Solar cell, stacked cell, and photovoltaic module

Abstract

The present disclosure relates to the field of photovoltaic technology, and provides a solar cell, a laminated cell and a photovoltaic module. The solar cell comprises a substrate having a first surface comprising a first boundary region extending along a first direction, the first boundary region comprising a first region and a second region located on opposite sides of the first region along the first direction; and an edge grid line arranged adjacent to the first boundary region, the edge grid line comprising a first main body portion extending along the first direction and a first avoiding portion connected to the first main body portion, the first avoiding portion being opposite to the first region in a second direction and being bent away from the first region; wherein an included angle between a first side, at which the first avoiding portion is connected to the first main body portion, and the first main body portion is 90°-165°, thereby at least improving the yield and reliability of the solar cell.

Description

Technical Field

[0001] This disclosure relates to the field of photovoltaic technology, and in particular to a solar cell, a tandem cell, and a photovoltaic module. Background Technology

[0002] Currently, with the increasing depletion of fossil fuels, solar energy, as a clean and renewable new energy source, is being developed and utilized more and more widely. Solar cells are the core device for photoelectric conversion, directly converting sunlight into electrical energy. Their working principle is based on the photovoltaic effect: light illuminating a semiconductor material generates electron-hole pairs, which separate under the influence of a built-in electric field to form photogenerated charge carriers. These carriers are then collected and extracted through metal electrodes, thus achieving efficient output of electrical energy.

[0003] However, during the fabrication process of existing solar cells, due to structural design or process factors, unintended carrier recombination or current leakage can easily occur, affecting the conversion efficiency and product yield of solar cells. Utility Model Content

[0004] This disclosure provides a solar cell, a tandem cell, and a photovoltaic module, which at least helps to improve the yield and reliability of solar cells.

[0005] According to some embodiments of this disclosure, one aspect of this disclosure provides a solar cell, comprising: a substrate having a first surface, the first surface including a first boundary region extending along a first direction, the first boundary region including a first region and second regions located on opposite sides of the first region along the first direction; a plurality of grid lines located on the first surface and spaced apart along a second direction, the grid lines extending along the first direction, the plurality of grid lines including edge grid lines disposed adjacent to the first boundary region, the edge grid lines including a first main body portion and a first clearance portion connected to the first main body portion, the first main body portion extending along the first direction, the first clearance portion being directly opposite the first region in the second direction and bent toward a direction away from the first region; wherein, the first clearance portion includes a first side connected to the first main body portion, the included angle between the first side and the first main body portion being 90°~165°.

[0006] In some embodiments, the solar cell further includes a passivation layer located on the first surface, wherein the thickness of the passivation layer corresponding to the first region is less than the thickness of the passivation layer corresponding to the second region.

[0007] In some embodiments, the first clearance portion is trapezoidal, triangular, or arc-shaped.

[0008] In some embodiments, the width of the first clearance portion in the first direction is 2mm to 4mm.

[0009] In some embodiments, the width of the first clearance portion in the second direction is 0.4 mm to 0.7 mm.

[0010] In some embodiments, the distance between the first clearance portion and the nearest battery edge in the first direction is 41 mm to 44 mm.

[0011] In some embodiments, the passivation layer thickness corresponding to the first region is 20nm to 40nm, and the passivation layer thickness corresponding to the second region is 70nm to 90nm.

[0012] In some embodiments, the first surface includes a second boundary region extending along the second direction, and the second boundary region includes a third region and a fourth region located on opposite sides of the third region along the second direction, and the thickness of the passivation layer corresponding to the third region is less than the thickness of the passivation layer corresponding to the fourth region; in the first direction, the gate line disposed adjacent to the third region is close to a first end of the third region and contracts toward the side away from the third region.

[0013] In some embodiments, the solar cell further includes: an edge connecting line disposed adjacent to the second boundary region, the edge connecting line including a second main body portion and a second clearance portion connected to the second main body portion, the second main body portion extending along the second direction, the second clearance portion being directly opposite the third region in the first direction and bending toward a direction away from the third region, and the second clearance portion being connected to the first end.

[0014] In some embodiments, the shape of the second clearance portion is trapezoidal, triangular, or arc-shaped.

[0015] In some embodiments, the width of the second clearance portion in the second direction is 2mm to 4mm.

[0016] In some embodiments, the width of the second clearance portion in the first direction is 0.4 mm to 0.7 mm.

[0017] In some embodiments, the distance between the second clearance portion and the nearest battery edge in the second direction is 41 mm to 44 mm.

[0018] In some embodiments, the passivation layer thickness corresponding to the third region is 20nm to 40nm, and the passivation layer thickness corresponding to the fourth region is 70nm to 90nm.

[0019] According to some embodiments of this disclosure, another aspect of this disclosure also provides a tandem battery, comprising: a bottom battery, the bottom battery being a solar cell as described in any of the preceding claims; and a perovskite battery located on one side of the bottom battery.

[0020] According to some embodiments of this disclosure, in another aspect, this disclosure also provides a photovoltaic module, including: a battery string, which is formed by connecting a plurality of solar cells as described in any one of the above claims, or by connecting a plurality of stacked cells as described above; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film facing away from the battery string.

[0021] The technical solutions provided in this disclosure have at least the following advantages: This disclosure improves the electrical performance and structural reliability of solar cells by optimizing the edge grid line structure. Specifically, the edge grid line includes a first main body extending along a first direction and a first clearance portion connected thereto. The first clearance portion faces the first region in a second direction and bends away from the region. On the one hand, the first clearance portion effectively avoids the risk of excessive grid line penetration that may occur in the first region during sintering, thereby significantly reducing the probability of leakage and short circuit, improving the parallel resistance of the solar cell, and increasing the yield and long-term reliability of the solar cell. On the other hand, the angle between the first clearance portion and the first main body is 90°~165°. This angle design aims to avoid stress concentration due to an excessively small or large turning angle, thereby reducing the risk of grid breakage and improving the structural integrity and mechanical reliability of the edge grid line. Attached Figure Description

[0022] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a silicon wafer fixed using a "three-point" graphite boat structure in existing technology; Figure 2 A schematic diagram showing the location of the markings on the battery surface provided in an embodiment of this disclosure; Figure 3 A partial cross-sectional structural diagram of a solar cell provided in an embodiment of this disclosure; Figure 4This is a top view schematic diagram of a solar cell provided in an embodiment of the present disclosure; Figure 5 This is a partial structural schematic diagram of a solar cell provided in an embodiment of the present disclosure; Figure 6 This is a partial structural diagram of the edge grid line provided in an embodiment of the present disclosure; Figure 7 This is a schematic diagram of another partial structure of a solar cell provided in an embodiment of this disclosure; Figure 8 This is a partial structural diagram of the edge connection line provided in an embodiment of the present disclosure; Figure 9 This is a schematic diagram of the electroluminescence test results provided in an embodiment of this disclosure; Figure 10 This is a partial cross-sectional structural diagram of a stacked battery provided in an embodiment of the present disclosure; Figure 11 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in an embodiment of this disclosure.

[0024] Explanation of reference numerals in the attached figures: 1. Check point, 2. Silicon wafer, A-mark, 100. Substrate, 110. Grid line, 120. First surface, 101. First boundary region I. First region, 111. Second region, 121. Edge grid line, 122. First main body, 123. First clearance part, 124. First side, 125. Second boundary region II. Third region, 131. Fourth region, 141. First end, 126. Edge connection line, 130. Second main body, 132. Second clearance part, 133. Second side, 134. Stacked cell, 10. Bottom cell, 20. Perovskite cell, 30. Solar cell, 40. Encapsulation film, 41. Cover plate, 42. Detailed Implementation

[0025] In the manufacturing process of solar cells, a dielectric passivation layer, such as silicon nitride (SiNx), is typically deposited on the surface of the silicon wafer to achieve surface passivation, reduce carrier recombination, and also provide anti-reflection functionality. This process is generally completed in a PECVD (Plasma-Enhanced Chemical Vapor Deposition) machine, and the silicon wafer needs to be fixed and transported within the reaction chamber using a graphite boat.

[0026] refer to Figure 1 Currently, the industry generally adopts the "three-point" graphite boat structure, which supports the silicon wafer 2 from the back through three points 1 to ensure its stability during the high-temperature deposition process.

[0027] However, in actual processes, it was found that due to the physical obstruction of the precursor gas by the jamming area, the passivation layer at that location was not deposited sufficiently, resulting in a localized area of ​​thin passivation layer, i.e., a "jamming mark". (Reference) Figure 2 In the diagram, the "stuck spot" (A) not only reduces the passivation effect, leading to an increased local surface recombination rate, but also causes the grid lines to over-penetrate at weak points in the passivation layer during subsequent screen printing and sintering, contacting unintended doped areas and forming parasitic conductive paths. This results in decreased parallel resistance and a lower fill factor, severely impacting the cell's conversion efficiency and product yield. Furthermore, the tiny gaps between the stuck spot and the silicon wafer may leave conductive materials such as silver paste during the printing process. Under high-temperature processing conditions, this residual paste is prone to carbonization, forming carbonaceous contaminants. If the contaminated graphite boat is not cleaned promptly and enters the PECVD equipment with the next batch of cells, the carbides or metallic impurities attached to its surface may be released and deposited in the reaction chamber, causing chamber contamination. This type of contamination not only affects the film quality of subsequent batches of cells but may also lead to indirect contamination of the coating environment across batches, further exacerbating passivation layer defects and device performance fluctuations.

[0028] To alleviate this problem, two improvement paths have been explored in the field: The first approach is to optimize the graphite boat structure, adjust the position of the clamping points, or reduce the diameter of the clamping caps to ensure that the clamping marks avoid the gate line area. However, excessively reducing the size of the clamping caps can lead to insufficient clamping force on the silicon wafer, making it prone to slippage or even detachment at high temperatures, resulting in the risk of fragmentation and equipment failure. The second approach is to add a "film reinforcement" process after the main coating process to locally thicken the clamping mark area. While this method can restore the integrity of the passivation layer to some extent, it requires an additional deposition step, increases equipment investment and process complexity, significantly raising production costs.

[0029] Based on an in-depth analysis of the aforementioned technical problems, this disclosure creatively proposes a solar cell that effectively avoids the risk of leakage and short circuit caused by excessive penetration of the grid lines in the first region during the sintering process by setting a first avoidance part in the edge grid lines that is directly opposite to the first region and bends outward, thereby improving the parallel resistance, yield and long-term reliability of the solar cell.

[0030] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They 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 on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

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

[0035] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. Furthermore, when describing a component as "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a portion of the edge of the entire surface.

[0036] In the description of the embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. The formation or placement of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be placed between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or placement of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" can refer to a layer, film, region, portion, structure, etc.

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

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

[0039] refer to Figures 3 to 8 A solar cell includes a substrate 100 and multiple grid lines 120.

[0040] The substrate 100 has a first surface 101, the first surface 101 includes a first boundary region I extending along a first direction X, and the first boundary region I includes a first region 111 and a second region 121 located on opposite sides of the first region 111 along the first direction X.

[0041] The first boundary region I is a strip-shaped region extending along the first direction X, located at the edge of the battery. The first region 111 is the region that contacts the mounting point of the graphite boat when the substrate 100 is located inside the graphite boat. The second region 121 is the other regions in the first boundary region I excluding the first region 111.

[0042] In some embodiments, the width of the first boundary region I in the second direction Y is equal to the width of the first region 111 in the second direction Y.

[0043] It should be noted that, in other embodiments, the width of the first boundary region I in the second direction Y may be greater than the width of the first region 111 in the second direction Y.

[0044] It should be noted that the definitions of the first boundary region, the first region, and the second region apply to the entire battery cell, as well as to half or more of the battery cell after it has been cut along a third direction (perpendicular to the first direction X). That is, after the entire battery cell is cut, if a certain half of the cell still contains the marking area on the original entire battery cell, then the corresponding area on that half of the cell is still considered as the first boundary region, the first region, and the second region as defined in this disclosure.

[0045] The substrate 100 is used to receive incident light and generate photogenerated carriers. In some embodiments, the substrate 100 may be a semiconductor substrate 100, such as silicon, germanium, germanium-silicon, or silicon on an insulator.

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

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

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

[0049] The substrate 100 can be an N-type semiconductor substrate 100 or a P-type semiconductor substrate 100. The N-type semiconductor substrate 100 is doped with an N-type dopant element, which can be any one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate 100 is doped with a P-type dopant element, which can be any one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0050] The solar cells provided in this disclosure include, but are not limited to, BC cells (BackContact cells), TOPCON cells (Tunnel Oxide Passivated Contact cells), PERC cells (Passivated emitter and real cell cells), HIT / HJT cells (Heterojunction Technology cells), and one or any combination of gridless or multi-grid solar cells.

[0051] In some embodiments, the solar cell is a back-contact cell. Taking a single-sided cell as an example, the second surface of the substrate 100 serves as the light-receiving surface for receiving incident light, and the first surface 101 of the substrate 100 serves as the back-lighting surface. It should be noted that the light-receiving surface and the back-lighting surface are relative terms. The luminous flux of the light received by the light-receiving surface is greater than that of the back-lighting surface. The "back-lighting surface" described in this embodiment can also receive light.

[0052] refer to Figures 5 to 6 The grid lines 120 are located on the first surface 101 and are spaced apart along the second direction Y. The grid lines 120 extend along the first direction X. The multiple grid lines 120 include edge grid lines 122 disposed adjacent to the first boundary region I. The edge grid lines 122 include a first main body portion 123 and a first clearance portion 124 connected to the first main body portion 123. The first clearance portion 124 is located in the area shown by the dashed box in the figure. The first main body portion 123 extends along the first direction X. The first clearance portion 124 is directly opposite to the first region 111 in the second direction Y and bends away from the first region 111. The first clearance portion 124 includes a first side 125 connected to the first main body portion 123. The included angle θ between the first side 125 and the first main body portion 123 is 90°~165°.

[0053] It is understood that edge grid lines 122 refer to one or more rows of grid lines near the first boundary area I. The number of edge grid lines 122 can be set according to the size and shape of the checkpoint to achieve effective avoidance of the first area 111.

[0054] The projections of the first avoidance portion 124 and the first region 111 in the battery thickness direction do not overlap, that is, the two are staggered in planar layout, thereby effectively avoiding the first region 111, preventing excessive penetration of the grid line during sintering, thereby reducing the risk of leakage and improving the electrical performance and reliability of the battery.

[0055] Furthermore, the included angle θ between the first side 125 and the first main body 123 is 90°~165°. This angle design aims to avoid stress concentration due to an excessively small or large turning angle, thereby reducing the risk of grid breakage and improving the structural integrity and mechanical reliability of the edge grid line 122.

[0056] In some embodiments, the included angle θ between the first side 125 and the first main body 123 is 120°~135°.

[0057] The embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings.

[0058] See Figure 3 In some embodiments, the passivation layer 110 is located on the first surface 101, and the thickness of the passivation layer 110 corresponding to the first region 111 is less than the thickness of the passivation layer 110 corresponding to the second region 121.

[0059] In some embodiments, the passivation layer 110 is located on the surface of the semiconductor doped layer. The passivation layer 110 can significantly reduce the surface recombination rate and improve the open-circuit voltage of the solar cell. The passivation layer 110 may include a single-layer film structure or a stacked film structure, and the material of the passivation layer 110 may be any one or more of the following materials: silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0060] In some embodiments, the thickness of the passivation layer 110 on the first surface 101 can be determined by ellipsometer or reflectance spectroscopy. Because the first region 111 is physically blocked by the graphite boat during the thin film deposition process, the diffusion of the precursor gas is restricted, resulting in a significantly smaller passivation layer thickness in this region than the passivation layer thickness in the unblocked second region 121.

[0061] In the prior art, this thickness difference can easily lead to excessive penetration of the passivation layer 110 corresponding to the first region 111 during subsequent screen printing and sintering processes. This can cause it to come into contact with the unintended doped region, forming a parasitic conductive path, resulting in a decrease in parallel resistance and a reduction in fill factor, which seriously affects the conversion efficiency and product yield of the battery.

[0062] To avoid this problem, this disclosure starts with the graphic design of the grid line structure. By optimizing the grid line layout, the edge grid lines actively bypass the first area 111, fundamentally avoiding the overlapping contact between the grid lines and the first area 111.

[0063] In some embodiments, the first clearance portion 124 is trapezoidal, triangular, or arc-shaped. (See reference) Figures 5 to 7 In this disclosure, the first avoidance part 124 is described as a trapezoidal shape.

[0064] It should be noted that the shape of the first avoidance part 124 refers to the contour features presented by its overall extension path, specifically manifested as a trapezoidal, triangular or arc-shaped direction; however, the first avoidance part 124 itself is an open conductive line and does not form a closed loop, but only serves as part of the grid line to realize the functions of current conduction and area avoidance.

[0065] Understandably, the checkpoints on the graphite boat have various geometric shapes, such as rectangles, circles, or triangles. To achieve precise avoidance of the first zone 111, the contour of the first avoidance part 124 needs to be adapted to the specific shape of the checkpoint, so as to minimize the additional effective battery area occupied while completely avoiding the first zone 111.

[0066] For example, when the obstruction point is square or rectangular, the overall orientation of the first avoidance portion 124 can be set as a trapezoidal profile; when the obstruction point is circular, it can be set as an arc-shaped orientation accordingly. By matching the extension path of the first avoidance portion 124 with the projected shape of the obstruction point, high-precision avoidance of the first region 111 can be achieved, preventing the edge grid lines 122 from overlapping and contacting the first region 111. This effectively suppresses excessive penetration of the grid lines into the first region 111 during sintering, reduces the risk of leakage, improves the parallel resistance, fill factor, and overall electrical performance of the solar cell, and simultaneously increases the product manufacturing yield.

[0067] refer to Figure 6 In some embodiments, the width d1 of the first clearance portion 124 in the first direction X is 2mm to 4mm, for example, specifically 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm or 4mm.

[0068] For example, the projection width of the obstruction point on the graphite boat in the first direction X is 1.7mm to 2mm. In order to achieve precise avoidance of the first area 111 formed by the obstruction point, the width design of the first avoidance part 124 along the first direction X not only needs to take into account the size of the obstruction point itself, but also reserves a certain safety margin to cope with minor deviations or edge effects in the manufacturing process, so as to ensure that the first avoidance part 124 can completely avoid the first area 111.

[0069] By setting the width of the first clearance portion 124 to be greater than the actual width of the blocking point, incomplete clearance due to manufacturing tolerances or thermal expansion can be effectively prevented, ensuring that the first area 111 is always uncovered. At the same time, the width range of 2mm to 4mm minimizes the occupation of the effective light-receiving area of ​​the battery while ensuring clearance effect, thus maintaining a high photoelectric conversion efficiency.

[0070] refer to Figure 6 In some embodiments, the width d2 of the first clearance portion 124 in the second direction Y is 0.4mm to 0.7mm, for example, specifically 0.4mm, 0.5mm, 0.6mm or 0.7mm.

[0071] To ensure that the first avoidance portion 124 can completely avoid the first region 111, its width in the second direction Y must satisfy a geometric constraint: the difference between the projected width of the blocking point in the second direction Y and the distance of the first main body portion 123 from the nearest battery edge is less than the width of the first avoidance portion 124 in the second direction Y. In other words, the width of the first avoidance portion 124 in the second direction Y must be greater than the width of the portion of the projected width of the blocking point in the second direction Y that exceeds the width of the first main body portion 123. This ensures that the first avoidance portion 124 has sufficient lateral space to bend into the battery cell and completely avoid the first region 111, preventing the grid lines from covering the first region 111. This suppresses excessive penetration and leakage during the sintering process and improves the parallel resistance and conversion efficiency of the battery.

[0072] The projection width of the card point in the second direction Y refers to the width of the portion of the projection of the card point in the second direction Y that is located on the battery.

[0073] refer to Figure 7 In some embodiments, the distance k1 of the first clearance portion 124 from the nearest battery edge in the first direction X is 41mm to 44mm, for example, specifically 41mm, 42mm, 43mm or 44mm. Here, the distance of the first clearance portion 124 from the nearest battery edge in the first direction X refers to the distance of the geometric center of the first clearance portion 124 from the nearest battery edge in the first direction X.

[0074] For example, the geometric center of the projection of the graphite boat's locking point in the first direction X is 40.5mm to 41.5mm from the nearest cell edge. By setting the distance of the first clearance portion 124 from the nearest cell edge in the first direction X within the range of 41mm to 44mm, a safety offset of 0mm to 2.5mm is formed relative to the center of the locking point. This effectively achieves spatial misalignment avoidance without significantly increasing the area of ​​the first clearance portion 124, ensuring that even if there is a slight positional deviation in the first region 111, the first clearance portion 124 can still maintain isolation from the first region 111. This significantly reduces the risk of grid line penetration during screen printing and sintering, suppresses leakage and parallel resistance decrease, and improves the electrical performance and manufacturing yield of the solar cell.

[0075] In some embodiments, the passivation layer 110 corresponding to the first region 111 has a thickness of 20nm to 40nm, for example, specifically 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, or 40nm; the passivation layer 110 corresponding to the second region has a thickness of 70nm to 90nm, for example, specifically 70nm, 71nm, 72nm, 73nm, 74nm, 75nm, 76nm, 77nm, 78nm, 79nm, 80nm, 81nm, 82nm, 83nm, 84nm, 85nm, 86nm, 87nm, 88nm, 89nm, or 90nm.

[0076] Furthermore, to further enhance the overall performance of the gate structure, the material of the first clearance portion 124 may differ from that of at least a portion of the first main body portion 123. For example, the first main body portion 123 may use a highly conductive silver paste to ensure excellent conductivity; while the first clearance portion 124 may use a paste with stronger adhesion or a lower sintering temperature, thereby enhancing its interfacial bonding strength with the passivation layer 110 and reducing damage to the underlying film during high-temperature sintering. Through this differentiated material configuration, the conductivity and interfacial stability are optimized in different zones, significantly improving the reliability and durability of the gate structure.

[0077] In some embodiments, the first clearance portion 124 is formed by sintering a first slurry, and at least a portion of the first main body portion 123 is formed by sintering a second slurry, wherein the viscosity of the first slurry is greater than that of the second slurry.

[0078] The adhesion refers to the adhesion or interfacial bonding strength between the grid lines and the underlying passivation layer 110 after the sintering of the paste. For example, the first paste can be a high-adhesion silver paste containing glass phase components or organic coupling agents that enhance interfacial bonding; the second paste is a standard high-conductivity silver paste, which focuses on reducing bulk resistance.

[0079] It should be noted that the first clearance part 124 is not a continuous straight line structure, but is composed of multiple line segments connected together, including multiple bending points or corners, such as the connection between the first side 125 and the first main body part 123, which is in the shape of a non-continuous straight line.

[0080] Because the first clearance portion 124 has multiple structural inflection points, local stress concentration is prone to occur during high-temperature sintering and subsequent thermal cycling. If the adhesion is insufficient, delamination may occur at the interface between the gate line and the passivation layer 110, leading to defects such as gate breakage or false printing, which seriously affects the current collection capability. By using a first paste with higher adhesion in the first clearance portion 124, the interfacial bonding strength between the first clearance portion 124 and the passivation layer 110 can be significantly enhanced, effectively suppressing stress release and crack propagation caused by geometric abrupt changes, thereby avoiding the risk of gate breakage. At the same time, at least a portion of the first main body portion 123 still uses a second paste with high conductivity, taking into account the overall conductivity performance. This functional partitioning design significantly improves the structural robustness and manufacturing yield of the edge gate lines while ensuring efficient carrier transport.

[0081] It should be noted that the second paste can be the same as or different from the paste used for the grid lines 120 located in the region of the solar cell other than the first boundary region I.

[0082] In some embodiments, the first main body 123 includes a plurality of first sub-main bodies arranged at intervals along a first direction X, and one of the first sub-main bodies is connected to the first clearance portion 124; wherein the material of the first sub-main body that is spaced apart from the first clearance portion 124 is different from the material of the first clearance portion 124.

[0083] The edge gate line 122 provided in this embodiment has a segmented structure. The first main body 123 of the edge gate line 122 is composed of multiple first sub-main bodies arranged at intervals along the first direction X. At least one first sub-main body is connected to the first clearance part 124 to receive charge carriers from the clearance region and transfer them to the main gate or the bus region. At least one first sub-main body that is not directly connected to the first clearance part 124 and is spatially spaced apart is formed by sintering a different paste than the first clearance part 124. Specifically, since the first clearance part 124 has a bent structure and multiple turning points, stress concentration is likely to occur during sintering and thermal cycling. Using a first paste with high adhesion can effectively suppress the risk of interface delamination and gate breakage, ensuring structural reliability. The first sub-main body that is far away from the first clearance part 124 does not have the problem of stress concentration. Therefore, a paste with high conductivity is preferred to optimize the overall conduction performance of the gate line. By using this material differentiation design, the stability of the edge grid line 122 under complex layouts is improved, while the cost is reduced, balancing performance, yield and economy.

[0084] In some embodiments, the material of the first sub-body portion connected to the first clearance portion 124 is the same as the material of the first clearance portion 124.

[0085] Due to its numerous geometric transitions and complex structure, the first clearance section 124 uses a high-adhesion first paste to enhance its bonding strength with the passivation layer 110. If the first sub-body section connected to it uses a paste with lower adhesion, a region of abrupt change in interface properties will form at the junction, becoming a weak point for mechanical stress release and easily leading to delamination, cracking, or grid breakage. Using the same material can achieve a smooth stress transition and improve the overall structural integrity. Furthermore, during the screen printing process, if the first clearance section 124 and the first sub-body section connected to it are considered as a single functional unit and the same paste is used uniformly, frequent paste changes or multi-layer printing processes can be avoided in the same electrode pattern, reducing the difficulty of process control and improving production efficiency and yield.

[0086] It should be noted that in other embodiments, the material of the first sub-body portion connected to the first clearance portion 124 may be different from the material of the first clearance portion 124.

[0087] refer to Figures 4 to 5 In some embodiments, the first surface 101 includes a second boundary region II extending along the second direction Y, and the second boundary region II includes a third region 131 and a fourth region 141 located on opposite sides of the third region 131 along the second direction Y, and the thickness of the passivation layer 110 corresponding to the third region 131 is less than the thickness of the passivation layer 110 corresponding to the fourth region 141; in the first direction X, the gate line 120 disposed adjacent to the third region 131 approaches the first end 126 of the third region 141 and contracts toward the side away from the third region 131.

[0088] The second boundary region II is a strip-shaped region extending along the second direction Y, located at the edge of the battery. The third region 131 is the region that contacts the locking point of the graphite boat when the substrate 100 is located inside the graphite boat. The fourth region 141 is the other regions in the second boundary region II except for the third region 131.

[0089] In some embodiments, the width of the second boundary region II in the first direction X is equal to the width of the third region 131 in the first direction X.

[0090] It should be noted that, in other embodiments, the width of the second boundary region II in the first direction X may be greater than the width of the third region 131 in the first direction X.

[0091] It should be noted that the definitions of the second boundary region, the third region, and the fourth region apply to the entire battery cell, as well as to half or more of the battery cell cut along a third direction (perpendicular to the first direction X). That is, after the entire battery cell is cut, if a certain half-cell still contains the marking area on the original entire battery cell, then the corresponding area on that half-cell is still considered as the second boundary region, the third region, and the fourth region as defined in this disclosure. Specifically, in the entire battery cell, one second boundary region includes two third regions; while in the half-cell cell, one second boundary region includes one third region.

[0092] Because the diffusion of precursor gas is restricted in the third region 131 due to the physical obstruction of the graphite boat during the thin film deposition process, the deposition thickness of the passivation layer 110 in this region is significantly smaller than the passivation layer thickness corresponding to the unobstructed fourth region 141.

[0093] In the prior art, this thickness difference can easily lead to excessive penetration of the passivation layer 110 corresponding to the third region 131 during subsequent screen printing and sintering processes. This can cause contact with the unintended doped region, forming a parasitic conductive path, resulting in a decrease in parallel resistance and a reduction in fill factor, which seriously affects the conversion efficiency and product yield of the battery.

[0094] To circumvent this problem, this disclosure avoids the third region 131 by controlling the length and endpoint position of the grid line 120 adjacent to the third region 131. Specifically, in the first direction X, the first end 126 of the grid line 120 adjacent to the third region 131 does not extend to the edge of the cell, but is retracted away from the third region 131. This retraction design ensures that the projection of the grid line 120 near the third region 131 in the cell thickness direction does not overlap with the third region 131 at all, thereby preventing the grid line from penetrating the thin passivation layer 110 below the third region 131 during high-temperature sintering, effectively suppressing local leakage current, and improving the parallel resistance and fill factor of the cell. This solution does not require increasing the complexity of the grid line pattern; leakage risk can be avoided simply by adjusting the grid line length. It has the advantages of simple process, easy control, and good compatibility, and is suitable for the production and manufacturing of large-scale high-efficiency solar cells.

[0095] refer to Figures 7 to 8 In some embodiments, the solar cell further includes: an edge connecting line 130 disposed adjacent to the second boundary region II, the edge connecting line 130 including a second main body portion 132 and a second clearance portion 133 connected to the second main body portion 132, wherein the second clearance portion 133 is located in the area shown by the dashed box in the figure, the second main body portion 132 extends along the second direction Y, the second clearance portion 133 is directly opposite to the third region 131 in the first direction X and bends toward a direction away from the third region 131, and the second clearance portion 133 is connected to the first end 126.

[0096] It is understood that the edge connection line 130 connects to the first end of the gate line 120 disposed adjacent to the third region 131, and is used to collect the current collected by the gate line 120 disposed adjacent to the third region 131.

[0097] The projections of the second avoidance portion 133 and the third region 131 in the battery thickness direction do not overlap, meaning that the two are staggered in planar layout, thereby effectively avoiding the area of ​​the third region 131 where the passivation layer is relatively thin, preventing excessive penetration of the grid lines during sintering, thereby reducing the risk of leakage and improving the electrical performance and reliability of the battery.

[0098] The second avoidance part 133 includes a second side 134 connected to the second main body part 132. The included angle α between the second side 134 and the second main body part 132 is 90°~165°. This angle design is intended to avoid stress concentration due to the turning angle being too small or too large, thereby reducing the risk of grid breakage and improving the structural integrity and mechanical reliability of the edge connection line 130.

[0099] In other embodiments, the included angle α between the second side 134 and the second main body 132 is 120°~135°.

[0100] In some embodiments, the second clearance portion 133 is trapezoidal, triangular, or arc-shaped. (See reference) Figures 7 to 8 This disclosure uses the shape of the second avoidance part 133 as an example to illustrate the concept.

[0101] It should be noted that the shape of the second avoidance part 133 refers to the contour features presented by its overall extension path, specifically manifested as a trapezoidal, triangular or arc-shaped direction; however, the second avoidance part 133 itself is an open conductive line and does not form a closed loop, but only serves as part of the grid line to realize the functions of current conduction and area avoidance.

[0102] Understandably, the obstruction points on the graphite boat have various geometric shapes, such as rectangles, circles, or triangles. To achieve precise avoidance of the third zone 131, the contour of the second avoidance part 133 needs to be adapted to the specific shape of the obstruction point, so as to minimize the additional effective battery area occupied while completely avoiding the third zone 131.

[0103] For example, when the obstruction point is square or rectangular, the overall orientation of the second avoidance portion 133 can be set as a trapezoidal profile; when the obstruction point is circular, it can be set as an arc-shaped orientation accordingly. By matching the extension path of the second avoidance portion 133 with the projected shape of the obstruction point, high-precision avoidance of the third region 131 can be achieved, preventing the edge connection line 130 from overlapping with the third region 131. This effectively suppresses excessive penetration of the grid lines into the third region 131 during sintering, reduces the risk of leakage, improves the parallel resistance, fill factor, and overall electrical performance of the solar cell, and simultaneously increases the product manufacturing yield.

[0104] refer to Figure 8 In some embodiments, the width d3 of the second clearance portion 133 in the second direction Y is 2mm to 4mm, for example, specifically 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm or 4mm.

[0105] For example, the projection width of the obstruction point on the graphite boat in the second direction Y is 1.7mm to 2mm. In order to achieve precise avoidance of the third area 131 formed by the obstruction point, the width design of the second avoidance part 133 along the second direction Y not only needs to take into account the size of the obstruction point itself, but also reserves a certain safety margin to cope with minor deviations or edge effects in the manufacturing process, so as to ensure that the second avoidance part 133 can completely avoid the third area 131.

[0106] By setting the width of the second clearance section 133 to be greater than the actual width of the blocking point, incomplete clearance due to manufacturing tolerances or thermal expansion can be effectively prevented, ensuring that the third area 131 is always uncovered. At the same time, the width range of 2mm to 4mm minimizes the occupation of the effective light-receiving area of ​​the battery while ensuring clearance effect, thus maintaining a high photoelectric conversion efficiency.

[0107] refer to Figure 8 In some embodiments, the width d4 of the second clearance portion 133 in the first direction X is 0.4mm to 0.7mm, for example, specifically 0.4mm, 0.5mm, 0.6mm or 0.7mm.

[0108] To ensure that the second avoidance portion 133 can completely avoid the third region 131, its width in the first direction X must satisfy a geometric constraint: the difference between the projected width of the blocking point in the first direction X and the distance of the second main body portion 132 from the nearest battery edge is less than the width of the second avoidance portion 133 in the first direction X. In other words, the width of the second avoidance portion 133 in the first direction X must be greater than the width of the portion of the projected width of the blocking point in the first direction X that exceeds the width of the second main body portion 132. This ensures that the second avoidance portion 133 has sufficient lateral space to bend into the battery cell and completely avoid the third region 131, preventing the grid lines from covering the third region 131. This suppresses excessive penetration and leakage during the sintering process and improves the parallel resistance and conversion efficiency of the battery.

[0109] The projection width of the card point in the first direction X refers to the width of the portion of the projection of the card point in the first direction X that is located on the battery.

[0110] refer to Figure 7 In some embodiments, the distance k2 of the second clearance portion 133 from the nearest battery edge in the second direction Y is 41mm to 44mm, for example, specifically 41mm, 42mm, 43mm or 44mm. Here, the distance of the second clearance portion 133 from the nearest battery edge in the second direction Y refers to the distance of the geometric center of the second clearance portion 133 from the nearest battery edge in the second direction Y.

[0111] For example, the geometric center of the projection of the graphite boat's locking point in the second direction Y is 43.5mm to 44.5mm from the nearest cell edge. By setting the distance of the second clearance portion 133 from the nearest cell edge in the second direction Y to the range of 41mm to 44mm, a safety offset of 0mm to 2.5mm is formed relative to the center of the locking point. This effectively achieves spatial misalignment without significantly increasing the area of ​​the second clearance portion 133, ensuring that even if there is a slight positional deviation in the third region 131, the second clearance portion 133 can still maintain isolation from the third region 131. This significantly reduces the risk of grid line penetration during screen printing and sintering, suppresses leakage and parallel resistance decrease, and improves the electrical performance and manufacturing yield of the solar cell.

[0112] In some embodiments, the passivation layer thickness corresponding to the third region is 20nm to 40nm, for example, specifically 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, or 40nm; the passivation layer thickness corresponding to the fourth region is 70nm to 90nm, for example, specifically 70nm, 71nm, 72nm, 73nm, 74nm, 75nm, 76nm, 77nm, 78nm, 79nm, 80nm, 81nm, 82nm, 83nm, 84nm, 85nm, 86nm, 87nm, 88nm, 89nm, or 90nm.

[0113] Furthermore, to further enhance the overall performance of the edge connection lines, the material of the second clearance portion 133 may differ from that of at least a portion of the second main body portion 132. For example, the second main body portion 132 may use a highly conductive silver paste to ensure excellent conductivity; while the second clearance portion 133 may use a paste with stronger adhesion or a lower sintering temperature, thereby enhancing its interfacial bonding strength with the passivation layer 110 and reducing damage to the underlying film during high-temperature sintering. Through this differentiated material configuration, the conductivity and interfacial stability are optimized in different zones, significantly improving the reliability and durability of the gate structure.

[0114] In some embodiments, the second clearance portion 133 is formed by sintering a third slurry, and at least a portion of the second main body portion 132 is formed by sintering a fourth slurry, wherein the adhesion of the third slurry is greater than that of the fourth slurry.

[0115] It should be noted that the second avoidance part 133 is not a continuous straight line structure, but is composed of multiple line segments connected together, including multiple bending points or corners, such as the connection between the second side 134 and the second main body part 132, which is in the shape of a non-continuous straight line.

[0116] Because the second clearance portion 133 has multiple structural inflection points, local stress concentration is prone to occur during high-temperature sintering and subsequent thermal cycling. If the adhesion is insufficient, delamination may occur at the interface between the gate line and the passivation layer 110, leading to defects such as gate breakage or false printing, which seriously affects the current collection capability. By using a third paste with higher adhesion in the second clearance portion 133, the interfacial bonding strength between the second clearance portion 133 and the passivation layer 110 can be significantly enhanced, effectively suppressing stress release and crack propagation caused by geometric abrupt changes, thereby avoiding the risk of gate breakage. At the same time, at least a portion of the second main body portion 132 still uses a fourth paste with high conductivity, taking into account the overall conductivity performance. This functional partitioning design significantly improves the structural robustness and manufacturing yield of the edge gate lines while ensuring efficient carrier transport.

[0117] It should be noted that the third slurry can be the same as or different from the first slurry; the fourth slurry can be the same as or different from the second slurry.

[0118] In some embodiments, the second main body portion 132 includes a plurality of second sub-main body portions arranged at intervals along the second direction Y, and one of the second sub-main body portions is connected to the second clearance portion 133; wherein the material of the second sub-main body portion spaced apart from the second clearance portion 133 is different from the material of the second clearance portion 133.

[0119] The edge connection line 130 provided in this embodiment has a segmented structure. The second main body 132 of the edge connection line 130 is composed of multiple second sub-main bodies arranged at intervals along the second direction Y. At least one second sub-main body is connected to the second clearance part 133 to receive charge carriers from the clearance region and transfer them to the main gate or the bus region. At least one second sub-main body is not directly connected to the second clearance part 133 and is spatially spaced apart from it. It is formed by sintering a different paste than the second clearance part 133. Specifically, since the second clearance part 133 has a bent structure and multiple turning points, stress concentration is likely to occur during sintering and thermal cycling. Using a third paste with high adhesion can effectively suppress the risk of interface delamination and gate breakage, ensuring structural reliability. The second sub-main body far from the second clearance part 133 does not have the problem of stress concentration. Therefore, a paste with high conductivity is preferred to optimize the overall grid line conductivity. By using this material differentiation design, the stability of the edge connection line 130 under complex layouts is improved, while the cost is reduced, balancing performance, yield and economy.

[0120] In some embodiments, the material of the second sub-body portion connected to the second clearance portion 133 is the same as the material of the second clearance portion 133.

[0121] Due to its numerous geometric transitions and complex structure, the second clearance section 133 uses a third paste with high adhesion to enhance its bonding strength with the passivation layer 110. If the second sub-body section connected to it uses a paste with lower adhesion, a region of abrupt change in interface properties will form at the junction, becoming a weak point for mechanical stress release and easily leading to delamination, cracking, or grid breakage. Using the same material can achieve a smooth stress transition and improve the overall structural integrity. Furthermore, during the screen printing process, if the second clearance section 133 and the second sub-body section connected to it are considered as a single functional unit and the same paste is used uniformly, frequent paste changes or multi-layer printing processes can be avoided in the same electrode pattern, reducing the difficulty of process control and improving production efficiency and yield.

[0122] It should be noted that in other embodiments, the material of the second sub-body portion connected to the second clearance portion 133 may be different from the material of the second clearance portion 133.

[0123] Understandably, both the first clearance section 124 and the second clearance section 133 are clearance structures designed to avoid "stick marks". In the solar cell coating process, graphite boats typically load solar cells back-to-back, meaning two cells are placed on each boat blade, symmetrically arranged with their backs facing each other. When N sticking points are set on one side of the graphite boat, each sticking point contacts the surface of one solar cell, thus directly forming N sticking marks on the surface of each solar cell.

[0124] Because the two batteries are mounted symmetrically back-to-back, their respective N locking points are axially symmetrically distributed on the battery plane with respect to the center of the battery cell. In other words, the locking point positions of the two batteries on the same blade are mirror images of each other.

[0125] To ensure that the jamming marks on the battery are effectively avoided regardless of which side of the boat blade it is positioned on, this embodiment of the present disclosure pre-defines 2N avoidance structures in the grid line design of a single battery cell. N of these avoidance structures correspond to the N jamming marks of the battery in a certain mounting position, while the other N correspond to the jamming marks in a symmetrical mounting position. This compatible design ensures that when the battery is mounted on either side, all jamming marks are within the avoidance range of the avoidance structures, and the grid lines will not cover the weak areas of the passivation layer.

[0126] For example, when a graphite boat has three locking points on one side, each battery surface actually forms three locking point imprints. However, in the electrode pattern design, a total of six avoidance structures are set, corresponding to the locking point imprint positions in the two loading states. In this way, regardless of whether the battery is placed on the front or back of the boat blade, its locking point imprints can be precisely avoided, thereby effectively preventing the grid lines from penetrating the passivation layer in the locking point imprint area during sintering, avoiding leakage, and improving parallel resistance and battery yield.

[0127] To verify the effectiveness of the grid structure of the solar cell provided in this disclosure in suppressing the leakage risk in the printing area, two groups of 10 cells each were selected for leakage performance testing. The control group used cells with a traditional printing design, i.e., cells where the grid lines overlap with the printing area; the experimental group used cells with the new printing design described in the embodiments of this disclosure, i.e., cells where the grid lines avoid the printing area. The test results are shown in Table 1.

[0128] Table 1

[0129] The data shows that, compared with the control group, the parallel resistance (Rsh) of the experimental group increased from 1803Ω to 1957Ω, and the reverse bias leakage current (IRev) decreased from 0.019A to 0.016A, indicating that the solar cell provided in this disclosure can effectively reduce the overall leakage level of the cell and improve electrical reliability.

[0130] Simultaneously, reverse-biased electroluminescence (REE) tests were performed on both sets of batteries. (Reference) Figure 9 Figure a shows the EL test results of the experimental group, and figure b shows the EL test results of the control group. The cells in the control group showed obvious linear or clustered bright spots in multiple card-marked areas, indicating the existence of significant local leakage channels; while the cells in the experimental group did not show obvious leakage in the card-marked areas, with only a few discontinuous weak bright spots at the local edges. This shows that the solar cell provided in this disclosure can effectively avoid grid line coverage in high-risk areas and significantly suppress leakage behavior caused by weak passivation layer.

[0131] The experimental results above demonstrate that this disclosure, by optimizing the grid line structure layout, incorporates a first avoidance portion in the edge grid lines that faces the thinner passivation layer and bends away from the cell center, while a second avoidance portion in the edge connecting lines faces the third region and also bends outwards. This achieves precise avoidance of the first and third regions, which are areas prone to jamming. This design effectively prevents excessive penetration of the electrode into the thin passivation layer region during sintering, significantly suppresses the risk of local leakage and short circuits, and improves the parallel resistance, cell yield, and long-term operational reliability of the solar cell. Furthermore, the first and second avoidance portions utilize a conductive paste with higher adhesion, significantly enhancing the interfacial bonding strength between the avoidance structure and the underlying passivation layer. This effectively alleviates stress concentration caused by abrupt geometric changes, suppresses interfacial delamination and crack propagation, and thus avoids structural failures such as grid breakage. Simultaneously, at least a portion of the first and second main bodies still uses a highly conductive paste, ensuring the mechanical stability of critical areas while also considering the overall electrode conductivity and current carrying capacity. This functional zoning design significantly improves the structural robustness and manufacturing yield of the edge electrodes while ensuring efficient carrier transport. Furthermore, by setting the shape, size, and position of the first and second avoidance parts according to the shape, size, and position of the locking points on the graphite boat, high-precision avoidance of the first region is achieved, preventing overlapping contact between the edge grid lines and the first region. This effectively suppresses excessive penetration of the grid lines into the first region during sintering, reduces the risk of leakage, improves the parallel resistance, fill factor, and overall electrical performance of the solar cell, and simultaneously increases product manufacturing yield.

[0132] According to some embodiments of this disclosure, another aspect of this disclosure provides a tandem battery, including the solar cell as described in the above embodiments. The tandem battery provided in yet another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. For parts that are the same as or corresponding to the previous embodiment, please refer to the corresponding descriptions of the foregoing embodiments; detailed descriptions will not be repeated below.

[0133] Figure 10 This is a partial cross-sectional structural diagram of a stacked battery provided in an embodiment of this disclosure.

[0134] refer to Figure 10 The tandem solar cell 10 includes a bottom cell 20 and a perovskite cell 30.

[0135] The bottom cell 20 is a solar cell as described in the above embodiment.

[0136] The perovskite solar cell 30 is located on one side of the bottom cell 20.

[0137] In some embodiments, an intermediate layer may be included between the bottom cell 20 and the perovskite cell 30, and the charge carriers in the bottom cell 20 and the perovskite cell 30 are connected in series through recombination in the intermediate layer. The intermediate layer may be a transparent conductive layer.

[0138] According to some embodiments of this disclosure, another aspect of this disclosure also provides a photovoltaic module, which is formed by connecting multiple solar cells provided in the foregoing embodiments, or by connecting multiple tandem solar cells provided in the foregoing embodiments. The following will describe in detail another embodiment of the photovoltaic module provided by this disclosure with reference to the accompanying drawings. For parts that are the same as or corresponding to the previous embodiment, please refer to the corresponding descriptions of the foregoing embodiments; detailed descriptions will not be repeated below.

[0139] Figure 11 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in an embodiment of this disclosure.

[0140] refer to Figure 11 The photovoltaic module provided in this embodiment includes: a battery string, an encapsulating film 41, and a cover plate 42.

[0141] The battery string is formed by connecting multiple solar cells 40 as described in the above embodiments, or by connecting multiple stacked batteries provided in the aforementioned embodiments.

[0142] The encapsulating film 41 is used to cover the surface of the battery string.

[0143] Cover plate 42 is used to cover the surface of the encapsulating film away from the battery string.

[0144] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the solar cell, and the second encapsulating layer covers the other of the front or back sides of the solar cell. Specifically, at least one of the first or second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first or second encapsulating layer can also be an EP film, an EPE film, or a PVP film. Here, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film + POE film + EVA film; and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. Co-extruded films can be manufactured by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0145] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0146] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0147] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A solar cell, characterized in that, include: The substrate has a first surface, the first surface including a first boundary region extending along a first direction, and the first boundary region including a first region and second regions located on opposite sides of the first region along the first direction; Multiple grid lines are located on the first surface and are spaced apart along the second direction. The grid lines extend along the first direction. The multiple grid lines include edge grid lines disposed adjacent to the first boundary area. The edge grid lines include a first main body portion and a first clearance portion connected to the first main body portion. The first main body portion extends along the first direction. The first clearance portion is directly opposite to the first area in the second direction and bends away from the first area. The first clearance portion includes a first side connected to the first main body portion, and the included angle between the first side and the first main body portion is 90°~165°.

2. The solar cell according to claim 1, characterized in that, The solar cell also includes: A passivation layer is located on the first surface, and the thickness of the passivation layer corresponding to the first region is less than the thickness of the passivation layer corresponding to the second region.

3. The solar cell according to claim 1, characterized in that, The first clearance part is trapezoidal, triangular or arc-shaped.

4. The solar cell according to claim 1, characterized in that, The width of the first clearance portion in the first direction is 2mm to 4mm.

5. The solar cell according to claim 1, characterized in that, The width of the first clearance portion in the second direction is 0.4mm to 0.7mm.

6. The solar cell according to claim 1, characterized in that, The distance between the first clearance portion and the nearest battery edge in the first direction is 41mm to 44mm.

7. The solar cell according to claim 2, characterized in that, The passivation layer thickness corresponding to the first region is 20nm to 40nm, and the passivation layer thickness corresponding to the second region is 70nm to 90nm.

8. The solar cell according to claim 2, characterized in that, The first surface includes a second boundary region extending along the second direction, and the second boundary region includes a third region and a fourth region located on opposite sides of the third region along the second direction, and the thickness of the passivation layer corresponding to the third region is less than the thickness of the passivation layer corresponding to the fourth region. In the first direction, the grid line disposed adjacent to the third region is close to the first end of the third region and tapers away from the third region.

9. The solar cell according to claim 8, characterized in that, The solar cell also includes: An edge connecting line is provided adjacent to the second boundary area. The edge connecting line includes a second main body and a second clearance part connected to the second main body. The second main body extends along the second direction. The second clearance part is directly opposite the third area in the first direction and bends away from the third area. The second clearance part is connected to the first end.

10. The solar cell according to claim 9, characterized in that, The second clearance part is trapezoidal, triangular or arc-shaped.

11. The solar cell according to claim 9, characterized in that, The width of the second clearance portion in the second direction is 2mm to 4mm.

12. The solar cell according to claim 9, characterized in that, The width of the second clearance portion in the first direction is 0.4mm to 0.7mm.

13. The solar cell according to claim 9, characterized in that, The distance between the second clearance portion and the nearest battery edge in the second direction is 41mm to 44mm.

14. The solar cell according to claim 8, characterized in that, The passivation layer thickness corresponding to the third region is 20nm to 40nm, and the passivation layer thickness corresponding to the fourth region is 70nm to 90nm.

15. A stacked battery, characterized in that, include: A bottom battery, wherein the bottom battery is a solar cell according to any one of claims 1 to 14; A perovskite solar cell, wherein the perovskite solar cell is located on one side of the bottom solar cell.

16. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple solar cells according to any one of claims 1 to 14, or by connecting multiple stacked cells as described in claim 15; An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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