A solar cell and a photovoltaic module

Abstract

The application discloses a solar cell and a photovoltaic module. The solar cell comprises a cell body, the cell body has a light-receiving surface and a back surface arranged oppositely, the light-receiving surface comprises a middle area and an edge area arranged around the middle area, and a color difference area is formed in the edge area; the back surface is provided with an electrode collection area, the electrode collection area comprises P-type collection areas and N-type collection areas of two opposite conductive types which are alternately arranged at intervals along a first direction; and a colored layer is arranged in the edge area and at least partially covers the color difference area, and a normal projection of the colored layer on the back surface does not overlap the electrode collection area. In this way, by arranging the colored layer in the edge area around the cell body, the color difference of the light-receiving surface of the cell body can be eliminated, and the influence on the carrier collection of the back surface of the cell body can be avoided, so that the appearance of the product is improved without loss of the cell efficiency.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic technology, specifically relating to a solar cell and a photovoltaic module. Background Technology

[0002] In the manufacturing process of solar cells, it is usually necessary to deposit a dielectric layer or a doped semiconductor layer on the back of the cell. During the deposition process, it is inevitable that a coating will be formed around the edge of the cell, resulting in a color difference between the edge and the center of the cell, i.e., a color difference area exists at the edge of the cell.

[0003] In related technologies, wet etching is typically used to remove the coating on the front side of the solar cell in order to eliminate color difference areas. However, wet etching can easily damage the edges of the solar cell, reducing its conversion efficiency. Summary of the Invention

[0004] This application aims to provide a solar cell and photovoltaic module that can solve the problem that removing the coating on the front side of the cell in related technologies can easily cause damage to the edge of the cell, thus reducing the conversion efficiency of the cell.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application disclose a solar cell, comprising: The battery body has a light-receiving surface and a backlighting surface arranged opposite to each other. The light-receiving surface includes a central region and an edge region arranged around the central region. A color difference region is formed in the edge region. The backlighting surface is provided with an electrode collection area, which includes two types of P-type collection areas and N-type collection areas of opposite conductivity arranged alternately along a first direction. A coloring layer is disposed in the edge region and at least partially covers the color difference region, and the orthographic projection of the coloring layer on the backlight surface does not overlap with the electrode collection region.

[0006] Secondly, embodiments of this application propose a photovoltaic module, which includes multiple battery strings, each battery string including multiple solar cells and multiple interconnecting elements, the interconnecting elements being used to connect the multiple solar cells in series; wherein, the solar cells are the solar cells described in the first aspect.

[0007] In the embodiments of this application, a coloring layer is provided around the perimeter of the battery body, and the coloring layer at least partially covers the color difference area present in the edge area, thereby reducing the color difference on the light-receiving surface of the battery body. Simultaneously, the coloring layer also serves to passivate the edges of the battery body and provide leakage protection. For solar cells, the light-receiving surface is the primary light absorption pathway. The coverage of the coloring layer on the front area will cause light blocking, thus affecting the light absorption of the electrode collection area on the back surface. For back-contact batteries, the electrode collection areas are all located on the back surface. When the orthographic projection of the coloring layer on the back surface partially overlaps with the electrode collection area on the back surface, it will cause a difference between illuminated and unilluminated areas in the same polarity electrode collection area. The illuminated area generates a high carrier concentration, while the unilluminated area generates a low carrier concentration. This carrier concentration gradient generates a potential difference, driving carriers in the illuminated area to migrate laterally to the unilluminated area, resulting in recombination. Therefore, the projection of the coloring layer onto the backlight surface does not overlap with the electrode collection area on the backlight surface, so as to avoid the coloring layer blocking the light of the electrode collection area, thereby reducing the carrier recombination caused by uneven light exposure in the electrode collection area. In this way, by setting the coloring layer on the four edges of the battery body, the color difference of the light-receiving surface of the battery body can be eliminated, while avoiding the influence on the carrier collection on the backlight surface of the battery body, thereby improving the appearance of the product without sacrificing battery efficiency.

[0008] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein: Figure 1 This is a schematic diagram of the back surface structure of a solar cell according to an embodiment of this application; Figure 2 This is a schematic diagram of the light-receiving surface structure of a solar cell according to an embodiment of this application; Figure 3 This is a side cross-sectional view of a corresponding edge portion of a solar cell according to an embodiment of this application; Figure 4 This is a side sectional view of the corresponding edge portion of another solar cell according to an embodiment of this application; Figure 5 This is a side sectional view of the corresponding edge portion of a solar cell according to an embodiment of this application; Figure 6 This is a SEM image of the corresponding edge portion of the solar cell according to an embodiment of this application; Figure 7 This is a schematic diagram of the film structure of the solar cell corresponding to the N-region and P-region according to an embodiment of this application; Figure 8 This is a SEM image of the coloring layer according to an embodiment of this application; Figure 9 EDS of the coloring layer according to the embodiments of this application Figure 1 ; Figure 10 EDS of the coloring layer according to the embodiments of this application Figure 2 ; Figure 11 This is a schematic diagram showing the discontinuous arrangement of the color layer in the color difference area according to an embodiment of this application.

[0010] Figure label: 10: Battery body; 101: Light-receiving surface; 101a: Middle region; 101b: Edge region; 101c: Color difference region; 102: Backlight surface; 102a: Electrode collection region; 1021: N-type collection region; 1022: P-type collection region; 1023: Spacing region; 102b: Non-electrode collection region; 103: Side surface; A: First side edge; B: Second side edge; C: Chamfered edge; 11: Semiconductor substrate; 12: Film structure ; 121a: Tunneling oxide layer; 122a: N-type doped layer; 123a: First transparent conductive layer; 121b: Intrinsic amorphous silicon layer; 122b: P-type doped layer; 123b: Second transparent conductive layer; 123c: Isolation opening; 124: Passivation layer; 125: Antireflection layer; 13: First electrode; 14: Second electrode; 20: Coloring layer; 201: Cavity; 202: Carbon agglomerate; X: First direction; Y: Second direction. Detailed Implementation

[0011] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0012] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0014] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0015] The solar cells and photovoltaic modules provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0016] like Figures 1 to 6 As shown, a solar cell according to some embodiments of this application includes: a cell body 10 and a coloring layer 20. The cell body 10 has a light-receiving surface 101 and a backlighting surface 102 disposed opposite to each other. The light-receiving surface 101 includes a central region 101a and an edge region 101b surrounding the central region 101a. A color difference region 101c is formed in the edge region 101b. The backlighting surface 102 is provided with an electrode collecting region 102a, which includes two types of opposite conductivity, N-type collecting regions 1021 and P-type collecting regions 1022, arranged alternately along a first direction X. The coloring layer 20 is disposed in the edge region 101b and at least partially covers the color difference region 101c, and the orthographic projection of the coloring layer 20 on the backlighting surface 102 does not overlap with the electrode collecting region 102a. Specifically, the orthographic projection of the coloring layer 20 on the backlighting surface 102 does not overlap with the N-type collecting region 1021 and the P-type collecting region 1022.

[0017] In this embodiment, a coloring layer 20 is provided on the periphery 101b of the battery body 10, and the coloring layer 20 at least partially covers the color difference region 101c present in the periphery 101b, thereby reducing the color difference of the light-receiving surface 101 of the battery body 10. Simultaneously, the coloring layer 20 also serves to passivate the edges of the battery body 10 and provide leakage protection. For solar cells, the light-receiving surface 101 is the primary light absorption pathway. The coverage of the light-receiving surface 101 by the coloring layer 20 will cause light blocking, thus affecting the light absorption of the electrode collection region 102a of the backlight surface 102. For back-contact batteries, the electrode collection regions 102a are all located on the backlight surface 102. When the orthographic projection of the coloring layer 20 on the backlight surface 102 partially overlaps with the electrode collection regions 102a in the backlight surface 102, it will cause a difference between illuminated and unilluminated areas in the electrode collection regions 102a of the same polarity. The carrier concentration generated in the illuminated area is high, and the carrier concentration generated in the unilluminated area is low. The carrier concentration gradient will generate a potential difference, driving the carriers in the illuminated area to migrate laterally to the unilluminated area, resulting in recombination. Therefore, the orthographic projection of the coloring layer 20 on the backlight surface 102 should not overlap with the electrode collection regions 102a in the backlight surface 102 to reduce the light blocking of the electrode collection regions 102a by the coloring layer 20, thereby reducing carrier recombination in the electrode collection regions 102a due to uneven light exposure. In this way, by providing a coloring layer 20 in the surrounding edge region 101b of the battery body 10, the color difference of the light-receiving surface 101 of the battery body 10 can be eliminated, while also avoiding the impact on the carrier collection of the backlight surface 102 of the battery body 10, thereby improving the appearance of the battery product without sacrificing battery efficiency.

[0018] Specifically, the solar cell in this application can be a back-contact cell, and the electrodes of the back-contact cell are all disposed on the back surface, such as... Figure 1 , Figure 2 and Figure 7 As shown, the solar cell includes a cell body 10, which has a light-receiving surface 101 for receiving sunlight and a back-lighting surface 102 opposite to the light-receiving surface 101. The cell body 10 may include a semiconductor substrate 11, an N-type doped layer 122a, and a P-type doped layer 122b, both formed on the back side of the semiconductor substrate 11. The N-type doped layer 122a and the P-type doped layer 122b are alternately distributed along a first direction X, or the P-type doped layer 122b may extend and cover the portion of the N-type doped layer 122a opposite to the semiconductor substrate 11. The N-type doped layer 122a and the P-type doped layer 122b have opposite conductivity types to collect and export electrons and holes respectively, thereby forming a current. Furthermore, other functional film structures such as passivation layers and anti-reflection layers may also be disposed on the semiconductor substrate 11, which can be flexibly configured as needed and are not limited here.

[0019] Furthermore, such as Figure 1 and Figure 7 As shown, the backlight surface 102 of the battery body 10 includes an electrode collection region 102a and a non-electrode collection region 102b surrounding the electrode collection region 102a. The electrode collection region 102a includes N-type collection regions 1021 and P-type collection regions 1022 arranged alternately along a first direction X. The N-type collection region 1021 is provided with a first electrode 13, and the P-type collection region 1022 is provided with a second electrode 14. The non-electrode collection region 102b refers to a film layer structure disposed in the non-electrode collection region 102b and having conductive properties that is not electrically connected to conductive electrodes, solder strips, or other interconnection structures. In other words, the non-electrode collection region 102b cannot conduct charge carriers through conductive electrodes or other interconnection structures. The electrode collection region 102a refers to the N-type doped layer 122a, P-type doped layer 122b and other film structures that are disposed in the electrode collection region 102a and have conductive properties. These structures need to be electrically connected to the conductive electrode, solder strip and other interconnection structures in order to export the charge carriers (including electrons and holes) they have collected.

[0020] The N-type collection region 1021 is provided with at least an N-type doped layer 122a and a first electrode 13 for collecting and exporting electrons; the P-type collection region 1022 is provided with at least a P-type doped layer 122b and a second electrode 14 for collecting and exporting holes, thereby forming a photocurrent.

[0021] It is understandable that during the battery manufacturing process, dielectric layers, doped layers, and other film structures are formed on the back surface 102 of the battery body 10. These film structures are typically prepared using deposition coating. During the coating operation on the back surface 102, a wrap-around coating inevitably forms at the edge of the light-receiving surface 101. Because the color of this wrap-around coating differs from the color of other areas of the light-receiving surface 101, a color difference exists between the edge region 101b and the middle region 101a of the light-receiving surface 101 in the final battery. Furthermore, the battery cell manufacturing process involves multiple wet processes such as polishing or texturing, which may cause differences in the morphology of the edge region of the light-receiving surface compared to other regions. For example, uneven texturing at the edge region and uniform texturing at the middle region can lead to different reflectivities between the edge and middle regions, resulting in a color difference between the edge and middle regions and affecting the appearance of the battery product.

[0022] In related technologies, to address the edge color difference problem on the light-receiving surface 101 of the battery, wet etching is used in the battery manufacturing process to remove the surrounding coating at the battery edge, or wet etching is used to make the morphology of the edge area consistent with that of the middle area to eliminate the appearance color difference. However, while this method can eliminate the color difference, the process is complex and the etching process can easily damage the battery edge, reducing the battery's conversion efficiency. Therefore, a further solution is to use light-shielding materials to form a coloring layer 20 on the edge area 101b of the light-receiving surface 101 using 3D printing or coating to cover the color difference area 101c, thereby eliminating the impact of color difference on the product's appearance. This avoids damage to the battery cell edge caused by wet etching and also utilizes the retained surrounding coating to synergistically improve the passivation effect of the edge area, improving both the appearance and the battery's electrical performance.

[0023] However, the inventors discovered through research that, since the coloring layer 20 blocks the light-receiving surface 101 of the battery body 10, if the light-blocking area of ​​the coloring layer 20 is too large, and this light-blocking area covers part of the electrode collection area 102a of the backlight surface 102, that is, when there is an overlap between the orthographic projection of the coloring layer 20 on the backlight surface 102 and the electrode collection area 102a of the backlight surface 102, the light received by different positions in the same electrode collection area 102a is uneven. The area covered by the coloring layer 20 (i.e., the non-illuminated area) receives less light and generates fewer or even almost no charge carriers; while the area not covered by the coloring layer 20 (i.e., the illuminated area) receives light normally and generates more charge carriers. In this way, there is a potential difference between the illuminated area and the non-illuminated area within the same electrode collection region 102a. Affected by the potential difference, the carriers in the illuminated area will migrate to the non-illuminated area, forming a forward bias voltage in the non-illuminated area, which becomes a highly efficient carrier recombination region. This causes the photogenerated carriers generated in the illuminated area to recombine in the non-illuminated area, resulting in carrier loss and reducing the power generation efficiency of the battery.

[0024] Therefore, this application uses a non-transparent insulating material, such as ink, to form a coloring layer 20 in the edge region 101b of the battery body 10 through printing, 3D printing, or spraying. This coloring layer 20 covers the color difference region 101c within the edge region 101b, thereby reducing or even eliminating the color difference problem on the light-receiving surface 101 of the battery body 10. Furthermore, by ensuring that the orthographic projection of the coloring layer 20 onto the backlight surface 102 does not overlap with the electrode collection region 102a of the backlight surface 102, the influence of the coloring layer 20 on carrier collection in the electrode collection region 102a of the backlight surface 102 is reduced.

[0025] The statement that the orthographic projection of the coloring layer 20 on the backlight surface 102 does not overlap with the electrode collection area 102a of the backlight surface 102 means that, along the direction perpendicular to the backlight surface 102, there is no overlapping area between the orthographic projection of the coloring layer 20 on the backlight surface 102 and the orthographic projection of the electrode collection area 102a on the backlight surface 102.

[0026] It should be noted that the coloring layer 20, the N-type collection region 1021 or the P-type collection region 1022 are usually strip-shaped structures. However, within the scope of protection defined by the technical concept of this application, the specific implementation of the coloring layer 20, the N-type collection region 1021 or the P-type collection region 1022 not only includes its basic structure, but also covers a variety of physical morphological changes caused by specific variable parameters in the preparation or application process. Specifically, due to the influence of process parameters such as the received raw materials (including but not limited to differences in their type, batch, or year characteristics), molding or curing processes, and the application direction and method of coloring materials, the edges of the coloring layer 20, the N-type collection area 1021, or the P-type collection area 1022 may exhibit controllable regular deformations such as local protrusions or depressions. These changes in the morphology of the coloring layer 20, the N-type collection area 1021, or the P-type collection area 1022 caused by reasonable fluctuations in implementation conditions may result in a certain overlap between the orthographic projections of the coloring layer 20 and the N-type collection area 1021 or the P-type collection area 1022 in a small local area. These overlap phenomena caused by reasonable fluctuations in implementation conditions are due to the actual implementation process conditions and should be considered to fall within the protection scope of the claims of this application.

[0027] It is understood that the light-receiving surface 101 of the battery body 10 has four sides, and color difference areas 101c may be formed at the corresponding edges of each side. The coloring layer 20 can be arranged around the circumference of the light-receiving surface 101, and the coloring layer 20 can be arranged continuously around the circumference of the light-receiving surface 101 or intermittently around the light-receiving surface 101, as long as the color difference of the light-receiving surface 101 can be eliminated. In addition, on the light-receiving surface 101, the width of the coloring layer 20 arranged at different positions corresponding to the same side can be the same or different, and the width of the coloring layer 20 arranged at different sides can be the same or different. In practical applications, it can be flexibly set according to the actual position and area of ​​the color difference areas 101c around the edges of the light-receiving surface 101, and no limitation is made here.

[0028] The back-contact cells include, but are not limited to: back-contact heterojunction solar cells (HBC cells), back-contact tunneled oxide passivated contact cells (TBC cells), composite passivated back-contact cells (HPBC cells), and back-contact hybrid cells (HBC cells). It is understood that back-contact cells do not have electrode structures on the front side, thus requiring a higher aesthetic appeal for the light-receiving surface 101. This application further improves the color consistency of the light-receiving surface 101 of the back-contact cell by forming a coloring layer 20 on the edge region 101b of the light-receiving surface 101 of the cell body 10, thereby enhancing its aesthetics.

[0029] It should be noted that the 3D printing nozzle used for printing the coloring layer in the application can be a piezoelectric dispensing valve, a pneumatic dispensing valve, or a mechanical screw valve, etc. The specific type of control valve used by the printing nozzle can be flexibly selected according to the requirements of ink viscosity, solid content, printing accuracy and production cycle, etc., and is not limited here.

[0030] In some embodiments, such as Figure 7 As shown, the solar cell is configured as a back-contact hybrid cell. The cell body 10 includes a semiconductor substrate 11 and a film structure 12 disposed on the surface of the semiconductor substrate 11. From the surface of the semiconductor substrate 11 away from the semiconductor substrate 11, the film structure 12 in the N-type collecting region 1021 includes a tunneling oxide layer 121a and an N-type doped layer 122a stacked sequentially. Thus, a first conductive film layer is formed in the N-type collecting region 1021 by the tunneling oxide layer 121a and the N-type doped layer 122a to reduce contact resistance and improve conductivity. The film structure 12 in the P-type collecting region 1022 includes a P-type doped layer 122b. A second conductive film layer is formed in the P-type collecting region 1022 by the P-type doped layer 122b to improve passivation and suppress carrier recombination, thereby balancing passivation and conductivity and improving cell conversion efficiency. Optionally, the P-type collecting region 1022 also includes an intrinsic amorphous silicon layer 121b to further improve the passivation effect of the P-type collecting region.

[0031] In some embodiments, the backlight surface 102 further includes a spacer region 1023 between the P-type collecting region 1022 and the N-type collecting region 1021. Along a direction parallel to the backlight surface 102, the N-type doped layer 122a disposed in the N-type collecting region 1021 and the P-type doped layer 122b disposed in the P-type collecting region 1022 are spaced apart. This spacer region 1023 separates the N-type doped layer 122a and the P-type doped layer 122b, thereby preventing short circuits between them.

[0032] In other embodiments, the backlight surface 102 further includes a spacer region 1023 between the P-type collection region 1022 and the N-type collection region 1021. An N-type doped layer 122a is also disposed within the spacer region 1023, and a P-type doped layer 122b extends to cover the surface of the portion of the N-type doped layer 122a corresponding to the spacer region 1023. The P-type doped layer 122b and the N-type doped layer 122a located within the spacer region 1023 are spaced apart along the thickness direction of the battery body 10 to suppress leakage. Furthermore, by extending both the N-type doped layer 122a and the P-type doped layer 122b into the spacer region 1023, the N-type doped layer 122a and the P-type doped layer 122b have a larger area ratio on the backlight surface 102. This also reduces the amount of etching required for partial etching of the entire P-type doped layer 122b and the N-type doped layer 122a during battery manufacturing, thereby improving manufacturing efficiency.

[0033] Furthermore, a first transparent conductive layer 123a is provided in the N-type collection region 1021, and the first transparent conductive layer 123a is disposed on the surface of the N-type doped layer 122a; a second transparent conductive layer 123b is provided in the P-type collection region 1022, and the second transparent conductive layer 123b is disposed on the surface of the P-type doped layer 122b. The first transparent conductive layer 123a and the second transparent conductive layer 123b are disconnected to form an isolation opening 123c. Electrode structures are also provided in the N-type collection region 1021 and the P-type collection region 1022. By providing transparent conductive layers, the collection capability of the electrode structures for charge carriers generated within the battery body 10 can be improved.

[0034] In this application, the N-type doped layer 122a may contain one or more elements from Group VA (e.g., phosphorus), and the P-type doped layer 122b may contain one or more elements from Group IIIA (e.g., boron). The crystal phases of the N-type doped layer 122a and the P-type doped layer 122b may be amorphous, microcrystalline, nanocrystalline, single-crystal, or polycrystalline. For example, the materials of both the N-type doped layer 122a and the P-type doped layer 122b may both comprise doped polycrystalline silicon, or the material of the N-type doped layer 122a may comprise doped polycrystalline silicon, and the material of the P-type doped layer 122b may comprise at least one of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. Both the P-type doped layer 122b and the N-type doped layer 122a can be obtained by in-situ doping on the surface of a semiconductor substrate, or by deposition on the surface of a semiconductor substrate. The configuration can be flexibly set according to design requirements, and this application does not impose any limitations on this.

[0035] In some embodiments, such as Figure 7As shown, the materials of the first transparent conductive layer 123a and the second transparent conductive layer 123b may include indium tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), etc. The materials of the first transparent conductive layer 123a and the second transparent conductive layer 123b may be the same or different. For example, in the battery manufacturing process, an ITO layer can be fabricated on the entire backlight surface 102. Then, the ITO layer between the N-type collecting region 1021 and the P-type collecting region 1022 is removed by means of laser, etching paste, or photolithography to form an isolation opening 123c, thereby isolating the ITO layers of the N-type collecting region 1021 and the P-type collecting region 1022, and thus forming the first transparent conductive layer 123a and the second transparent conductive layer 123b.

[0036] Optionally, such as Figure 1 As shown, the area surrounding the electrode collection area 102a along the circumference of the battery body 10 is the non-electrode collection area 102b, and the orthographic projection of the coloring layer 20 onto the backlight surface 102 falls within the non-electrode collection area 102b; as Figure 3 As shown, from the edge of the light-receiving surface 101 to the center, the width of the coloring layer 20 is W1, and the width of the non-electrode collection area 102b is W2, satisfying: W1≤W2.

[0037] In this embodiment, by setting the width W1 of the coloring layer 20 to be less than or equal to the width W2 of the non-electrode collection area 102b, it is ensured that the orthographic projection of the coloring layer 20 on the backlight surface 102 does not overlap with the electrode collection area 102a of the backlight surface 102, so as to avoid the coloring layer 20 blocking the light of the electrode collection area 102a, thereby reducing the carrier recombination caused by uneven light exposure in the electrode collection area 102a. Thus, by setting the coloring layer 20 in the peripheral edge area 101b of the battery body 10, the color difference of the light-receiving surface 101 of the battery body 10 can be eliminated, and the influence on the carrier collection of the backlight surface 102 of the battery body can be avoided, thereby improving the appearance of the product without sacrificing battery efficiency.

[0038] Specifically, such as Figure 1As shown, the backlight surface 102 of the battery body 10 is provided with alternating N-type collection areas 1021 and P-type collection areas 1022 arranged along the first direction X. An interval 1023 is provided between adjacent N-type collection areas 1021 and P-type collection areas 1022 for insulation isolation. The N-type collection areas 1021 and P-type collection areas 1022 form a strip-like structure extending along the second direction Y. The outermost electrode collection area 102a along the first direction X is designated as an edge electrode collection area. This edge electrode collection area can be either an N-type collection area 1021 or a P-type collection area 1022. A certain interval area is reserved between the edge electrode collection area and the edge of the battery body 10; this interval area is a non-electrode collection area 101b. Along the second direction Y, a certain interval area is also reserved at both ends of each N-type collection area 1021 or P-type collection area 1022 from the edge of the battery body 10; this interval area is also a non-electrode collection area 101b.

[0039] like Figure 7 As shown, in this application, the area containing the N-type collection area 1021, the P-type collection area 1022, and the interval area 1023 is designated as the electrode collection area 102a, and the non-electrode collection area 102b is disposed around the electrode collection area 102a. Furthermore, the orthographic projection of the coloring layer 20 disposed on the edge region 101b of the light-receiving surface 101 onto the backlight surface 102 falls on the non-electrode collection area 102b, and the width W1 of the coloring layer 20 is set to be less than or equal to the width W2 of the non-electrode collection area 102b. In this way, it is ensured that the orthographic projection of the coloring layer 20 onto the backlight surface 102 does not overlap with the electrode collection area 102a of the backlight surface 102, so as to avoid the coloring layer 20 blocking the light of the electrode collection area 102a.

[0040] Optionally, such as Figure 3 As shown, the width of the color difference region 101c from the edge to the center of the light-receiving surface 101 is W3, satisfying: W3≤W2. In this application, the width W3 of the color difference region 101c is less than or equal to the width W2 of the non-electrode collection region 102b. Thus, when the coloring layer 20 is set, it can be ensured that the coloring layer 20 completely covers the color difference region 101c, while avoiding the coloring layer 20 from blocking the electrode collection region 102a of the backlight surface 102, thereby improving the appearance of the product without sacrificing battery efficiency.

[0041] In the fabrication process of solar cells, there is a phenomenon of coating around the edge of the light-receiving surface 101, which causes a color difference region 101c to appear at the edge of the light-receiving surface 101. Due to the influence of the actual process, the width of the color difference region 101c fluctuates. If the color difference region 101c of the light-receiving surface 101 is wide, the width of the color difference region 101c will be greater than the width of the non-electrode collection region 102b. In this case, if the color layer 20 is directly set on the color difference region 101c and the color layer 20 completely covers the color difference region 101c, the orthographic projection of the actual set color layer 20 on the backlight surface 102 will partially overlap with the electrode collection region 102a of the backlight surface 102.

[0042] Therefore, in this application, a partial removal step of the front-side coating is added during the battery processing. The coating on the edge region 101b of the light-receiving surface 101 is partially removed using wet etching or laser etching. A portion of the coating in the middle region 101a near the light-receiving surface 101 is etched away, leaving a narrower area of ​​the coating near the edge of the light-receiving surface 101. This ensures that the width W3 of the color difference region 101c is less than or equal to the width W2 of the non-electrode collection region 102b. Then, a coloring layer 20 is formed on the coating to cover the remaining coating. This ensures that the coloring layer 20 effectively covers the color difference region 101c of the light-receiving surface 101, and that the projection of the coloring layer 20 onto the backlight surface 102 does not overlap with the electrode collection region 102a of the backlight surface 102, thereby reducing the impact of the coloring layer 20 on carrier collection in the electrode collection region 102a.

[0043] It should be noted that the specific decoating process and the width of the decoating layer to be removed can be flexibly set according to actual needs, as long as the coloring layer 20 can effectively cover the color difference area 101c and the orthogonal projection of the coloring layer 20 on the backlight surface 102 does not overlap with the electrode collection area 102a. No limitation is made here.

[0044] In some embodiments, such as Figure 3 As shown, the width W1 of the coloring layer 20 satisfies 20um-1000um. For example, the width W1 can be set to: 20um, 30um, 50um, 100um, 200um, 300um, 500um, 700um, 1000um, etc. In this application, by setting the width W1 of the coloring layer 20 to be between 50um and 1000um, on the one hand, by setting a certain width of the coloring layer 20, the color difference region 101c can be effectively covered, thereby reducing the color difference problem of the light-receiving surface 101. On the other hand, it avoids the coloring layer 20 set on the edge region 101b of the light-receiving surface 101 being too wide, which could easily block the light of the electrode collection region 102a of the backlight surface 102 and affect the carrier collection of the electrode collection region 102a.

[0045] It is understood that the light-receiving surface 101 of the battery body 10 has a polygonal structure, such as a rectangle, and the coloring layer 20 is disposed around the circumferential edge of the light-receiving surface 101. Therefore, the measurement method for the width of the portion of the coloring layer 20 corresponding to each side of the polygonal structure includes: measuring the actual width value of the portion of the coloring layer 20 at different positions along a direction perpendicular to each side, and averaging the multiple measured actual width values ​​to obtain the width W1 of the portion of the coloring layer 20 corresponding to that side. It should be noted that the width of the coloring layer 20 disposed on different sides of the light-receiving surface 101 can be the same or different, and this is not limited.

[0046] In some embodiments, such as Figure 3 As shown, the width W2 of the non-electrode collection region 102b satisfies: W2 ≤ 1000 μm. For example, the width W2 can be set to: 1 μm, 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 500 μm, 800 μm, 1000 μm, etc. In this application, by setting the width W2 of the non-electrode collection region 102b to be less than or equal to 1000 μm, the area occupied by the non-electrode collection region 102b on the backlight surface 102 is avoided from being too large, resulting in a large ineffective area on the backlight surface 102 and reducing the power generation efficiency of the battery.

[0047] In some embodiments, such as Figure 3 As shown, the width W3 of the color difference region 101c satisfies: W3 ≤ 1000 μm. For example, the width W3 can be set to: 1 μm, 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 500 μm, 800 μm, 1000 μm, etc. In this application, by setting the width of the color difference region 101c to be less than or equal to 1000 μm, when the color difference region 101c is covered by the color layer 20, the area covered by the color layer 20 is prevented from being too large and affecting the carrier collection of the electrode collection region 102a of the backlight surface 102. Furthermore, it also prevents the color difference region 101c from being too wide and affecting the light absorption rate of the light-receiving surface 101.

[0048] Optionally, such as Figure 4As shown, the non-electrode collection region 102b is a polished surface (e.g., a surface with a tower-based structure formed after alkaline polishing), and at least a portion of the electrode collection region 102a is a textured surface, for example, the P-type collection region 1022 is textured. In this application, the non-electrode collection region 102b is located at the edge of the backlight surface 102 of the battery body 10. By making the non-electrode collection region 102b a polished surface, defects at the edge of the battery body 10 are reduced, lowering the probability of microcracks appearing at the edge of the battery body 10. Simultaneously, making at least a portion of the electrode collection region 102a a textured surface enhances the light-receiving area of ​​the corresponding portion of the electrode collection region 102a, increasing the light absorption rate. The textured surface also helps increase the bonding force between the film structure 12 and the semiconductor substrate, reducing contact resistance and increasing the fill factor, thereby improving the power generation efficiency of the battery. Furthermore, a transition slope is provided between the polished surface of the non-electrode collection region 102b and the textured surface of the electrode collection region 102a to reduce stress concentration at the junction of the polished and textured surfaces.

[0049] Specifically, a polished surface can be formed in the non-electrode collection area 102b by alkaline polishing or other methods. Then, by masking and texturing, the non-electrode collection area 102b retains the polished surface while a textured surface is formed on the corresponding part of the electrode collection area 102a. The textured surface can be formed only in the P-type collection area 1022, or only in the N-type collection area 1021, or both in the P-type collection area 1022 and the N-type collection area 1021. The textured surface can have a pyramid structure. The specific texturing process and the size of the textured surface can be flexibly set according to actual needs and are not limited here.

[0050] Optionally, such as Figure 3 As shown, from the edge of the light-receiving surface 101 to the center, the width of the color difference region 101c is W3, and the width of the color layer 20 is W1, satisfying: 0.8W3≤W1≤2W3. For example, the width W1 can be set to 0.8 times, 1 times, 1.2 times, 1.5 times, 1.8 times, 2 times, etc., the width W3.

[0051] In this embodiment, by setting the relationship between the width W3 of the color difference region 101c and the width W1 of the color layer 20, the width of the color layer 20 is reasonably set according to the width of the color difference region 101c. This ensures that the color layer 20 can effectively cover the color difference region 101c. At the same time, it avoids the color layer 20 being too wide, reducing the light-blocking effect of the color layer 20 on the light-receiving surface 101 and the impact on the carrier collection of the electrode collection region 102a of the backlight surface 102.

[0052] In some embodiments, the thickness of the coloring layer 20 is 5µm-100µm. For example, the thickness of the coloring layer 20 can be set to 5µm, 10µm, 30µm, 50µm, 80µm, 100µm, etc. By setting the thickness range of the coloring layer 20, it is possible to avoid the coloring layer 20 being too thin to effectively cover the color difference area 101c, and to avoid the coloring layer 20 being too thick to cause a large height difference at different positions on the backlight surface, thereby avoiding the problem of fragmentation in subsequent lamination processes.

[0053] Optionally, such as Figure 4 As shown, the color difference area 101c is set as a polished surface, and the part of the light-receiving surface 101 outside the color difference area 101c is set as a velvety surface. A transition slope is formed at the junction between the polished surface and the velvety surface.

[0054] In this embodiment, by making the portion of the light-receiving surface 101 in the color difference region 101c a polished surface, the coloring material has a smaller extensibility on the polished surface, resulting in a denser coloring layer 20. This allows for effective masking and coverage of the color difference region 101c using a thinner and denser coloring layer 20. However, if the surface of the color difference region 101c is uneven, the overall thickness of the coloring layer 20 needs to be increased to ensure effective masking. This not only increases processing costs but also affects the processing of subsequent components due to the excessively thick coloring layer 20. Furthermore, the portion of the light-receiving surface 101 outside the color difference region 101c is provided with a textured surface, which improves the light absorption rate of the light-receiving surface 101. A transition slope is formed at the junction between the polished surface and the textured surface, and the coloring layer 20 can partially or completely cover the transition slope. This ensures that the color layer 20 fully covers the color difference area 101c, and also prevents the color layer 20 from extending directly onto the velvet surface and affecting the light absorption rate of the middle area 101a.

[0055] In some embodiments, the area of ​​the light-receiving surface 101 outside the color difference region 101c can be textured to form a pyramidal textured surface, thereby improving the light absorption rate of the light-receiving surface 101. The portion of the battery body 10 located within the color difference region 101c can be a polished surface. The polished surface can be formed into a relatively flat surface with a pyramidal structure through alkaline polishing or similar methods. Compared to the textured surface, the coloring layer 20 has less extension on the polished surface, which can further restrict the diffusion of the coloring layer 20 onto the textured surface. Of course, the surface of the battery body 10 located within the color difference region 101c can also be textured. This textured surface can be the same size as the textured surface of the intermediate region 101a, or it can be different in size. Those skilled in the art can flexibly set it according to actual needs, and no limitation is made here.

[0056] In some embodiments, the width of the polished surface corresponding to the color difference region 101c is 30µm-150µm. For example, the width of the polished surface is set to 30µm, 50µm, 80µm, 100µm, 120µm, 150µm, etc. In this application, by controlling the width of the polished surface corresponding to the color difference region 101c, the width of the color layer 20 that needs to be covered is reduced, thereby preventing the projection of the color layer 20 from covering the electrode collection area of ​​the backlight surface.

[0057] Understandably, in terms of process implementation, the polished surface can be formed by coating a mask around the edge of the light-receiving surface 101, protecting the silicon wafer from damage. Then, alkaline etching is used to form a textured structure in the non-mask area of ​​the light-receiving surface 101, resulting in a structure where the color difference area 101c is polished and the non-color difference area is textured. The width of the polished surface is controlled by adjusting the width of the mask coating. The width of the polished surface can be adjusted by controlling the width of the mask coating, specifically by using laser or wet processes to remove part of the coating. If too much coating is removed, the process requires high precision, is difficult, and easily damages the edges of the solar cell, disrupting edge passivation. If too little coating is removed, the polished surface is too wide, causing the color layer 20 to cover the electrode collection area 102a of the backlight surface 102, affecting the battery's power generation efficiency. Therefore, limiting the width of the polished surface to 30μm-150μm can effectively protect the edge passivation while avoiding the influence of the coloring layer 20 on the carrier collection of the backlight surface 102.

[0058] In some embodiments, the battery body 10 includes a semiconductor substrate 11. The light-receiving surface 101 of the semiconductor substrate 11 has a chromatic aberration region 101c. In the direction away from the semiconductor substrate 11, a tunneling oxide layer 121a, an N-type doped layer 122a, a passivation layer 124, an antireflection layer 125, and a P-type doped layer 122b are sequentially disposed within the chromatic aberration region 101c. The coloring layer 20 at least partially covers the P-type doped layer 122b within the chromatic aberration region 101c. It should be noted that the structure of the battery body 10 can be found in [reference needed]. Figure 7 , Figure 7 The film structure within the color difference region 101c is not shown in detail. The tunneling oxide layer 121a, N-type doped layer 122a, and P-type doped layer 122b within the color difference region 101c are formed by winding deposition during the film preparation process on the backlight side.

[0059] It is understandable that during the battery manufacturing process, due to different manufacturing processes, the reasons for the generation of color difference region 101c on the light-receiving surface 101 are also different, and correspondingly, the film structure 12 in the color difference region 101c is also different.

[0060] In this embodiment, during the fabrication of the N-region and P-region film structures, the N-region film structure (including the tunneling oxide layer 121a and the N-type doped layer 122a) and the P-region film structure (including the P-type doped layer 122b) will be coated around the edge of the light-receiving surface 101, resulting in a color difference region 101c at the edge of the light-receiving surface 101. Although this coating phenomenon causes a color difference on the light-receiving surface 101, the coating can also passivate and protect the edge region 101b of the light-receiving surface 101. Therefore, in this embodiment, by retaining a portion of the N-region and P-region film structures coated around the edge of the light-receiving surface 101 and by providing a coloring layer 20 to cover the color difference region 101c, the color difference of the light-receiving surface 101 can be eliminated, and the passivation and protection of the edge region 101b of the light-receiving surface 101 of the battery body 10 can be improved.

[0061] Furthermore, in this embodiment, the battery body 10 has a polished surface on the surface of the color difference region 101c, while the portion outside the color difference region 101c has a textured surface. The film structure within the color difference region 101c includes a tunneling oxide layer 121a, an N-type doped layer 122a, a passivation layer 124, an antireflection layer 125, and a P-type doped layer 122b, making the color difference between the color difference region 101c and other areas of the light-receiving surface 101 more obvious in appearance. Therefore, the coloring layer 20 around the perimeter of the light-receiving surface 101 can be set as a continuous surrounding structure, thus ensuring that the coloring layer 20 can fully cover the color difference region 101c around the perimeter of the light-receiving surface 101, thereby improving the effect of eliminating color difference.

[0062] Optionally, such as Figure 5 As shown, the light-receiving surface 101 is textured with a velvety surface in both the color difference region 101c and the portion outside the color difference region 101c. In this application, by making the entire light-receiving surface 101 textured, the texturing operation of the light-receiving surface 101 is facilitated, and the light-trapping ability of the light-receiving surface 101 is improved.

[0063] In some embodiments, the battery body 10 includes a semiconductor substrate 11. The light-receiving surface 101 of the semiconductor substrate 11 has a chromatic aberration region 101c. In the direction away from the semiconductor substrate 11, a passivation layer 124, an antireflection layer 125, and a P-type doped layer 122b are sequentially disposed within the chromatic aberration region 101c. The coloring layer 20 at least partially covers the P-type doped layer 122b within the chromatic aberration region 101c. It should be noted that the structure of the battery body 10 can be found in [reference needed]. Figure 7 , Figure 7 The film structure within the color difference region 101c is not shown in detail. The P-type doped layer 122b within the color difference region 101c is formed by winding deposition during the preparation of the P-type doped layer 122b on the backlight surface.

[0064] In this embodiment, by setting the light-receiving surface 101 of the battery body 10 to a textured surface, the morphological consistency of different positions of the light-receiving surface 101 is improved, thereby reducing the appearance color difference caused by the different reflectivity of different areas of the light-receiving surface 101. At the same time, retaining a portion of the P-region film structure 12 around the edge of the light-receiving surface 101 (i.e., the P-type doped layer 122b) can passivate and protect the edge of the light-receiving surface 101, and also reduce the degree of color difference in the edge region 101b of the light-receiving surface 101.

[0065] Furthermore, since the color difference in the color difference region 101c in this embodiment is mainly caused by the presence of the P-type doped layer 122b, and the P-type doped layer is relatively thin, the resulting color difference is relatively small. Therefore, as... Figure 11 As shown, when setting the color layer 20, the color layer 20 can be set as an intermittent structure. Only the color layer 20 needs to be used to cover the areas with obvious color differences. In this way, the amount of material used in the color layer 20 can be reduced, thereby reducing the material cost.

[0066] In some embodiments, the thickness of the tunneling oxide layer 121a in the chromatic aberration region 101c gradually decreases along the edge of the light-receiving surface 101 towards the center, and / or the thickness of the N-type doped layer 122a gradually decreases. This reduces the light-shielding effect of the tunneling oxide layer 121a and the N-type doped layer 122a on the central region 101a of the light-receiving surface 101.

[0067] In some embodiments, the thickness of the P-type doped layer 122b in the chromatic difference region 101c gradually decreases along the edge of the light-receiving surface 101 towards the center. Further, an interface passivation layer 124 is provided between the P-type doped layer 122b and the antireflection layer 125, the interface passivation layer 124 comprising intrinsic amorphous silicon.

[0068] Optionally, such as Figure 3 and Figure 4 As shown, the battery body 10 also has a side surface 103 connecting the light-receiving surface 101 and the back-lighting surface 102, and the coloring layer 20 extends at least partially to cover the side surface 103. In this application, by setting the coloring layer 20 to at least partially extend to cover the side surface 103 of the battery body 10, it is possible to ensure that the coloring layer 20 can fully cover the color difference area 101c of the edge region 101b of the light-receiving surface 101. At the same time, the coloring layer 20 can also be used to passivate the side surface 103 of the battery body 10 and protect against leakage, thereby helping to improve the performance of the solar cell.

[0069] In some embodiments, the coloring layer 20 can be formed by 3D printing. During the printing process, the coverage area of ​​the print head extends beyond the edge of the light-receiving surface 101 by a certain distance. Thus, while the coloring layer 20 is being formed in the color difference area 101c, it extends to cover the side surface 103 of the battery body 10, so that the side surface 103 is partially or completely covered by the coloring layer 20. Of course, the side surface 103 of the battery body 10 may not have the coloring layer 20 provided; those skilled in the art can flexibly configure it according to actual needs, and this is not limited here. Furthermore, the forming method of the coloring layer 20 can be flexibly selected, and is not limited here.

[0070] In some embodiments, a wrap-around coating is further provided between the side surface 103 of the battery body 10 and the coloring layer 20. Further, the thickness of the wrap-around coating gradually decreases along the direction from the backlight surface 102 to the light-receiving surface 101. The wrap-around coating may be a tunneling oxide layer 121a and an N-type doped layer 122a; or, the wrap-around coating may be a passivation layer 124 and an antireflection layer 125; or, the wrap-around coating may be a P-type doped layer 122b; or, the wrap-around coating may be a transparent conductive layer, or, the wrap-around coating may be one or a combination of two or more of the aforementioned film layers. By forming a wrap-around coating on the side surface 103 of the battery body 10, the side surface 103 of the battery body 10 is passivated and leakage protection is provided, thereby helping to improve the performance of the solar cell.

[0071] Optionally, such as Figure 4 As shown, a cavity 201 is formed between a portion of the coloring layer 20 and the battery body 10. In this application, by forming a cavity 201 between a portion of the coloring layer 20 and the battery body 10, a gap exists between the coloring layer 20 and the battery body 10 at the cavity 201. This gap is filled with air. Since the refractive indices of air, the coloring layer 20, and the battery body 10 are all different, when light enters the battery body 10, some of the light that is not absorbed and utilized by the battery body 10 is emitted from the part of the surface of the battery body 10 covered by the coloring layer 20. Due to the presence of the cavity 201, the light can form a light cavity effect within the cavity 201. This allows some of the emitted light to be reflected or refracted multiple times and re-enter the battery body 10, thereby improving the light utilization rate of the battery body 10 and increasing the power generation efficiency of the battery.

[0072] It should be noted that the coloring layer 20 can cover the edge region 101b of the light-receiving surface 101 of the battery body 10, and can also extend to cover the side surface 103 of the battery body 10. The cavity 201 can be provided between the coloring layer 20 and the light-receiving surface 101, or between the coloring layer 20 and the side surface 103, or the cavity 201 can be provided on both the light-receiving surface 101 and the side surface 103. There is no limitation on this.

[0073] Optionally, such as Figure 2 As shown, the light-receiving surface 101 has two first sides A arranged opposite each other along the first direction X, and two second sides B arranged opposite each other along the second direction Y, the second direction Y being perpendicular to the first direction X; the coloring layer 20 is arranged circumferentially around the battery body 10, and the width of the coloring layer 20 corresponding to the first side A is greater than the width of the coloring layer 20 corresponding to the second side B.

[0074] In the process of manufacturing photovoltaic modules from cells, interconnecting elements are used to connect the cells in series. The extension direction of the interconnecting elements is consistent with the first direction X. The interconnecting elements will contact the edge of the cell body 10 along the first direction X, so that the edge of the cell body 10 will be subjected to the tensile force of the interconnecting elements, which can easily lead to microcracks. To address this, this application sets the width of the coloring layer 20 covering the two sides of the cell body 10 in the first direction X to be wider, thereby protecting the corresponding edge portion of the cell body 10 and reducing the risk of microcracks at the edge of the cell body 10.

[0075] It should be noted that the width of the color layer 20 corresponding to the first side A refers to the average width of the color layer 20 along the direction perpendicular to the first side A and parallel to the light-receiving surface 101. The width of the color layer 20 corresponding to the second side B can be measured in the same way.

[0076] Optionally, such as Figure 2 As shown, the light-receiving surface 101 also has a chamfered edge C, which is connected between the adjacent first side A and second side B. The width of the color layer 20 corresponding to the chamfered edge C is greater than the width of the partial color layer 20 corresponding to the first side A, and / or the width of the partial color layer 20 corresponding to the chamfered edge C is greater than the width of the partial color layer 20 corresponding to the second side B.

[0077] In this embodiment, the battery body 10 has a chamfered portion. During the component manufacturing process, stress concentration occurs at the chamfered portion, which can easily lead to local microcracks. To address this, this application increases the width of the coloring layer 20 corresponding to the chamfered edge C of the light-receiving surface 101, thereby enhancing the protective effect of the coloring layer 20 on the chamfered portion of the battery body 10 and reducing the probability of microcracks appearing at the chamfered portion. Simultaneously, the coloring layer 20 also improves the passivation effect at the chamfered portion, reducing carrier recombination in the corresponding area.

[0078] In some embodiments, the coloring layer 20 includes a substrate, a colorant, and a matting agent, wherein the substrate includes at least one of silicone or alicyclic epoxy resin, and the colorant includes carbon black.

[0079] In this embodiment, the substrate of the coloring layer 20 can be at least one of organosilicon or alicyclic epoxy resin, so that the coloring layer can be prepared by printing, and the requirements of low-temperature rapid curing can be met, reducing the diffusion of the coloring material to the center of the textured surface. Furthermore, carbon black is used as a colorant to match the color of the coloring layer 20 with the color of the light-receiving surface, and carbon black also provides reinforcement. In addition, by adding a matte agent to the coloring material, the coloring layer 20 has a certain matte finish, which can reduce the reflection of light by the coloring layer 20 and improve the light absorption rate of the battery.

[0080] Specifically, the coloring layer 20 in this application uses a coloring material, prepared through printing, coating, or inkjet printing. The coloring material can be an organosilicon ink, an alicyclic epoxy resin ink, or a UV adhesive ink. The main components of the coloring material include: a matrix material, a crosslinking agent, a colorant, and functional additives. In this application, the matrix material is preferably organosilicon oil or epoxy resin. Compared to traditional ink systems that add a large amount of solvent, organosilicon inks use silicone oil to partially or completely replace the solvent, which can improve the curing and crosslinking effect and increase the adhesion and stability of the coloring material. For alicyclic epoxy resin inks, the matrix material is an alicyclic epoxy resin adhesive, which can reduce the amount of solvent used or even eliminate the need for solvent. The colorant can be carbon black, which serves both a coloring and material reinforcing function. The crosslinking agent can be determined based on the selected matrix material. Functional additives can be flexibly selected according to actual needs, such as defoamers, leveling agents, and dispersants. In addition, using silica as a matting agent can not only improve the surface reflectivity of the coloring layer 20, but also enhance its anti-aging properties.

[0081] Furthermore, the D50 particle size of the silica is 3µm-10µm. For example, the D50 particle size of the silica can be set to 3µm, 5µm, 7µm, 9µm, 10µm, etc. This avoids the silica particle size being too large, which would be detrimental to the dispersion of silica and would also affect the printing performance of the coloring material. On the other hand, it avoids the silica particle size being too small, which would affect the scattering effect of the coloring layer 20.

[0082] The mass percentage content of silica in the coloring layer 20 is 0.5wt%~10wt%. For example, the mass percentage content of silica is set to 0.5wt%, 1wt%, 2wt%, 5wt%, 7wt%, 10wt%, etc. By controlling the content of silica, the scattering effect of the coloring layer 20 can be improved by adding silica, while also taking into account the printability of the coloring material.

[0083] In some embodiments, during the processing of the coloring layer 20, silicone-based inks, UV-adhesive inks, or alicyclic epoxy resins can be used as coloring materials. When preparing the coloring layer 20 using silicone-based inks or alicyclic epoxy resins, curing can be achieved through heating and baking or through photoinjection. Photoinjection, a conventional process for solar cells, can activate hydrogen atoms in the passivated film, saturate dangling bonds, reduce carrier recombination, and thus improve the efficiency of the solar cell. If silicone-based inks are used to prepare the coloring layer before the photoinjection process, the coloring layer 20 can be cured simultaneously during the photoinjection process. This simplifies the production process, facilitates assembly line operation, and further reduces surface recombination of the solar cell while curing the coloring layer 20, improving carrier collection efficiency and battery performance. When using UV-adhesive inks to prepare the coloring layer 20, curing can be achieved through UV light irradiation. The specific curing method and process can be flexibly set according to the selection of the coloring layer 20 material and are not limited here.

[0084] In some embodiments, carbon black can be used as a colorant in the coloring layer 20, resulting in a dark color layer 20, such as black, to match or closely resemble the color of the light-receiving surface 101 of the battery body 10. Thus, the coloring layer 20 contains carbon elements, and the mass percentage of carbon elements is set to 0.5 wt%-2 wt%. Specifically, the mass percentage content of carbon elements in the coloring layer 20 can be set to 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2 wt%, etc.

[0085] In this application, carbon black is added to the coloring material. Carbon black can act as both a colorant and a reinforcing agent, improving the structural strength and wear resistance of the coloring layer 20. Furthermore, by controlling the mass percentage content of carbon elements in the coloring layer 20 between 0.5 wt% and 5 wt%, it is possible to avoid the carbon content in the coloring layer 20 being too low, resulting in a color that is too light and cannot effectively cover the color difference area 101c. At the same time, it is also possible to avoid the carbon content in the coloring layer 20 being too high, which would increase the hardness of the coloring layer 20 material, reduce the adhesion between the coloring material and the battery body 10, and also prevent the coloring layer 20 from being too hard, which could easily lead to microcracks in the battery body 10.

[0086] It is understandable that an energy dispersive spectroscopy (EDS) instrument combined with a scanning electron microscope (SEM) can be used to perform elemental analysis on the colored layer 20. Specific experimental methods for elemental analysis using EDS and SEM can be referenced from relevant techniques and will not be elaborated here. Specifically, such as... Figures 8 to 10 As shown, Figure 8This is a scanning electron microscope (SEM) image of the colored layer 20. Figure 9 This is a schematic diagram showing the distribution of each element in color layer 20. Figure 10 This is a schematic diagram showing the distribution of carbon elements in coloring layer 20.

[0087] In some embodiments, carbon black is used as a colorant, and the D50 particle size of the carbon black in the coloring material is set to 3µm-10µm, for example, the D50 particle size of carbon black is set to 3µm, 4µm, 5µm, 7µm, 8µm, 10µm, etc. This avoids the carbon black particle size being too small, which is not conducive to dispersion, and also avoids the carbon black particle size being too large, which would affect the printability of the coloring material.

[0088] The carbon black content in the coloring material is set to a mass percentage of 0.5wt%-10wt%, for example, 0.5wt%, 1wt%, 2wt%, 5wt%, 7wt%, 10wt%, etc. By controlling the mass percentage of carbon in the coloring layer 20, it is possible to avoid the carbon black content in the coloring layer 20 being too low, resulting in a color that is too light and cannot effectively cover the color difference area 110; at the same time, it is also possible to avoid the carbon black content in the coloring layer 20 being too high, which would increase the hardness of the coloring layer 20 material, reduce the adhesion between the coloring material and the battery body 10, and make the battery body 10 prone to microcracks if the coloring layer 20 is too hard.

[0089] Optionally, such as Figures 8 to 10 As shown, the coloring layer 20 contains carbon aggregates 202, and the maximum one-dimensional size of the carbon aggregates 202 is 0.5um-10um.

[0090] In this embodiment, by forming carbon aggregates 202 in the coloring layer 20, the moderate carbon aggregates 202 have higher light scattering efficiency than single carbon particles, which can significantly deepen the blackness and opacity of the coloring layer 20, and improve the opacity of the coloring layer 20 for the color difference region 101c. At the same time, the carbon aggregates 202 can form physical entanglement or chemical bonding with the resin matrix, thereby improving the wear resistance and adhesion of the coloring layer 20, reducing the risk of the coloring layer 20 falling off the battery body 10, and also improving the isolation and protection of the edge region 101b of the light-receiving surface 101 of the battery body 10.

[0091] Furthermore, during the preparation of the color layer 20 using coloring materials, the carbon agglomerates 202 present in the coloring materials can impart pseudoplastic rheological properties (i.e., shear thinning properties) to the coloring materials. Consequently, during printing or inkjet printing, the viscosity of the coloring materials decreases under shear force, which is beneficial for the transfer of the coloring materials. Moreover, when the coloring materials are left to stand after being attached to the battery body 10, the viscosity rises, which can prevent the color layer 20 from settling and dripping.

[0092] In this application, carbon agglomerates 202 are aggregated structures formed by the aggregation of some carbon particles in the coloring material, which can be tested and analyzed by scanning electron microscopy and energy dispersive spectroscopy, such as... Figure 8 and Figure 10 As shown, the carbon agglomerate 202 is an aggregate of carbon particles with a maximum one-dimensional size greater than or equal to 0.5 μm. It should be noted that the specific preparation process of the coloring material can be flexibly set according to actual needs, as long as it can ensure that the final colored layer 20 has at least one carbon agglomerate 202, and no limitation is made here.

[0093] In this application, carbon agglomerates 202 are aggregated structures formed by the aggregation of primary carbon black particles in the coloring material, which can be tested and analyzed by scanning electron microscopy and energy dispersive spectroscopy. The primary particles in carbon black are its smallest structural units, and these primary particles often aggregate to form carbon agglomerates 202 due to intermolecular forces. In this application, the particle size of the primary particles is selected to be less than 30 nm. Under this condition, the carbon agglomerate size formed is moderate, resulting in better ink printability. Furthermore, using primary carbon black particles with a particle size of less than 30 nm for coloring results in a bluish hue in the prepared coloring layer 20, thereby enabling the color of the coloring layer 20 to better match the color of the light-receiving surface of the battery body 10. Figure 8 As shown, the carbon agglomerate 202 is an aggregate of carbon particles with a maximum one-dimensional size of 0.5 μm to 10 μm. It should be noted that the specific preparation process of the coloring material can be flexibly set according to actual needs, as long as it can ensure that the final colored layer 20 has at least one carbon agglomerate 202, and no limitation is made here.

[0094] In some embodiments, the transmittance of the coloring layer 20 is 5% to 16%. The lower the transmittance, the more light the coloring layer 20 absorbs and the less light it transmits, resulting in a better covering effect. For example, the transmittance can be set to 5%, 8%, 10%, 12%, 15%, 16%, etc., and the transmittance can be tested by optical testing instruments such as a spectrophotometer or a transmittance meter.

[0095] In some embodiments, the gloss level of the coloring layer 20 is 5 to 40. Gloss level reflects the matte finish of the coloring layer 20; a lower gloss level indicates a more matte finish. Imparting a certain matte finish to the coloring layer reduces the reflectivity of the ink itself and increases scattering, which is more compatible with the optical properties of the solar cell. For example, the gloss level can be set to: 5, 10, 15, 20, 25, 30, 35, 40, etc., wherein the gloss level can be measured using a gloss meter under a 60° incident angle condition.

[0096] In some embodiments, such as Figure 7As shown, the fabrication method of the solar cell provided in this application embodiment is illustrated using a back-contact hybrid cell as an example: Example 1 S1, the semiconductor substrate 11 is cleaned and the surface of the semiconductor substrate 11 is polished using an alkaline polishing process. The polishing thickness of the front and back sides of the semiconductor substrate 11 is 5μm-10μm. The polished surface of the semiconductor substrate 11 forms a polished surface with a tower-based texture structure.

[0097] S2, a first conductive film layer is formed on the back side of the semiconductor substrate 11 using a CVD process. The first conductive film layer includes a tunneling oxide layer 121a and an N-type doped layer 122a sequentially formed on the back side of the semiconductor substrate 11. S3, a dielectric mask layer is formed on the first conductive film layer. The dielectric mask layer includes one or a combination of SiNx, SiOx, SiOxNy, etc. In steps S2 and S3, a coating layer is formed around the periphery of the semiconductor substrate 11. S4, based on a graphical design, uses a laser film-opening method to vaporize and ablate part of the first conductive film layer and dielectric mask layer to form an opening area, which is the area where the P-type collection area 1022 is located. S5, using wet etching or laser etching, or other de-coating methods, remove part of the dielectric mask layer on the front edge of the semiconductor substrate 11. The dielectric mask layer on the front edge is not completely removed, and part of the dielectric mask layer near the front edge of the semiconductor substrate 11 is retained, so that the first conductive film layer under the dielectric mask layer can cover the edge and side of the semiconductor substrate 11, thereby improving the passivation effect on the edge and side of the semiconductor substrate 11. The area where the part of the de-coating layer is retained on the front of the semiconductor substrate 11 is the color difference region 101c. S6, texturing is performed on the area on the front side of the semiconductor substrate 11 without the surrounding coating and on the opening area obtained in step S4 to form a pyramid-shaped textured surface; and all dielectric mask layers are removed by wet etching or other methods. S7, a passivation layer 124 and an antireflection layer 125 are sequentially formed on the front side of the semiconductor substrate 11; S8, a second conductive film layer is formed on the back side of the semiconductor substrate 11. The second conductive film layer includes an intrinsic amorphous silicon layer 121b and a P-type doped layer 122b sequentially formed on the back side of the semiconductor substrate 11. S9, using laser to remove the second conductive film layer at the corresponding position of the N-type collection region 1021; S10, a transparent conductive layer (TCO) thin film is formed on the back side of the semiconductor substrate 11. The TCO thin film may include one or a stack of ITO (indium tin oxide), IWO (tungsten tin oxide), ITiO (titanium tin oxide), ICO (cerium tin oxide), etc. S11, a portion of the TCO film located between the N-type collection region 1021 and the P-type collection region 1022 is etched away to form an isolation opening 123c, so as to insulate and isolate the TCO film of the N-type collection region 1021 from the TCO film of the P-type collection region 1022. S12, electrode structures are fabricated on the N-type collection region 1021 and the P-type collection region 1022 respectively to obtain the battery body 10; S13, a coloring layer 20 is formed in the periphery edge region 101b of the light-receiving surface 101 of the battery body 10, so as to cover the color difference region 101c of the light-receiving surface 101 through the coloring layer 20, so as to partially or completely eliminate the color difference of the light-receiving surface 101.

[0098] It should be noted that, compared to the prior art, in Embodiment 1 of this application, a partial decoupling step is added to remove part of the decoupling layer at the front edge of the semiconductor substrate 11, while retaining a narrower decoupling layer for subsequent coverage by the coloring layer 20. This avoids damage to the cell edge caused by complete decoupling and also reduces the obstruction of the electrode collection area 102a of the backlight surface 102 by the coloring layer 20, thereby improving the product's appearance without sacrificing cell efficiency. It should be understood that when the solar cell is of other types, the processing steps can be performed similarly and will not be repeated here.

[0099] Example 2 Steps S1 to S4 are the same as in Example 1; S5. Using wet etching or laser etching, or other de-coating methods, remove all dielectric mask layers on the front edge of the semiconductor substrate 11 to increase the area of ​​the front textured surface and increase the light trapping capability of the light-receiving surface 101.

[0100] S6, texturing is performed on the front side of the semiconductor substrate 11 and the opening area obtained in step S4 to form a textured surface with a pyramid structure. S7, a passivation layer 124 and an antireflection layer 125 are sequentially formed on the front side of the semiconductor substrate 11; S8, a second conductive film layer is formed on the back side of the semiconductor substrate 11. The second conductive film layer includes an intrinsic amorphous silicon layer 121b and a P-type doped layer 122b sequentially formed on the back side of the semiconductor substrate 11. The intrinsic amorphous silicon layer 121b and the P-type doped layer 122b are formed by wrap-around plating on the front side of the semiconductor substrate 11. The wrap-around plating area of ​​the second conductive film layer on the front side is the color difference region 101c.

[0101] Steps S9 to S13 are the same as in Example 1.

[0102] It should be noted that, compared to the prior art, in Embodiment 2 of this application, by adding a partial removal of the plating layer, the plating layer on the front edge of the semiconductor substrate 11 is completely removed to reduce the color difference problem caused by the first conductive film layer and the polished surface at the front edge. However, completely removing the plating layer will reduce the passivation effect of the front edge. Therefore, a second conductive film layer is further formed on the front edge to create a plating layer. Since the second conductive film layer is thinner, the color difference in the resulting color difference area 101c is less severe. Therefore, the coloring layer 20 can be set as an intermittent structure, only partially covering areas with obvious color differences. In this way, the amount of material used in the coloring layer 20 can be reduced, thereby reducing material costs, and the front edge can be passivated by the second conductive film layer, achieving a balance between cost control and passivation effect.

[0103] Optionally, embodiments of this application also provide a photovoltaic module, which includes multiple cell strings, each cell string including multiple solar cells and multiple interconnecting elements (e.g., solder ribbons), the interconnecting elements being used to connect the multiple solar cells in series; wherein, the solar cells are the solar cells in the above embodiments.

[0104] Specifically, a photovoltaic module includes multiple cell strings, each of which is formed by connecting multiple solar cells in series. When the solar cells are interconnected using solder ribbons, the interconnecting components may come into contact with the edge region 101b of the cell. By providing a coloring layer 20 around the edge region 101b of the cell body 10, and ensuring that the coloring layer 20 at least partially covers the color difference region 101c present in the edge region 101b, the color difference of the light-receiving surface 101 of the cell body 10 is reduced. Furthermore, the presence of the coloring layer 20 also protects the edge of the cell body 10, preventing scratches during subsequent cell interconnection and thus affecting efficiency. Furthermore, the projection of the coloring layer 20 onto the backlight surface 102 is made to not overlap with the electrode collection area 102a in the backlight surface 102, so as to avoid the coloring layer 20 blocking the light of the electrode collection area 102a, thereby reducing the carrier recombination caused by uneven light exposure in the electrode collection area 102a. In this way, by providing the coloring layer 20 in the surrounding edge area 101b of the battery body 10, the color difference of the light-receiving surface 101 of the battery body 10 can be eliminated, and the influence on the carrier collection of the backlight surface 102 of the battery body can be avoided, thereby improving the appearance of the battery product without sacrificing battery efficiency.

[0105] In some embodiments, the photovoltaic module further includes: a front panel, a back panel, and an encapsulating film layer, wherein the front panel and the back panel are stacked, the encapsulating film layer is disposed between the front panel and the back panel, and the battery string is embedded in the encapsulating film layer. The encapsulating film layer encapsulates and protects the battery string, and the encapsulating film layer serves to bond and fix the front panel and the back panel.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0107] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A solar cell, characterized in that, include: The battery body has a light-receiving surface and a backlighting surface arranged opposite to each other. The light-receiving surface includes a central region and an edge region arranged around the central region. A color difference region is formed in the edge region. The backlighting surface is provided with an electrode collection area, which includes two types of P-type collection areas and N-type collection areas of opposite conductivity arranged alternately along a first direction. A coloring layer is disposed in the edge region and at least partially covers the color difference region, and the orthographic projection of the coloring layer on the backlight surface does not overlap with the electrode collection region.

2. The solar cell according to claim 1, characterized in that, The backlight surface also includes a non-electrode collection area, which is arranged around the electrode collection area. The orthogonal projection of the coloring layer on the backlight surface falls within the non-electrode collection area. From the edge of the light-receiving surface to the center, the width of the coloring layer is W1, and the width of the non-electrode collection area is W2, satisfying: W1≤W2.

3. The solar cell according to claim 2, characterized in that, The width of the color difference zone is W3, which satisfies: W3≤W2.

4. The solar cell according to claim 3, characterized in that, The width W1 of the coloring layer is between 20um and 1000um; And / or, the width W2 of the non-electrode collection area satisfies: W2≤1000um; And / or, the width W3 of the color difference region satisfies: W3≤1000um.

5. The solar cell according to claim 2, characterized in that, The non-electrode collection area is set as a polished surface, and at least a portion of the electrode collection area is set as a textured surface.

6. The solar cell according to any one of claims 1-5, characterized in that, From the edge of the light-receiving surface to the center, the width of the color difference area is W3, and the width of the coloring layer is W1, satisfying: 0.8W3≤W1≤2W3; and / or, the thickness of the coloring layer is 5um-100um.

7. The solar cell according to any one of claims 1-5, characterized in that, The color difference area is set as a polished surface, and the portion of the light-receiving surface outside the color difference area is set as a velvety surface. A transition slope is formed at the junction between the polished surface and the velvety surface.

8. The solar cell according to claim 7, characterized in that, The width of the polished surface is 30μm-150μm.

9. The solar cell according to claim 7, characterized in that, The battery body includes a semiconductor substrate, and the light-receiving surface of the semiconductor substrate is provided with the chromatic aberration region. In the direction away from the semiconductor substrate, a tunneling oxide layer, an N-type doped layer, a passivation layer, an antireflection layer and a P-type doped layer are sequentially provided in the chromatic aberration region. The coloring layer at least partially covers the P-type doped layer in the chromatic aberration region.

10. The solar cell according to any one of claims 1-5, characterized in that, The light-receiving surface is made of velvet in both the color difference area and the portion outside the color difference area.

11. The solar cell according to claim 10, characterized in that, The battery body includes a semiconductor substrate, and the light-receiving surface of the semiconductor substrate is provided with the chromatic aberration region. In the direction away from the semiconductor substrate, a passivation layer, an antireflection layer and a P-type doped layer are sequentially provided in the chromatic aberration region. The coloring layer at least partially covers the P-type doped layer in the chromatic aberration region.

12. The solar cell according to claim 10, characterized in that, The coloring layer dots are arranged intermittently.

13. The solar cell according to any one of claims 1-5, characterized in that, The battery body also has a side surface connecting the light-receiving surface and the backlight surface, and the coloring layer extends at least partially to cover the side surface.

14. The solar cell according to claim 13, characterized in that, A cavity is formed between part of the coloring layer and the battery body.

15. The solar cell according to any one of claims 1-5, characterized in that, The light-receiving surface has a first side edge disposed opposite to each other along a first direction and a second side edge disposed opposite to each other along a second direction. A chamfer edge is provided between adjacent first side edges and second side edges. The second direction is perpendicular to the first direction. The width of the coloring layer corresponding to the chamfer edge is greater than the width of the coloring layer corresponding to the first side edge, and / or the width of the coloring layer corresponding to the chamfer edge is greater than the width of the coloring layer corresponding to the second side edge.

16. The solar cell according to any one of claims 1-5, characterized in that, The backlight surface further includes a spacing region between the P-type and N-type collecting regions. The N-type collecting region has an N-type doped layer, and the P-type collecting region has a P-type doped layer. Along a direction parallel to the backlight surface, the N-type doped layer and the P-type doped layer are spaced apart to form the spacer region; Alternatively, the N-type doped layer is further disposed within the spacer region, and the P-type doped layer extends to cover the surface of the portion of the N-type doped layer corresponding to the spacer region. The P-type doped layer and the N-type doped layer located within the spacer region are spaced apart along the thickness direction of the battery body.

17. The solar cell according to claim 16, characterized in that, The N-type doped layer includes a doped polycrystalline silicon layer; the P-type doped layer includes at least one of a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer.

18. The solar cell according to any one of claims 1-5, characterized in that, The coloring layer includes a substrate, a colorant, and a matting agent, wherein the substrate includes at least one of organosilicon or alicyclic epoxy resin, and the colorant includes carbon black.

19. The solar cell according to claim 18, characterized in that, The matting agent includes silicon dioxide, and the particle size of the silicon dioxide is 3um-10um.

20. The solar cell according to claim 18, characterized in that, The coloring layer contains carbon aggregates, the maximum one-dimensional size of which is 0.5um-10um.

21. A photovoltaic module, characterized in that, The photovoltaic module includes multiple battery strings, each battery string including multiple solar cells and multiple interconnects, the interconnects being used to connect the multiple solar cells in series; wherein the solar cells are the solar cells according to any one of claims 1-20.

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