prism-shaped protrusion 210, the pyramid-shaped protrusion 220 and the prism-shaped protrusion 210 have the same size (the size refers to the diagonal length of the projection of the pyramid-shaped protrusion 220 or the prism-shaped protrusion 210 on the silicon substrate 10 along the first direction D1). Optionally, the size of the pyramid-shaped protrusion 220 and the prism-shaped protrusion 210 is 2 to 4 μm (including the endpoints). For example, the size of the pyramid-shaped protrusion 220 and the prism-shaped protrusion 210 can be 2 μm, 2.5 μm, 3.2 μm, etc.

[0061] Figure 2 FIG. 1 is a schematic diagram of another solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 2The present application provides an optional implementation mode in which the passivation structure 40a-2 further includes a polysilicon layer 43a-2, and the polysilicon layer 43a-2 is located between the first aluminum oxide layer 41a-2 and the silicon nitride layer 42a-2.

[0062] Specifically, in this embodiment, the passivation structure 40a-2 includes a first aluminum oxide layer 41a-2, a polysilicon layer 43a-2 and a silicon nitride layer 42a-2. The first aluminum oxide layer 41a-2 is located on one side of the first velvet structure 21, the polysilicon layer 43a-2 is located on the side of the first aluminum oxide layer 41a-2 away from the first velvet structure 21, and the silicon nitride layer 42a-2 is located on the side of the polysilicon layer 43a-2 away from the first velvet structure 21. In this embodiment, the first aluminum oxide layer 41a-2 is located on the side of the first aluminum oxide layer 41a-2 away from the first velvet structure 21. -2 and the silicon nitride layer 42a-2 are provided with a polysilicon layer 43a-2. In this way, the first aluminum oxide layer 41a-2 is provided on the relatively gentle surface of the first velvet structure 21, which is beneficial to improving the surface passivation effect of the solar cell 100, increasing the synergy between the polysilicon layer 43a-2 and the first aluminum oxide layer 41a-2, and jointly reducing the recombination rate of carriers, which is further beneficial to improving the passivation effect of the solar cell 100, and further beneficial to improving the conversion efficiency of the solar cell 100.

[0063] Figure 3 FIG. 1 is a schematic diagram of another solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 3 The present application provides an optional implementation manner in which the passivation structure 40a-3 further includes a second aluminum oxide layer 44a-3, and the second aluminum oxide layer 44a-3 is located between the polysilicon layer 43a-3 and the silicon nitride layer 42a-3.

[0064] Specifically, in this embodiment, the passivation structure 40a-3 includes a first aluminum oxide layer 41a-3, a polysilicon layer 43a-3, a second aluminum oxide layer 44a-3 and a silicon nitride layer 42a-3, the first aluminum oxide layer 41a-3 is located on one side of the first velvet structure 21, the polysilicon layer 43a-3 is located on the side of the first aluminum oxide layer 41a-3 away from the first velvet structure 21, the second aluminum oxide layer 44a-3 is located on the side of the polysilicon layer 43a-3 away from the first velvet structure 21, and the silicon nitride layer 42a-3 is located on the second aluminum oxide layer 44a-3. The aluminum oxide layer 44a-3 is on the side away from the first velvet structure 21. In this embodiment, the first aluminum oxide layer 41a-3 is arranged on the relatively flat surface of the first velvet structure 21, which is beneficial to improving the surface passivation effect of the solar cell 100. The polysilicon layer 43a-3 cooperates with the first aluminum oxide layer 41a-3 to jointly reduce the recombination rate of carriers. The second aluminum oxide layer 44a-3 is beneficial to preventing the slurry from burning through, thereby further improving the passivation effect, and is also beneficial to provide support and protection for the polysilicon layer 43a-3.

[0065] It should be noted that, in order to clearly illustrate the first aluminum oxide layer 41a-3 and the second aluminum oxide layer 44a-3, the present application fills the first aluminum oxide layer 41a-3 and the second aluminum oxide layer 44a-3 in different styles, but they are actually both aluminum oxide layers.

[0066] Please continue to refer to Figure 3 In order to further improve the passivation effect of the solar cell 100, the present application defines the thickness of the first aluminum oxide layer 41a-3 and the second aluminum oxide layer 44a-3. Optionally, the thickness of the first aluminum oxide layer 41a-3 along the first direction D1 is L1, 2nm≤L1≤8nm. Optionally, the thickness of the second aluminum oxide layer 44a-3 along the first direction D1 is L2, 1nm≤L2≤4nm.

[0067] Specifically, the first aluminum oxide layer 41a-3 is located on one side of the first velvet structure 21. When the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is less than 2nm, the thickness of the first aluminum oxide layer 41a-3 is too small, which may lead to poor passivation effect. When the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is greater than 8nm, the thickness of the first aluminum oxide layer 41a-3 is too thick, which is not conducive to the contact effect between the gate line 30 and the silicon substrate 10. Therefore, the thickness L1 of the first aluminum oxide layer 41a-3 is set to 2nm≤L1≤8nm. Such a setting is not only beneficial to improving the passivation effect, but also beneficial to reducing the impact on the contact effect. The present application provides an optional implementation manner that the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is 4nm; the present application provides another optional implementation manner that the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is 5nm; the present application provides still another optional implementation manner that the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is 2nm; the present application provides still another optional implementation manner that the thickness L1 of the first aluminum oxide layer 41a-3 along the first direction D1 is set to 3nm≤L1≤6nm.

[0068] The second aluminum oxide layer 44a-3 is arranged on the side of the polysilicon layer 43a-3 away from the first velvet structure 21. When the thickness L2 of the second aluminum oxide layer 44a-3 along the first direction D1 is less than 1nm, the thickness of the second aluminum oxide layer 44a-3 is relatively small, and the passivation effect is not significantly improved; when the thickness L2 of the second aluminum oxide layer 44a-3 along the first direction D1 is greater than 4nm, the thickness of the second aluminum oxide layer 44a-3 is relatively large, which affects the contact effect; therefore, the thickness L2 of the second aluminum oxide layer 44a-3 is set to 1nm≤L2≤4nm. Such a setting is beneficial to improving the passivation effect and reducing the impact on the contact effect. The present application provides an optional implementation manner that the thickness L2 of the second aluminum oxide layer 44a-3 along the first direction D1 is 2nm; the present application provides another optional implementation manner that the thickness L2 of the second aluminum oxide layer 44a-3 along the first direction D1 is 3nm; the present application provides yet another optional implementation manner that the thickness L2 of the second aluminum oxide layer 44a-3 along the first direction D1 is set to 1nm≤L2≤2nm.

[0069] It should be noted that in the present application, the passivation layer can be covered on the light-receiving surface 101 of the silicon substrate 10, the passivation layer can be covered on the backlight surface 102 of the silicon substrate 10, or the passivation layer can be covered on both the light-receiving surface 101 and the backlight surface of the silicon substrate 10. Such an arrangement is conducive to improving the passivation effect of the solar cell 100, thereby improving the conversion efficiency of the solar cell 100, but the present application is not limited to this and can be selected according to actual conditions. The passivation layer referred to in the present application includes a passivation structure, and the area corresponding to the gate line in the passivation layer is called a passivation structure. In the present application Figure 1-Figure 3 The passivation structures 40a-1, 40a-2 and 40a-3 are embodiments of the passivation structures of the light-receiving surface 101 of the solar cell 100 provided in the present application. For the sake of clarity, different reference numerals are set for the passivation structures in different embodiments, and the specific film layers included in the corresponding passivation structures are also distinguished by reference numerals.

[0070] Figure 4 FIG. 1 is a schematic diagram of another solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 4 The present application provides an optional implementation mode in which the backlight surface 102 of the silicon substrate 10 also includes a first velvet structure 21 b and a second velvet structure 22 b ; the gate line 30 b and the passivation structure 40 b - 1 are also located on one side of the backlight surface 102 of the silicon substrate 10 .

[0071] Specifically, in order to improve the passivation effect on the surface of the solar cell 100, the present application sets different velvet structures on the light-receiving surface 101 of the silicon substrate 10, and sets a relatively flat first velvet structure 21 in the area corresponding to the grid line 30, and sets a second velvet structure 22 with pyramid-shaped protrusions 220 in other areas. Such a setting is conducive to improving the passivation effect of the light-receiving surface 101 of the solar cell 100. In order to further improve the passivation effect of the solar cell 100, the present embodiment also sets a first velvet structure 21b and a second velvet structure 22b on the backlight surface 102 of the silicon substrate 10, and sets the velvet corresponding to the grid line 30b of the backlight surface 102 as the first velvet structure 21b, the first velvet structure 21b includes a prism-shaped protrusion 210b, and the velvet corresponding to other areas of the backlight surface 102 is set to the second velvet structure 22b, the second velvet structure 22b includes a pyramid-shaped protrusion 220b, and a passivation structure 40b-1 is included between the grid line 30b and the first velvet structure 21b. The passivation structure 40b-1 includes a first aluminum oxide layer 41b-1 and a silicon nitride layer 42b-1, wherein the first aluminum oxide layer 41b-1 is located on one side of the first velvet structure 21b, and the silicon nitride layer 42b-1 is located on the side of the first aluminum oxide layer 41b-1 away from the first velvet structure 21b. Since the first aluminum oxide layer 41b-1 has a better passivation effect when it is formed on a relatively flat surface, it is beneficial to improve the passivation effect of the solar cell 100, thereby reducing the recombination loss on the surface of the solar cell 100, and further improving the conversion efficiency of the solar cell 100. This embodiment is beneficial to improving the passivation effect of the light-receiving surface 101 and the backlight surface 102, and further to improving the conversion efficiency of the solar cell 100.

[0072] Figure 5 FIG. 1 is a schematic diagram of another solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 5 The present application provides an optional implementation mode in which the passivation structure 40b-2 further includes a polysilicon layer 43b-2, and the polysilicon layer 43b-2 is located between the first aluminum oxide layer 41b-2 and the silicon nitride layer 42b-2.

[0073] Specifically, in the present embodiment, the passivation structure 40b-2 of the backlight surface 102 of the solar cell 100 includes a first aluminum oxide layer 41b-2, a polycrystalline silicon layer 43b-2 and a silicon nitride layer 42b-2. The first aluminum oxide layer 41b-2 is located on one side of the first velvet structure 21b, the polycrystalline silicon layer 43b-2 is located on the side of the first aluminum oxide layer 41b-2 away from the first velvet structure 21b, and the silicon nitride layer 42b-2 is located on the side of the polycrystalline silicon layer 43b-2 away from the first velvet structure 21b. In this way, the first aluminum oxide layer 41b-2 is arranged on the relatively flat surface of the first velvet structure 21b, which is beneficial to improving the surface passivation effect of the solar cell 100, increasing the synergy between the polycrystalline silicon layer 43b-2 and the first aluminum oxide layer 41b-2, and jointly reducing the recombination rate of carriers, which is further beneficial to improving the passivation effect of the backlight surface 102 of the solar cell 100, and thus is beneficial to improving the conversion efficiency of the solar cell 100.

[0074] It should be noted that the polysilicon layer in the present application is a doped polysilicon layer. Taking the N-type TOPCon battery as an example, the polysilicon layer on the light-receiving surface 101 of the silicon substrate 10 is a boron-doped polysilicon layer, and the polysilicon layer on the backlight surface 102 of the silicon substrate 10 is a phosphorus-doped polysilicon layer. The present application is only described by this example and is not limited to this.

[0075] Figure 6 FIG. 1 is a schematic diagram of another solar cell provided in an embodiment of the present application. Please refer to FIG. Figure 6 Optionally, the passivation structure 40b-3 further includes a second aluminum oxide layer 44b-3, and the second aluminum oxide layer 44b-3 is located between the polysilicon layer 43b-3 and the silicon nitride layer 42b-3.

[0076] Specifically, in this embodiment, the passivation structure 40b-3 of the backlight surface 102 of the solar cell 100 includes a first aluminum oxide layer 41b-3, a polycrystalline silicon layer 43b-3, a second aluminum oxide layer 44b-3 and a silicon nitride layer 42b-3, the first aluminum oxide layer 41b-3 is located on one side of the first velvet structure 21b, the polycrystalline silicon layer 43b-3 is located on the side of the first aluminum oxide layer 41b-3 away from the first velvet structure 21b, the second aluminum oxide layer 44b-3 is located on the side of the polycrystalline silicon layer 43b-3 away from the first velvet structure 21b, and the silicon nitride layer 42b-3 is located on the second aluminum oxide layer 41b-3. The aluminum layer 44b-3 is on the side away from the first velvet structure 21b. In this embodiment, the first aluminum oxide layer 41b-3 is arranged on the relatively flat surface of the first velvet structure 21b, which is beneficial to improving the surface passivation effect of the solar cell 100. The polysilicon layer 43b-3 and the first aluminum oxide layer 41b-3 cooperate to jointly reduce the recombination rate of carriers. The second aluminum oxide layer 44b-3 is beneficial to preventing the slurry from burning through, thereby further improving the passivation effect of the backlight surface 102 of the solar cell 100, and is also beneficial to provide support and protection for the polysilicon layer 43 of the backlight surface 102.

[0077] It should be noted that this application Figure 4-Figure 6 The embodiment shown is only for illustrating the design of the light-receiving surface 101 of the silicon substrate 10 of the present application, and can also be applied to the backlight surface 102 of the silicon substrate 10. At the same time, the design of the backlight surface 102 of the silicon substrate 10 does not affect the design of the light-receiving surface 101 of the silicon substrate 10. Figure 4-Figure 6 The passivation structures 40b-1, 40b-2 and 40b-3 in the figure are embodiments of the passivation structure of the backlight surface 102 of the solar cell 100 provided in the present application. For the sake of clarity, different reference numerals are set for the passivation structures in different embodiments, and the specific film layers included in the corresponding passivation structures are also distinguished by reference numerals.

[0078] Based on the same inventive concept, the present application also provides a photovoltaic module. Figure 7 FIG. 1 is a schematic diagram of a photovoltaic module provided in an embodiment of the present application. Please refer to FIG. Figure 7 The photovoltaic assembly 200 includes a solar cell 100, and the solar cell 100 is any one of the solar cells 100 provided in the above embodiments of the present application.

[0079] Specifically, the present application also provides a photovoltaic module 200, which includes any solar cell 100 provided in the embodiments of the present application, and the photovoltaic module 200 also includes a front cover, a front film, a back film and a back plate, the solar cell 100 is located between the front film and the back film, the front cover is located on the side of the front film away from the solar cell 100, and the back plate is located on the side of the back film away from the solar cell 100. The photovoltaic module 200 provided by the present application includes a solar cell 100, which is conducive to improving the passivation effect and the conversion efficiency, so the present application is also conducive to improving the power of the photovoltaic module 200.

[0080] It should be noted that the embodiment of the photovoltaic assembly 200 provided in the embodiment of the present application can refer to the embodiment of the solar cell 100 mentioned above, and will not be described again.

[0081] In summary, the solar cell and photovoltaic module provided by the utility model achieve at least the following beneficial effects:

[0082] The solar cell and photovoltaic module provided by the present application, wherein the solar cell includes a silicon substrate, the light-receiving surface of the silicon substrate includes a first velvet structure and a second velvet structure, the first velvet structure includes a plurality of prism-shaped protrusions, and the second velvet structure includes a plurality of pyramid-shaped protrusions; the solar cell also includes a grid line and a passivation structure, the grid line and the passivation structure are at least located on one side of the light-receiving surface of the silicon substrate, and the passivation structure is located between the grid line and the first velvet structure; the passivation structure includes a first aluminum oxide layer and a silicon nitride layer, the first aluminum oxide layer is located on one side of the silicon substrate, and the silicon nitride layer is located on the side of the first aluminum oxide layer away from the silicon substrate. The solar cell provided by the present application, the grid line is located on the first velvet structure, the grid line and the first velvet structure include a passivation structure, the first velvet structure includes a prism-shaped protrusion, the first velvet structure is relatively flat compared to the pyramid-shaped protrusion of the second velvet structure, and the first aluminum oxide layer in the passivation structure is formed on a flat surface, and the passivation effect is better, therefore, the present application is conducive to improving the passivation effect of the solar cell, thereby helping to reduce the composite loss on the surface of the solar cell, and further helping to improve the conversion efficiency of the solar cell.

[0083] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A solar cell, characterized in that: It comprises a silicon substrate, wherein the light-receiving surface of the silicon substrate comprises a first velvet structure and a second velvet structure, the first velvet structure and the second velvet structure do not overlap, the first velvet structure comprises a plurality of prism-shaped protrusions, and the second velvet structure comprises a plurality of pyramid-shaped protrusions; The solar cell further comprises a grid line and a passivation structure, wherein the grid line and the passivation structure are at least located on one side of the light-receiving surface of the silicon substrate, and the passivation structure is located between the grid line and the first velvet structure; The orthographic projection of the gate line on the silicon substrate along a first direction and the orthographic projection of the passivation structure on the silicon substrate along the first direction both overlap with the orthographic projection of the first velvet structure on the silicon substrate along the first direction, and both do not overlap with the orthographic projection of the second velvet structure on the silicon substrate along the first direction, and the first direction is the thickness direction of the silicon substrate; The passivation structure includes a first aluminum oxide layer and a silicon nitride layer. The first aluminum oxide layer is located on one side of the silicon substrate, and the silicon nitride layer is located on a side of the first aluminum oxide layer away from the silicon substrate.

2. The solar cell according to claim 1, characterized in that: The height of the prism-shaped protrusion along the first direction is H1, H1<1 μm; the height of the pyramid-shaped protrusion along the first direction is H2, 1 μm≤H2≤2 μm.

3. The solar cell according to claim 1, characterized in that The passivation structure further includes a polysilicon layer located between the first aluminum oxide layer and the silicon nitride layer.

4. The solar cell according to claim 3, characterized in that: The passivation structure further includes a second aluminum oxide layer located between the polysilicon layer and the silicon nitride layer.

5. The solar cell according to claim 4, characterized in that: The thickness of the first aluminum oxide layer along the first direction is L1, 2nm≤L1≤8nm.

6. The solar cell according to claim 5, characterized in that: The thickness of the second aluminum oxide layer along the first direction is L2, 1nm≤L2≤4nm.

7. The solar cell according to claim 1, characterized in that The backlight surface of the silicon substrate also includes the first velvet structure and the second velvet structure; The gate line and the passivation structure are also located on the backlight side of the silicon substrate.

8. The solar cell according to claim 7, characterized in that: The passivation structure further includes a polysilicon layer located between the first aluminum oxide layer and the silicon nitride layer.

9. The solar cell according to claim 8, characterized in that The passivation structure further includes a second aluminum oxide layer located between the polysilicon layer and the silicon nitride layer.

10. A photovoltaic module, characterized in that: A solar cell comprising the solar cell according to any one of claims 1 to 9.

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