Solar cell and manufacturing method thereof, laminated cell, and photovoltaic module

Abstract

The embodiment of the present disclosure relates to the photovoltaic field, and provides a solar cell, a manufacturing method thereof, a laminated cell and a photovoltaic module, wherein the solar cell comprises: providing a substrate, the substrate comprises opposite first and second surfaces, and the first surface comprises first and second regions arranged alternately; forming a protective layer on the first surface; etching the protective layer and the substrate in the second region to form a first groove; forming a first doped conductive layer in the first groove; and forming a first electrode electrically connected with the first doped conductive layer. The performance of the formed solar cell can be improved.

Description

TECHNICAL FIELD

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

[0002] Photovoltaic power generation refers to converting solar energy into electrical energy through the photovoltaic effect of a semiconductor, for example, a TOPCON (Tunnel Oxide Passivated Contact) cell is attracting more and more attention due to its good photoelectric conversion performance.

[0003] However, in the process of forming the doped conductive layer, damage to the doped conductive layer and the substrate will occur, which will affect the short-circuit current and conversion efficiency of the cell. Therefore, it is necessary to provide a manufacturing method of a solar cell to reduce the damage to the doped conductive layer and the substrate. SUMMARY

[0004] The present disclosure provides a solar cell, a manufacturing method thereof, a stacked cell, and a photovoltaic module, which can at least reduce the damage to the doped conductive layer in the process of forming the solar cell, thereby improving the performance of the formed solar cell.

[0005] According to some embodiments of the present disclosure, the present disclosure provides a manufacturing method of a solar cell, which includes: providing a substrate, the substrate including opposite first and second surfaces, the first surface including first and second regions arranged alternately; forming a protective layer on the first surface; etching the protective layer and the substrate in the second region to form a first groove; forming a first doped conductive layer in the first groove; and forming a first electrode electrically connected to the first doped conductive layer.

[0006] In some embodiments, the method of forming the protective layer includes: performing an oxidation treatment, the process parameters of the oxidation treatment including: a process time of 3000s-4500s, a process temperature of 850℃-1000℃, and a gas flow of oxygen of 2000sccm-20000sccm.

[0007] In some embodiments, the method of forming the first groove includes: performing a first laser treatment, the first laser treatment irradiating the protective layer in the second region; and performing a first etching treatment, the first etching treatment etching the protective layer in the second region and the substrate.

[0008] In some embodiments, the parameters of the first laser processing include: a power of 30w-40w, and a laser type of green skin laser or purple skin laser; and the parameters of the first etching processing include: a volume percentage concentration of an etching solution of 8%-13%.

[0009] In some embodiments, after forming the first doped conductive layer, further comprising: forming a tunneling layer covering at least part of the second surface; and forming a second doped conductive layer covering a surface of the tunneling layer.

[0010] In some embodiments, before forming the protective layer, further comprising: performing a first texturing process to form a first pyramid structure on the first surface; and after forming the second doped conductive layer, further comprising: performing a second texturing process to form a second pyramid structure on the second surface, wherein a base size of the first pyramid structure is smaller than a base size of the second pyramid structure.

[0011] In some embodiments, the process parameters of the first texturing process include: a process temperature of 70°C-75°C, a volume percentage concentration of a texturing solution of 0.4%-0.7%, and a volume percentage concentration of a first additive of 0.2%-0.5%; and the process parameters of the second texturing process include: a process temperature of 75°C-80°C, a volume percentage concentration of a texturing solution of 0.4%-0.7%, and a volume percentage concentration of a second additive of 0.2%-0.5%, wherein a protection capability of the first additive is greater than a protection capability of the second additive.

[0012] In some embodiments, before forming the first doped conductive layer, further comprising: performing a third texturing process to form a third pyramid structure in the first groove, wherein a base size of the third pyramid structure is smaller than or equal to a base size of the first pyramid structure.

[0013] In some embodiments, the method of forming the second doped conductive layer includes: forming a second initial doped conductive layer covering a surface of the tunneling layer; and removing the second initial doped conductive layer in the first region, and remaining the second initial doped conductive layer as the second doped conductive layer.

[0014] In some embodiments, the method of removing part of the second initial doped conductive layer includes: performing a second laser processing to irradiate a surface of the second initial doped conductive layer in the first region; and performing a second etching processing to etch the second initial doped conductive layer in the first region.

[0015] According to some embodiments of the present disclosure, another aspect of the embodiments of the present disclosure further provides a solar cell formed by using the method for manufacturing a solar cell partially or entirely as described above, comprising: a substrate, the substrate comprising opposite first and second surfaces, the first surface comprising first and second regions arranged alternately, and the substrate further comprising a first groove; a first doped conductive layer, the first doped conductive layer being located in the first groove; and a first electrode, the first electrode being in electrical connection with the first doped conductive layer.

[0016] In some embodiments, the substrate further comprises: a first pyramid structure, the first pyramid structure being located on the first surface; and a second pyramid structure, the second pyramid structure being located on the second surface, and a base size of the first pyramid structure being smaller than a base size of the second pyramid structure.

[0017] In some embodiments, the substrate further comprises: a third pyramid structure, the third pyramid structure being located in the first groove, and a base size of the third pyramid structure being smaller than or equal to a base size of the first pyramid structure.

[0018] According to some embodiments of the present disclosure, still another aspect of the embodiments of the present disclosure further provides a stacked cell, comprising: a bottom cell, a composite layer, and a perovskite top cell stacked in a preset direction; wherein the bottom cell is a solar cell formed by using the method for manufacturing a solar cell partially or entirely as described above, or is a solar cell partially or entirely as described above.

[0019] According to some embodiments of the present disclosure, still another aspect of the embodiments of the present disclosure further provides a photovoltaic module and a cell string, the cell string comprising: a plurality of solar cells formed by using the method for manufacturing a solar cell as described above, or a plurality of solar cells as described above, or a plurality of stacked cells as described above; a solder strip, the solder strip being in electrical connection with at least two solar cells or stacked cells to connect adjacent solar cells or stacked cells in series; an encapsulant film, the encapsulant film being used to cover a surface of the cell string; and a cover plate, the cover plate being used to cover a surface of the encapsulant film away from the cell string.

[0020] The technical scheme provided by the embodiments of the present disclosure has at least the following advantages: first, a protective layer is formed on the first surface of the substrate first, which protects the substrate that does not need to be etched during the process of forming the first groove, and then a first doped conductive layer is formed in the first groove. By defining the position of the first doped conductive layer first, the first doped conductive layer is avoided from being processed again during the process of forming the first doped conductive layer, and at the same time, the protective layer also acts as a barrier layer during the process of forming the first doped conductive layer, which can also avoid the damage of the substrate during the process of forming the first doped conductive layer, thereby improving the reliability of the solar cell piece. Second, by forming the first groove, the overflow of the glue during the process of forming the first electrode is reduced, thereby reducing the loss of glue, and at the same time, the first doped conductive layer is formed in the first groove, so that the first electrode can more deeply contact the first doped conductive layer, and the protrusion of the first region can reduce the unnecessary contact between the first electrode and the substrate, and also can avoid the leakage current. BRIEF DESCRIPTION OF DRAWINGS

[0021] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are shown by way of illustration in the drawings. These embodiments are described in enough detail to enable those skilled in the art to practice the embodiments and it is understood that the description is not intended to limit the embodiments to the specifically disclosed embodiments. The drawings are in simplified form and are not to precise scale as is common in literature of this type as the emphasis is generally upon the principles of operation of the embodiments rather than the precise construction. There are several aspects of the embodiments with the technology disclosed herein. For purposes of clarity, the figures are not drawn to scale and are provided merely to explain the principles of the embodiments. The description and drawings are only illustrative of selected embodiments, and are not intended to limit the scope of the disclosure. Numerous alternative embodiments can be derived from the technology, which is intended to be its broadest scope, and which is measured throughout this detailed description.

[0022] Figure 1 A structural schematic diagram of a substrate in an embodiment of the present disclosure;

[0023] Figure 2 A structural schematic diagram of forming a protective layer in an embodiment of the present disclosure;

[0024] Figure 3 A structural schematic diagram of forming a first groove in an embodiment of the present disclosure;

[0025] Figure 4 A structural schematic diagram of forming a first doped conductive layer in an embodiment of the present disclosure;

[0026] Figure 5 A structural schematic diagram formed after a back-throw process in an embodiment of the present disclosure;

[0027] Figure 6 A structural schematic diagram of forming an initial tunneling layer and a second semiconductor layer in an embodiment of the present disclosure;

[0028] Figure 7A structure schematic diagram for forming a second initial doped conductive layer in an embodiment of the present disclosure;

[0029] Figure 8 A structure schematic diagram for removing part of the second initial doped conductive layer in an embodiment of the present disclosure;

[0030] Figure 9 A structure schematic diagram for performing a second texturing treatment to form in an embodiment of the present disclosure;

[0031] Figure 10 A structure schematic diagram for forming a first electrode and a second electrode in an embodiment of the present disclosure;

[0032] Figure 11 A structure schematic diagram of a stacked battery provided in an embodiment of the present disclosure.

[0033] Legend of reference signs:

[0034] 100, substrate; 110, first surface; 120, second surface; 130, first region; 140, second region; 101, protective layer; 150, first groove; 102, first doped conductive layer; 103, first electrode; 160, first pyramid structure; 170, third pyramid structure; 104, tunneling layer; 105, second doped conductive layer; 115, second initial doped conductive layer; 114, initial tunneling layer; 125, second semiconductor layer; 106, glass layer; 180, second pyramid structure; 108, passivation layer; 107, second electrode.

[0035] 400, bottom cell; 401, composite layer; 402, perovskite top cell; 412, hole transport layer; 422, perovskite absorption layer; 432, electron transport layer; 442, electrode; 404, back electrode. DETAILED DESCRIPTION

[0036] As known from the background art, in the process of forming a local first doped conductive layer, a first doped conductive layer covering the entire surface of the substrate is usually first formed, and then part of the first doped conductive layer is removed by laser etching to form a local first doped conductive layer. However, by this method of first forming and then laser etching, not only the first doped conductive layer is damaged, but also the substrate is damaged.

[0037] In the embodiments of the present disclosure, first, a protective layer is formed on the first surface of the substrate, the protective layer protects the substrate which does not need to be etched in the process of forming the first groove, then the first doped conductive layer located in the first groove is formed, by defining the position of the first doped conductive layer in advance, the first doped conductive layer is avoided from being processed again in the process of forming the first doped conductive layer, at the same time, the protective layer also acts as a barrier layer in the process of forming the first doped conductive layer, and the substrate can also be avoided from being damaged in the process of forming the first doped conductive layer, so as to avoid affecting the reliability of the first area of the substrate, thereby improving the reliability of the solar cell piece; secondly, by forming the first groove, the glue overflow in the process of forming the first electrode is reduced when the first electrode is formed, thereby reducing the loss of glue, at the same time, the first doped conductive layer is formed in the first groove, so that the first electrode can more deeply contact the first doped conductive layer, and the protrusion of the first area can reduce unnecessary contact between the first electrode and the substrate, and also can avoid leakage current.

[0038] In the description of the embodiments of the present disclosure, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0039] In this paper, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present disclosure. The appearance of this phrase in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the existence of A, the existence of A and B, and the existence of B. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0041] In the description of the embodiments of the present disclosure, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0042] In the description of the embodiments of the present disclosure, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present disclosure.

[0043] In the description of the embodiments of the present disclosure, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0044] In the corresponding drawings of the embodiments of the present disclosure, in order to better understand and facilitate the description, the thickness and area of the layer are enlarged. When describing that a component (such as a layer, a film, a region or a substrate) is on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing that a component is on the surface of another component or a component surface is formed or provided with another component, it means that there is no third component between the two components. In addition, when describing that a component is "formed substantially" on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on the edge of the entire surface.

[0045] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded and other components can also be further included. In addition, when a layer, film, region or plate and the like component is referred to as "on / over" another component, it can be "directly on" another component (i.e. between the surface of another component and another component without other components), or another component can exist therebetween. In addition, when a layer, film, region, plate and the like component is "directly on" another component, or when a layer, film, region, plate and the like component is on the surface of another component, it means that there is no other component therebetween.

[0046] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the article "a", "an" is intended to include one or more articles based on the context in which the article is used. In addition, the terms "comprising", "including", "containing", and "having" are intended to be inclusive and mean that there can be additional

[0047] Embodiments of the present disclosure will be described in detail below with reference to the drawings. However, it should be understood that the technical details are presented in the embodiments of the present disclosure to make the reader better understand the present disclosure. However, the technical solutions claimed by the present disclosure can be implemented even without these technical details and based on various changes and modifications of the following embodiments.

[0048] Reference Figures 1 to 10 , Figures 1 to 10 A structure diagram corresponding to each step of a manufacturing method of a solar cell provided by an embodiment of the present disclosure is shown.

[0049] In some embodiments, the manufacturing method of the solar cell can include: providing a substrate 100, the substrate 100 including opposite first and second surfaces 110 and 120, the first surface 110 including first and second regions 130 and 140 arranged alternately.

[0050] The manufacturing method of the solar cell can further include: forming a protective layer 101 on the first surface 110.

[0051] The manufacturing method of the solar cell can further include: etching the protective layer 101 and the substrate 100 on the second region 140 to form a first recess 150.

[0052] The manufacturing method of the solar cell can further include: forming a first doped conductive layer 102 in the first recess 150.

[0053] The manufacturing method of the solar cell can further include: forming a first electrode 103 electrically connected to the first doped conductive layer 102.

[0054] In the embodiments of the present disclosure, first, the protective layer 101 is formed on the first surface 110 of the substrate 100, the protective layer 101 protects the substrate 100 which does not need to be etched in the process of forming the first groove 150, and then the first doped conductive layer 102 located in the first groove 150 is formed. By defining the position of the first doped conductive layer 102 in advance, the second processing of the first doped conductive layer 102 in the process of forming the first doped conductive layer 102 is avoided, and at the same time, the protective layer 101 also acts as a barrier layer in the process of forming the first doped conductive layer 102, which can also avoid damage to the substrate 100 in the process of forming the first doped conductive layer 102, thereby avoiding affecting the reliability of the first region 130, thereby improving the reliability of the solar cell piece. Secondly, by forming the first groove 150, the overflow of the slurry in the process of forming the first electrode 103 is reduced, thereby reducing the loss of the slurry, and at the same time, the first doped conductive layer 102 is formed in the first groove 150, so that the first electrode 103 can more deeply contact the first doped conductive layer 102, and the protrusion of the first region 130 can reduce unnecessary contact between the first electrode 103 and the substrate 100, and also can avoid leakage current.

[0055] Reference Figure 1 , Figure 1 FIG. 1 is a schematic diagram of a structure of a substrate according to an embodiment of the present disclosure.

[0056] In some embodiments, the material of the substrate 100 can be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, for example, can be silicon or germanium. Among them, the elemental semiconductor material can be single-crystalline, polycrystalline, amorphous or microcrystalline (a state of both single-crystalline and amorphous, referred to as microcrystalline), for example, silicon can be at least one of single-crystalline silicon, polycrystalline silicon, amorphous silicon or microcrystalline silicon. The material of the substrate 100 can also be a compound semiconductor material. Common compound semiconductor materials include but are not limited to silicon germanium, silicon carbide, gallium arsenide, indium gallium, perovskite, cadmium telluride, copper indium selenium and the like.

[0057] The substrate 100 can be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type doping element, and the N-type doping element can be at least one of a group V element such as phosphorus (P) element, bismuth (Bi) element, antimony (Sb) element or arsenic (As) element. The P-type semiconductor substrate is doped with a P-type element, and the P-type doping element can be at least one of a group III element such as boron (B) element, aluminum (Al) element, gallium (Ga) element or indium (In) element.

[0058] In some embodiments, a first texturing process is also performed to form first pyramid structures 160 on the first surface 110. The first texturing process performed on the first surface 110 can enhance the light absorption efficiency of the first surface 110 of the substrate 100. The first pyramid structures 160 are surface texturing structures corresponding to the substrate 100. The first pyramid structures 160 can reduce the reflectivity of the surface of the substrate 100 and form light traps, thereby enhancing the light absorption effect of the substrate 100 and improving the photoelectric conversion efficiency of the solar cell.

[0059] In some embodiments, the process parameters of the first texturing process include: a process temperature of 70-75°C, for example, 70°C, 71°C, 72°C, 73°C, 74°C or 75°C; a volume percentage concentration of the texturing solution of 0.4%-0.7%, for example, 0.4%, 0.5%, 0.6% or 0.7%; and a volume percentage concentration of the first additive of 0.2%-0.5%, for example, 0.2%, 0.3%, 0.4% or 0.5%.

[0060] The process temperature provides an etching environment for the first texturing process, so as to facilitate the formation of the first pyramid structures 160. The texturing solution is used to etch part of the substrate 100 to form the first pyramid structures 160. The first additive is used to protect the substrate 100 from excessive damage caused by the first texturing process, while controlling the formation of the first pyramid structures 160 on the surface of the substrate 100.

[0061] In some embodiments, the first surface 110 can be a front surface, and the second surface 120 can be a back surface. The front surface can be used as a light-receiving surface of the solar cell to receive incident light. The back surface can be used as a back light surface. In other embodiments, the solar cell wafer is a bifacial cell, and the first surface 110 and the second surface 120 can both be used as light-receiving surfaces to receive incident light. It can be understood that the back light surface referred to in the embodiments of the present application can also receive incident light, but the degree of reception of the incident light is weaker than that of the light-receiving surface, and thus the back light surface is defined.

[0062] The first region 130 and the second region 140 of the substrate 100 can be divided according to whether they are aligned with the formed first electrode 103. For example, a position offset from the first electrode 103 is defined as the first region 130, and a position aligned with the first electrode 103 is defined as the second region 140.

[0063] In some embodiments, the width of the second region 140 can be greater than the width of the first electrode 103 along the arrangement direction of the first electrode 103, so as to reduce the alignment difficulty in forming the first electrode 103, thereby reducing the difficulty of the manufacturing method of the solar cell wafer.

[0064] Reference Figure 2 , Figure 2 The structure of forming a protective layer on the basis of the above-mentioned structure is shown in FIG. 1C. Figure 1 The structure of forming a protective layer on the basis of the above-mentioned structure is shown in FIG. 1C.

[0065] In some embodiments, the method of forming the protective layer 101 can include: performing an oxidation treatment, and the process parameters of the oxidation treatment include: a process time of 3000s-4500s, for example, 3000s, 3200s, 3500s, 3800s, 4000s, or 4500s, etc.; a process temperature of 850°C-1000°C, for example, 850°C, 900°C, 930°C, 950°C, 980°C, or 1000°C, etc.; and a gas flow of oxygen of 2000sccm-20000sccm, for example, 2000sccm, 5000sccm, 7000sccm, 10000sccm, 12000sccm, 15000sccm, 18000sccm, or 20000sccm, etc.

[0066] By converting part of the substrate 100 into the protective layer 101 through the oxidation treatment, the compactness and uniformity of the formed protective layer 101 can be improved, so that the protection ability of the protective layer 101 can be improved. The higher the compactness, the stronger the ability to block etching and diffusion ions, and the lower the possibility of affecting the substrate 100 in the subsequent process of forming the first doped conductive layer 102.

[0067] For the process time, the longer the process time, the thicker the thickness of the formed protective layer 101, and the shorter the process time, the thinner the thickness of the formed protective layer 101. If the process time is less than 3000s, the thickness of the formed protective layer 101 will be too thin, which will reduce the protection ability of the protective layer 101, and the improvement effect cannot meet the expectation. If the process time is greater than 4500s, it may cause the thickness of the substrate 100 converted into the protective layer 101 to be too thick, which will reduce the ability of the substrate 100 to generate photo-generated carriers, and will reduce the performance of the formed solar cell.

[0068] For the process temperature, the higher the process temperature, the faster the rate of forming the protective layer 101, and the lower the process temperature, the slower the rate of forming the protective layer 101. If the process temperature is less than 850°C, the effect of forming the protective layer 101 will be too slow, which will cause the time required to form the protective layer 101 of the target thickness to be too long, and will reduce the efficiency of the solar cell manufacturing method. If the process temperature is greater than 1000°C, it may cause certain impact on the substrate 100 itself, which may reduce the reliability of the formed solar cell. Therefore, setting the process temperature to be 850°C-1000°C can improve the efficiency of forming the protective layer 101 while improving the reliability of forming the solar cell.

[0069] For the gas flow of oxygen, the higher the gas flow of oxygen, the faster the rate of forming the protective layer 101, the lower the gas flow of oxygen, the slower the rate of forming the protective layer 101, if the gas flow of oxygen is less than 2000sccm, it may cause the rate of forming the protective layer 101 to be too slow, if the gas flow of oxygen is greater than 20000sccm, it may cause waste of oxygen, limited by the reaction rate, it will cause excess oxygen, at the same time, the gas flow of oxygen is too large, which causes the process of forming the protective layer 101 to be difficult to control, resulting in too much substrate 100 being converted into the protective layer 101.

[0070] In some embodiments, the protective layer 101 can also be formed by deposition, which can facilitate the control of the thickness of the protective layer 101 to form a protective layer 101 with the required thickness.

[0071] The material of the protective layer 101 can be silicon oxide and the like, which can be changed according to the requirements or the material of the substrate 100.

[0072] Reference Figure 3 , Figure 3 The structure diagram of forming the first groove on the basis of the structure diagram provided by an embodiment of the present disclosure. Figure 2

[0073] In some embodiments, the method of forming the first groove 150 includes: performing a first laser treatment, the first laser treatment irradiates the protective layer 101 located in the second area 140; performing a first etching treatment, the first etching treatment etches the protective layer 101 and the substrate 100 located in the second area 140. The first laser treatment can modify the protective layer 101 and the substrate 100, so as to facilitate the removal of the first etching treatment, the first laser treatment can reduce the difficulty of removing the protective layer 101 and the substrate 100, so as to facilitate the formation of the first groove 150, at the same time, by removing part of the substrate 100, the damaged substrate 100 in the first laser treatment process can be removed, thereby improving the reliability of the formed solar cell piece.

[0074] It should be noted that the modification here can refer to changing the state of the material of the protective layer 101 and the substrate 100 by laser treatment, the protective layer 101 and the substrate 100 located in the second area 140 become more loose, so as to facilitate etching.

[0075] The protective layer 101 located in the second area 140 here refers to the orthographic projection on the surface of the substrate 100 located in the second area 140.

[0076] ​In some embodiments, the parameters of the first laser processing include: a power of 30w-40w, for example, 30w, 32w, 34w, 36w, 38w or 40w, etc., and a laser type of green skin laser or purple skin laser; the parameters of the first etching processing include: a volume percentage concentration of the etching solution of 8%-13%, for example, 8%, 9%, 10%, 11%, 12% or 13%.

[0077] For the power, the greater the power, the stronger the modification ability of the first laser processing, and the smaller the power, the worse the modification effect, therefore, the power is set to be greater than or equal to 30w, so that the first laser processing has a better modification effect, and if the power is greater than 40w, it may cause excessive damage to the substrate 100 by the first laser processing.

[0078] For the laser type, compared with the green skin laser, the wavelength of the purple skin laser is smaller, the penetration depth of the film layer is smaller, and the energy of the purple skin laser is more concentrated on the surface of the film layer, which are all conducive to reducing the probability of causing greater laser damage to the substrate 100 by the first laser.

[0079] For the volume percentage concentration of the etching solution, the volume percentage concentration here refers to the volume ratio of the solute and the solvent, for example, the etching solution is hydrofluoric acid, which refers to the volume ratio of hydrofluoric acid and water solvent, the higher the volume percentage concentration of the etching solution, the faster the etching rate, and the greater the probability of causing damage to the substrate 100, therefore, the volume percentage concentration of the etching solution is set to be 8%-13%, considering the processing rate of the first etching processing and the reliability of the formed solar cell piece.

[0080] In some embodiments, the etching solution is an acidic solution, for example, the hydrofluoric acid solution, the water content in the etching solution can be 400L-500L, and the content of hydrofluoric acid can be 40L-50L.

[0081] Reference Figure 4 , Figure 4 to form the first doped conductive layer on the basis of Figure 3 The structural schematic diagram of the first doped conductive layer.

[0082] In some embodiments, the process of forming the first doped conductive layer 102 can include: performing a diffusion process, the diffusion process dopes the doped ions into the partial thickness of the substrate 100, so as to convert part of the substrate 100 into the first doped conductive layer 102, it can be understood that since the protective layer 101 is formed before the first doped conductive layer 102 is formed, only the substrate 100 exposed by the first groove 150 is subjected to the diffusion process, so as to directly form the first doped conductive layer 102 located in the first groove 150.

[0083] Compared with related solutions, the first doped conductive layer 102 is formed by directly performing the diffusion process, thereby reducing the step of laser etching the first doped conductive layer 102, reducing mechanical damage caused by the laser etching process, and avoiding damage to the substrate 100 caused by the laser etching process, thereby improving the reliability of the formed solar cell.

[0084] In some embodiments, the process of forming the first doped conductive layer 102 can further include: forming a first semiconductor layer covering the protective layer 101 and the exposed surface of the substrate 100 in the first groove 150, then removing the first semiconductor layer on the surface of the protective layer 101, and performing a diffusion process to convert the first semiconductor layer in the first groove 150 into the first doped conductive layer 102. Similarly, the first semiconductor layer on the surface of the protective layer 101 is removed before the diffusion process is performed. Since the protective layer 101 is present, the substrate 100 can be prevented from being damaged, and the protective layer 101 can also prevent the doping ions from diffusing into the substrate 100 during the diffusion process, thereby improving the reliability of the formed solar cell.

[0085] In some embodiments, before the first doped conductive layer 102 is formed, a third texturing process can be performed to form a third pyramid structure 170 in the first groove 150, and the base size of the third pyramid structure 170 is less than or equal to the base size of the first pyramid structure 160. By forming the third pyramid structure 170 in the first groove 150, the light reflectivity of the formed solar cell can be further reduced, thereby improving the absorption effect of the substrate 100 on the incident light.

[0086] In some embodiments, the third texturing process can be the same as the first texturing process, so that the base size of the third pyramid structure 170 is equal to the base size of the first pyramid structure 160. Setting the third texturing process to be the same as the first texturing process can reduce the process complexity of the solar cell. In some embodiments, the third texturing process can be different from the first texturing process. For example, the third additive has stronger protection, so that the base size of the third pyramid structure 170 is smaller than the base size of the first pyramid structure 160. For the substrate 100 exposed by the first groove 150, the first doped conductive layer 102 and the first electrode 103 will be formed in the first groove 150 later, which will cause shading to the substrate 100 corresponding to the first groove 150. Therefore, by reducing the base size of the third pyramid structure 170, the flatness of the surface of the substrate 100 in the first groove 150 can be improved, and the uniformity of the first doped conductive layer 102 formed by depositing the first semiconductor layer can be improved.

[0087] The third texturing process can be the same as the first texturing process, which means that the process temperature, the type and the volume percentage concentration of the texturing solution, and the type and the volume percentage concentration of the first additive and the third additive are all the same.

[0088] Referring to Figure 5 , Figure 5 On the basis of Figure 4 the back-throwing process, a structure schematic diagram is formed.

[0089] In some embodiments, the back-throwing process removes the first pyramid structure 160 formed on the second surface 120 by the first texturing process and removes the protective layer 101 on the back surface, so as to form a structure layer on the second surface 120.

[0090] Referring to Figures 6 to 9 , a tunneling layer 104 and a second doped conductive layer 105 are formed.

[0091] In some embodiments, after the first doped conductive layer 102 is formed, the method further includes: forming a tunneling layer 104, the tunneling layer 104 covering at least part of the second surface 120; and forming a second doped conductive layer 105, the second doped conductive layer 105 covering a surface of the tunneling layer 104. The tunneling layer 104 has a chemical passivation effect on the substrate 100, reduces the defect state density on the back surface of the substrate 100 by saturating dangling bonds on the back surface of the substrate 100, and reduces the carrier recombination rate by reducing the recombination center on the surface of the substrate 100. The second doped conductive layer 105 also has a field passivation effect. Specifically, the second doped conductive layer 105 forms an electrostatic field on the back surface of the substrate 100, which points to the inside of the substrate 100, so that the minority carriers escape from the interface, thereby reducing the minority carrier concentration and reducing the carrier recombination rate at the interface of the substrate 100, so as to increase the open-circuit voltage, the short-circuit current, and the fill factor of the solar cell sheet, and improve the photoelectric conversion efficiency of the solar cell sheet.

[0092] The material of the tunneling layer 104 can include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride. The material of the second doped conductive layer 105 can include at least one of amorphous silicon, polycrystalline silicon, or silicon carbide.

[0093] In some embodiments, the method of forming the second doped conductive layer 105 comprises: forming a second initial doped conductive layer 115, the second initial doped conductive layer 115 covering the surface of the tunneling layer 104; removing the second initial doped conductive layer 115 located in the first region 130, and the remaining second initial doped conductive layer 115 as the second doped conductive layer 105. By forming the second initial doped conductive layer 115 first, and then removing part of the second initial doped conductive layer 115 to form the second doped conductive layer 105, the difficulty of forming the second doped conductive layer 105 can be reduced, and at the same time, the second initial doped conductive layer 115 located in the first region 130 is removed, and the second initial doped conductive layer 115 located in the second region 140 is retained, so that the first doped conductive layer 102 located on the first surface and the second doped conductive layer 105 located on the second surface are opposite, which can facilitate the collection of carriers in the substrate, thereby improving the transmission efficiency of the carriers.

[0094] Reference Figure 6 and Figure 7 , Figure 6 to form the initial tunneling layer and the second semiconductor layer, Figure 5 is a structural schematic diagram of forming the second initial doped conductive layer on the basis of Figure 7 . Figure 6

[0095] In some embodiments, the initial tunneling layer 114 covers the entire second surface 120, and the second initial doped conductive layer 115 covers the surface of the initial tunneling layer 114.

[0096] In some embodiments, the method of forming the second initial doped conductive layer 115 can comprise: forming a second semiconductor layer 125, and performing a doping process to convert the second semiconductor layer 125 into the second initial doped conductive layer 115.

[0097] It can be understood that in the process of forming the second initial doped conductive layer 115, a glass layer 106 is also formed, the glass layer 106 is located on the surface of the second initial doped conductive layer 115 away from the substrate 100, and the glass layer 106 is related to the doping process, for example, when the doping process dopes phosphorus elements into the second semiconductor layer 125, a phosphorus-silicon glass layer is formed.

[0098] Reference Figure 8 , Figure 8 is a structural schematic diagram of removing part of the second initial doped conductive layer 115 on the basis of Figure 7 .

[0099] ​In some embodiments, the method of removing part of the second initial doped conductive layer 115 comprises: performing a second laser treatment, the second laser treatment irradiates the surface of the second initial doped conductive layer 115 located in the first region 130; performing a second etching treatment, the second etching treatment etches the second initial doped conductive layer 115 located in the first region 130. It can be understood that the glass layer 106 will be formed in the process of forming the second initial doped conductive layer 115, and the glass layer 106 will affect the etching efficiency of the second etching treatment, therefore, the glass layer 106 can be modified by the second laser treatment to facilitate the removal of the glass layer 106 and the second initial doped conductive layer 115 by the second etching treatment.

[0100] Reference Figure 9 , Figure 9 for the second texturing treatment. Figure 8 The structure schematic diagram formed on the basis of the second texturing treatment.

[0101] In some embodiments, after the second doped conductive layer 105 is formed, the method further comprises: performing a second texturing treatment, the second texturing treatment forms a second pyramid structure 180 on the second surface 120, and the base size of the first pyramid structure 160 is smaller than the base size of the second pyramid structure 180. By forming the second pyramid structure 180 on the second surface 120, and the base size of the second pyramid structure 180 is larger than the base size of the first pyramid structure 160, the differential texturing of the first surface 110 and the second surface 120 is formed, and the second pyramid structure 180 with larger base size can improve the reflectivity of the second surface 120, and when the light is transmitted from the first surface 110 to the second surface 120 inside the substrate 100, the second pyramid structure 180 can reflect the light again into the substrate 100, thereby improving the bifaciality of the formed solar cell sheet, and further improving the open voltage of the formed solar cell sheet.

[0102] In some embodiments, the process parameters of the second texturing treatment comprise: the process temperature is 75℃-80℃, for example, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃, the volume percentage concentration of the texturing solution is 0.4%-0.7%, for example, 0.4%, 0.5%, 0.6% or 0.7%, the volume percentage concentration of the second additive is 0.2%-0.5%, for example, 0.2%, 0.3%, 0.4% or 0.5%, and the protection ability of the first additive is greater than that of the second additive.

[0103] The process temperature provides an etching environment for the second texturing process to form the second pyramid structure 180. The texturing solution is used to etch part of the substrate 100 to form the second pyramid structure 180. The second additive is used to protect the substrate 100 from being damaged too much by the second texturing process, while controlling the formation of the second pyramid structure 180 on the surface of the substrate 100.

[0104] For the second additive, since the protection ability of the second additive is less than that of the first additive, the etching effect of the second texturing process is faster when forming the second pyramid structure 180, so as to form the second pyramid structure 180 with a larger base structure size.

[0105] Reference Figure 10 , Figure 10 to form the first electrode and the second electrode. Figure 9

[0106] The materials of the first electrode 103 and the second electrode 107 can be metal, such as copper, silver, nickel, or aluminum.

[0107] In some embodiments, a passivation layer 108 is further formed before forming the first electrode 103 and the second electrode 107. The passivation layer 108 covers the first surface 110 and the surface of the first doped conductive layer 102, and covers the second surface 120 and the surface of the second doped conductive layer 105.

[0108] The material of the passivation layer 108 can be at least one of silicon oxide, aluminum oxide, silicon nitride, or silicon oxynitride.

[0109] In some embodiments, the passivation layer 108 can be a single-layer structure. In some embodiments, the passivation layer 108 can also be a multi-layer structure. The materials of the layers in the multi-layer structure can be different from each other, or the materials of part of the number of layers can be different from each other, and the materials of the remaining part of the number of layers can be the same. For example, the passivation layer 108 can be a multi-layer structure of a silicon nitride layer and an aluminum oxide layer.

[0110] In some embodiments, removing the protective layer 101 on the first surface 110 can be further included before forming the passivation layer 108.

[0111] ​In some embodiments, the projections of the first electrode 103 and the second electrode 107 on the surface of the substrate can both be located within the second region 140, and the projections of the first electrode 103 and the second electrode 107 on the surface of the substrate are located in the same region of the substrate, which is considered that the first electrode 103 and the second electrode 107 are directly opposite. The projections of the first electrode and the second electrode on the surface of the substrate can also be staggered, that is, the projections of the first electrode and the second electrode on the surface of the substrate are located in different regions of the substrate, for example, the projection of the first electrode on the surface of the substrate is located in the second region, and the projection of the second electrode on the surface of the substrate is located in the first region.

[0112] In the embodiments of the present disclosure, first, the protective layer 101 is formed on the first surface 110 of the substrate 100, the protective layer 101 protects the substrate 100 which does not need to be etched in the process of forming the first groove 150, and then the first doped conductive layer 102 located in the first groove 150 is formed. By defining the position of the first doped conductive layer 102 in advance, the subsequent secondary processing of the first doped conductive layer 102 in the process of forming the first doped conductive layer 102 is avoided. At the same time, the protective layer 101 also acts as a barrier layer in the process of forming the first doped conductive layer 102, which can also avoid damage to the substrate 100 in the process of forming the first doped conductive layer 102, thereby avoiding affecting the reliability of the first region 130, thereby improving the reliability of the solar cell piece. Secondly, by forming the first groove 150, the overflow of glue in the process of forming the first electrode 103 is reduced, thereby reducing the loss of glue. At the same time, the first doped conductive layer 102 is formed in the first groove 150, so that the first electrode 103 can more deeply contact the first doped conductive layer 102, and the protrusion of the first region 130 can reduce unnecessary contact between the first electrode 103 and the substrate 100, and also avoid leakage current.

[0113] Another embodiment of the present disclosure provides a solar cell piece, which can be formed by the method for manufacturing a solar cell piece as described above. The solar cell piece provided by the embodiments of the present disclosure will be described below with reference to the accompanying drawings. The same or corresponding parts as in the above embodiments can refer to the above embodiments, and the following will not be described again.

[0114] Reference Figure 10 In some embodiments, the solar cell piece can include: a substrate 100 including opposite first and second surfaces 110 and 120, the first surface 110 including first and second regions 130 and 140 arranged alternately, and the substrate 100 further including a first groove 150.

[0115] The solar cell piece can further include: a first doped conductive layer 102 located in the first groove 150.

[0116] The solar cell wafer can further include a first electrode 103 in contact with the first doped conductive layer 102.

[0117] In some embodiments, the substrate 100 further includes a first pyramid structure 160 on the first surface 110, and a second pyramid structure 180 on the second surface 120, and a base size of the first pyramid structure 160 is smaller than a base size of the second pyramid structure 180. By setting the base size of the second pyramid structure 180 to be larger than the base size of the first pyramid structure 160, the first surface 110 and the second surface 120 can be textured differently, and the second pyramid structure 180 with the larger base size can increase the reflectivity of the second surface 120, and when light is transmitted from the first surface 110 to the second surface 120 inside the substrate 100, the second pyramid structure 180 can reflect the light again inside the substrate 100, thereby increasing the bifaciality of the solar cell wafer formed, and further increasing the open voltage of the solar cell wafer formed.

[0118] Here, the larger base size can mean that the average base size of the first pyramid structure in a certain area is larger than the average base size of the second pyramid structure in the same area, or that the base size of any first pyramid structure in a certain area is larger than the base size of the second pyramid structure, and the base size can mean the side length or the diagonal length of the base of the first pyramid structure.

[0119] In some embodiments, the substrate 100 further includes a third pyramid structure 170 in the first groove 150, and the base size of the third pyramid structure 170 is smaller than or equal to the base size of the first pyramid structure 160. For the substrate 100 exposed by the first groove 150, the first doped conductive layer 102 and the first electrode 103 can block light from the substrate 100 corresponding to the first groove 150, and therefore, the flatness of the surface of the substrate 100 in the first groove 150 can be improved by reducing the base size of the third pyramid structure 170, and the uniformity of the first doped conductive layer 102 can be improved.

[0120] In some embodiments, the base size of the first pyramid structure 160 can be 1 μm to 3 μm, for example, 1 μm, 2 μm, or 3 μm. The base size of the second pyramid structure 180 can be 5 μm to 10 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

[0121] Another embodiment of the present disclosure provides a stacked cell. The bottom cell in the stacked cell can be a solar cell piece as in the above embodiments, or a solar cell piece formed by the method for manufacturing a solar cell piece as above. The stacked cell provided by the embodiment of the present disclosure will be described below with reference to the accompanying drawings. The same or corresponding parts as in the above embodiments can be referred to the above embodiments, and the following will not be described in detail.

[0122] Reference Figure 11 , Figure 11 FIG. 1 is a structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure.

[0123] The stacked cell can include: a bottom cell 400, a composite layer 401 and a perovskite top cell 402 stacked in sequence along a preset direction; wherein the bottom cell 400 is a solar cell piece formed by the method for manufacturing a solar cell piece as above, or a solar cell piece as above.

[0124] The back electrode 404 in the bottom cell 400 can refer to the second electrode 107 in the above embodiments.

[0125] The material of the composite layer 401 includes a transparent conductive oxide (TCO) for providing lateral conductivity and light transmission. For example, the material can be indium tin oxide (ITO), hydrogenated indium oxide (IO:H) or zinc oxide (ZnO), etc.

[0126] The perovskite top cell 402 can include: a hole transport layer 412, a perovskite absorption layer 422, an electron transport layer 432 and an electrode 442.

[0127] Another embodiment of the present disclosure also provides a photovoltaic module, including: a cell string, the cell string including: a plurality of solar cell pieces formed by the method for manufacturing a solar cell piece as above, or including a plurality of solar cell pieces as above, or including a plurality of stacked cells as above; a solder strip, the solder strip being electrically connected with at least two solar cell pieces or stacked cells to connect adjacent solar cell pieces or stacked cells in series; an encapsulant film, the encapsulant film being used to cover the surface of the cell string; a cover plate, the cover plate being used to cover the surface of the encapsulant film away from the cell string.

[0128] In some embodiments, the encapsulation film comprises a first encapsulation layer covering one of the front side or the back side of the solar cell and a second encapsulation layer covering the other of the front side or the back side of the solar cell. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate (EVA) film, a polyolefin elastomer (POE) film, or a polyethylene terephthalate (PET) film, or at least one of the first encapsulation layer or the second encapsulation layer can also be an EP film, an EPE film, or a PVP film. The EP film refers to a co-extrusion film formed by stacking an EVA film and a POE film, the EPE film refers to a co-extrusion film formed by stacking an EVA film, a POE film, and an EVA film in sequence, and the PVP film refers to a co-extrusion film formed by stacking a POE film, an EVA film, and a POE film in sequence. The co-extrusion film can be prepared by extruding one or more raw materials onto another film prepared in advance or by bonding different types of films to each other during film processing.

[0129] In some cases, the first encapsulation layer and the second encapsulation layer have a boundary before lamination, and after lamination, the photovoltaic module is formed without the concept of the first encapsulation layer and the second encapsulation layer, i.e., the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film.

[0130] In some embodiments, the cover plate can be a glass cover plate, a plastic cover plate, or the like having a light-transmitting function. Specifically, the surface of the cover plate facing the encapsulation film can be a concave-convex surface or a suede surface comprising a plurality of convex structures, thereby increasing the utilization rate of incident light. The cover plate comprises a first cover plate opposite the first encapsulation layer and a second cover plate opposite the second encapsulation layer.

[0131] It is understood by those skilled in the art that the above embodiments are specific embodiments for implementing the present disclosure, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the embodiments of the present disclosure, and therefore the protection scope of the embodiments of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A method for manufacturing a solar cell, characterized by, The application relates to a solar cell manufacturing method. The method comprises the following steps: providing a substrate, the substrate comprising opposite first and second surfaces, the first surface comprising first and second regions arranged alternately; forming a protective layer on the first surface; etching the protective layer and the substrate in the second region to form a first groove; forming a first doped conductive layer in the first groove; 2. The method of claim 1, wherein the step of forming the first and second electrodes is performed by screen printing. forming a first electrode electrically connected to the first doped conductive layer.

3. The method of claim 1, wherein the step of forming the first and second electrodes is performed by screen printing. The method for forming the protective layer comprises an oxidation treatment, and the process parameters of the oxidation treatment include a process time of 3000s-4500s, a process temperature of 850 DEG C-1000 DEG C, and a gas flow of oxygen of 2000sccm-20000sccm. The method for forming the first groove comprises the following steps: performing a first laser treatment on the protective layer in the second region; 4. The method of claim 3, wherein the step of forming the first and second electrodes is performed by screen printing. performing a first etching treatment on the protective layer in the second region and the substrate.

5. The method of claim 1, wherein the step of forming the first and second electrodes is performed by screen printing. The parameters of the first laser treatment include a power of 30w-40w and a laser type of green skin laser or purple skin laser; the parameters of the first etching treatment include a volume percentage concentration of an etching solution of 8%-13%. After the first doped conductive layer is formed, the method further comprises the following steps: forming a tunneling layer covering at least part of the second surface; 6. The method of claim 5, wherein the step of forming the first and second electrodes is performed by screen printing. forming a second doped conductive layer covering the surface of the tunneling layer. Before the protective layer is formed, the method further comprises a first texturing treatment for forming a first pyramid structure on the first surface. After the second doped conductive layer is formed, the method further comprises a second texturing treatment for forming a second pyramid structure on the second surface, and the base size of the first pyramid structure is smaller than the base size of the second pyramid structure. The base size of the first pyramid structure refers to the side length or the diagonal length of the base of the first pyramid structure, and the base size of the second pyramid structure refers to the side length or the diagonal length of the base of the second pyramid structure.

7. The solar cell manufacturing method according to claim 6, wherein the process parameters of the first texturing treatment include a process temperature of 70 DEG C-75 DEG C, a volume percentage concentration of a texturing solution of 0.4%-0.7%, and a volume percentage concentration of a first additive of 0.2%-0.5%; and the process parameters of the second texturing treatment include a process temperature of 75 DEG C-80 DEG C, a volume percentage concentration of a texturing solution of 0.4%-0.7%, a volume percentage concentration of a second additive of 0.2%-0.5%, and the protective ability of the first additive is greater than that of the second additive.

8. The method of claim 6, wherein the step of forming the first and second electrodes is performed by screen printing. The method further comprises, before forming the first doped conductive layer, performing a third texturing process, the third texturing process forming third pyramid structures in the first recess, the third pyramid structures having a base size less than or equal to the base size of the first pyramid structures; the base size of the third pyramid structures refers to the length of a side or a diagonal of the base of the second pyramid structures.

9. The method of claim 5, wherein the step of forming the first and second electrodes is performed by screen printing. The method of forming the second doped conductive layer comprises: forming a second initial doped conductive layer, the second initial doped conductive layer covering the surface of the tunneling layer; removing the second initial doped conductive layer located in the first region, leaving the second initial doped conductive layer as the second doped conductive layer.

10. The method of claim 9, wherein the step of forming the first and second electrodes is performed by screen printing. The method of removing part of the second initial doped conductive layer comprises: performing a second laser treatment, the second laser treatment irradiating the surface of the second initial doped conductive layer located in the first region; performing a second etching treatment, the second etching treatment etching the second initial doped conductive layer located in the first region.

11. A solar cell formed by the method of any one of claims 1 to 10, wherein comprise: a substrate comprising opposite first and second surfaces, the first surface comprising first and second regions arranged alternately, the substrate further comprising a first recess; a first doped conductive layer located in the first recess; a first electrode in electrical contact with the first doped conductive layer; a protective layer located only in the first region.

12. The solar cell of claim 11, wherein, The substrate further comprises: first pyramid structures located on the first surface; second pyramid structures located on the second surface, and the base size of the first pyramid structures is less than the base size of the second pyramid structures; wherein the base size of the first pyramid structures refers to the length of a side or a diagonal of the base of the first pyramid structures, and the base size of the second pyramid structures refers to the length of a side or a diagonal of the base of the second pyramid structures.

13. The solar cell of claim 12, wherein, The substrate further comprises third pyramid structures located in the first recess, the base size of the third pyramid structures being less than or equal to the base size of the first pyramid structures; the base size of the third pyramid structures refers to the length of a side or a diagonal of the base of the second pyramid structures.

14. A stacked battery characterized by comprising: comprise: a bottom cell, a composite layer and a perovskite top cell stacked in sequence along a predetermined direction; wherein the bottom cell is a solar cell piece formed by the method for manufacturing a solar cell piece according to any one of claims 1 to 10, or a solar cell piece according to any one of claims 11 to 13.

15. A photovoltaic module, characterized by, comprise: a cell string comprising: a plurality of solar cell pieces formed by the method for manufacturing a solar cell piece according to any one of claims 1 to 10, or a plurality of solar cell pieces according to any one of claims 11 to 13, or a plurality of stacked cells according to claim 14; and a solder strip electrically connected to at least two solar cell pieces or stacked cells to connect adjacent solar cell pieces or stacked cells in series; An encapsulation film for covering a surface of the battery string; A cover plate for covering a surface of the encapsulation film away from the battery string.

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