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

Abstract

The application provides a solar cell, a manufacturing method thereof and a photovoltaic module, and relates to the photovoltaic field. The solar cell comprises a substrate comprising opposite first and second surfaces, the first surface having a groove, the first surface around the groove, the bottom surface of the groove and the side surface of the groove each having a microstructure, the plurality of microstructures comprising a first conical structure, a second conical structure and a columnar structure, the height direction of the first conical structure intersecting the height direction of the second conical structure, and the side surface of the columnar structure being inclined towards the peripheral direction of the groove; and a first passivation layer located on the first surface. The application at least solves the problem of low solar light absorption rate of the solar cell in the prior art.

Description

TECHNICAL FIELD

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

[0002] At present, solar cells are used more and more widely as a new energy alternative. Solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electric energy.

[0003] The absorption rate of the solar cell to sunlight in the prior art is low, resulting in low photoelectric conversion efficiency of the solar cell.

[0004] The above information disclosed in the background section is only used to enhance the understanding of the background of the technology described herein, therefore, the background section can contain certain information which is not known to the skilled person in the art as prior art in the country. SUMMARY

[0005] The main purpose of the present application is to provide a solar cell, a manufacturing method thereof and a photovoltaic module, to at least solve the problem of low absorption rate of the solar cell to sunlight in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a solar cell is provided, comprising: a substrate comprising opposite first and second surfaces, the first surface having a groove, the first surface outside the groove, the bottom surface of the groove and the side surface of the groove each having a microstructure, a plurality of the microstructures comprising: a first conical structure, a second conical structure and a columnar structure, the height direction of the first conical structure intersecting the height direction of the second conical structure, the side surface of the columnar structure being inclined towards the outer circumferential direction of the groove; a first passivation layer on the first surface.

[0007] Optionally, the columnar structure comprises a first prism and a second prism, the plane in which the side surface of the first prism lies and the plane in which the side surface of the second prism lies intersect, the side surface of the groove comprises a first buffer zone, a de-fuzzing zone and a second buffer zone arranged in sequence in a first direction, the first prism is located in the first buffer zone, the first conical structure is located in the de-fuzzing zone, the second prism is located in the second buffer zone, and the first direction is perpendicular to the first surface and points from the first surface to the second surface.

[0008] Optionally, the included angle between the first surface and the side surface of the first prism is an acute angle.

[0009] Optionally, the included angle between the bottom surface of the groove and the side surface of the second prism is an obtuse angle.

[0010] Optionally, the height of the first prism in the first direction is 0.5~2μm.

[0011] Optionally, the height of the second prism in the first direction is 0.5~5μm.

[0012] Optionally, the height of the first prism in the second direction is 0.5~2μm, and the second direction is perpendicular to both the first direction and the first intersection direction, wherein the first intersection direction is the extension direction of the intersection line between the side of the first prism and the first surface.

[0013] Optionally, the height of the second prism in the third direction is 0.5~2μm, the third direction is perpendicular to the first direction and the second intersection direction, and the second intersection direction is the extension direction of the intersection line between the side of the first prism and the bottom surface of the groove.

[0014] Optionally, the groove has a depth of 10~100μm in the fourth direction and a width of 3~10μm in the fifth direction, wherein the fourth direction is perpendicular to the first surface and the fifth direction is perpendicular to the fourth direction.

[0015] Optionally, the height of the first conical structure is 0.5~3μm.

[0016] Optionally, the second conical structure is located on the bottom surface of the groove and on the first surface.

[0017] Optionally, the protrusion height of the second conical structure located on the bottom surface of the groove is a first height, and the protrusion height of the second conical structure located on the first surface is a second height, wherein the first height is less than the second height.

[0018] Optionally, the first passivation layer is also located on the bottom surface and the side surface of the groove. The solar cell further includes: a first doped conductive layer located in the substrate and in contact with the first passivation layer, wherein the surface of the first doped conductive layer away from the second surface is a portion of the first surface; a tunneling oxide layer located on the second surface; a second doped conductive layer located on the side of the tunneling oxide layer away from the substrate, wherein the second doped conductive layer has the same doping type as the substrate and a different doping type than the first doped conductive layer; a second passivation layer located on the side of the second doped conductive layer away from the tunneling oxide layer; a first electrode located on the side of the first passivation layer away from the first doped conductive layer; and a second electrode located on the side of the second passivation layer away from the second doped conductive layer.

[0019] Optionally, the first passivation layer is located on the first surface surrounding the groove. The solar cell further includes: a third doped conductive layer located on one side of the groove, away from the first passivation layer; a fourth doped conductive layer located on the other side of the groove, away from the first passivation layer, wherein the fourth doped conductive layer has the same doping type as the substrate, and the third doped conductive layer has a different doping type than the fourth doped conductive layer; a third passivation layer located on the sides of the third and fourth doped conductive layers away from the first passivation layer, on the bottom surface of the groove, and on the side surface of the groove; a fourth passivation layer located on the second surface; a third electrode located on the side of the third passivation layer away from the third doped conductive layer; and a fourth electrode located on the side of the third passivation layer away from the fourth doped conductive layer.

[0020] Optionally, the second surface has the groove, and the solar cell further includes: a fifth doped conductive layer located on the side of the first passivation layer away from the first surface; a first transparent conductive layer located on the side of the fifth doped conductive layer away from the first passivation layer, on the bottom surface and side surface of the groove on the first surface; a fifth passivation layer located on the second surface; a sixth doped conductive layer located on the side of the fifth passivation layer away from the second surface, wherein the sixth doped conductive layer has the same doping type as the substrate and a different doping type than the fifth doped conductive layer; a second transparent conductive layer located on the side of the sixth doped conductive layer away from the fifth passivation layer, on the bottom surface and side surface of the groove on the second surface; a fifth electrode located on the side of the first transparent conductive layer away from the fifth doped conductive layer; and a sixth electrode located on the side of the second transparent conductive layer away from the sixth doped conductive layer.

[0021] Optionally, the first passivation layer includes: a borosilicate glass layer located on the surface of the first doped conductive layer away from the second surface; a silicon oxide layer located on the bottom surface and the side surface of the groove; an aluminum oxide layer located on the side of the borosilicate glass layer away from the first doped conductive layer, and on the side of the silicon oxide layer away from the bottom surface and the side surface of the groove; and an antireflective layer located on the side of the aluminum oxide layer away from the borosilicate glass layer and the silicon oxide layer.

[0022] Optionally, the thickness of the silicon oxide layer is 50~150 nm.

[0023] According to another aspect of this application, a method for fabricating a solar cell is provided, comprising: providing an initial structure, the initial structure including an initial substrate and an initial passivation layer, the initial substrate including opposing third and second surfaces, the third surface having microstructures, and the initial passivation layer located on the third surface; removing a portion of the initial passivation layer and a portion of the initial substrate to form an initial groove located in the initial substrate; texturing the bottom and sides of the initial groove to form the microstructures on the sides and bottom of the initial groove respectively, the texturized initial groove forming a groove, and the remaining initial substrate forming a substrate, wherein the plurality of microstructures include: a first conical structure, a second conical structure, and a columnar structure, the height direction of the first conical structure intersecting the height direction of the second conical structure, and the side of the columnar structure inclined toward the outer periphery of the groove.

[0024] Optionally, the bottom and sides of the initial groove are texturized to form the microstructure on the sides and bottom of the initial groove, respectively. This includes etching the bottom and sides of the initial groove with a mixed solution at an ambient temperature of 60~90°C to form the microstructure on the sides and bottom of the initial groove, wherein the mixed solution includes an alkaline solution and a texturizing additive.

[0025] Optionally, the volume of the alkaline solution is 0.5~20L, and the volume of the flocking additive is 0.5~10L.

[0026] Optionally, the initial structure further includes an initial doped conductive layer located in the initial substrate, the initial doped conductive layer being in contact with the initial passivation layer. Removing a portion of the initial passivation layer and a portion of the initial substrate to form an initial groove in the initial substrate includes: using a laser etching process to remove a portion of the initial passivation layer, exposing a portion of the initial doped conductive layer, with the remaining initial passivation layer forming an oxide layer; and using a wet etching process to sequentially remove the exposed initial doped conductive layer and the exposed initial substrate to obtain the initial groove.

[0027] Optionally, the initial passivation layer is removed by laser etching, which includes: removing the initial passivation layer by laser beam etching with a laser beam having an output power of 10-90% of the maximum output power and a scanning speed of 5000-40000 mm / s, wherein the laser beam includes one of the following: an infrared laser beam, an ultraviolet laser beam, or a green laser beam.

[0028] Optionally, the remaining initial doped conductive layer forms a first doped conductive layer, and the oxide layer is a borosilicate glass layer. After texturing the bottom and sides of the initial groove, the method further includes: forming a silicon oxide layer on the bottom and sides of the groove using an oxidation process; forming an aluminum oxide layer on the surface of the borosilicate glass layer away from the first doped conductive layer, and on the surface of the silicon oxide layer away from the bottom and sides of the groove; and forming an antireflection layer on the surface of the aluminum oxide layer away from the borosilicate glass layer and the silicon oxide layer to obtain a first passivation layer.

[0029] According to another aspect of this application, a photovoltaic module is provided, comprising any of the solar cells described herein.

[0030] This application offers the following beneficial technical effects: In a solar cell, a groove is formed on the first surface of the substrate. Microstructures are provided on the first surface of the substrate, the bottom surface of the groove, and the side surface of the groove. These microstructures include a first conical structure, a second conical structure, and a columnar structure. The height directions of the first and second conical structures are different. In other words, the solar cell of this application has microstructures on both the surface and the side surface, which intersect. Under the combined action of these two sets of microstructures in different directions, light from more angles can be scattered and enter the interior of the solar cell, effectively suppressing the specular reflection effect, greatly reducing light reflection loss, improving the light trapping effect, and thus improving the overall light absorption efficiency of the solar cell. Furthermore, since multiple microstructures can provide multiple reflective surfaces, incident light can interact with surfaces of various angles and curvatures, allowing the incident light to be reflected multiple times in different directions. This increases the propagation path length of light within the solar cell. The farther the light travels inside the cell, the more opportunities it has to interact with the cell material, thereby significantly increasing the probability of photogenerated carrier generation and improving the photoelectric conversion efficiency of the cell. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0032] Figure 1 A partial cross-sectional structural schematic diagram of a solar cell provided in an embodiment of this application is shown;

[0033] Figure 2 A partial cross-sectional structural schematic diagram of another solar cell provided according to an embodiment of this application is shown;

[0034] Figure 3The image shows an SEM (Scanning Electron Microscope) test image of a solar cell provided according to an embodiment of this application;

[0035] Figure 4 A partial cross-sectional structural schematic diagram of a TOPCon solar cell provided according to an embodiment of this application is shown;

[0036] Figure 5 A partial cross-sectional view of a back-contact solar cell according to an embodiment of this application is shown.

[0037] Figure 6 A partial cross-sectional structural schematic diagram of a heterojunction solar cell according to an embodiment of this application is shown;

[0038] Figure 7 A schematic flowchart illustrating a method for manufacturing a solar cell according to an embodiment of this application is shown.

[0039] Figure 8 A partial cross-sectional structural schematic diagram of an initial structure provided according to an embodiment of this application is shown;

[0040] Figure 9 A schematic diagram of a structure obtained after removing a portion of the initial passivation layer according to an embodiment of this application is shown;

[0041] Figure 10 A schematic diagram of the structure after forming an initial groove is shown according to an embodiment of this application;

[0042] Figure 11 A partial cross-sectional structural schematic diagram of another solar cell provided according to an embodiment of this application is shown;

[0043] Figure 12 A schematic diagram of a single-crystal silicon crystal structure according to an embodiment of this application is shown;

[0044] Figure 13 A schematic diagram of three crystal orientations of a single-crystal silicon crystal provided according to an embodiment of this application is shown;

[0045] Figure 14 A schematic diagram of a rhombic structure composed of 111 crystal orientations of multiple adjacent unit cells of a single crystal silicon according to an embodiment of this application is shown.

[0046] Figure 15 An SEM image of a second conical structure in a solar cell provided according to an embodiment of this application is shown.

[0047] The above figures include the following reference numerals:

[0048] 10. Substrate; 11. Groove; 12. First conical structure; 13. Second conical structure; 14. Columnar structure; 15. First doped conductive layer; 16. First prism; 17. Second prism; 18. First passivation layer; 19. Tunneling oxide layer; 20. Second doped conductive layer; 21. Second passivation layer; 22. First electrode; 23. Second electrode; 25. First transparent conductive layer; 26. Second transparent conductive layer; 27. First antireflection layer; 28. Second antireflection layer; 2 9. Initial substrate; 30. Initial doped conductive layer; 31. Initial trench; 32. Initial passivation layer; 33. Oxide layer; 34. Third doped conductive layer; 35. Fourth doped conductive layer; 36. Third passivation layer; 37. Fourth passivation layer; 38. Third electrode; 39. Fourth electrode; 40. Fifth doped conductive layer; 41. Sixth doped conductive layer; 42. Fifth passivation layer; 43. Fifth electrode; 44. Sixth electrode; 45. Third antireflection layer; 46. Fourth antireflection layer. Detailed Implementation

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0051] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0052] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] As described in the background section, existing technologies suffer from the problem of low solar energy absorption rates in solar cells. To address this technical problem, embodiments of this application provide a solar cell, a method for manufacturing the same, and a photovoltaic module.

[0054] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0055] An embodiment of this application provides a solar cell. Figure 1 A schematic cross-sectional view of a solar cell according to an embodiment of this application is shown as an example. Figure 1 As shown, the solar cell includes:

[0056] The substrate 10 includes a first surface and a second surface opposite to each other. The first surface has a groove 11. Microstructures are respectively provided on the first surface, the bottom surface, and the side surface of the groove 11. The plurality of microstructures include a first cone structure 12, a second cone structure 13, and a columnar structure 14. The height direction of the first cone structure 12 intersects the height direction of the second cone structure 13. The side surface of the columnar structure 14 is inclined towards the outer periphery of the groove.

[0057] Specifically, the outer periphery direction of the groove 11 is the direction from the groove 11 to the first surface on the outer periphery of the groove 11. The inclination of the side of the columnar structure 14 towards the outer periphery of the groove means that the side of the columnar structure 14 is not perpendicular to the first surface, but has a certain inclination angle relative to the first surface. At least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the first surface, at least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the bottom surface of the groove, and at least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the side of the groove. The first cone-shaped structure 12 and the second cone-shaped structure 13 can specifically be pyramidal structures, such as pyramidal structures. The columnar structure 14 can specifically be a prism structure. The height direction of the first cone-shaped structure 12 can be perpendicular to the height direction of the second cone-shaped structure 13. The substrate can be a silicon substrate, and the material of the silicon substrate can include monocrystalline silicon, polycrystalline silicon, amorphous silicon, and microcrystalline silicon, etc.

[0058] The first passivation layer 18 is located on the first surface.

[0059] In the embodiment described, a groove is formed on the first surface of the substrate. Microstructures are formed on the first surface of the substrate, the bottom surface of the groove, and the side surface of the groove. Multiple microstructures include a first conical structure, a second conical structure, and a columnar structure. The height directions of the first and second conical structures are different. In other words, the solar cell of this application has microstructures on both the surface and the side surface, which intersect. Under the combined action of these two sets of microstructures in different directions, light from more angles can be scattered and enter the interior of the solar cell, thereby effectively suppressing the specular reflection effect, greatly reducing light reflection loss, improving the light trapping effect, and thus improving the overall light absorption efficiency of the solar cell. Furthermore, since multiple microstructures can provide multiple reflective surfaces, incident light can interact with surfaces of various angles and curvatures, allowing the incident light to be reflected multiple times in different directions. This increases the propagation path length of light within the solar cell. The farther the light travels inside the cell, the more opportunities it has to interact with the cell material, thereby significantly increasing the probability of photogenerated carrier generation and improving the photoelectric conversion efficiency of the cell.

[0060] In the microstructure described in this application, there are multiple first cone-shaped structures, multiple second cone-shaped structures, and multiple columnar structures, with multiple first cone-shaped structures, multiple second cone-shaped structures, and multiple columnar structures densely distributed on the substrate.

[0061] In this application, the columnar structure is a micro-convex structure located on at least one of the first surface, the bottom surface of the groove, and the side surface. The columnar structure may include a structure formed by two opposing surfaces (referred to as the upper surface and the lower surface) and at least one side surface. In the columnar structure, the upper and lower surfaces may be parallel or non-parallel; when there are multiple side surfaces, the common edge of each pair of adjacent quadrilateral side surfaces may be parallel or non-parallel. That is, the columnar structure may include at least one of a prism, a cylinder, a prism-like structure (i.e., a prism whose upper and lower surfaces are not parallel and / or whose common side edges are not parallel), and a cylinder-like structure (i.e., a cylinder whose upper and lower surfaces are not parallel).

[0062] The prisms, cylinders, prism-like structures, and cylinder-like structures mentioned can be regular prisms or oblique prisms. Specifically, when the columnar structure includes prisms and / or prism-like structures, it can be a triangular prism, a triangular prism-like structure, a square prism, a square prism-like structure, a pentagonal prism, or a pentagonal prism-like structure, etc.

[0063] In this application, the first cone-shaped structure and the second cone-shaped structure can specifically be tetrahedral pyramids, also known as pyramid structures.

[0064] Since there are three types of microstructures—first cone-shaped, second cone-shaped, and columnar—in some exemplary solutions, the first type of microstructure can be provided on the first surface of the groove's outer periphery, the second type of microstructure can be provided on the side surface of the groove, and the third type of microstructure can be provided on the bottom surface of the groove. That is, the types of microstructures provided on any two of the first surface, the side surface, and the bottom surface of the groove are different. For example, multiple second cone-shaped structures are provided on the first surface, multiple first cone-shaped structures are provided on the side surface of the groove, and multiple prism-shaped structures are provided on the bottom surface of the groove. In other exemplary solutions, two types of microstructures can be provided on the first surface of the groove's outer periphery, two types of microstructures can be provided on the side surface of the groove, and two types of microstructures can be provided on the bottom surface of the groove. Some microstructures provided on any two of the first surface, the side surface, and the bottom surface of the groove are the same. For example, the first surface is provided with second cone-shaped structures and prism-shaped structures, the side surface of the groove is provided with first cone-shaped structures and prism-shaped structures, and the bottom surface of the groove is provided with second cone-shaped structures and prism-shaped structures. In still other exemplary solutions, all three types of microstructures are provided on the first surface of the groove's outer periphery, the side surface, and the bottom surface of the groove. In other exemplary embodiments, at least one of the first surface of the groove's outer periphery, the side surface of the groove, and the bottom surface of the groove is provided with a microstructure, while the remaining surfaces are provided with multiple microstructures. The types of microstructures on the three surfaces can be the same or different. For example, a second cone-shaped structure is provided on the first surface, a second cone-shaped structure is provided on the bottom surface of the groove, and a first cone-shaped structure and a prism structure are provided on the side surface of the groove; or, for another example, a second cone-shaped structure and a prism structure are provided on the first surface, a second cone-shaped structure is provided on the bottom surface of the groove, and a first cone-shaped structure and a prism structure are provided on the side surface of the groove. Of course, the arrangement of microstructures on the first surface of the groove's outer periphery, the side surface of the groove, and the bottom surface of the groove is not limited to the exemplary embodiments described above. In addition to the exemplary embodiments described above, those skilled in the art can flexibly set the types of microstructures on the first surface of the groove's outer periphery, the side surface of the groove, and the bottom surface of the groove according to actual needs.

[0065] In some alternative embodiments, such as Figure 1 , Figure 2 as well as Figure 3 As shown, the columnar structure 14 includes a first prism 16 and a second prism 17. The plane containing the side surface of the first prism 16 and the plane containing the side surface of the second prism 17 intersect. The side surface of the groove 11 includes a first buffer zone, a down-exit zone, and a second buffer zone arranged sequentially along a first direction. The first prism 16 is located in the first buffer zone, the first conical structure 12 is located in the down-exit zone, and the second prism 17 is located in the second buffer zone. The first direction is perpendicular to the first surface and points from the first surface to the second surface. That is, the first direction is the direction from the opening of the groove 11 to the bottom surface of the groove 11.

[0066] In the embodiment described, on the side of the groove, a first buffer zone and a second buffer zone are located on either side of the texturing area. These two buffer zones ensure the normal growth and morphological optimization of the conical textured surface in the texturing area, further enabling the formation of a first conical structure in the texturing area whose height direction intersects (e.g., perpendicularly) the first direction. This first conical structure captures light that is not effectively absorbed by the microstructures on the first surface of the substrate, thereby further improving the light-trapping capability of the solar cell. Furthermore, the first prism formed by the first buffer zone and the prism structure formed by the second buffer zone further enhance the roughness of the groove side, further reducing direct reflection of light from the side and further reducing light escape from the cell interior back to the surface, thus further improving light capture efficiency. This multi-level microstructure design on the side of the groove further solves the problem of low light capture efficiency in traditional solar cells. By adjusting the arrangement of the microstructures, the path of light inside the cell can be precisely controlled, significantly improving the cell's light absorption and conversion efficiency.

[0067] In some exemplary embodiments, the first prism may specifically include one or more of a triangular prism, a quasi-triangular prism, a square prism, and a quasi-square prism. The second prism may specifically include at least one of a triangular prism and a quasi-triangular prism.

[0068] In some embodiments, the texturing region is the growth region of the first conical structure 12, in which the etching solution can penetrate deep into and act on the surface of the substrate 10 to form a highly efficient texturing structure, such as the pyramid-shaped first conical structure 12. This region can improve the light trapping ability and short-circuit current of the battery, allowing the texturing structure to develop to its maximum extent, capturing more sunlight and converting it into electrical energy.

[0069] In some embodiments, such as Figure 2 As shown, a plurality of first prisms 16 are located in the first buffer zone, and the sides of the plurality of first prisms 16 serve as part of the sides of the groove 11. A plurality of second prisms 17 are located in the second buffer zone, and the sides of the plurality of second prisms 17 serve as part of the sides of the groove 11.

[0070] In one embodiment of this application, such as Figure 2 As shown, the angle θ between the first surface and the side surface of the first prism 16 is an acute angle. Figure 2As shown, the first prism 16 is adjacent to the first surface, and the side of the first prism 16 is inclined towards the outer periphery of the groove 11, so that the first surface and the side of the first prism 16 form an acute angle in the shape of a brim. This shape structure can not only avoid the etching process of the microstructure on the side of the groove 11 from damaging the first surface of the substrate 10, but also ensure that the morphology of the first cone-shaped structure 12 near the first buffer zone in the textured area is better, and can form a complete textured structure, playing a transitional role in the formation of the morphology of the first cone-shaped structure 12.

[0071] It should be noted that in the statement that the angle θ between the first surface and the side surface of the first prism 16 is an acute angle, "the first surface" refers to the plane on the first surface where the base of the microstructure is located. This plane is parallel to the second surface. In other words, the angle θ between the second surface and the extended side surface of the first prism 16 is an acute angle.

[0072] Furthermore, the acute angle design between the first surface and the side of the first prism 16 allows incident light to be reflected at a larger angle when it contacts the first prism 16, increasing the path length of light inside the battery. This design utilizes the principle of total internal reflection, guiding light to a longer path even when light is incident perpendicularly, thereby improving light absorption efficiency.

[0073] In some embodiments, such as Figure 2 As shown, the angle α between the bottom surface of the groove 11 and the side surface of the second prism 17 is an obtuse angle. Figure 2 As shown, the second prism 17 is adjacent to the bottom surface of the groove 11, and the side surface of the second prism 17 is inclined towards the outer periphery of the groove 11, so that the bottom surface of the groove 11 and the side surface of the second prism 17 form an obtuse angle. This shape structure can not only avoid the etching process of the microstructure on the side surface of the groove 11 from damaging the bottom surface of the groove 11, but also ensure that the morphology of the first cone-shaped structure 12 near the second buffer zone in the velvet area is better, and can form a complete velvet structure, playing a transitional role in the formation of the morphology of the first cone-shaped structure 12.

[0074] It should be noted that the angle α between the bottom surface of the groove 11 and the side surface of the second prism 17 is an obtuse angle. The "bottom surface of the groove 11" refers to the plane where the base of the bottom microstructure is located. This plane is parallel to the second surface. In other words, the angle α between the second surface and the extended side surface of the second prism 17 is an acute angle.

[0075] and, Figure 2The obtuse angle design between the bottom surface of the groove 11 and the side surface of the second prism 17 allows light reflected from inside the battery to be reflected again at a larger angle when it comes into contact with the second prism 17, increasing the number of light reflections and the path length. This design utilizes the principle of multiple reflections of light, so that even when light is reflected from inside the battery at a small angle, it can be scattered again by the inclined surface of the second prism 17, thereby improving the light absorption efficiency.

[0076] In other embodiments of this application, such as Figure 2 As shown, the height h1 of the first prism 16 in the first direction is 0.5~2μm. For example, the height h1 of the first prism 16 in the first direction can be 0.5μm, 0.8μm, 1.0μm, 1.3μm, 1.6μm, or 2μm, etc., or other values ​​within the range. By setting the height of the first prism 16 along the first direction to the range, it can be further ensured that the texturing area can expose a complete conical structure after etching, thereby further ensuring a better morphology of the first conical structure 12.

[0077] According to some other embodiments of this application, such as Figure 2 As shown, the height h2 of the second prism 17 in the first direction is 0.5~5μm. For example, the height of the second prism 17 in the first direction can be 0.5μm, 1.0μm, 1.5μm, 2μm, 3μm, 4μm, 4.5μm, or 5μm, etc., or other values ​​within the range. By setting the height of the second prism 17 along the first direction to the range, it can be further ensured that the texturing area can expose a complete conical structure after etching, thereby further ensuring a better morphology of the first conical structure 12.

[0078] In some embodiments, such as Figure 2 As shown, the height h3 of the first prism 16 in the second direction is 0.5~2μm. The second direction is perpendicular to both the first direction and the first intersection direction. The first intersection direction is the extension direction of the intersection line between the side of the first prism 16 and the first surface. For example, the height h3 of the first prism 16 in the second direction can be 0.5μm, 0.6μm, 0.8μm, 1μm, 1.6μm, 1.9μm, or 2μm, or other values ​​within the range. By setting the height of the first prism 16 along the second direction to the specified height range, a first conical structure 12 of the required height can be obtained, thereby further ensuring a better morphology of the first conical structure 12.

[0079] In some embodiments, such as Figure 2As shown, the height h4 of the second prism 17 in the third direction is 0.5~2μm. The third direction is perpendicular to the first direction and the second intersection direction, which is the direction of the intersection line between the side of the first prism 16 and the bottom surface of the groove 11. For example, the height h4 of the second prism 17 in the third direction can be 0.5μm, 0.6μm, 0.8μm, 1μm, 1.6μm, 1.9μm, or 2μm, or other values ​​within the range. By setting the height of the second prism 17 along the third direction to the specified range, a first conical structure 12 of the required height can be obtained, thereby further ensuring a better morphology of the first conical structure 12.

[0080] It should be noted that the second direction is the same as or opposite to the third direction. The height of the first prism 16 in the second direction and the height of the second prism 17 in the third direction are the etching depths for etching the side of the groove 11.

[0081] In one alternative, such as Figure 2 As shown, the depth h5 of the groove 11 in the fourth direction is 10~100μm. For example, the depth h5 of the groove 11 in the fourth direction can be 10μm, 30μm, 50μm, 70μm, or 100μm, or other values ​​within the range. The width w of the groove 11 in the fifth direction is 3~10μm. For example, the width of the groove 11 in the fifth direction can be 3μm, 5μm, 6μm, 8μm, 9μm, or 10μm, or other values ​​within the range. The fourth direction is perpendicular to the first surface, and the fifth direction is perpendicular to the fourth direction. This depth and width range is determined based on the wavelength of light and the absorption characteristics of the battery material. This range further ensures that light can undergo multiple reflections and scatterings after entering the groove 11, increasing the path length of light inside the battery, improving light absorption efficiency, and further increasing the scattering and absorption of light inside the battery.

[0082] In some embodiments, the fourth direction may be the same as or opposite to the first direction. The fifth direction may be the same as or opposite to both the second direction and the third direction.

[0083] Since the pyramidal shape of the texturing area (i.e., the first conical structure 12) requires a certain height, that is, a certain depth of etching into the substrate is needed to expose the rhomboid apex structure, the setting of the first buffer zone and the second buffer zone allows the texturing area to form the first conical structure 12 with the apex structure. In addition, if the depth h5 of the groove in the fourth direction is less than or equal to the sum of h1 and h2, the texturing area will not form a complete texturing structure, but only a depression. Therefore, h5 is set to be greater than (h1 + h2).

[0084] Furthermore, the height of the first conical structure 12 is 0.5~3μm. For example, the height of the first conical structure 12 can be 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, or 3μm, or other values ​​within the range. Setting the height of the first conical structure 12 within the range can further ensure effective scattering of incident light and avoid the problem of low light utilization caused by the light trapping effect, thereby further improving the light absorption rate and the short-circuit current of the battery.

[0085] The height direction of the first conical structure 12 can be perpendicular to the first direction, or it can intersect the first direction at an acute angle.

[0086] In some embodiments, the second conical structure 13 is located on the bottom surface of the groove 11 and on the first surface. The second conical structure 13 located on the bottom surface and the first surface of the groove 11 increases the probability that incident light rays incident on the bottom surface and the first surface of the groove 11 at different angles are absorbed by the second conical structure 13 after undergoing at least one reflection, and increases the probability that light rays are reflected by the second conical structure 13 to the side surface of the groove 11 after undergoing at least one reflection, and then absorbed by the first conical structure 12 after undergoing at least one reflection. This is beneficial to improving the absorption rate of incident light rays on the first surface of the substrate 10, the bottom surface and the side surface of the groove 11.

[0087] Furthermore, the height of the second conical structure 13 is 0.5~3μm. For example, the height of the second conical structure 13 can be 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, or 3μm, etc., or other values ​​within the range.

[0088] In some embodiments, the height direction of the second cone-shaped structure 13 may be parallel to the first direction, that is, the height of the second cone-shaped structure 13 is perpendicular to the height of the first cone-shaped structure 12; the height of the second cone-shaped structure 13 may also intersect the first direction at an acute angle.

[0089] In other embodiments, the protrusion height of the second conical structure 13 located on the bottom surface of the groove 11 is a first height, and the protrusion height of the second conical structure 13 located on the first surface is a second height, wherein the first height is smaller than the second height. The higher protrusion height of the second conical structure 13 on the first surface allows for more effective scattering of vertically and obliquely incident light, increasing the path length of light within the battery and thus improving light absorption. Conversely, the smaller protrusion height of the second conical structure 13 on the bottom surface of the groove 11 reduces the additional carrier transport time introduced by light scattering while maintaining light scattering, facilitating the rapid movement of carriers to the electrode. Furthermore, the higher protrusion height of the second conical structure 13 can be formed on the first surface using standard processes, while forming a lower-height second conical structure 13 on the bottom surface of the groove 11 helps reduce the complexity of process control.

[0090] Of course, in addition to the aforementioned height relationship, when designing the structure of the solar cell, those skilled in the art can also set the first height to be the same as the second height; or the first height can be set to be greater than the second height.

[0091] In this application, the reflectivity of the first conical structure 12 and the second conical structure 13 can be 5% to 20%, respectively. The base side length of the first conical structure 12 and the second conical structure 13 can be 2 μm to 5 μm.

[0092] In practical applications, the solar cell of this application can be of various types, such as TOPCon (Tunnel Oxide Passivated Contact) cell, BC (Back Contact) cell, HJT (Heterojunction with Intrinsic Thin Layer) cell, and Perc (Passivated Emitter and RearCell) cell.

[0093] Embodiments of this application provide a cell structure for a TOPCon solar cell, such as... Figure 4 As shown, the first passivation layer 18 is also located on the bottom surface of the groove 11 and the side surface of the groove 11. The solar cell further includes:

[0094] A first doped conductive layer 15 is located in the substrate 10 and is in contact with the first passivation layer 18. The surface of the first doped conductive layer 15 away from the second surface is a portion of the first surface.

[0095] Tunneling oxide layer 19 is located on the second surface;

[0096] The second doped conductive layer 20 is located on the side of the tunneling oxide layer 19 away from the substrate 10. The doping type of the second doped conductive layer 20 is the same as that of the substrate 10, and the doping type of the second doped conductive layer 20 is different from that of the first doped conductive layer 15.

[0097] Specifically, when the substrate 10 and the second doped conductive layer 20 are P-type doped, the first doped conductive layer 15 is N-type doped; when the substrate 10 and the second doped conductive layer 20 are N-type doped, the first doped conductive layer 15 is P-type doped.

[0098] The second passivation layer 21 is located on the side of the second doped conductive layer 20 away from the tunneling oxide layer 19;

[0099] The first electrode 22 is located on the side of the first passivation layer 18 away from the first doped conductive layer 15;

[0100] Specifically, the orthogonal projection of the first electrode 22 onto the substrate 10 lies within the first doped conductive layer 15. The first electrode 22 forms an electrical contact with the first doped conductive layer 15.

[0101] The second electrode 23 is located on the side of the second passivation layer 21 away from the second doped conductive layer 20.

[0102] Specifically, the second electrode 23 forms an electrical contact with the second doped conductive layer 20.

[0103] In the embodiment, the first passivation layer 18 and the second passivation layer 21 can passivate, reduce carrier recombination loss between the doped conductive layer and the electrode, and improve the short-circuit current and open-circuit voltage of the TOPCon solar cell, thereby improving the cell conversion efficiency; the tunneling oxide layer 19 can realize selective carrier transport; the second doped conductive layer 20 plays a field passivation role; the first doped conductive layer 15 and the substrate 10 form a PN junction.

[0104] in, Figure 4 An exemplary embodiment is shown where the second surface is not texturized. In other embodiments, the second surface may also have the second conical structure.

[0105] Optionally, the first surface of the substrate 10 includes alternating first and third regions, with the first doped conductive layer 15 contacting the first region and the groove 11 located in the third region. In this embodiment, the first doped conductive layer 15 contacts the first region but not the third region, which can reduce carrier recombination loss in the third region, improve the short-circuit current of the battery, and reduce the saturated dark current density in the third region.

[0106] Optionally, the material of the first passivation layer 18 may be one or more of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, or silicon carbonitride. In some embodiments, the first passivation layer 18 may be a single-layer structure. In other embodiments, the first passivation layer 18 may also be a multilayer structure. In some embodiments, the first passivation layer 18 may be formed using a PECVD (Plasma Enhanced Chemical Vapor Deposition) method.

[0107] Optionally, the material of the second passivation layer 21 may be one or more of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, or silicon carbonitride. In some embodiments, the second passivation layer 21 may be a single-layer structure. In other embodiments, the second passivation layer 21 may also be a multilayer structure. In some embodiments, the second passivation layer 21 may be formed using a PECVD method.

[0108] Optionally, the materials and film structures of the first passivation layer 18 and the second passivation layer 21 may be the same or different.

[0109] Optionally, the first passivation layer 18 can prevent metal atoms in the first electrode 22 from diffusing into the first doped conductive layer 15, thereby reducing carrier recombination loss between the first electrode 22 and the first conductive layer and reducing problems such as low photoelectric conversion efficiency of solar cells caused by carrier recombination loss.

[0110] Optionally, the tunneling oxide layer 19 can cause an asymmetric shift in the energy band of the second surface, making the barrier for majority carriers lower than that for minority carriers. Therefore, majority carriers can more easily tunnel through the tunneling oxide layer 19, while minority carriers have difficulty passing through, thus achieving selective carrier transport. Furthermore, the tunneling oxide layer 19 can also chemically passivate the substrate 10. In some embodiments, the material of the tunneling oxide layer 19 can be a dielectric material, such as silicon oxide.

[0111] Optionally, the material of the second doped conductive layer 20 can be doped silicon, which may specifically include doped polycrystalline silicon, doped microcrystalline silicon, or doped amorphous silicon.

[0112] Optionally, the solar cell is a single-sided cell, meaning it receives solar energy only through the first surface of the substrate 10. In some embodiments, the solar cell is a double-sided cell, meaning both the first and second surfaces of the substrate 10 are used to receive solar energy.

[0113] Optionally, the substrate 10 is an N-type semiconductor substrate 10, meaning that the substrate 10 is doped with N-type ions, which can be any one of phosphorus, arsenic, or antimony. The first doped conductive layer 15 can be a P-type doped layer, doped with P-type ions, which can be any one of boron, aluminum, or gallium. The first doped conductive layer 15 forms a PN junction with the substrate 10. The first doped conductive layer 15 can be obtained by diffusion doping the surface layer of the substrate 10 with P-type ions, and the doped portion of the substrate 10 is converted into the first doped conductive layer 15. The second doped conductive layer 20 is an N-type conductive layer, doped with N-type ions.

[0114] Optionally, such as Figure 4 As shown, both the first passivation layer 18 and the second passivation layer 21 are single-layer film structures. The solar cell may further include: a first anti-reflection layer 27, located between the first passivation layer 18 and the first electrode 22, and covering the surface of the first passivation layer 18 away from the first doped conductive layer 15 and the groove 11; and a second anti-reflection layer 28, located between the second passivation layer 21 and the second electrode 23, and covering the surface of the second passivation layer 21 away from the second doped conductive layer 20.

[0115] Optionally, the first passivation layer is a multilayer film structure, specifically comprising: a borosilicate glass layer located on the surface of the first doped conductive layer away from the second surface; a silicon oxide layer located on the bottom surface and the side surface of the groove; an aluminum oxide layer located on the side of the borosilicate glass layer away from the first doped conductive layer, and on the side of the silicon oxide layer away from the bottom surface and the side surface of the groove; and an antireflective layer located on the side of the aluminum oxide layer away from the borosilicate glass layer and the silicon oxide layer. In this embodiment, the borosilicate glass layer can effectively passivate surface defects of the first doped conductive layer, reduce the surface recombination rate, and thus improve the open-circuit voltage of the battery. A silicon oxide layer is formed on the bottom and sides of the groove, which not only has a passivation effect but also, due to its higher refractive index than air, reduces direct light reflection on the surface, promotes heat dissipation and absorption of light inside the battery, increases the short-circuit current, and plays a role in light management. An aluminum oxide layer is formed on the borosilicate glass layer and the silicon oxide layer to further reduce surface recombination. An anti-reflection layer is formed on the outermost layer of the battery's light-receiving surface. This film directly faces the incident light and has a low refractive index, which can significantly reduce light reflection loss, ensuring that more light can penetrate into the battery and improve the short-circuit current.

[0116] Optionally, the thickness of the silicon oxide layer is 50-150 nm. For example, the thickness of the silicon oxide layer can be 60 nm, 80 nm, or 100 nm, or other values ​​within this range. Within this thickness range, the silicon oxide layer can effectively passivate surface defects, increase the open-circuit voltage (Voc) by reducing nonradiative recombination, thereby improving the photoelectric conversion efficiency of the battery. At the same time, the thickness range helps to maintain the stability of the structure and the mechanical strength of the battery.

[0117] Optionally, the thickness of the first doped conductive layer 15 can be 0.1~1 μm. The thickness of the tunneling oxide layer 19 can be 1~3 nm. The thickness of the second doped conductive layer 20 can be 50~300 nm. The doping concentration of the second doped conductive layer 20 can be 1×10⁻⁶. 17 cm -3 ~1×10 20 cm -3 The thickness of the alumina layer can be 2~10 nm.

[0118] Embodiments of this application provide a battery structure for a back-contact solar cell, such as... Figure 5 As shown, the first passivation layer 18 is located on the first surface surrounding the groove 11, and the solar cell further includes:

[0119] The third doped conductive layer 34 is located on the side of the first passivation layer 18 away from the first surface on one side of the groove 11.

[0120] Specifically, the third doped conductive layer 34 is located on one side of the groove 11 and on the side of the first passivation layer 18 away from the first surface.

[0121] The fourth doped conductive layer 35 is located on the side of the first passivation layer 18 away from the first surface on the other side of the groove 11. The fourth doped conductive layer 35 has the same doping type as the substrate 10, and the third doped conductive layer 34 has a different doping type than the fourth doped conductive layer 35.

[0122] Specifically, the fourth doped conductive layer 35 is located on the other side of the groove 11, and on the side of the first passivation layer 18 away from the first surface. The third doped conductive layer 34 and the fourth doped conductive layer 35 are isolated from each other by the groove 11.

[0123] The third passivation layer 36 is located on the side of the third doped conductive layer 34 and the fourth doped conductive layer 35 away from the first passivation layer 18, on the bottom surface of the groove 11, and on the side surface of the groove 11.

[0124] The fourth passivation layer 37 is located on the second surface;

[0125] The third electrode 38 is located on the side of the third passivation layer 36 away from the third doped conductive layer 34;

[0126] Specifically, the orthographic projection of the third electrode 38 onto the substrate 10 lies within the orthographic projection of the third doped conductive layer 34 onto the substrate 10. The third electrode 38 forms an electrical contact with the third doped conductive layer 34.

[0127] The fourth electrode 39 is located on the side of the third passivation layer 36 away from the fourth doped conductive layer 35.

[0128] Specifically, the orthographic projection of the fourth electrode 39 onto the substrate 10 lies within the orthographic projection of the fourth doped conductive layer 35 onto the substrate 10. The fourth electrode 39 and the fourth doped conductive layer 35 form an electrical contact.

[0129] In the embodiment, the first passivation layer 18 can reduce the recombination rate of photogenerated electrons and holes on the first surface of the substrate 10; the groove 11 separates the third doped conductive layer 34 and the fourth doped conductive layer 35, reducing the possibility of leakage current between the third doped conductive layer 34 and the fourth doped conductive layer 35, and improving the reliability of the solar cell; the third passivation layer 36 and the fourth passivation layer 37 can enhance the carrier concentration on the surface of the back contact solar cell, increase the short-circuit current and open-circuit voltage of the back contact solar cell, thereby improving the cell efficiency; the third doped conductive layer 34 and the substrate 10 form a PN junction.

[0130] Among them, such as Figure 5 As shown, the second surface of the substrate 10 has a microstructure, specifically the second conical structure 13.

[0131] Optionally, the first surface can be the back of the solar cell, i.e., the surface that is not directly exposed to sunlight. The second surface can be the front of the solar cell, i.e., the surface that can be directly exposed to sunlight.

[0132] Optionally, the material of the third passivation layer 36 may be one or more of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, or silicon carbonitride. In some embodiments, the third passivation layer 36 may be a single-layer structure. In other embodiments, the third passivation layer 36 may also be a multilayer structure.

[0133] Optionally, the material of the fourth passivation layer 37 may be one or more of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, or silicon carbonitride. In some embodiments, the fourth passivation layer 37 may be a single-layer structure. In other embodiments, the fourth passivation layer 37 may also be a multilayer structure.

[0134] Optionally, the first passivation layer 18 may include at least one of silicon oxide, aluminum oxide, silicon nitride, silicon oxynitride, amorphous silicon, and polycrystalline silicon. The lattice of the first passivation layer 18 can be well matched with the lattice of the substrate 10, meaning the first passivation layer 18 can effectively passivate the first surface of the substrate 10, thereby reducing the recombination rate of photogenerated electrons and holes on the first surface of the substrate 10. The first passivation layer 18 and the P-type doped layer can form a tunneling passivation contact structure, which can improve the hole collection efficiency of the P-type doped layer. The first passivation layer 18 and the N-type doped layer can form a tunneling passivation contact structure, which can improve the electron collection efficiency of the N-type doped layer. The thickness of the first passivation layer 18 can be 1~3 nm.

[0135] Optionally, the first passivation layer 18 may include a first doping type tunneling layer corresponding to the third doped conductive layer 34 (the first doping type is the same as the doping type of the third doped conductive layer 34), and a second doping type tunneling layer corresponding to the fourth doped conductive layer 35 (the second doping type is the same as the doping type of the fourth doped conductive layer 35).

[0136] Optionally, the third doped conductive layer 34 can be at least one of doped amorphous silicon, doped polycrystalline silicon, doped microcrystalline silicon, and doped silicon carbide. The fourth doped conductive layer 35 can be at least one of doped amorphous silicon, doped polycrystalline silicon, doped microcrystalline silicon, and doped silicon carbide. The thickness of the third doped conductive layer 34 can be 50~300 nm. The doping concentration of the third doped conductive layer 34 can be 1×10⁻⁶. 17 cm -3 ~1×10 20 cm -3 The thickness of the fourth doped conductive layer 35 can be 50~300 nm. The doping concentration of the third doped conductive layer 34 can be 1×10⁻⁶. 17 cm -3 ~1×10 20 cm -3 .

[0137] Optionally, the first surface has a plurality of the grooves 11, the first surface includes alternating first and second regions, the third doped conductive layer 34 is located in the first region, the fourth doped conductive layer 35 is located in the second region, and adjacent first and second regions are separated by the grooves 11.

[0138] Optionally, the size of the third doped conductive layer 34 is the same as the size of the first region, and the size of the fourth doped conductive layer 35 is the same as the size of the second region.

[0139] In some embodiments, the size of the third doped conductive layer 34 is larger than the size of the fourth doped conductive layer 35. This ensures that the back-contact solar cell has good collection performance for both holes and electrons, which is beneficial to improving the performance and conversion efficiency of the back-contact solar cell.

[0140] Optionally, the orthographic projection area of ​​the third electrode 38 on the substrate 10 is smaller than the area of ​​the first region, and the orthographic projection is located in the first region. The orthographic projection area of ​​the fourth electrode 39 on the substrate 10 is smaller than the area of ​​the second region, and the orthographic projection is located in the second region.

[0141] Optionally, along the thickness direction of the substrate 10, the distance between the first region and the second surface is greater than the distance between the second region and the second surface. That is, the fourth doped conductive layer 35 is closer to the second surface than the third doped conductive layer 34, causing the third doped conductive layer 34 and the fourth doped conductive layer 35 to be misaligned along the thickness direction of the substrate 10. This further reduces the possibility of leakage current between the third doped conductive layer 34 and the fourth doped conductive layer 35, thereby further improving the reliability of the back-contact solar cell and increasing its efficiency and output power.

[0142] Optionally, the distance between the first region and the second surface is a first distance, and the distance between the second region and the second surface is a second distance. The first distance can be 2~10μm; the second distance can be 2~10μm; and the difference between the first distance and the second distance can be 1~5μm.

[0143] Optionally, the third passivation layer 36 comprises an aluminum oxide layer and a silicon nitride layer sequentially stacked in a direction away from the third doped conductive layer 34 and the fourth doped conductive layer 35. The fourth passivation layer 37 comprises an aluminum oxide layer and a silicon nitride layer sequentially stacked in a direction away from the second surface. The thickness of the aluminum oxide layer is 2-10 nm. The thickness of the silicon nitride layer is 50-150 nm.

[0144] Optionally, such as Figure 5 As shown, the solar cell may further include: a third antireflection layer 45, located between the third passivation layer 36 and the third electrode 38 and between the third passivation layer 36 and the fourth electrode 39, and covering the surface of the third passivation layer 36 away from the third doped conductive layer 34, the fourth doped conductive layer 35 and the groove 11; and a fourth antireflection layer 46, located on the surface of the fourth passivation layer 37 away from the substrate 10.

[0145] Embodiments of this application also provide a cell structure for a heterojunction solar cell, such as... Figure 6 As shown, the second surface has the groove 11, and the solar cell further includes:

[0146] The fifth doped conductive layer 40 is located on the side of the first passivation layer 18 away from the first surface;

[0147] The first transparent conductive layer 25 is located on the side of the fifth doped conductive layer 40 away from the first passivation layer 18, on the bottom surface and the side surface of the groove 11 on the first surface.

[0148] The fifth passivation layer 42 is located on the second surface;

[0149] The sixth doped conductive layer 41 is located on the side of the fifth passivation layer 42 away from the second surface. The sixth doped conductive layer 41 has the same doping type as the substrate 10, but the doping type of the sixth doped conductive layer 41 is different from that of the fifth doped conductive layer 40.

[0150] The second transparent conductive layer 26 is located on the side of the sixth doped conductive layer away from the fifth passivation layer 42, on the bottom surface and the side surface of the groove on the second surface;

[0151] The fifth electrode 43 is located on the side of the first transparent conductive layer 25 away from the fifth doped conductive layer 40;

[0152] The sixth electrode 44 is located on the side of the second transparent conductive layer 26 away from the sixth doped conductive layer 41.

[0153] In the embodiment, the first passivation layer 18 and the fifth passivation layer 42 are used to passivate defects on the surface of the substrate 10, thereby reducing carrier recombination; the first transparent conductive layer 25 and the second transparent conductive layer 26 have light transmittance and conductivity, and are used to collect photogenerated carriers and allow sunlight to enter the battery; the sixth doped conductive layer 41 plays a field passivation role; the fifth doped conductive layer 40 and the substrate 10 form a PN junction, which also affects carrier transport between interfaces.

[0154] In some embodiments, such as Figure 6 As shown, the first and second surfaces of the substrate 10 each have microstructures.

[0155] Optionally, the thickness of the first passivation layer 18 and the fifth passivation layer 42 is 1~3nm, and the first passivation layer 18 and the fifth passivation layer 42 can be intrinsic amorphous silicon layers without doping.

[0156] Optionally, the thickness of the fifth doped conductive layer 40 is 50~300 nm, and the doping concentration is 1×10⁻⁶. 17 cm -3 ~1×10 20 cm -3 The sixth doped conductive layer 41 has a thickness of 50~300nm and a doping concentration of 1×10⁻⁶. 17 cm -3 ~1×10 20 cm -3 .

[0157] Optionally, the materials of the first transparent conductive layer 25 and the second transparent conductive layer 26 are independently selected from one or more of indium tin oxide (ITO) and aluminum zinc oxide. The thickness of the first transparent conductive layer 25 can be 10~500 nm. The thickness of the second transparent conductive layer 26 can be 10~500 nm.

[0158] Optionally, the grooves 11 on the first surface and the grooves 11 on the second surface are symmetrically distributed along a direction perpendicular to the thickness of the substrate 10.

[0159] The solar cells described in this application will now be described in detail with reference to specific embodiments and comparative examples.

[0160] Example 1

[0161] This embodiment provides a solar cell, including:

[0162] The substrate includes a first surface and a second surface opposite to each other. The first surface has a groove. The first surface on the outer periphery of the groove and the bottom surface of the groove have a plurality of second conical structures. The side surface of the groove includes a first buffer zone, a texturing zone and a second buffer zone arranged sequentially along a first direction. The first buffer zone has a plurality of first prisms, the texturing zone has a plurality of first conical structures, and the second buffer zone has a plurality of second prisms. The height direction of the first conical structure intersects the height direction of the second conical structure.

[0163] A first passivation layer is located on the first surface.

[0164] Comparative Example 1

[0165] This comparative example provides a solar cell, the only difference from Example 1 being that the first surface of the substrate in this comparative example has no groove, no second conical structure located on the bottom surface of the groove, and no first conical structure, first prism, and second prism located on the side surface of the groove.

[0166] Comparative Example 2

[0167] This comparative example provides a solar cell, the only difference from Example 1 being that this comparative example does not have the first conical structure, the first prism, and the second prism located on the side of the groove.

[0168] The surface reflectivity of the solar cells used in Example 1 and Comparative Example 1 was tested, and the test results are shown in Table 1:

[0169] Table 1

[0170]

[0171]

[0172] As can be seen from the experimental data in Table 1, for light in the wavelength range of 300nm to 780nm, the surface reflectivity of the solar cell in Example 1 is lower than that in Comparative Example 1 and Comparative Example 2, indicating that the technical solution of this application can improve the light trapping effect of the solar cell.

[0173] Embodiments of this application also provide a method for manufacturing a solar cell. It should be noted that this method for manufacturing a solar cell is used to produce any of the aforementioned solar cells.

[0174] Figure 7 This is a flowchart of a method for manufacturing a solar cell according to an embodiment of this application. Figures 8 to 11 This is a schematic diagram of the structure obtained after each process step in the fabrication method of a solar cell. For example... Figures 7 to 11 As shown, the method includes the following steps:

[0175] Step S201, as follows Figure 8 As shown, an initial structure is provided, the initial structure including an initial substrate 29 and an initial passivation layer 32, the initial substrate 29 including opposing third and second surfaces, the third surface having microstructures, and the initial passivation layer 32 located on the third surface;

[0176] Step S202: Remove a portion of the initial passivation layer 32 and a portion of the initial substrate 29 to form an initial groove 31 located in the initial substrate 29;

[0177] Specifically, the remaining initial passivation layer 32 can form a first passivation layer. The third surface after forming the initial groove 31 serves as the first surface.

[0178] Step S203, as follows Figure 11 As shown, the bottom and side surfaces of the initial groove 31 are texturized to form the microstructures on the side and bottom surfaces of the initial groove 31, respectively. The texturized initial groove 31 forms groove 11, and the remaining initial substrate 29 forms substrate 10. The multiple microstructures include: a first cone structure 12, a second cone structure 13, and a columnar structure 14. The height direction of the first cone structure 12 intersects the height direction of the second cone structure 13, and the side surface of the columnar structure 14 is inclined towards the outer periphery of the groove 11.

[0179] Specifically, the third surface with the groove forms the first surface. The outer peripheral direction of the groove 11 is the direction from the groove 11 to the first surface on the outer periphery of the groove 11. The inclination of the side of the columnar structure 14 towards the outer peripheral direction of the groove means that the side of the columnar structure 14 is not perpendicular to the first surface, but has a certain inclination angle relative to the first surface. At least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the first surface, at least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the bottom surface of the groove, and at least a portion of the first cone-shaped structure 12, the second cone-shaped structure 13, and the columnar structure 14 is located on the side of the groove. The first cone-shaped structure 12 and the second cone-shaped structure 13 can specifically be pyramidal structures, such as pyramidal structures. The columnar structure 14 can specifically be a prism structure. The height direction of the first cone-shaped structure 12 can be perpendicular to the height direction of the second cone-shaped structure 13. The substrate 10 may be a silicon substrate 10, and the material of the silicon substrate 10 may include monocrystalline silicon, polycrystalline silicon, amorphous silicon, and microcrystalline silicon, etc.

[0180] In this embodiment, an initial substrate and an initial passivation layer on a third surface of the initial substrate are first provided, wherein the third surface has microstructures. Then, a portion of the initial passivation layer and a portion of the substrate are removed to form an initial groove. Finally, the sides of the initial groove are texturized to form microstructures on the sides and bottom of the initial groove. These microstructures include a first conical structure, a second conical structure, and a columnar structure, with the first and second conical structures having different height directions. The solar cell obtained by this method has microstructures on both the surface and the side surfaces, which intersect. Under the combined action of these two sets of microstructures in different directions, light from more angles can be scattered and enter the interior of the solar cell, thereby effectively suppressing specular reflection, greatly reducing light reflection loss, improving light trapping effect, and thus improving the overall light absorption efficiency of the solar cell. Furthermore, since various microstructures can provide a variety of reflective surfaces, incident light can interact with surfaces of various angles and curvatures, allowing the incident light to be reflected multiple times in different directions. This increases the propagation path length of light inside the solar cell. The farther the light travels inside the cell, the more opportunities it has to interact with the cell materials, thereby significantly increasing the probability of generating photogenerated carriers and improving the photoelectric conversion efficiency of the cell.

[0181] In some embodiments, the microstructure on the third surface may be the second conical structure 13, the height direction of which intersects (e.g., is perpendicular to) the third surface.

[0182] In one optional embodiment, the bottom and sides of the initial groove 31 are texturized to form the microstructures on the bottom and sides of the initial groove 31, respectively. This includes etching the bottom and sides of the initial groove 31 with a mixed solution at an ambient temperature of 60-90°C to form the microstructures on the bottom and sides of the initial groove 31, wherein the mixed solution includes an alkaline solution and a texturing additive. In this embodiment, etching the bottom and sides of the initial groove 31 with an alkaline solution to form microstructures can increase the complexity of the battery surface morphology without compromising the overall structural integrity of the battery. These microstructures can significantly increase light scattering on the battery surface, extend the light path length, thereby increasing the effective absorption of light inside the battery, increasing the short-circuit current, and thus improving the overall photoelectric conversion efficiency. Furthermore, the microstructures obtained after texturing can reduce direct reflection of light on the battery surface, causing incident light to be scattered and absorbed at different angles, significantly reducing reflectivity, which helps to improve the light capture rate and battery performance.

[0183] In this application, the volume of the alkaline solution is 0.5~20L, and the volume of the texturing additive is 0.5~10L.

[0184] In some embodiments, a mixed solution is used to etch the bottom and side surfaces of the initial groove 31 to form the microstructures on the side and bottom surfaces of the initial groove 31, respectively. This includes: etching the bottom and side surfaces of the initial groove 31 with a mixed solution to form a plurality of first prisms 16, a plurality of first cone structures 12, and a plurality of second prisms 17 on the side surfaces of the initial groove 31. The plurality of first prisms 16 are located in a first buffer zone, the plurality of first cone structures 12 are located in a down-exit zone, and the plurality of second prisms 17 are located in a second buffer zone. The first buffer zone, the down-exit zone, and the second buffer zone are arranged sequentially along a first direction on the side surfaces of the groove. The first direction is perpendicular to the first surface and points from the first surface to the second surface. The height direction of the first cone structure 12 intersects (e.g., is perpendicular to) the first direction. A second cone structure 13 is formed on the bottom surface of the initial groove 31. The height direction of the second cone structure 13 is parallel to or intersects the first direction.

[0185] In other embodiments, the initial structure further includes an initial doped conductive layer 30 located in the initial substrate 29, the initial doped conductive layer 30 being in contact with the initial passivation layer 32, removing a portion of the initial passivation layer 32 and a portion of the initial substrate 29 to form an initial groove 31 located in the initial substrate 29, including: Figure 8 and Figure 9As shown, a portion of the initial passivation layer 32 is removed using a laser etching process, exposing a portion of the initial doped conductive layer 30, and the remaining initial passivation layer 32 forms an oxide layer 33; as Figure 9 and Figure 10 As shown, the exposed initial doped conductive layer 30 and the exposed initial substrate 29 are sequentially removed using a wet etching process to obtain the initial groove 31. In this embodiment, a portion of the initial passivation layer 32 is first removed using laser etching. Laser etching can precisely control the amount of initial passivation layer 32 to be removed, forming a high-precision, localized structure and avoiding damage to other parts of the battery. Then, a portion of the exposed initial doped conductive layer 30 and a portion of the initial substrate 29 are sequentially removed using wet etching, resulting in an initial groove 31 with a better morphology. This facilitates the formation of well-shaped microstructures on the sides and bottom of the initial groove 31. The combined use of laser etching and wet etching can achieve precise manufacturing of complex structures while controlling costs, reducing material waste, and improving the economic efficiency of the entire battery manufacturing process.

[0186] Furthermore, the doping type of the initial doped conductive layer 30 is different from that of the initial substrate 29. Removing part of the initial doped conductive layer 30 reduces carrier recombination caused by heterogeneous element doping, which can improve the open-circuit voltage of the battery.

[0187] To further achieve precise localized removal of the initial passivation layer 32, according to some alternative embodiments of this application, a laser etching process is used to remove a portion of the initial passivation layer 32, including: using a laser beam with an output power of 10-90% of the maximum output power and a scanning speed of 5000-40000 mm / s to etch and remove a portion of the initial passivation layer 32, wherein the laser beam includes one of the following: an infrared laser beam, an ultraviolet laser beam, or a green laser beam. In this embodiment, within the specified power and speed range, the laser can precisely remove the initial passivation layer 32 within a preset area without affecting the surrounding area, avoiding structural damage caused by excessive etching, maintaining the integrity and flatness of the battery surface, and facilitating subsequent processes; laser etching with an output power in the range of 10-90% can ensure the rapid and efficient removal of the initial passivation layer 32, and the control of the scanning speed can further optimize the etching time and accuracy; using infrared, ultraviolet, or green laser beams, the most suitable wavelength can be selected according to the absorption characteristics of the material, thereby minimizing the heat-affected zone, reducing thermal damage to the battery surface, and maintaining the high quality and performance stability of the battery surface.

[0188] In one exemplary embodiment, such as Figure 8 and Figure 9As shown, the remaining initial doped conductive layer 30 forms the first doped conductive layer 15, and the oxide layer 33 is a borosilicate glass layer. After texturing the bottom and sides of the initial groove 31, the method further includes: forming a silicon oxide layer on the bottom and sides of the groove using an oxidation process; forming an aluminum oxide layer on the surface of the borosilicate glass layer away from the first doped conductive layer, and on the surface of the silicon oxide layer away from the bottom and sides of the groove; and forming an antireflection layer on the surface of the aluminum oxide layer away from the borosilicate glass layer and the silicon oxide layer to obtain a first passivation layer, i.e., the first passivation layer includes the borosilicate glass layer, the silicon oxide layer, the aluminum oxide layer, and the antireflection layer. By sequentially forming a silicon oxide layer, an aluminum oxide layer, and an antireflection layer on the surface of the initial groove after texturing, not only can the surface passivation and light trapping effect be enhanced, and the contact performance improved, but the formation of the silicon oxide layer and the aluminum oxide layer also increases the mechanical strength and chemical stability of the solar cell, thus increasing the stability and quality of the structure.

[0189] In addition, such as Figure 8 As shown, the second surface of the initial substrate 29 also has a microstructure. In some embodiments, the second surface of the initial substrate 29 has a second conical structure 13. A second doped conductive layer 20 and a second passivation layer 21 are also stacked sequentially on the second surface of the initial substrate 29. The doping type of the second doped conductive layer 20 is the same as that of the initial substrate 29, but different from that of the first doped conductive layer 15.

[0190] The following explains the principle of etching the sides of the initial groove to form a textured surface: The structure of a single-crystal silicon crystal is as follows... Figure 12 As shown, single-crystal silicon crystals exhibit three crystal orientations: 100, 110, and 111. The structures of these three crystal orientations are as follows: Figure 13 As shown, the atomic density of single-crystal silicon with the three crystal orientations is in the order of 111 > 110 > 100. Therefore, the reaction rate of single-crystal silicon with the alkali is in the order of 111 < 110 < 100. During the wet etching process of the bottom and side surfaces of the initial groove 31 using a mixed solution, anisotropic etching of the single-crystal silicon can be performed by adjusting the etching conditions, exposing the 111 crystal orientation. It can be considered that the 111 crystal orientations of multiple adjacent unit cells of single-crystal silicon form a rhombic structure, such as... Figure 14 As shown. During conventional texturing (i.e., etching to form the second cone-shaped structure), the apex of the upper pyramid (such as...) will be exposed. Figure 15 As shown), if a vertical plane of a certain width exists simultaneously, a pyramid structure will grow in both the horizontal and vertical planes. The exposed 111 crystal orientation is the apex of different sides of the rhombus, thus obtaining the first cone-shaped structure located on the side of the groove.

[0191] Embodiments of this application also provide a photovoltaic module, including any of the solar cells described above.

[0192] The photovoltaic module includes any of the aforementioned solar cells. In this solar cell, a groove is formed on the first surface of the substrate. Microstructures are formed on the first surface of the substrate, the bottom surface of the groove, and the side surface of the groove. The microstructures include a first conical structure, a second conical structure, and a columnar structure. The height directions of the first and second conical structures are different. That is, the solar cell of this application has microstructures on both the surface and the side surface, which intersect. Under the combined action of these two sets of microstructures in different directions, light from more angles can be scattered and enter the interior of the solar cell, thereby effectively suppressing the specular reflection effect, greatly reducing light reflection loss, improving the light trapping effect, and thus improving the overall light absorption efficiency of the solar cell. Furthermore, the multiple reflections of incident light in different directions increase the propagation path length of the light inside the solar cell. The farther the light travels inside the cell, the more opportunities it has to interact with the cell material, thereby significantly increasing the probability of photogenerated carrier generation and improving the photoelectric conversion efficiency of the cell.

[0193] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0194] As can be seen from the above description, the embodiments described in this application achieve the following technical effects:

[0195] In the solar cell of this application, a groove is formed on the first surface of the substrate. Microstructures are formed on the first surface of the substrate, the bottom surface of the groove, and the side surface of the groove. Multiple microstructures include a first conical structure, a second conical structure, and a columnar structure. The height directions of the first and second conical structures are different. That is, the solar cell of this application has microstructures on both the surface and the side surface, which intersect. Under the combined action of these two sets of microstructures with different directions, light from more angles can be scattered and enter the interior of the solar cell, thereby effectively suppressing the specular reflection effect, greatly reducing light reflection loss, improving the light trapping effect, and thus improving the overall light absorption efficiency of the solar cell. Furthermore, since multiple microstructures can provide multiple reflective surfaces, incident light can interact with surfaces of various angles and curvatures, allowing the incident light to be reflected multiple times in different directions. This increases the propagation path length of light inside the solar cell. The farther the light travels inside the cell, the more opportunities it has to interact with the cell materials, thereby significantly increasing the probability of photogenerated carrier generation and improving the photoelectric conversion efficiency of the cell.

[0196] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A solar cell, characterized in that, include: The substrate includes a first surface and a second surface opposite to each other. The first surface has a groove. Microstructures are respectively provided on the first surface, the bottom surface, and the side surface of the groove. The plurality of microstructures include a first cone structure, a second cone structure, and a columnar structure. The height direction of the first cone structure intersects the height direction of the second cone structure. The side surface of the columnar structure is inclined toward the outer periphery of the groove. A first passivation layer is located on the first surface. The columnar structure includes a first prism and a second prism. The plane containing the side surface of the first prism intersects the plane containing the side surface of the second prism. The side surface of the groove includes a first buffer zone, a pile-out zone, and a second buffer zone arranged sequentially along a first direction. The first prism is located in the first buffer zone, the first conical structure is located in the pile-out zone, and the second prism is located in the second buffer zone. The first direction is perpendicular to the first surface and points from the first surface to the second surface. The angle between the first surface in contact with the first prism and the side surface of the first prism is an acute angle.

2. The solar cell according to claim 1, characterized in that, The angle between the bottom surface of the groove and the side surface of the second prism is an obtuse angle.

3. The solar cell according to claim 1, characterized in that, The height of the first prism in the first direction is 0.5~2μm.

4. The solar cell according to claim 1, characterized in that, The height of the second prism in the first direction is 0.5~5μm.

5. The solar cell according to claim 1, characterized in that, The height of the first prism in the second direction is 0.5~2μm. The second direction is perpendicular to the first direction and the first intersection direction, respectively. The first intersection direction is the extension direction of the intersection line between the side of the first prism and the first surface.

6. The solar cell according to claim 1, characterized in that, The height of the second prism in the third direction is 0.5~2μm. The third direction is perpendicular to the first direction and the second intersection direction. The second intersection direction is the extension direction of the intersection line between the side of the first prism and the bottom surface of the groove.

7. The solar cell according to claim 1, characterized in that, The groove has a depth of 10~100μm in the fourth direction and a width of 3~10μm in the fifth direction. The fourth direction is perpendicular to the first surface, and the fifth direction is perpendicular to the fourth direction.

8. The solar cell according to claim 1, characterized in that, The height of the first cone-shaped structure is 0.5~3μm.

9. The solar cell according to claim 1, characterized in that, The second conical structure is located on the bottom surface of the groove and on the first surface.

10. The solar cell according to claim 9, characterized in that, The height of the protrusion of the second cone-shaped structure on the bottom surface of the groove is the first height, and the height of the protrusion of the second cone-shaped structure on the first surface is the second height, wherein the first height is less than the second height.

11. The solar cell according to claim 1, characterized in that, The first passivation layer is also located on the bottom surface and the side surface of the groove, and the solar cell further includes: A first doped conductive layer is located in the substrate and in contact with the first passivation layer, wherein the surface of the first doped conductive layer away from the second surface is a portion of the first surface; A tunneling oxide layer is located on the second surface; The second doped conductive layer is located on the side of the tunneling oxide layer away from the substrate. The doping type of the second doped conductive layer is the same as that of the substrate, and the doping type of the second doped conductive layer is different from that of the first doped conductive layer. The second passivation layer is located on the side of the second doped conductive layer away from the tunneling oxide layer; The first electrode is located on the side of the first passivation layer away from the first doped conductive layer; The second electrode is located on the side of the second passivation layer away from the second doped conductive layer.

12. The solar cell according to claim 1, characterized in that, The first passivation layer is located on the first surface surrounding the groove, and the solar cell further includes: The third doped conductive layer is located on one side of the groove, on the side of the first passivation layer away from the first surface; The fourth doped conductive layer is located on the side of the first passivation layer away from the first surface on the other side of the groove. The fourth doped conductive layer has the same doping type as the substrate, and the third doped conductive layer has a different doping type from the fourth doped conductive layer. The third passivation layer is located on the side of the third doped conductive layer and the fourth doped conductive layer away from the first passivation layer, on the bottom surface of the groove, and on the side surface of the groove. A fourth passivation layer is located on the second surface; The third electrode is located on the side of the third passivation layer away from the third doped conductive layer; The fourth electrode is located on the side of the third passivation layer away from the fourth doped conductive layer.

13. The solar cell according to claim 1, characterized in that, The second surface has the groove, and the solar cell further includes: The fifth doped conductive layer is located on the side of the first passivation layer away from the first surface; The first transparent conductive layer is located on the side of the fifth doped conductive layer away from the first passivation layer, on the bottom surface and the side surface of the groove on the first surface; The fifth passivation layer is located on the second surface; The sixth doped conductive layer is located on the side of the fifth passivation layer away from the second surface. The doping type of the sixth doped conductive layer is the same as that of the substrate, and the doping type of the sixth doped conductive layer is different from that of the fifth doped conductive layer. The second transparent conductive layer is located on the side of the sixth doped conductive layer away from the fifth passivation layer, on the bottom surface and the side surface of the groove on the second surface; The fifth electrode is located on the side of the first transparent conductive layer away from the fifth doped conductive layer; The sixth electrode is located on the side of the second transparent conductive layer away from the sixth doped conductive layer.

14. The solar cell according to claim 11, characterized in that, The first passivation layer includes: A borosilicate glass layer is located on the surface of the first doped conductive layer that is away from the second surface; A silicon oxide layer is located on the bottom surface and the side surface of the groove; An aluminum oxide layer is located on the side of the borosilicate glass layer away from the first doped conductive layer, and on the side of the silicon oxide layer away from the bottom surface and the side surface of the groove; An antireflective layer is located on the side of the alumina layer away from the borosilicate glass layer and the silicon oxide layer.

15. The solar cell according to claim 14, characterized in that, The thickness of the silicon oxide layer is 50~150nm.

16. A method for manufacturing a solar cell, characterized in that, include: An initial structure is provided, the initial structure including an initial substrate and an initial passivation layer, the initial substrate including opposing third and second surfaces, the third surface having microstructures, and the initial passivation layer located on the third surface; A portion of the initial passivation layer and a portion of the initial substrate are removed to form an initial groove located in the initial substrate; The bottom and sides of the initial groove are texturized to form the microstructures on the sides and bottom of the initial groove, respectively. The texturized initial groove forms a groove, and the remaining initial substrate forms a substrate. The plurality of microstructures include: a first cone-shaped structure, a second cone-shaped structure, and a columnar structure. The height direction of the first cone-shaped structure intersects the height direction of the second cone-shaped structure, and the side of the columnar structure is inclined towards the outer periphery of the groove. The columnar structure includes a first prism and a second prism. The plane containing the side surface of the first prism intersects the plane containing the side surface of the second prism. The side surface of the groove includes a first buffer zone, a pile-out zone, and a second buffer zone arranged sequentially along a first direction. The first prism is located in the first buffer zone, the first conical structure is located in the pile-out zone, and the second prism is located in the second buffer zone. The first direction is perpendicular to the third surface and points from the third surface to the second surface. The angle between the third surface in contact with the first prism and the side surface of the first prism is an acute angle.

17. The method for manufacturing a solar cell according to claim 16, characterized in that, The bottom and sides of the initial groove are texturized to form the microstructure on the sides and bottom of the initial groove, respectively, including: At an ambient temperature of 60~90℃, a mixed solution is used to etch the bottom and side surfaces of the initial groove to form the microstructure on the side and bottom surfaces of the initial groove, respectively. The mixed solution includes an alkaline solution and a texturing additive.

18. The method for manufacturing a solar cell according to claim 17, characterized in that, The volume of the alkaline solution is 0.5~20L, and the volume of the flocking additive is 0.5~10L.

19. The method for manufacturing a solar cell according to claim 16, characterized in that, The initial structure further includes an initial doped conductive layer located in the initial substrate, the initial doped conductive layer being in contact with the initial passivation layer, and removing a portion of the initial passivation layer and a portion of the initial substrate to form an initial groove located in the initial substrate, including: A portion of the initial passivation layer is removed using a laser etching process, thereby exposing a portion of the initial doped conductive layer, and the remaining initial passivation layer forms an oxide layer. The initial doped conductive layer and the initial substrate are removed sequentially using a wet etching process to obtain the initial groove.

20. The method for manufacturing a solar cell according to claim 19, characterized in that, The initial passivation layer is partially removed using a laser etching process, including: The initial passivation layer is removed by etching with a laser beam at 10-90% of the maximum output power and a scanning speed of 5000-40000 mm / s. The laser beam includes one of the following: an infrared laser beam, an ultraviolet laser beam, or a green laser beam.

21. The method for manufacturing a solar cell according to claim 19, characterized in that, The remaining initial doped conductive layer forms a first doped conductive layer, and the oxide layer is a borosilicate glass layer. After texturing the bottom and sides of the initial groove, the method further includes: An oxidation process is used to form a silicon oxide layer on the bottom surface and the sides of the groove; An aluminum oxide layer is formed on the surface of the borosilicate glass layer away from the first doped conductive layer, on the surface of the silicon oxide layer away from the bottom surface of the groove, and on the side surface of the groove. An antireflection layer is formed on the surface of the alumina layer away from the borosilicate glass layer and the silicon oxide layer to obtain a first passivation layer.

22. A photovoltaic module, characterized in that, The solar cell includes any one of claims 1 to 15.

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