Battery sheet, manufacturing method and manufacturing device thereof, and photovoltaic module

Abstract

The present disclosure relates to the field of photovoltaics, and provides a cell, a manufacturing method and manufacturing equipment thereof, and a photovoltaic module. The cell comprises a substrate having opposite first and second surfaces and a side wall between the first and second surfaces, the first surface having first and second regions arranged alternately; a first doped portion located at least on the first region and the side wall, the first doped portion on the side wall having a recess; a second doped portion located in the second region and at least part of the recess, the second doped portion having a different doping type from the first doped portion; a first electrode electrically connected to the first doped portion; and a second electrode electrically connected to the second doped portion, which can improve the reliability of the cell.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and in particular to a solar cell, its manufacturing method, manufacturing equipment, and photovoltaic module. Background Technology

[0002] As fossil fuels are gradually depleted, solar energy is becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy. Solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy.

[0003] Back-contact solar cells are crystalline silicon solar cells where both the emitter and base electrodes are located on the back of the cell. Because there are no metal grid electrodes obstructing the front of the cell, back-contact cells increase light absorption efficiency and significantly improve short-circuit current. Furthermore, the use of amorphous or microcrystalline silicon, or doped silicon, to passivate the cell surface enhances open-circuit voltage. These factors effectively increase the conversion efficiency of back-contact solar cells, making them a promising technology with excellent development prospects. Summary of the Invention

[0004] This disclosure provides a solar cell, a method for manufacturing the same, manufacturing equipment, and a photovoltaic module, which can at least improve the reliability of the solar cell.

[0005] This disclosure provides a solar cell, comprising: a substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; a first doped portion located at least in the first region and the sidewall, the first doped portion located in the sidewall having a pit; a second doped portion located in the second region and at least part of the pit, the doping type of the second doped portion being different from the doping type of the first doped portion; a first electrode electrically connected to the first doped portion; and a second electrode electrically connected to the second doped portion.

[0006] Optionally, the size of the pit is 0.5μm to 10μm, and / or the depth of the pit is 0.25μm to 5μm.

[0007] Optionally, the ratio of the area of ​​the pit on the sidewall to the area of ​​the first doped portion on the sidewall is 1:20 to 1:5.

[0008] Optionally, the pits located on the sidewall have a greater density of arrangement near the first surface than the pits near the second surface.

[0009] Optionally, the pit extends into the substrate, and the difference between the width of the pit on the substrate surface and the width of the pit on the surface of the first doped portion is 0 μm to 1 μm.

[0010] Optionally, the recess can be funnel-shaped, conical, or pyramidal.

[0011] Optionally, the first doped portion also covers the edge of the second surface adjacent to the sidewall.

[0012] Optionally, the first doped portion located on the second surface has a pit, and the second doped portion is also located within the pit on the second surface.

[0013] Optionally, the pit located on the sidewall is a first pit, and the pit located on the second surface is a second pit, wherein the arrangement density of the first pit is greater than that of the second pit.

[0014] Optionally, the pit located on the sidewall is a first pit, and the pit located on the second surface is a second pit, wherein the size of the first pit is larger than the size of the second pit.

[0015] Optionally, it further includes: a tunneling layer located between the first doped portion and the substrate; and an amorphous layer located between the second doped portion and the substrate, wherein the amorphous layer is also located within the pit.

[0016] Optionally, it further includes: a conductive layer located between the second doped portion and the second electrode, the conductive layer being spaced apart from the first doped portion.

[0017] This disclosure also provides a method for manufacturing a solar cell, comprising: obtaining a substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; forming a first doped portion, the first doped portion being located at least on the first region and the sidewall, and the first doped portion on the sidewall having a pit; forming a second doped portion, the second doped portion being located in the second region and at least part of the pit, the doping type of the second doped portion being different from the doping type of the first doped portion; forming a first electrode, the first electrode being electrically connected to the first doped portion; and forming a second electrode, the second electrode being electrically connected to the second doped portion.

[0018] Optionally, the method for forming the first doped portion includes: forming an initial first doped portion located on the first surface, the second surface, and the sidewall; forming a mask layer located at least on the first region and the sidewall; performing a texturing process, wherein the texturing process forms a textured structure on the second surface and partially etches the mask layer and the initial first doped portion located on the sidewall to form the pit; removing the initial first doped portion not covered by the mask layer, and the remaining initial first doped portion is used as the first doped portion.

[0019] Optionally, before performing the texturing process, the process further includes: performing laser treatment, wherein the laser treatment irradiates the mask layer, and the irradiation position of the laser treatment corresponds to the position of the pit.

[0020] Optionally, the mask layer is also located on the portion of the second surface adjacent to the sidewall, and the texturing process further forms the pits on the mask layer located on the second surface.

[0021] This disclosure also provides an apparatus for manufacturing a solar cell, for forming the aforementioned solar cell, or for a method of manufacturing the aforementioned solar cell, comprising: a support stage for supporting a substrate, the substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; a first process apparatus for forming a first doped portion and a second doped portion, the first doped portion being at least located on the first region and the sidewall, and the first doped portion located on the sidewall having a pit; the second doped portion being located in the second region and at least part of the pit, the doping type of the second doped portion being different from the doping type of the first doped portion; and a second process apparatus for forming a first electrode and a second electrode, the first electrode being electrically connected to the first doped portion; and the second electrode being electrically connected to the second doped portion.

[0022] This disclosure also provides a photovoltaic module, comprising: a battery string, the battery string comprising: a plurality of battery cells as described above, or battery cells formed by a method for manufacturing a plurality of battery cells as described above; or battery cells formed by an apparatus for manufacturing a plurality of battery cells as described above; a solder ribbon electrically connected to at least two of the battery cells to connect adjacent battery cells in series; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film away from the battery string.

[0023] The technical solution provided in this disclosure has at least the following advantages: the first doped portion extends to the sidewall of the substrate, and a pit is formed on the first doped portion located on the sidewall to accommodate the second doped portion, thereby forming a leakage channel on the sidewall of the substrate. On the one hand, when the cell is blocked, the leakage channel can improve the hot spot effect of the cell; on the other hand, compared with setting the leakage channel on the first surface, setting it on the sidewall can reduce the carrier recombination between the first doped portion and the second doped portion, thus avoiding affecting the photoelectric conversion efficiency of the cell. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a cross-sectional schematic diagram of a battery cell provided in an embodiment of the present disclosure; Figure 2 This is a partial cross-sectional structural schematic diagram provided in an embodiment of the present disclosure; Figure 3 This is a schematic cross-sectional view of another battery cell provided in an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the structure of another battery cell provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of the structure of yet another type of battery cell provided in an embodiment of this disclosure; Figure 6 A SEM image of a pit provided in one embodiment of this disclosure; Figure 7 This is a SEM image of the sidewall of a battery cell provided in an embodiment of the present disclosure; Figure 8 This is a schematic diagram of the structure corresponding to the formation of the initial first doped portion and the mask layer provided in an embodiment of the present disclosure; Figure 9 This is a schematic diagram of a structure corresponding to a texturing process provided in an embodiment of the present disclosure; Figure 10 This is a schematic diagram of the structure corresponding to the formation of an amorphous layer and a second doped portion according to an embodiment of the present disclosure; Figure 11This is a schematic diagram of the structure corresponding to the formation of a conductive layer according to an embodiment of the present disclosure; Figure 12 This is a schematic diagram of the structure corresponding to the formation of the first electrode and the second electrode according to an embodiment of the present disclosure; Figure 13 A schematic diagram of a battery cell manufacturing apparatus provided in an embodiment of this disclosure; Figure 14 This is a partial three-dimensional structural diagram of a photovoltaic module provided in an embodiment of the present disclosure; Figure 15 This is a partial cross-sectional structural diagram of a photovoltaic module provided in an embodiment of the present disclosure.

[0026] Explanation of reference numerals in the attached figures: 100, Substrate; 110, First surface; 120, Second surface; 130, Sidewall; 140, First region; 150, Second region; 101, First doped portion; 111, Recess; 102, Second doped portion; 103, First electrode; 104, Second electrode; 121, First recess; 131, Second recess; 105, Tunneling layer; 106, Amorphous layer; 107, Conductive layer; 108, Passivation layer; 109, Antireflection layer; 200, Mask layer; 141, Initial first doped portion; 10, Support stage; 11, First process apparatus; 12, Second process apparatus; 40, Solar cell; 43, Solder ribbon; 41, Encapsulating film; 42, Cover plate. Detailed Implementation

[0027] In photovoltaic (PV) modules, when a back-contact cell in a series circuit is shaded, the shaded cell stops generating electricity, while the adjacent cell, which is exposed to normal sunlight, applies a reverse bias. At this point, the shaded cell becomes a load, consuming the energy generated by the other cells, causing its temperature to rise significantly and creating a localized hot spot effect. This effect not only severely impairs the performance of the back-contact cell but also poses a significant threat to the safety of the PV module.

[0028] In this embodiment of the present disclosure: the first doped portion extends to the sidewall of the substrate, and a pit is formed on the first doped portion located on the sidewall to accommodate the second doped portion, thereby forming a leakage channel on the sidewall of the substrate. On the one hand, the leakage channel can improve the hot spot effect of the solar cell when the cell is blocked; on the other hand, compared with setting the leakage channel on the first surface, setting it on the sidewall can reduce the carrier recombination between the first doped portion and the second doped portion, thus avoiding affecting the photoelectric conversion efficiency of the solar cell.

[0029] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0032] In the description of embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0033] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0034] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0035] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is enlarged for clarity. Throughout the specification, the same reference numerals denote the same elements. It should be understood that when referring to an element (e.g., a layer, film, region, or substrate) as being "on" another element, it may be directly on that other element, or intermediate elements may be present. Conversely, when referring to an element as being "directly on" another element, it indicates that no intermediate elements are present.

[0036] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly" on the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0037] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description and claims of the various embodiments described, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0038] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0039] refer to Figure 1 and Figure 2 , Figure 1 This is a cross-sectional view of a battery cell provided in one embodiment of the present disclosure. Figure 2 This is a partial cross-sectional structural diagram of an embodiment of the present disclosure. It should be noted that the diagram only shows a part of the structure of the battery cell. In reality, the battery cell may have more first doped portions, second doped portions, first electrodes, and second electrodes.

[0040] In some embodiments, the battery cell may include: a substrate 100 having opposing first surfaces 110 and second surfaces 120, and a sidewall 130 located between the first surfaces 110 and the second surfaces 120, the first surface 110 having alternating first regions 140 and second regions 150.

[0041] The solar cell may further include a first doped portion 101, which is located at least on the first region 140 and the sidewall 130, and the first doped portion 101 located on the sidewall 130 has a pit 111.

[0042] The solar cell may further include a second doped portion 102, which is located in the second region 150 and at least part of the pit 111, and the doping type of the second doped portion 102 is different from the doping type of the first doped portion 101.

[0043] The solar cell may also include a first electrode 103, which is electrically connected to the first doped portion 101.

[0044] The solar cell may also include a second electrode 104, which is electrically connected to the second doped portion 102.

[0045] In this embodiment of the present disclosure: the first doped portion 101 extends to the sidewall 130 of the substrate 100, and a pit 111 is provided on the first doped portion 101 located on the sidewall 130 to accommodate the second doped portion 102, thereby forming a leakage channel on the sidewall 130 of the substrate 100. On the one hand, the leakage channel can improve the hot spot effect of the solar cell when the solar cell is blocked; on the other hand, compared with setting the leakage channel on the first surface 110, setting it on the sidewall 130 can reduce the carrier recombination between the first doped portion 101 and the second doped portion 102, and avoid affecting the photoelectric conversion efficiency of the solar cell.

[0046] In some embodiments, the material of the substrate 100 may be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. The elemental semiconductor material may be monocrystalline, polycrystalline, amorphous, or microcrystalline (a state simultaneously possessing both monocrystalline and amorphous states is called microcrystalline). For example, silicon may be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0047] In some embodiments, the substrate 100 may also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium arsenide, perovskite, cadmium telluride, copper indium selenide, etc.

[0048] The substrate 100 can also be a sapphire substrate, a silicon substrate on an insulator, or a germanium substrate on an insulator.

[0049] 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 dopant element, which can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate is doped with a P-type dopant element, which can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0050] When the battery cell is a single-sided cell, the second surface 120 can serve as a light-receiving surface to receive incident light, and the first surface 110 serves as a backlighting surface. When the battery cell is a double-sided cell, both the first and second surfaces can serve as light-receiving surfaces and can be used to receive incident light. It is understood that the backlighting surface referred to in the embodiments of this disclosure can also receive incident light, but the degree of reception of incident light is weaker than that of the light-receiving surface, and therefore it is defined as a backlighting surface.

[0051] The first zone 140 and the second zone 150 are different areas artificially divided on the first surface 110 for ease of explanation; in the actual solar cell, there are no clearly divided areas.

[0052] The first doped portion 101 may be an additional film layer formed on the surface of the substrate 100, such as an additional polysilicon layer, and the polysilicon layer is doped to form the first doped portion 101; the first doped portion 101 may also be formed by doping the substrate 100 to form the first doped portion 101 within the substrate 100.

[0053] In some embodiments, the size of the pit 111 is 0.5μm to 10μm, for example, 0.5μm to 3μm, 3μm to 7μm or 7μm to 10μm, or it can be 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc. For the pit 111, the larger the size of the pit 111, the larger the contact area between the second doped part 102 and the first doped part 101 within the pit 111, and the better the ability to improve the hot spot phenomenon of the solar cell. At the same time, if the size of the pit 111 is too large, it will lead to an excessively large contact area between the second doped part 102 and the first doped part 101, resulting in recombination. In addition, forming the pit 111 requires etching the first doped part 101 located on the sidewall 130. If the pit 111 is too large, the probability of damaging the substrate 100 during the etching process will be greater. Therefore, setting the size of the pit 111 to 0.5μm~10μm can improve the ability to improve the hot spot phenomenon while avoiding excessive damage to the substrate 100.

[0054] It should be noted that the size of the recess 111 here can refer to the length, width, or diagonal length of the orthographic projection of the recess 111 in the thickness direction of the base 100. For example, if the orthographic projection of the recess 111 in the thickness direction of the base 100 is a regular quadrilateral, the size of the recess 111 is the side length or diagonal length of the regular quadrilateral.

[0055] In practical applications, the projection pattern of the recess 111 onto the thickness direction of the base 100 can also be an irregular polygon. In this case, the side length and diagonal length of the projection pattern of the recess 111 onto the thickness direction of the base 100 are not absolute, but are artificially defined to characterize the size of the recess 111. For example, the projection pattern of the recess 111 onto the thickness direction of the base 100 is an irregular quadrilateral. In this case, the length of the recess 111 can be defined as the side length of the longest side of the irregular quadrilateral, the width of the recess 111 can be defined as the side length of the shortest side of the irregular quadrilateral, and the diagonal length of the recess 111 can be defined as the length of the longest diagonal of the irregular quadrilateral. It is understood that the above is only an exemplary illustration, and in practice, it can be flexibly defined according to actual needs. In addition, the orthographic projection of the pit 111 onto the thickness direction of the base 100 can be an irregular quadrilateral, or other irregular polygons, circles, or irregular shapes that are approximately circular. In this case, the size of the pit 111 is determined by selecting multiple regions with different specific areas at the bottom of the pit 111. These regions can be flexibly defined according to actual needs, and then the average value of the side length, diagonal, or diameter of the multiple regions with different specific areas is calculated.

[0056] In some embodiments, the dimensions of the pit 111 can be measured using testing equipment such as optical microscopes, laser confocal microscopes, scanning electron microscopes, transmission electron microscopes, X-ray diffractometers, and atomic force microscopes.

[0057] In some embodiments, the depth of the pit 111 is 0.25 μm to 5 μm, for example, 0.25 μm to 1 μm, 1 μm to 3 μm, or 3 μm to 5 μm. It can also be 0.25 μm, 0.5 μm, 1 μm, 2 μm, or 3 μm, etc. Similarly, the deeper the pit 111, the larger the volume that can accommodate the second doped portion 102, and the stronger the ability to improve the hot spot effect of the solar cell. At the same time, if the size of the pit 111 is too deep, the damage to the substrate 100 will be greater. Setting the depth of the pit 111 to 0.25 μm to 5 μm takes into account the ability to improve the hot spot effect while reducing the damage to the substrate 100.

[0058] In some embodiments, the ratio of the area of ​​the pit 111 on the sidewall 130 to the area of ​​the first doped portion 101 on the sidewall 130 is 1:20 to 1:5, for example, it can be 1:20 to 1:10 or 1:10 to 1:5, or it can be 1:20, 1:15, 1:10 or 1:5, etc. In other words, the proportion of the pit 111 on the first doped portion 101 on the sidewall 130 is 5% to 20%. The higher the proportion of the pit 111, the better the effect of improving the hot spot effect of the solar cell. At the same time, if the proportion of the pit 111 is too high, the contact area between the first doped portion 101 and the second doped portion 102 will be further increased, which may lead to an increase in carrier recombination. Therefore, setting the ratio of the area of ​​the pit 111 on the sidewall 130 to the area of ​​the first doped portion 101 on the sidewall 130 to 1:20 to 1:5 improves the hot spot effect while avoiding affecting the photoelectric conversion efficiency of the solar cell.

[0059] It should be noted that the area of ​​the pits 111 on the sidewall 130 here refers to the sum of the areas of all the pits 111 on the sidewall 130 projected onto the sidewall 130 of the substrate 100, and the area of ​​the first doped portion 101 refers to the area projected onto the sidewall 130.

[0060] The area of ​​pit 111 can be obtained using testing equipment such as 3D confocal microscope, 3D optical profilometer, scanning electron microscope, transmission electron microscope, X-ray diffractometer, and atomic force microscope.

[0061] In some embodiments, the pits 111 located on the sidewall 130 have a higher density near the first surface 110 than near the second surface 120. It is understood that both the first doped portion 101 and the second doped portion 102 are located on the first surface 110. Therefore, for the battery cell, the first surface 110 is a high current density region. A higher density of pits 111 near the first surface 110 means a higher density of leakage channels in the region near the first surface 110, which facilitates the diversion of excess current from the battery and more effectively suppresses localized overheating.

[0062] It is also understandable that the photogenerated carriers in the solar cell are mainly generated near the second surface 120 and need to migrate to the first surface 110 to be collected by the first electrode 103 and the second electrode 104. The arrangement density of the pits 111 near the second surface 120 is lower, which means that the arrangement density of the leakage channels near the second surface 120 is lower. This avoids the photogenerated carriers from recombinating at the leakage channels before reaching the first surface 110, thus avoiding serious current loss.

[0063] It should be noted that the density here refers to the number of pits per unit area.

[0064] In some embodiments, the pit 111 extends into the substrate 100, and the width of the pit 111 on the substrate 100 is smaller than the width of the pit 111 flush with the surface of the first doped portion 101. That is, during the formation of the pit 111, the width of the first doped portion 101 is etched, while the width of the substrate 100 is etched, resulting in a morphology that is wide on the surface and narrow in the middle. Setting the width on the substrate 100 to be small can reduce damage to the substrate 100, thereby improving the reliability of the solar cell. Setting the width flush with the surface of the first doped portion 101 to be large can increase the contact area between the first doped portion 101 and the second doped portion 102, thereby improving the effect of improving hot spot phenomenon.

[0065] Correspondingly, the morphology after the formation of the second doped portion 102 is such that the width of the portion of the second doped portion 102 flush with the first doped portion 101 is greater than the width of the portion of the second doped portion 102 flush with the substrate 100.

[0066] It is understandable that the pit 111 will be filled with the second doped part 102, and the size of the pit 111 can actually correspond to the size of the second doped part 102 located in the pit 111.

[0067] refer to Figure 6 and Figure 7 ,in, Figure 6 This is a SEM image of a pit provided in one embodiment of the present disclosure. Figure 7 This is a SEM image of the sidewall of a battery cell provided in an embodiment of the present disclosure. It should be noted that an SEM image refers to a scanning electron microscope image.

[0068] In some embodiments, the pit 111 extends into the substrate 100, and the difference between the width of the pit 111 on the surface of the substrate 100 and the width of the pit 101 on the surface of the first doped portion 101 is 0 μm to 1 μm, for example, 0 μm to 0.5 μm or 0.5 μm to 1 μm, or it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.5 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, etc.

[0069] It should be noted that the width on the surface of the substrate 100 here refers to the width of the portion of the pit 111 flush with the surface of the substrate 100, and the width on the surface of the first doped portion 101 here refers to the width of the portion of the pit 111 flush with the first doped portion 101. On the one hand, controlling the difference between the width of the portion of the pit 111 flush with the surface of the substrate 100 and the width of the portion of the pit 111 flush with the first doped portion 101 can reduce the difficulty of the process. On the other hand, it avoids that the width difference is too large, which may cause voids or breaks in the second doped portion 102 during the formation of the second doped portion 102 located in the pit 111, thereby avoiding affecting the reliability of the solar cell.

[0070] In some embodiments, the pit 111 is funnel-shaped, conical, or pyramidal. Regardless of whether it is funnel-shaped, conical, or pyramidal, it has a small bottom and a large top, and the change is continuous. In this way, when the second doped portion 102 is formed in the pit 111, the reliability of the formed second doped portion 102 can be improved. At the same time, the small bottom can reduce damage within the substrate 100, and the large top can increase the current conduction rate when leakage occurs.

[0071] It should be noted that the term "pit 111" here refers to a funnel-shaped, conical, or pyramidal shape. It can mean that the pit 111 is similar to a funnel, a cone, or a pyramid, and its shape is roughly funnel-shaped, conical, or pyramidal.

[0072] Correspondingly, the shape of the second doped portion 102 located on the sidewall 130 is funnel-shaped, conical, or pyramidal.

[0073] In some embodiments, the first doped portion 101 also covers the edge of the second surface 120 adjacent to the sidewall 130. That is, during the formation of the first doped portion 101, the first doped portion 101 is not only deposited around the sidewall 130 of the substrate 100, but also around the second surface 120 of the substrate 100. By also providing the first doped portion 101 on the second surface 120 of the substrate 100, it is convenient to set a leakage structure on the second surface 120, thereby improving the effect of the solar cell on hot spot effect.

[0074] refer to Figure 2 and Figure 3 ,in, Figure 3 This is a schematic cross-sectional view of another battery cell provided in an embodiment of the present disclosure.

[0075] In some embodiments, the first doped portion 101 located on the second surface 120 has a pit 111, and the second doped portion 102 is also located within the pit 111 of the second surface 120. By providing the pit 111 on the second surface 120, it is convenient to form the second doped portion 102 within the pit 111, thereby constructing a leakage channel on the second surface 120. By constructing a leakage channel on the second surface 120, the solar cell can simultaneously utilize the sidewall 130 and the leakage channel of the second surface 120 to share the hot spot current.

[0076] In some embodiments, the pit 111 located on the sidewall 130 is the first pit 121, and the pit 111 located on the second surface 120 is the second pit 131. The arrangement density of the first pit 121 is greater than that of the second pit 131. For the second pit 131, the second surface 120 is the core region for the generation of photogenerated carriers. Although setting the pit 111 on the second surface 120 can improve the leakage response rate, it is also easy for carrier recombination to occur on the second surface 120. Therefore, the arrangement density of the first pit 121 is larger, and the arrangement density of the second pit 131 is smaller. Thus, the second doped portion 102 located in the second pit 131 is used as an auxiliary leakage portion, thereby avoiding affecting the photoelectric conversion efficiency of the solar cell while improving the leakage response rate.

[0077] It should be noted that the arrangement density here can refer to the number of pits 111 per unit area, or it can refer to the proportion of the area of ​​the pits 111 projected onto the surface of the substrate 100.

[0078] Correspondingly, the arrangement density of the second doped portion 102 located on the sidewall 130 is greater than the arrangement density of the second doped portion 102 located on the second surface 120.

[0079] In some embodiments, the recess 111 on the sidewall 130 is a first recess 121, and the recess 111 on the second surface 120 is a second recess 131, wherein the size of the first recess 121 is larger than the size of the second recess 131. Similarly, by setting the size of the first recess 121 to be large and the size of the second recess 131 to be small, the second doped portion 102 located in the second recess 131 is used as an auxiliary leakage current portion, thereby avoiding affecting the photoelectric conversion efficiency of the solar cell while improving the leakage current response rate.

[0080] Correspondingly, the size of the second doped portion 102 located on the sidewall 130 is larger than the size of the second doped portion 102 located on the second surface 120.

[0081] In some embodiments, the first region 140 can be disposed at the edge adjacent to the first surface 110 and the sidewall 130. That is, the first doped portion 101 near the sidewall 130 is retained. In this way, the first doped portion 101 located on the sidewall 130 can be connected to the first doped portion 101 located on the first surface 110, so that the leakage current in the edge region of the first surface 110 can be directly discharged through the sidewall 130, which meets the carrier transport requirements, without adding additional resistance and recombination loss, thus ensuring the interface stability and overall electrical performance of the cell.

[0082] In some embodiments, the material of the first doped portion 101 may include at least one of amorphous silicon, polycrystalline silicon, or silicon carbide. The material of the second doped portion 102 may include at least one of amorphous silicon, microcrystalline silicon, or nanocrystalline silicon.

[0083] In some embodiments, the solar cell may further include a tunneling layer 105, which is located between the first doped portion 101 and the substrate 100. The tunneling layer 105 provides a chemical passivation effect on the surface of the substrate 100. The material of the tunneling layer 105 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, magnesium fluoride, or amorphous silicon.

[0084] The second doped portion 102 may be an additional film layer formed on the surface of the substrate 100, such as an additional amorphous silicon layer, and the amorphous silicon layer is doped to form the second doped portion 102; the second doped portion 102 may also be formed by doping the substrate 100 to form the second doped portion 102 within the substrate 100.

[0085] The difference in doping type between the second doping part 102 and the first doping part 101 can mean that one of the second doping part 102 and the first doping part 101 is N-type doped and the other is P-type doped. For example, the first doping part 101 can be N-type doped and the second doping part 102 can be P-type doped.

[0086] In some embodiments, the solar cell may further include an amorphous layer 106, which is located between the second doped portion 102 and the substrate 100, and is also located within a pit 111. The amorphous layer 106 can saturate the dangling bonds of silicon, reducing the surface state density, thereby achieving chemical passivation.

[0087] The amorphous layer 106 comprises an amorphous silicon dielectric material. The amorphous layer 106 may include an amorphous silicon material into which no doping elements have been actively introduced. For example, the amorphous silicon inevitably contains some doping elements (e.g., doping elements introduced during the fabrication of the second doping portion 102 diffuse into the amorphous layer 106, resulting in the amorphous layer 106 containing the same doping elements), but this does not significantly alter the intrinsic conductivity of the amorphous silicon. In some embodiments, the amorphous silicon dielectric material may include one or more of amorphous silicon oxide, intrinsic amorphous silicon, amorphous silicon carbide, etc.

[0088] In some embodiments, the second doped portion 102 may be located within a portion of the pit 111, and in other embodiments, the second doped portion 102 may be provided in each pit 111.

[0089] refer to Figure 1 , Figure 3 and Figure 4 ,in, Figure 4 This is a schematic diagram of the structure of another type of battery cell provided in an embodiment of the present disclosure.

[0090] In some embodiments, the second doped portion 102 may be located only within the recess 111. In other embodiments, the second doped portion 102 covers the surface of the first doped portion 101 located on the sidewall 130. Compared to covering the surface of the first doped portion 101 located on the sidewall 130, the second doped portion 102 located only within the recess 111 can reduce the contact area with the first doped portion 101, avoiding excessive recombination between the first doped portion 101 and the second doped portion 102, which would affect the photoelectric conversion efficiency of the solar cell.

[0091] In some embodiments, the solar cell may further include a conductive layer 107, which is located between the second doped portion 102 and the second electrode 104, and is spaced apart from the first doped portion 101. The conductive layer 107 can improve the reliability of transmission between the second doped portion 102 and the second electrode 104.

[0092] The material of the conductive layer 107 may include at least one of indium tin oxide, tungsten-doped indium oxide, titanium-doped indium oxide, tin oxide, and aluminum-doped zinc oxide.

[0093] In some embodiments, the method further includes: a passivation layer 108 and an antireflection layer 109, wherein the passivation layer 108 is located at least on the second surface, and the antireflection layer 109 is located on the surface of the passivation layer 108 away from the substrate 100. The material of the passivation layer 108 includes at least one of hydrogen-containing silicon nitride, hydrogen-containing silicon oxynitride, hydrogen-containing silicon carbon oxynitride, and hydrogen-containing silicon carbon oxynitride. The material of the antireflection layer 109 includes at least one of aluminum oxide, silicon nitride, and silicon oxynitride.

[0094] refer to Figure 5 , Figure 5This disclosure provides a schematic diagram of the structure of yet another type of battery cell according to an embodiment.

[0095] In some embodiments, the first doped portion 101 located on the first region 140 adjacent to the sidewall 130 may not be connected to the first electrode 103. In other words, the first electrode 103 is not provided on the first region 140 adjacent to the sidewall 130.

[0096] In this embodiment of the present disclosure: the first doped portion 101 extends to the sidewall 130 of the substrate 100, and a pit 111 is provided on the first doped portion 101 located on the sidewall 130 to accommodate the second doped portion 102, thereby forming a leakage channel on the sidewall 130 of the substrate 100. On the one hand, the leakage channel can improve the hot spot effect of the solar cell when the solar cell is blocked; on the other hand, compared with setting the leakage channel on the first surface 110, setting it on the sidewall 130 can reduce the carrier recombination between the first doped portion 101 and the second doped portion 102, and avoid affecting the photoelectric conversion efficiency of the solar cell.

[0097] Another embodiment of this disclosure also provides a method for manufacturing a battery cell. This method can be used to form the aforementioned battery cell. The following will describe a method for manufacturing a battery cell according to another embodiment of this disclosure with reference to the accompanying drawings. It should be noted that the same or corresponding parts as those in the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0098] In some embodiments, the method of manufacturing a battery cell may include: obtaining a substrate 100 having opposing first surfaces 110 and second surfaces 120, and a sidewall 130 located between the first surfaces 110 and the second surfaces 120, wherein the first surface 110 has alternating first regions 140 and second regions 150.

[0099] The method of manufacturing the battery cell may further include: forming a first doped portion 101, the first doped portion 101 being located at least on the first region 140 and the sidewall 130, and the first doped portion 101 located on the sidewall 130 having a pit 111.

[0100] The method of manufacturing the solar cell may further include: forming a second doped portion 102, the second doped portion 102 being located in the second region 150 and at least part of the pit 111, the doping type of the second doped portion 102 being different from the doping type of the first doped portion 101.

[0101] The method of manufacturing the battery cell may also include: forming a first electrode 103, wherein the first electrode 103 is electrically connected to a first doped portion 101.

[0102] The method of manufacturing the solar cell may also include: forming a second electrode 104, wherein the second electrode 104 is electrically connected to the second doped portion 102.

[0103] refer to Figure 8 and Figure 9 In some embodiments, the method of forming the first doped portion 101 includes: forming an initial first doped portion 141, the initial first doped portion 141 being located on a first surface 110, a second surface 120, and a sidewall 130; forming a mask layer 200, the mask layer 200 being located at least on the first region 140 and the sidewall 130; performing a texturing process, the texturing process forming a textured structure on the second surface 120, and partially etching the mask layer 200 and the initial first doped portion 141 located on the sidewall 130 to form a pit 111; removing the initial first doped portion 141 that is not covered by the mask layer 200, and the remaining initial first doped portion 141 serving as the first doped portion 101.

[0104] The first doped portion 101, which is coated around the sidewall 130, is used as part of the leakage structure. At the same time, a pit 111 is formed on the initial first doped portion 141 on the sidewall 130 using a texturing process, thereby adapting to the existing production process without adding any additional process steps. Furthermore, by setting the pit 111 on the sidewall 130 and then forming the leakage structure on the sidewall 130, the process difficulty of forming the leakage structure can be reduced compared to setting the leakage structure on the first surface 110, and there is no need to adjust the screen for forming the first doped portion 101 and the second doped portion 102.

[0105] refer to Figure 8 This forms the initial first doped portion and the mask layer.

[0106] Before forming the initial first doped portion 141, a tunneling layer 105 may also be formed, which is located between the initial first doped portion 141 and the substrate 100.

[0107] In some embodiments, the substrate 100 may also be cleaned and polished before the tunneling layer 105 is formed.

[0108] The tunneling layer 105 can be formed by deposition, or the initial first doped part 141 can be formed by deposition.

[0109] In some embodiments, the method of forming the mask layer 200 may include: forming the mask layer 200 on the surface of the initial first doped portion 141 by deposition, wherein the material of the mask layer 200 may be silicon oxide or silicon nitride.

[0110] In other embodiments, the initial first doped portion 141 can be doped by doping to form a glass layer during the doping process. Then, a portion of the glass layer is irradiated with a laser to modify the glass layer, and a mask layer 200 is formed by removing the modified glass layer.

[0111] refer to Figure 9 The down-making process is then carried out.

[0112] In some embodiments, prior to the texturing process, the process further includes: laser treatment, in which the laser treatment irradiates the mask layer 200, and the irradiation position corresponds to the position of the pit 111. By irradiating the mask layer 200 with laser treatment, the mask layer 200 is modified, becoming sparser and easier to etch and remove, thus providing a process basis for forming the pit 111 in the texturing process.

[0113] In some embodiments, the mask layer 200 is formed by laser processing. During the formation of the mask layer 200, the mask layer 200 corresponding to the position of the pit 111 can be simultaneously irradiated by laser processing, thereby reducing the manufacturing process of the battery cell and reducing the process cost.

[0114] The texturing process is used to form a textural structure on the second surface 120, thereby improving the light absorption capacity of the second surface 120.

[0115] In some embodiments, the mask layer 200 is also located on the portion of the second surface 120 adjacent to the sidewall 130, and the texturing process further forms a pit 111 on the mask layer 200 located on the second surface 120. In other words, the first doped portion 101 located on the second surface 120 is retained, and a pit 111 is formed in the first doped portion 101 located on the second surface 120, thereby forming a leakage structure on the second surface 120 when the second doped portion 102 is subsequently formed.

[0116] In some embodiments, a velvety structure may also be formed within the second region 150.

[0117] refer to Figure 10 This forms an amorphous layer and a second doped portion.

[0118] An amorphous layer 106 can be formed by deposition, and the amorphous layer 106 is located at least in the second region 150.

[0119] The amorphous layer 106 can be formed by low-temperature deposition, for example, at a temperature below 250°C.

[0120] The second doped portion 102 can be formed by deposition.

[0121] Before forming the amorphous layer 106, a passivation layer 108 and an anti-reflection layer 109 can also be formed on the second surface 120.

[0122] refer to Figure 11 This forms a conductive layer.

[0123] The conductive layer 107 is located between the second doped portion 102 and the second electrode 104, and the conductive layer 107 is spaced apart from the first doped portion 101.

[0124] The conductive layer 107 can be formed by deposition, and then the conductive layer 107 can be separated from the first doped portion 101 by etching.

[0125] refer to Figure 12 This forms the first electrode and the second electrode.

[0126] The first electrode 103 and the second electrode 104 can be formed by printing.

[0127] Another embodiment of this disclosure also provides a battery cell manufacturing apparatus, which can be used to form the above-mentioned battery cell or to complete the above-mentioned battery cell manufacturing method. The battery cell manufacturing apparatus provided in another embodiment of this disclosure will be described below with reference to the accompanying drawings. The same or corresponding parts as those in the above embodiments can be referred to the above embodiments, and will not be repeated below.

[0128] refer to Figure 13 , Figure 13 This is a schematic diagram of a battery cell manufacturing apparatus provided in one embodiment of the present disclosure.

[0129] In some embodiments, the equipment for manufacturing solar cells may include: a support stage 10 for supporting a substrate, the substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions.

[0130] The equipment for manufacturing solar cells may further include: a first process apparatus 11, which is used to form a first doped portion and a second doped portion. The first doped portion is located at least in a first region and on a sidewall, and the first doped portion located on the sidewall has a pit. The second doped portion is located in a second region and at least part of the pit, and the doping type of the second doped portion is different from that of the first doped portion.

[0131] The equipment for manufacturing solar cells may further include: a second process apparatus 12, which is used to form a first electrode and a second electrode, wherein the first electrode is electrically connected to a first doped portion and the second electrode is electrically connected to a second doped portion.

[0132] The first process apparatus 11 can be a combination of a deposition apparatus and a doping apparatus, and the second process apparatus 12 can be a printing apparatus.

[0133] Another embodiment of this disclosure provides a photovoltaic module, which may include the solar cells as described in some or all of the above embodiments, or solar cells formed by the manufacturing method of the solar cells in some or all of the above embodiments. The photovoltaic module provided in another embodiment of this disclosure will be described below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0134] Figure 14 This is a partial three-dimensional structural diagram of a photovoltaic module provided in an embodiment of the present disclosure. Figure 15 for Figure 14 A schematic diagram of a cross-sectional structure along the cross-sectional direction AA1. It should be noted that... Figure 15 The image only shows the shape of the battery string.

[0135] refer to Figure 14 and Figure 15 The photovoltaic module includes: a battery string, which includes: a plurality of battery cells 40 as in any of the above embodiments, or battery cells 40 formed by the battery cell manufacturing method described in any of the above embodiments, or battery cells 40 formed by the battery cell manufacturing equipment described above; and a solder ribbon 43, which is electrically connected to at least two battery cells 40 to connect adjacent battery cells 40 in series.

[0136] The photovoltaic module also includes an encapsulating film 41, which is used to cover the surface of the cell string.

[0137] The photovoltaic module also includes a cover plate 42, which is used to cover the surface of the encapsulating film 41 away from the cell string.

[0138] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the solar cell, and the second encapsulating layer covers the other of the front or back sides of the solar cell. Specifically, at least one of the first or second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first or second encapsulating layer can also be an EP film, an EPE film, or a PVP film. Here, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film + POE film + EVA film; and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0139] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0140] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0141] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A battery cell, characterized in that, include: A substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; A first doped portion, the first doped portion being located at least in the first region and on the sidewall, and the first doped portion located on the sidewall having a pit; The second doped portion is located in the second region and at least part of the pit, and the doping type of the second doped portion is different from that of the first doped portion; The first electrode is electrically connected to the first doped portion; The second electrode is electrically connected to the second doped portion.

2. The battery cell according to claim 1, characterized in that, The size of the pit is 0.5μm to 10μm, and / or the depth of the pit is 0.25μm to 5μm.

3. The battery cell according to claim 1 or 2, characterized in that, The ratio of the area of ​​the pit on the sidewall to the area of ​​the first doped portion on the sidewall is 1:20 to 1:

5.

4. The battery cell according to claim 1, characterized in that, The pits located on the sidewall have a greater density of arrangement near the first surface than the pits near the second surface.

5. The battery cell according to claim 1, characterized in that, The pit extends into the substrate, and the difference between the width of the pit on the substrate surface and the width of the pit on the surface of the first doped portion is 0 μm to 1 μm.

6. The battery cell according to claim 1, characterized in that, The pit is funnel-shaped, conical, or pyramidal.

7. The battery cell according to claim 1, characterized in that, The first doped portion also covers the edge of the second surface adjacent to the sidewall.

8. The battery cell according to claim 7, characterized in that, The first doped portion located on the second surface has a pit, and the second doped portion is also located within the pit on the second surface.

9. The battery cell according to claim 8, characterized in that, The pit located on the sidewall is the first pit, and the pit located on the second surface is the second pit. The density of the first pit is greater than that of the second pit.

10. The battery cell according to claim 8, characterized in that, The pit located on the sidewall is the first pit, and the pit located on the second surface is the second pit. The size of the first pit is larger than the size of the second pit.

11. The battery cell according to claim 1, characterized in that, Also includes: A tunneling layer, wherein the tunneling layer is located between the first doped portion and the substrate; An amorphous layer is located between the second doped portion and the substrate, and the amorphous layer is also located within the pit.

12. The battery cell according to claim 11, characterized in that, Also includes: A conductive layer is located between the second doped portion and the second electrode, and the conductive layer is spaced apart from the first doped portion.

13. A method for manufacturing a battery cell, characterized in that, include: Obtain a substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; A first doped portion is formed, the first doped portion being located at least in the first region and on the sidewall, and the first doped portion located on the sidewall having a pit; A second doped portion is formed, the second doped portion being located in the second region and at least part of the pit, the doping type of the second doped portion being different from the doping type of the first doped portion; A first electrode is formed, and the first electrode is electrically connected to the first doped portion; A second electrode is formed, and the second electrode is electrically connected to the second doped portion.

14. The method for manufacturing a battery cell according to claim 13, characterized in that, The method of forming the first doped portion includes: forming an initial first doped portion, the initial first doped portion being located on the first surface, the second surface, and the sidewall; A mask layer is formed, the mask layer being located at least in the first region and on the sidewall; A texturing process is performed, wherein a texturing structure is formed on the second surface, and the mask layer and the initial first doped portion located on the sidewall are partially etched to form the pits; Remove the initial first doped portion that is not covered by the mask layer, and the remaining initial first doped portion is used as the first doped portion.

15. The method for manufacturing a battery cell according to claim 14, characterized in that, The process before the flocking process also includes: Laser processing is performed, wherein the laser processing irradiates the mask layer, and the irradiation position of the laser processing corresponds to the position of the pit.

16. The method for manufacturing a battery cell according to claim 14, characterized in that, The mask layer is also located on the portion of the second surface adjacent to the sidewall, and the texturing process also forms the pits on the mask layer located on the second surface.

17. An apparatus for manufacturing a solar cell, used to form a solar cell according to any one of claims 1 to 12, or for performing a method for manufacturing a solar cell according to any one of claims 13 to 16, characterized in that, include: A support platform for supporting a substrate, the substrate having opposing first and second surfaces, and a sidewall located between the first and second surfaces, the first surface having alternating first and second regions; A first process apparatus is used to form a first doped portion and a second doped portion. The first doped portion is located at least in the first region and on the sidewall, and the first doped portion located on the sidewall has a pit. The second doped portion is located in the second region and at least part of the pit, and the doping type of the second doped portion is different from that of the first doped portion. A second process apparatus is used to form a first electrode and a second electrode, wherein the first electrode is electrically connected to the first doped portion and the second electrode is electrically connected to the second doped portion.

18. A photovoltaic module, characterized in that, include: A battery string, comprising: a plurality of battery cells as described in any one of claims 1 to 12, or a plurality of battery cells formed by a method of manufacturing a plurality of battery cells as described in any one of claims 13 to 16; or a plurality of battery cells formed by an apparatus for manufacturing a plurality of battery cells as described in claim 17; and a solder ribbon electrically connected to at least two of the battery cells to connect adjacent battery cells in series. An encapsulating film, the encapsulating film being used to cover the surface of the battery string; A cover plate for covering the surface of the encapsulating film away from the battery string.

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