Photovoltaic cell and method of manufacturing the same, printing screen, laminated cell, photovoltaic module

Abstract

The present disclosure relates to the field of photovoltaics, and provides a photovoltaic cell, a manufacturing method thereof, a printing screen, a laminated cell, and a photovoltaic module. The photovoltaic cell comprises a cell substrate comprising a first surface and a second surface arranged oppositely; a first fine grid and a second fine grid on the first surface, the first fine grid and the second fine grid comprising a plurality of first parts arranged at intervals in a second direction, the first direction intersecting the second direction; in the first direction, the length of the first part in the first fine grid is a first length, and the length of the first part in the second fine grid is a second length, the first length being greater than the second length. The present disclosure is at least beneficial to improving the alignment accuracy and connection strength of the first part in the first fine grid and subsequent other conductive parts.

Description

Technical Field

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

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

[0003] Current photovoltaic cells mainly include BC cells (Back Contact Cell), TOPCON cells (Tunnel Oxide Passivated Contact Cell), PERC cells (Passivated Emitter and Rear Cell), and heterojunction cells (Heterojunction with Intrinsic Thin-layer, abbreviated as HIT or HJT).

[0004] However, further research is needed on how to effectively collect photogenerated carriers in photovoltaic cells in order to improve their photoelectric conversion efficiency. Summary of the Invention

[0005] This disclosure provides a photovoltaic cell and its manufacturing method, a printing screen, a tandem cell, and a photovoltaic module, which at least helps to improve the alignment accuracy and connection strength of the first part and subsequent conductive parts in the first fine grid.

[0006] This disclosure provides a photovoltaic cell, comprising: a cell substrate, the cell substrate including a first surface and a second surface disposed opposite to each other; a first grid and a second grid located on the first surface, the first grid and the second grid including a plurality of first portions arranged at intervals along a second direction; along the first direction, the length of the first portion in the first grid is a first length, the length of the first portion in the second grid is a second length, the first length is greater than the second length, and the first direction intersects the second direction.

[0007] Optionally, the ratio of the first length to the second length is 1.02 to 20.

[0008] Optionally, the first length is 7 μm to 100 μm; and / or, the second length is 5 μm to 98 μm.

[0009] Optionally, the difference between the first length and the second length is 2μm to 30μm.

[0010] Optionally, the thickness of the first portion in the first fine grid is a first thickness, and the thickness of the first portion in the second fine grid is a second thickness, wherein the first thickness is greater than the second thickness.

[0011] Optionally, the difference between the first thickness and the second thickness is 0.5 μm to 1.5 μm.

[0012] Optionally, the first thickness is 1 μm to 6 μm; and / or, the second thickness is 0.5 μm to 5 μm.

[0013] Optionally, along the second direction, the spacing between adjacent first portions in the first fine grid is a first spacing, and the spacing between adjacent first portions in the second fine grid is a second spacing, wherein the first spacing is greater than the second spacing.

[0014] Optionally, the ratio of the first spacing to the second spacing is 35 / 33 to 35 / 3.

[0015] Optionally, the first spacing is 50μm to 350μm; and / or, the second spacing is 30μm to 330μm.

[0016] Optionally, the first fine gate and the second fine gate further include a second portion extending along the second direction, the second portion being connected to a plurality of the first portions; along the first direction, the width of the second portion in the first fine gate is a first width, the width of the second portion in the second fine gate is a second width, and the first width is greater than the second width.

[0017] Optionally, the ratio of the first width to the second width is 5 / 4 to 10 / 3.

[0018] Optionally, the first width is 20μm to 50μm; and / or, the second width is 15μm to 40μm.

[0019] Optionally, the material of the first part includes at least one of silver, silver-plated copper, silver-copper alloy, silver-plated nickel, or silver-nickel alloy, and the material of the second part includes at least one of silver-plated copper, silver-copper alloy, silver-plated nickel, silver-nickel alloy, silver-plated tin, silver-tin alloy, copper, or nickel.

[0020] Optionally, it further includes: a third fine grid located on the first surface, the third fine grid being located on the side of the second fine grid away from the first fine grid; the length of the first portion in the third fine grid is a third length, the third length being less than the second length.

[0021] This disclosure also provides a printing screen, comprising: the printing screen having a first opening and a second opening; and along a first direction, the length of the first opening being greater than the length of the second opening.

[0022] Optionally, the spacing between adjacent first openings along the second direction is a third spacing, and the spacing between adjacent second openings along the second direction is a fourth spacing, wherein the third spacing is greater than the fourth spacing, and the first direction intersects the second direction.

[0023] This disclosure also provides a method for manufacturing a photovoltaic cell, comprising: forming a photovoltaic cell including a first grid and a second grid; the photovoltaic cell includes a cell substrate, the cell substrate including a first surface and a second surface disposed opposite to each other, the first grid and the second grid being located on the first surface, the first grid and the second grid including a plurality of first portions arranged at intervals along a second direction; along the first direction, the length of the first portion in the first grid is a first length, the length of the first portion in the second grid is a second length, the first length is greater than the second length, and the first direction intersects the second direction.

[0024] This disclosure also provides a tandem solar cell, comprising: a base cell, which is a photovoltaic cell as described in any of the preceding claims, or a photovoltaic cell formed using a printing screen as described in any of the preceding claims, or a photovoltaic cell formed by a manufacturing method of a photovoltaic cell as described in any of the preceding claims; and a perovskite cell located on one side of the base cell.

[0025] This disclosure also provides a photovoltaic module, comprising: a battery string, which is formed by connecting a plurality of photovoltaic cells as described in any of the preceding claims, or by connecting a plurality of photovoltaic cells formed using a printing screen as described in any of the preceding claims, or by connecting a plurality of photovoltaic cells formed by a method for manufacturing photovoltaic cells as described in any of the preceding claims, or by connecting a plurality of stacked cells as described in the preceding claims; an encapsulation layer for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulation layer opposite to the battery string.

[0026] The technical solution provided in this disclosure has at least the following advantages: The lengths of the first portion in the first fine grid and the first portion in the second fine grid are designed differently, with the first length being greater than the second length. On one hand, the first portion with the first length helps increase the alignment area between the first portion and subsequent conductive portions and reduces alignment errors, thereby ensuring the effective transmission of photogenerated carriers collected by the first portion by subsequent conductive portions. On the other hand, the first portion with the first length helps increase the connection area between the first portion and subsequent conductive portions, thereby increasing the connection strength and reducing the contact resistance between the first portion and subsequent conductive portions. Thus, for the first fine grid, the transmission efficiency of photogenerated carriers collected by the first portion by subsequent conductive portions can be comprehensively improved, and the risk of subsequent conductive portions detaching from the first portion can be reduced, thereby improving the structural stability of the first fine grid. Moreover, even if there is a certain degree of deformation in the area corresponding to the first fine grid in the printing screen, the first portion with the first length can still ensure the connection between the first portion and subsequent conductive portions, thereby helping to extend the service life of the printing screen and reducing the manufacturing cost of the first fine grid.

[0027] Furthermore, the second fine grid is generally subjected to less external force, and the area in the printing screen corresponding to the second fine grid is not easily deformed. The design of the second length of the first part is relatively small, which can also ensure that the first part and other subsequent conductive parts have sufficient connection area, thereby helping to reduce the material cost of the first part. Attached Figure Description

[0028] 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.

[0029] Figure 1 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. Figure 2 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 3 for Figure 2 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-section direction AA1. Figure 4 This is a third partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 5 for Figure 4 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-section direction AA1. Figure 6 This is a fourth partial top view structural diagram of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 7 for Figure 6 The diagram shows a schematic of a turning cross-sectional structure of a photovoltaic cell along the second cross-section direction BB1. Figure 8 This is a fifth partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 9 for Figure 8 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-section direction AA1. Figure 10 This is a sixth partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 11 This is a seventh partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 12 This is a partial top view schematic diagram of an eighth type of photovoltaic cell structure provided in an embodiment of the present disclosure; Figure 13 A partial top view of a printing screen provided in another embodiment of this disclosure; Figure 14 Another partial top view of the printing screen provided in another embodiment of this disclosure; Figure 15 This is a partial top view of the initial cell substrate in a method for manufacturing a photovoltaic cell according to another embodiment of the present disclosure. Figure 16 A partial cross-sectional structural diagram of a stacked battery provided in another embodiment of the present disclosure; Figure 17 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure; Figure 18 This is a cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0030] Explanation of reference numerals in the attached figures: 101. First side; 111. First zone; 121. Second zone; 131. Third zone; 12. Zone division; 102. Second side; 103. Fine grid; 113. First fine grid; 123. Second fine grid; 133. First part; 143. Second part; 153. Third fine grid; 104. Chamfer; 105. Cell substrate; 115. Edge area; 125. Center area; 105a. First edge; 105b. Second edge; 135. Initial cell substrate; 1351. Sixth zone; 1352. Seventh zone; 106. Printing screen; 116. First opening; 126. Second opening; 136. Fourth zone; 146. Fifth zone; 117. Bottom cell; 127. Perovskite cell; 40. Photovoltaic cell; 41. Encapsulation layer; 42. Cover plate; 43. Solder ribbon. Detailed Implementation

[0031] As can be seen from the background technology, the photoelectric conversion efficiency of photovoltaic cells needs to be improved.

[0032] Analysis revealed that, to balance the collection of photogenerated charge carriers and reduce carrier recombination in photovoltaic cells, the grid typically includes components for directly collecting charge carriers and components for transporting charge carriers, with these two components interconnected. However, when the two components are fabricated in batches, alignment misalignment can easily occur, leading to ineffective transport of collected charge carriers. Furthermore, as the lifespan of the printing screens used to fabricate the two components increases, the dimensional errors of the components formed using the printing screens also increase, further amplifying the alignment error between the two components.

[0033] This disclosure provides a photovoltaic cell and its manufacturing method, a printing screen, a tandem cell, and a photovoltaic module. In the photovoltaic cell, the lengths of the first portion in the first fine grid and the first portion in the second fine grid are differentiated, i.e., the first length is designed to be greater than the second length. On the one hand, the first portion with the first length is beneficial to increasing the alignment area between the first portion and subsequent conductive portions and reducing alignment errors, thereby ensuring the transmission effect of photogenerated carriers collected by the first portion by subsequent conductive portions. On the other hand, the first portion with the first length is beneficial to increasing the connection area between the first portion and subsequent conductive portions, thereby increasing the connection strength between the first portion and subsequent conductive portions and reducing the contact resistance between the first portion and subsequent conductive portions. Thus, for the first fine grid, the transmission efficiency of photogenerated carriers collected by the first portion by subsequent conductive portions can be comprehensively improved, and the risk of subsequent conductive portions detaching from the first portion can be reduced, thereby improving the structural stability of the first fine grid. Moreover, even if there is a certain degree of deformation in the area corresponding to the first fine grid in the printing screen, the first portion with the first length can still ensure the connection between the first portion and subsequent conductive portions, thereby helping to improve the service life of the printing screen and reducing the manufacturing cost of the first fine grid. Furthermore, the second fine grid is generally subjected to less external force, and the area in the printing screen corresponding to the second fine grid is not easily deformed. The design of the second length of the first part is relatively small, which can also ensure that the first part and other subsequent conductive parts have sufficient connection area, thereby helping to reduce the material cost of the first part.

[0034] 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 (including two), 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).

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] In the description of the embodiments disclosed herein, electrical connection between one component and another means that both components are made of conductive materials, and the two components are in direct contact and connected or connected via other conductive materials, so that current flows between the two components when the device is generating electricity. Electrical contact between one component and another means that the two components are not only in contact, but also that current flows between them when the device is generating electricity because both components are made of conductive materials.

[0040] In the description of embodiments of this disclosure, the terms "about," "approximately," "roughly," or "about" for a numerical value referring to a specific parameter include the numerical value, and those skilled in the art will understand that the deviation from the numerical value is within acceptable tolerances of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0041] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. Furthermore, when describing a component as being "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.

[0042] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. When a component (such as a layer, film, region, or substrate) is described as being on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be an intermediate component between the two components. Conversely, when a component is described as being on the surface of another component, or a component is "directly" on another component, or another component is formed or disposed on the surface of a component, it indicates that there is no intermediate component between the two components. For simplicity and clarity, various components may be drawn at any scale. In the drawings, some components may be omitted for simplicity.

[0043] 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 "the component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0044] The “components” mentioned above can refer to layers, films, regions, parts, structures, etc.

[0045] 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 embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0046] This disclosure provides a photovoltaic cell according to one embodiment. The photovoltaic cell provided by this disclosure will be described in detail below with reference to the accompanying drawings.

[0047] Reference Figures 1 to 3 The photovoltaic cell includes: a cell substrate 105, the cell substrate 105 including a first surface 101 and a second surface 102 disposed opposite to each other; a first grid 113 and a second grid 123 located on the first surface 101, the first grid 113 and the second grid 123 including a plurality of first portions 133 arranged at intervals along a second direction Y; along the first direction X, the length of the first portion 133 in the first grid 113 is a first length L1, the length of the first portion 133 in the second grid 123 is a second length L2, the first length L1 is greater than the second length L2, and the first direction X intersects the second direction Y.

[0048] In other words, the first surface 101 can be considered as being divided into at least a first region 111 and a second region 121 along the first direction X, and the fine grid 103 located on the first surface 101 includes a first fine grid 113 and a second fine grid 123. The first fine grid 113 can be considered as the fine grid 103 located in the first region 111, and the second fine grid 123 can be considered as the fine grid 103 located in the second region 121.

[0049] Figure 1 This is a partial top view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure. Figure 2 This is a partial top view schematic diagram of a photovoltaic cell provided in an embodiment of the present disclosure. Figure 3 for Figure 2 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-section direction AA1. It should be noted that... Figure 1 and Figure 2 The photovoltaic cell is divided into a first region 111 and a second region 121 by dashed lines. Furthermore, to clearly illustrate the difference between the first grid 113 and the second grid 123 in the photovoltaic cell, and to clearly illustrate the difference between the first portion 133 located in the first region 111 and the second region 121 respectively, Figure 1 The second part is not shown, and the first part 133 in the first fine grid 113 and the first part 133 in the second fine grid 123 are drawn using different filling methods; moreover, Figure 3The first zone 111 and the second zone 121 are cut off along the second direction Y by double wavy lines respectively.

[0050] It is worth noting that the division of the fine grid 103 in the photovoltaic cell into a first fine grid 113 and a second fine grid 123, and the division of different regions of the first surface 101, namely at least a first region 111 and a second region 121, are all used to reflect the differentiated design of the fine grid 103 located in different regions of the first surface 101. Among them, the first region 111 can be used for regions that may be subjected to greater external forces in the future, or for regions that are prone to deformation of the printing screen during the manufacturing process of the fine grid 103, such as bending. Based on this, the lengths of the first part 133 in the first fine gate 113 and the first part 133 in the second fine gate 123 are designed differently, that is, the first length L1 is designed to be greater than the second length L2. On the one hand, the longer first part 133 is conducive to increasing the alignment area between the first part 133 in the first fine gate 113 and other subsequent conductive parts, thereby reducing the alignment error between the first part 133 in the first fine gate 113 and other subsequent conductive parts, ensuring the connection between the first part 133 in the first fine gate 113 and other subsequent conductive parts, thereby ensuring the transmission effect of the photogenerated carriers collected by the first part 133 by the other subsequent conductive parts. On the other hand, the longer first part 133 is conducive to increasing the connection area between the first part 133 in the first fine gate 113 and other subsequent conductive parts, thereby increasing the connection strength between the first part 133 in the first fine gate 113 and other subsequent conductive parts, and reducing the contact resistance between the first part 133 in the first fine gate 113 and other subsequent conductive parts. Thus, for the first fine gate 113, the overall transmission efficiency of photogenerated carriers collected by the first part 133 can be improved, and the risk of the subsequent conductive parts detaching from the first part 133 can be reduced, thereby improving the structural stability of the first fine gate 113. Moreover, for the first fine gate 113, even if there is a certain degree of deformation in the area corresponding to the first fine gate 113 in the printing screen, the longer first part 133 can ensure the connection between the first part 133 and other subsequent conductive parts, thereby helping to improve the service life of the printing screen and reducing the manufacturing cost of the first fine gate 113.

[0051] Furthermore, the second fine grid 123 is generally subjected to less external force, and the area in the printing screen corresponding to the second fine grid 123 is not easily deformed. The second length L2 of the first part 133 is designed to be smaller, which can also ensure that the first part 133 and other subsequent conductive parts have sufficient connection area, thereby helping to reduce the material cost of the first part 133.

[0052] It should be noted that the aforementioned "other subsequent conductive parts" include at least the following situations: (Refer to...) Figure 2The first fine gate 113 and the second fine gate 123 may further include a second portion 143 extending along the second direction Y, the second portion 143 being connected to a plurality of first portions 133. Specifically, a single fine gate 103 includes a second portion 143 and a plurality of first portions 133 connected to the second portion 143 and spaced apart along the second direction Y. Based on this, "subsequent other conductive portions" may be the second portion 143.

[0053] In some embodiments, the intersection of the first direction X and the second direction Y includes: the first direction X and the second direction Y being orthogonal, or the angle formed by the first direction X and the second direction Y being an obtuse angle, or the angle formed by the first direction X and the second direction Y being an acute angle.

[0054] In some cases, the angle between the first direction X and the second direction Y can be between 10° and 90°, for example, 10°, 20°, 45°, 55°, 70°, 82°, or 90°. In some examples, the angle between the first direction X and the second direction Y can be between 45° and 90°, for example, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 90°.

[0055] In some embodiments, reference Figure 1 Compared to the first length L1 of any first part 133 in the first fine gate 113, the second length L2 of any first part 133 in the second fine gate 123 is smaller. In practical applications, due to process errors or other factors during the fabrication of the fine gate, when the first length of multiple first parts in the first fine gate is greater than the second length of multiple first parts in the second fine gate, there may be cases where the first length of individual (e.g., 1, 2, or 3) first parts in the first fine gate is smaller than the second length of individual first parts in the second fine gate.

[0056] The photovoltaic cell provided in one embodiment of this disclosure will be described in more detail below with reference to the accompanying drawings.

[0057] In some embodiments, in conjunction with reference Figure 2 and Figure 3 The battery substrate 105 includes a first surface 101 and a second surface 102 facing each other along a third direction Z, where the third direction Z is the thickness direction of the battery substrate 105; a fine grid 103 is located on the first surface 101. The fine grid 103 includes at least a first fine grid 113 and a second fine grid 123.

[0058] The battery substrate 105 can refer to a pre-fabricated component. For example, the battery substrate 105 can be composed of a crystalline silicon substrate and various functional thin film layers deposited on the surface of the crystalline silicon substrate. In some embodiments, the functional thin film layers grown on the crystalline silicon substrate may include a passivation layer and / or an anti-reflection layer; in other embodiments, the functional thin film layers on the crystalline silicon substrate may also be additionally added doped silicon layers. In other words, the battery substrate 105 is not a bare silicon wafer; the battery substrate 105 can be equipped with various functional thin film layers according to actual process requirements.

[0059] In some cases, photovoltaic cells can be cells with a fine grid 103 on one side, such as BC cells. In this case, the fine grid 103 is located only on the first side 101.

[0060] In some examples, BC cells include, but are not limited to, HBC cells (Heterojunction Back Contact Cell), TBC cells (TOPCon Back Contact Cell), HTBC cells (Heterojunction Tunnel Oxide Passivated Back Contact Cell), or HPBC cells (Hybrid Passivated Back Contact Cell).

[0061] In other cases, the photovoltaic cell can be a cell with fine grids 103 on both sides, such as TOPCON cells, PERC cells, or heterojunction cells. Thus, the fine grids 103 can be located not only on the first side 101 but also on the second side 102. It should be noted that the second side 102 can be divided into at least a first region 111 and a second region 121, just like the first side 101, and the fine grids on the second side 102 can have the same design as the fine grids 103 on the first side 101. Therefore, the identical or corresponding parts of the second side 102 and the first side can be referred to the description of the first side 101 in an embodiment of this disclosure, and will not be repeated here; the identical or corresponding parts of the fine grids on the second side 102 and the fine grids 103 on the first side 101 can be referred to the description of the fine grids 103 on the first side 101 in an embodiment of this disclosure, and will not be repeated here.

[0062] In some embodiments, in conjunction with reference Figure 2 and Figure 3The first fine gate 113 and the second fine gate 123 may also include a second part 143 extending along the second direction Y. Whether for the first fine gate 113 or the second fine gate 123, the length L of the first part 133 along the first direction X may be greater than the width W of the second part 143.

[0063] Furthermore, along the third direction Z, the second part 143 is directly opposite the first part 133. In other words, reference... Figure 2 Both ends of the first part 133 protrude beyond the second part 143. This also helps to maximize the alignment accuracy and connection area of ​​the first part 133 and the second part 143; or, along the first direction, one side of the second part is flush with the side of one end of the first part, and the other end of the first part protrudes beyond the second part. This also helps to maximize the alignment accuracy and connection area of ​​the first part 133 and the second part 143.

[0064] In other embodiments, in conjunction with reference to Figure 4 and Figure 5 The first fine grid 113 and the second fine grid 123 may further include a second portion 143 extending along the second direction Y. For both the first fine grid 113 and the second fine grid 123, the length L of the first portion 133 along the first direction X may be less than or equal to the width W of the second portion 143. Furthermore, the second portion 143 covers the first portion 133; in other words, the orthographic projection of the first portion 133 onto the battery substrate 105 lies within the orthographic projection of the second portion 143 onto the battery substrate 105, thereby maximizing the alignment accuracy and connection area of ​​the first portion 133 and the second portion 143.

[0065] Figure 4 This is a third partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 5 for Figure 4 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-sectional direction AA1. It should be noted that, to clearly illustrate the relative positional relationship between the first part 133 and the second part 143 within the photovoltaic cell, Figure 4 The second part 143 is drawn using perspective to reveal the first part 133, which is covered by the second part 143.

[0066] In both of the above embodiments, for both the first fine gate 113 and the second fine gate 123, the length L of the first part 133 along the first direction X can be 5μm to 100μm, for example, it can be 5μm to 10μm, 10μm to 20μm, 20μm to 30μm, 30μm to 40μm, 40μm to 50μm, 50μm to 60μm, 60μm to 70μm, 70μm to 80μm, 80μm to 90μm or 90μm to 100μm.

[0067] Optionally, the length L of the first part 133 may be 5 μm, 7 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 27 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 47 μm, 5 0μm, 53μm, 55μm, 58μm, 60μm, 62μm, 65μm, 68μm, 70μm, 72μm, 75μm, 77μm, 80μm, 83μm, 85μm, 88μm, 90μm, 92μm, 95μm, 98μm or 100μm, etc.

[0068] For both the first fine gate 113 and the second fine gate 123, the width W of the second part 143 along the first direction X can be 15μm to 40μm, for example, it can be 15μm to 20μm, 20μm to 25μm, 25μm to 30μm, 30μm to 35μm or 35μm to 40μm.

[0069] Optionally, the width W of the second part 143 can be 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, or 40μm, etc.

[0070] It should be noted that the relevant dimensions of the first part 133 and the second part 143 included in the first fine gate 113 and the second fine gate 123 will be described in detail in conjunction with the embodiments.

[0071] The following combination Figures 2 to 5 The differentiated design of the length of the first part 133 included in the first fine gate 113 and the second fine gate 123 in the first direction X, namely the first length L1 and the second length L2, is described in detail.

[0072] In some embodiments, in conjunction with reference Figures 2 to 5 The ratio of the first length L1 to the second length L2 can be 1.02 to 20, for example, it can be 1.02 to 5, 5 to 10, 10 to 15, or 15 to 20. Optionally, the ratio of the first length L1 to the second length L2 can be 1.02, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, etc.

[0073] On the one hand, by designing the ratio of the first length L1 to the second length L2 to be greater than or equal to 1.02, even if the length L of the first part 133 in the first direction X of a single fine gate 103 is large, that is, both the first length L1 and the second length L2 are large, it can be ensured that the first length L1 is greater than the second length L2. Moreover, when both the first length L1 and the second length L2 are large, for the first region 111 where the position of the first part 133 is prone to shift, the first part 133 itself has more area for connecting with other conductive parts formed subsequently, such as the second part 143. By designing the first length L1 to be slightly larger than the second length L2, the reduction in the alignment accuracy between the first part 133 and other conductive parts can be effectively avoided.

[0074] On the other hand, designing the ratio of the first length L1 to the second length L2 to be less than or equal to 20 helps control the degree of difference between the first length L1 and the second length L2, thus avoiding excessive size differences between the first portion 133 in the first fine grid 113 and the first portion 133 in the second fine grid 123. This reduces the difference in photogenerated carrier collection efficiency between the first portion 133 in the first fine grid 113 and the first portion 133 in the second fine grid 123, thereby improving the overall electrical performance of the photovoltaic cell. Furthermore, when both the first length L1 and the second length L2 are small, the size difference between the first portion 133 in the first fine grid 113 and the first portion 133 in the second fine grid 123 can be appropriately increased to effectively avoid reducing the alignment accuracy of the first portion 133 and other subsequent conductive parts.

[0075] In some embodiments, in conjunction with reference Figures 2 to 5The length of the first part 133 in the first fine gate 113, i.e. the first length L1, can be 7μm~100μm, for example, it can be 7μm~20μm, 20μm~30μm, 30μm~40μm, 40μm~50μm, 50μm~60μm, 60μm~70μm, 70μm~80μm, 80μm~90μm or 90μm~100μm. In this way, the value of the first length L1 can be flexibly selected between 7μm and 100μm according to the specific size of the photovoltaic cell, such as the size of the first fine grid 113 that can be used to lay out the first surface 101. Moreover, when the first length L1 is greater than the second length L2, on the one hand, designing the first length L1 to be greater than or equal to 7μm helps to avoid the second length L2 being too small, thereby ensuring that the first part 133 of the second fine grid 123 has good collection efficiency for photogenerated carriers. On the other hand, designing the first length L1 to be less than or equal to 100μm also helps to avoid the contact area between a single first part 133 and the cell substrate 105 being too large, thereby ensuring that the recombination area of ​​photogenerated carriers at the contact point between a single first part 133 and the cell substrate 105 is reduced, thus reducing the loss of photogenerated carriers.

[0076] Optionally, the first length L1 can be 7μm, 10μm, 13μm, 15μm, 18μm, 20μm, 23μm, 25μm, 27μm, 30μm, 32μm, 35μm, 38μm, 40μm, 42μm, 45μm, 47μm, 50μm, 53μm, 55μm, 58μm, 60μm, 62μm, 65μm, 68μm, 70μm, 72μm, 75μm, 77μm, 80μm, 83μm, 85μm, 88μm, 90μm, 92μm, 95μm, 97μm, or 100μm, etc.

[0077] In some cases, the first length L1 of the first part 133 in the first fine grid 113 can be measured by sampling. For example, a partial electron microscope (SEM) image of the area where the first part 133 of the first fine grid 113 is located can be taken, and 3 to 5 sampling areas can be selected in the first part 133. The length of each sampling area along the first direction X can be measured, and the average value can be calculated as the first length L1 of the first part 133 in the first fine grid 113.

[0078] In some embodiments, in conjunction with reference Figures 2 to 5The second length L2 can be 5μm to 98μm, for example, it can be 5μm to 10μm, 10μm to 20μm, 20μm to 30μm, 30μm to 40μm, 40μm to 50μm, 50μm to 60μm, 60μm to 70μm, 70μm to 80μm, 80μm to 90μm or 90μm to 98μm. Optionally, the second length L2 can be 5 μm, 7 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 27 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 47 μm, 50μm, 53μm, 55μm, 58μm, 60μm, 62μm, 65μm, 68μm, 70μm, 72μm, 75μm, 77μm, 80μm, 83μm, 85μm, 88μm, 90μm, 92μm, 95μm or 98μm, etc.

[0079] Thus, the value of the second length L2 can be flexibly selected within the range of 5μm to 98μm according to the specific size of the photovoltaic cell, such as the size of the second fine grid 123 that can be used to arrange the first surface 101. Moreover, when the first length L1 is greater than the second length L2, on the one hand, designing the second length L2 to be greater than or equal to 5μm helps to avoid the first length L1 and the second length L2 being too small, thereby ensuring that the first part 133 of the first fine grid 113 has good collection efficiency for photogenerated carriers, and also ensuring that the first part 133 of the second fine grid 123 has good collection efficiency for photogenerated carriers, and ensuring that the first length L1 can effectively avoid the reduction of the alignment accuracy between the first part 133 and other subsequent conductive parts. On the other hand, designing the second length L2 to be less than or equal to 98μm also helps to avoid the contact area between a single first part 133 and the cell substrate 105 being too large, thereby ensuring that the recombination area of ​​photogenerated carriers at the contact point between a single first part 133 and the cell substrate 105 is reduced, and reducing the loss of photogenerated carriers.

[0080] In some cases, the second length L2 of the first part 133 in the second fine grid 123 can also be measured by sampling. For example, a partial electron microscope (SEM) image of the area where the first part 133 of the second fine grid 123 is located can be taken, and 3 to 5 sampling areas can be selected in the first part 133. The length of each sampling area along the first direction X can be measured, and the average value can be calculated as the second length L2 of the first part 133 in the second fine grid 123.

[0081] In some embodiments, in conjunction with reference Figures 2 to 5The difference between the first length L1 and the second length L2 can be 2μm to 30μm, for example, 2μm to 9μm, 9μm to 16μm, 16μm to 23μm, or 23μm to 30μm. This allows the difference between the first length L1 and the second length L2 to be controlled within a suitable range, thus ensuring that the degree of difference between them is appropriate.

[0082] On the one hand, it helps to avoid excessive size difference between the first part 133 in the first fine grid 113 and the first part 133 in the second fine grid 123. Thus, from the perspective of balancing the collection efficiency of the first part 133 for photogenerated carriers, it reduces the difference in collection efficiency of the first part 133 in the first fine grid 113 and the first part 133 in the second fine grid 123 for photogenerated carriers, thereby improving the overall electrical performance of the photovoltaic cell.

[0083] On the other hand, when the values ​​of the first length L1 and the second length L2 are both small, the difference in size between the first part 133 in the first fine gate 113 and the first part 133 in the second fine gate 123 can be appropriately increased. For example, the difference between the first length L1 and the second length L2 can be designed to be 30 μm to effectively avoid the reduction in the alignment accuracy of the first part 133 and other subsequent conductive parts.

[0084] On the other hand, when the values ​​of the first length L1 and the second length L2 are both large, the first part 133 itself has more area for connection with the subsequently formed second part 143. Therefore, it is appropriate to reduce the size difference between the first part 133 in the first fine gate 113 and the first part 133 in the second fine gate 123. For example, designing the difference between the first length L1 and the second length L2 to be 2μm can not only effectively avoid the reduction of the alignment accuracy between the first part 133 and other subsequent conductive parts, but also minimize the difference in the collection efficiency of the first part 133 in the first fine gate 113 and the first part 133 in the second fine gate 123 for photogenerated carriers.

[0085] Optionally, the difference between the first length L1 and the second length L2 can be 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, or 30μm, etc.

[0086] In some embodiments, reference Figure 2Along the first direction X, the length L of different first portions 133 in the same fine gate 103 can be the same. In other words, for a single first fine gate 113, the first length L1 of different first portions 133 can be the same, for example, it can be the same value in the range of 7μm to 100μm; for a single second fine gate 123, the second length L2 of different first portions 133 can be the same, for example, it can be the same value in the range of 5μm to 98μm.

[0087] In other embodiments, the lengths of different first portions in the same fine gate may also be different along the first direction. In some cases, for a single first fine gate, the first length of different first portions can all be in the range of 7μm to 100μm, but the values ​​of the first lengths of different first portions are different; for a single second fine gate, the second length of different first portions can all be in the range of 5μm to 98μm, but the values ​​of the second lengths of different first portions are different.

[0088] The thickness of the first portion 133 included in each of the first fine grid 113 and the second fine grid 123 will be described in detail below.

[0089] In some embodiments, in conjunction with reference Figures 2 to 5 The thickness of the first part 133 in the first fine grid 113 is the first thickness H1, and the thickness of the first part 133 in the second fine grid 123 is the second thickness H2. The first thickness H1 can be greater than the second thickness H2.

[0090] It is worth noting that the first fine gate 113 experiences a larger external force compared to the second fine gate 123. Based on this, the thickness of the first portion 133 of the fine gates 103 located in different regions, such as the first fine gate 113 and the second fine gate 123, is differentiated. Specifically, in addition to designing the first length L1 to be greater than the second length L2, the first thickness H1 is also designed to be greater than the second thickness H2. This helps reduce the risk of the first portion 133 of the first fine gate 113 cracking or detaching from the battery substrate 105 under stress, thereby further improving the connection strength between the first portion 133 and other subsequent conductive parts in the first fine gate 113. Furthermore, the increased thickness can improve the carrier collection efficiency of the first portion 133 in the first fine gate 113. In addition, the second fine gate 123 generally experiences a smaller external force, and designing a smaller second thickness H2 for the first portion 133 ensures sufficient structural stability for the first portion 133 itself, thus guaranteeing sufficient connection strength between the first portion 133 and other subsequent conductive parts, thereby helping to reduce the material cost of the first portion 133.

[0091] In some cases, during the process of forming the first part 133 using a printing screen, the part of the printing screen corresponding to the first fine grid 113 is more easily deformed than the part corresponding to the second fine grid 123. Slight deformation also helps to form the first part 133 with a first thickness H1 on the first area 111, that is, it helps to form the first fine grid 113 with a thicker thickness of the first part 133.

[0092] In some cases, the thickness of the first part 133 is the thickness along the third direction Z, where the third direction Z is the thickness direction of the photovoltaic cell.

[0093] In some cases, the difference between the first thickness H1 and the second thickness H2 can be 0.5 μm to 1.5 μm, for example, it can be 0.5 μm to 1 μm or 1 μm to 1.5 μm.

[0094] It is worth noting that the first fine grid 113 and the second fine grid 123 may also include a second portion 143 extending along the second direction Y. The second portion 143 is located on the side of the first portion 133 away from the battery substrate 105. The total thickness of the first portion 133 and the second portion 143 can characterize the thickness of the fine grid 103. When the thickness of the second portion 143 in the first fine grid 113 is the same as the thickness of the second portion 143 in the second fine grid 123, the difference between the thickness of the first fine grid 113 and the thickness of the second fine grid 123 can be the difference between the first thickness H1 and the second thickness H2.

[0095] Based on this, the difference between the first thickness H1 and the second thickness H2 is designed to be 0.5μm~1.5μm, which helps to control the difference between the thickness of the first fine gate 113 and the thickness of the second fine gate 123 to be within a moderate range. When the solder strip is subsequently connected to multiple first fine gates 113 and second fine gates 123, the degree of bending of the solder strip from the first region 111 to the second region 121 can be reduced, thereby improving the connection stability between the solder strip and the first fine gate 113 and the second fine gate 123, and thus ensuring that the solder strip has a good connection effect with the first fine gate 113 and the second fine gate 123.

[0096] Optionally, the difference between the first thickness H1 and the second thickness H2 can be 0.5μm, 0.55μm, 0.6μm, 0.65μm, 0.7μm, 0.75μm, 0.8μm, 0.85μm, 0.9μm, 0.95μm, 1μm, 1.05μm, 1.1μm, 1.15μm, 1.2μm, 1.25μm, 1.3μm, 1.35μm, 1.4μm, 1.45μm, or 1.5μm.

[0097] In some cases, the first thickness H1 can be 1μm to 6μm, for example, it can be 1μm to 2μm, 2μm to 3μm, 3μm to 4μm, 4μm to 5μm or 5μm to 6μm.

[0098] On the one hand, designing the first thickness H1 to be greater than or equal to 1 μm, and based on the first thickness H1 being greater than the second thickness H2, not only can the value of the first thickness H1 be avoided being too small, but it is also beneficial to avoid the value of the second thickness H2 being too small, thereby ensuring that the first part 133 included in the first fine grid 113 and the second fine grid 123 have good collection efficiency for photogenerated carriers. On the other hand, designing the first thickness H1 to be less than or equal to 6 μm is beneficial to improving the structural stability of the first part 133 in the first fine grid 113 while minimizing the thickness of the first fine grid 113. After the solder ribbon is subsequently placed on the first fine grid 113, it is beneficial to reduce the portion of the solder ribbon located in the first region 111 and the stacking thickness of the first fine grid 113 on the battery substrate 105, thereby reducing the risk of cracks appearing on the solder ribbon or the first fine grid 113 after being subjected to stress.

[0099] Optionally, the first thickness H1 can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, or 1μm thicker than 1μm. μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm m, 4.8μm, 4.9μm, 5μm, 5.1μm, 5.2μm, 5.3μm, 5.4μm, 5.5μm, 5.6μm, 5.7μm, 5.8μm, 5.9μm or 6μm, etc.

[0100] In some examples, the first thickness H1 of the first portion 133 in the first fine grid 113 can be measured using a sampling method. For example, a partial electron microscope (SEM) image of the area where the first portion 133 is located in the first fine grid 113 can be taken, and 3 to 5 sampling areas can be selected in the first portion 133. The length of each sampling area along the third direction Z is measured, and the average value is calculated as the first thickness H1 of the first portion 133 in the first fine grid 113. Furthermore, when a second portion 143 is provided on a portion of the surface of the first portion 133, a partial electron microscope (SEM) image of the area where the portion of the first portion 133 exposed outside the second portion 143 is located can be taken, and based on this, 3 to 5 sampling areas can be selected to measure the first thickness H1 of the first portion 133.

[0101] In some cases, the second thickness H2 can be 0.5μm to 5μm, for example, it can be 0.5μm to 2μm, 2μm to 3.5μm or 3.5μm to 5μm.

[0102] On the one hand, designing the second thickness H2 to be greater than or equal to 0.5 μm helps to avoid the second thickness H2 being too small, thereby ensuring that the first part 133 in the second fine grid 123 has good collection efficiency for photogenerated carriers. On the other hand, designing the second thickness H2 to be less than or equal to 5 μm helps to improve the collection efficiency of the first part 133 in the second fine grid 123 for photogenerated carriers while minimizing the thickness of the second fine grid 123. After the solder ribbon is set on the second fine grid 123, it helps to reduce the stacking thickness of the portion of the solder ribbon located in the second region 121 and the second fine grid 123 on the battery substrate 105, thereby reducing the risk of cracks appearing on the solder ribbon or the second fine grid 123 under stress.

[0103] Optionally, the second thickness H2 can be 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, or 2.6μm. , 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm , 3.9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm or 5μm, etc.

[0104] In some examples, the second thickness H2 of the first portion 133 in the second fine grid 123 can also be measured using a sampling method. For example, a partial electron microscope (SEM) image of the area where the first portion 133 of the second fine grid 123 is located can be taken, and 3 to 5 sampling areas can be selected in the first portion 133. The length of each sampling area along the third direction Z is measured, and the average value is calculated as the second thickness H2 of the first portion 133 in the second fine grid 123. Furthermore, when the second portion 143 is provided on a portion of the surface of the first portion 133, a partial electron microscope (SEM) image of the area where the portion of the first portion 133 exposed outside the second portion 143 is located can be taken, and based on this, 3 to 5 sampling areas can be selected to measure the second thickness H2 of the first portion 133.

[0105] In some examples, along the first direction X, the thickness of different first portions 133 in the same fine gate 103 can be the same. In other words, for the first fine gate 113, the first thickness H1 of different first portions 133 can be the same, for example, it can be the same value between 1μm and 6μm; for the second fine gate 123, the second thickness H2 of different first portions 133 can be the same, for example, it can be the same value between 0.5μm and 5μm.

[0106] In other examples, the thickness of different first portions in the same fine gate can also be different along the first direction. In some cases, for the first fine gate, the first thickness of different first portions can all be in the range of 1 μm to 6 μm, but the values ​​of the first thickness of different first portions are different; for the second fine gate, the second thickness of different first portions can all be in the range of 0.5 μm to 5 μm, but the values ​​of the second thickness of different first portions are different.

[0107] The spacing between adjacent first portions 133 in the first fine grid 113 and the second fine grid 123 will be described in detail below.

[0108] In some embodiments, in conjunction with reference Figure 6 and Figure 7 Along the second direction Y, the spacing between adjacent first parts 133 in the first fine grid 113 is the first spacing D1, and the spacing between adjacent first parts 133 in the second fine grid 123 is the second spacing D2. The first spacing D1 can be greater than the second spacing D2.

[0109] Figure 6 This is a partial top view schematic diagram of a photovoltaic cell provided in one embodiment of the present disclosure. Figure 7 for Figure 6 The diagram shows a schematic of a turning cross-sectional structure of a photovoltaic cell along the second cross-section direction BB1.

[0110] The first fine grid 113 and the second fine grid 123 may further include a second portion 143 extending along the second direction Y. Along the second direction Y, the extension length of the second portion 143 in the first fine grid 113 is the same as, or slightly different from, the extension length of the second portion 143 in the second fine grid 123. Based on this, in a single fine grid 103, the larger the spacing between adjacent first portions 133, the fewer the number of first portions 133 connected to the second portion 143, meaning the sparser the arrangement density of the first portions 133 in a single fine grid 103.

[0111] Based on this, in addition to designing the first length L1 to be greater than the second length L2, the first spacing D1 is also designed to be greater than the second spacing D2. That is, the spacing of adjacent first parts 133 in the first fine grid 113 and the second fine grid 123 is differentiated, which is beneficial to reduce the arrangement density of the first parts 133 in the first fine grid 113. In conjunction with the first length L1 of the first parts 133 in the first fine grid 113, it helps to reduce the total material cost of multiple first parts 133 in the first fine grid 113 by reducing the number of first parts 133 connected to the second part 143.

[0112] In other words, with the first length L1 greater than the second length L2, and the first spacing D1 greater than the second spacing D2, compared to the first fine grid 113 having a longer first part 133 and a larger spacing between adjacent first parts 133, the second fine grid 123 has a shorter first part 133 and a smaller spacing between adjacent first parts 133. This is beneficial for reducing the difference in the total material cost of multiple first parts 133 in the first fine grid 113 and the second fine grid 123, and balancing the material cost of the first fine grid 113 and the second fine grid 123.

[0113] In some cases, the ratio of the first spacing D1 to the second spacing D2 can be 35 / 33 to 35 / 3, for example, it can be 5 / 4 to 1.5, 1.5 to 2, 2 to 2.5, 2.5 to 3, or 3 to 10 / 3. Optionally, the ratio of the first spacing D1 to the second spacing D2 can be 35 / 33, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, or 35 / 3, etc.

[0114] On the one hand, when the values ​​of the first length L1 and the second length L2 are both large, the reduction in the alignment accuracy of the first part 133 and the second part 143 can be effectively avoided. From the perspective of reducing the material cost of multiple first parts 133 in the fine gate 103, the values ​​of the first spacing D1 and the second spacing D2 can be increased, that is, the values ​​of the first spacing D1 and the second spacing D2 are both large. Based on this, the ratio of the first spacing D1 to the second spacing D2 is designed to be greater than or equal to 35 / 33. Even if the spacing between adjacent first parts 133 in a single fine gate 103 in the second direction Y is large, that is, the values ​​of the first spacing D1 and the second spacing D2 are both large, it can still be ensured that the first spacing D1 is greater than the second spacing D2. At this time, designing the first spacing D1 to be slightly larger than the second spacing D2 can reduce the difference in the arrangement density of the first parts 133 in the first fine gate 113 and the second fine gate 123, thereby reducing the difference in the carrier collection efficiency of the first fine gate 113 and the second fine gate 123.

[0115] On the other hand, when the values ​​of the first length L1 and the second length L2 are both small, the ratio of the first spacing D1 to the second spacing D2 is controlled to be less than large from the perspective of increasing the contact area between the fine grid 103 and the battery substrate 105. That is, the ratio of the first spacing D1 to the second spacing D2 is designed to be less than or equal to 35 / 3. This helps to ensure that the number of first parts 133 in the first fine grid 113 is not too small. Even if the connection between individual first parts 133 and second parts 143 in the first fine grid 113 is offset, the remaining number of first parts 133 can still ensure that there is a large contact area between the first fine grid 113 and the battery substrate 105. It also helps to avoid the difference in the arrangement density of the first parts 133 in the first fine grid 113 and the second fine grid 123 being too large.

[0116] In some cases, the first spacing D1 can be 50μm to 350μm, for example, it can be 50μm to 100μm, 100μm to 150μm, 150μm to 200μm, 250μm to 300μm or 300μm to 350μm.

[0117] It is worth noting that the size of the first spacing D1 affects the number of first portions 133 arranged in the first fine grid 113, and thus affects the contact area between a single first fine grid 113 and the battery substrate 105. Based on this, designing the first spacing D1 to be 50μm~350μm is beneficial for controlling the number of first portions 133 arranged in the first fine grid 113 to be within a moderate range, balancing the need for a sufficiently large contact area between the first fine grid 113 and the battery substrate 105, reducing the risk of carrier recombination caused by an excessively large contact area between the first fine grid 113 and the battery substrate 105, and also helps to control the material cost of the first portions 133 in the first fine grid 113 to be moderate.

[0118] Optionally, the first spacing D1 can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, 300μm, 310μm, 320μm, 330μm, 340μm, or 350μm, etc.

[0119] In some cases, the second spacing D2 can be 30μm to 330μm, for example, it can be 30μm to 80μm, 80μm to 130μm, 130μm to 180μm, 180μm to 230μm, 230μm to 280μm or 280μm to 330μm.

[0120] It is worth noting that the size of the second spacing D2 affects the number of first portions 133 in the second fine grid 123, and thus affects the contact area between a single second fine grid 123 and the battery substrate 105. Based on this, the second spacing D2 is designed to be 30μm~330μm. While ensuring that the first spacing D1 is larger than the second spacing D2, this helps to control the number of first portions 133 in the second fine grid 123 to be within a moderate range, ensuring that the second fine grid 123 has a sufficiently large contact area with the battery substrate 105, reducing the risk of carrier recombination caused by an excessively large contact area between the second fine grid 123 and the battery substrate 105, and also helps to control the material cost of the first portion 133 in the second fine grid 123 to be moderate.

[0121] Optionally, the second distance D2 may be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180μm, 190μm, 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, 300μm, 310μm, 320μm or 330μm, etc.

[0122] In some examples, along the first direction X, the spacing between adjacent first portions 133 in the same fine gate 103 can be the same. In other words, for the first fine gate 113, the first spacing D1 of adjacent first portions 133 can be the same, for example, it can be the same value in the range of 50μm to 350μm; for the second fine gate 123, the second spacing D2 of adjacent first portions 133 can be the same, for example, it can be the same value in the range of 30μm to 330μm.

[0123] In other examples, the spacing between adjacent first portions in the same fine gate can also be different along the first direction. In some cases, for the first fine gate, the first spacing between adjacent first portions can all be in the range of 50 μm to 350 μm, but the first spacing between two adjacent first portions is different from the first spacing between two other adjacent first portions; for the second fine gate, the second spacing between adjacent first portions can all be in the range of 30 μm to 330 μm, but the second spacing between two adjacent first portions is different from the second spacing between two other adjacent first portions.

[0124] The first fine gate 113 and the second fine gate 123 may further include a second portion 143 extending along the second direction Y. The width of the second portion 143 included in each of the first fine gate 113 and the second fine gate 123 will be described in detail below.

[0125] In some embodiments, in conjunction with reference Figure 8 and Figure 9 Along the first direction X, the width of the second part 143 in the first fine gate 113 is the first width W1, and the width of the second part 143 in the second fine gate 123 is the second width W2. The first width W1 can be greater than the second width W2.

[0126] Figure 8 This is a partial top view schematic diagram of a photovoltaic cell provided in an embodiment of this disclosure. Figure 9 for Figure 8 The diagram shows a cross-sectional structure of a photovoltaic cell along the first cross-section direction AA1.

[0127] It is worth noting that, compared to the alignment of the first portion 133 and the second portion 143 in the second fine gate 123, the first portion 133 and the second portion 143 in the first fine gate 113 are more prone to misalignment, and the first fine gate 113 is subjected to a larger external force. Based on this, the width W of the second portion 143 included in each of the first fine gate 113 and the second fine gate 123 is designed differently; that is, in addition to designing the first length L1 to be greater than the second length L2, the first width W1 is also designed to be greater than the second width W2. Thus, compared to the second fine gate 123, the alignment accuracy of the first portion 133 and the second portion 143 in the first fine gate 113 along the third direction Z can be improved by increasing both the first length L1 of the first portion 133 in the first fine gate 113 and the first width W1 of the second portion 143 in the first fine gate 113. In other words, for the first fine grid 113, even if the first part 133 is offset relative to the second part 143, the larger first length L1 can ensure that the offset first part 133 and the second part 143 still have a sufficiently large contact area, and the larger first width W1 can ensure that the second part 143 still has a sufficiently large contact area with the offset first part 133, thus providing double protection for the alignment of the first part 133 and the second part 143.

[0128] In some cases, the ratio of the first width W1 to the second width W2 can be 5 / 4 to 10 / 3, for example, it can be 5 / 4 to 1.5, 1.5 to 2, 2 to 2.5, 2.5 to 3 or 3 to 10 / 3.

[0129] On the one hand, designing the ratio of the first width W1 to the second width W2 to be 5 / 4 to 10 / 3 is beneficial to control the difference between the first width W1 and the second width W2 to be moderate, so as to avoid the size difference between the second part 143 in the first fine grid 113 and the second part 143 in the second fine grid 123 being too large. Thus, from the perspective of balancing the transmission efficiency of the second part 143 for photogenerated carriers, the difference in the transmission efficiency of the second part 143 in the first fine grid 113 and the second part 143 in the second fine grid 123 for the carriers in the first part 133 is reduced, thereby improving the overall electrical performance of the photovoltaic cell.

[0130] Optionally, the ratio of the first width W1 to the second width W2 can be 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3, 3.1, 3.15, 3.2, 3.25, 3.3, or 3.33, etc.

[0131] In some cases, the first width W1 can be 20μm to 50μm, for example, it can be 20μm to 25μm, 25μm to 30μm, 30μm to 35μm, 35μm to 40μm, 40μm to 45μm or 45μm to 50μm.

[0132] On the one hand, designing the first width W1 to be greater than or equal to 20 μm, based on the first width W1 being greater than the second width W2, not only avoids the first width W1 being too small, but also helps to avoid the second width W2 being too small, thereby ensuring that the second part 143 in the first fine gate 113 and the second fine gate 123 has good transport efficiency for charge carriers, and improving the alignment accuracy of the first part 133 and the second part 143 in the fine gate 103; on the other hand, designing the first width W1 to be less than or equal to 50 μm, while improving the transport efficiency of the second part 143 in the first fine gate 113 for charge carriers, helps to reduce the first width W1 of the second part 143 in the first fine gate 113 as much as possible, so as to reduce the material cost of the second part 143 in the first fine gate 113.

[0133] Optionally, the first width W1 can be 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, or 50μm, etc.

[0134] In some examples, the first width W1 of the second part 143 in the first fine grid 113 can be measured by sampling. For example, a partial electron microscope (SEM) image of the area where the second part 143 in the first fine grid 113 is located can be taken, and 3 to 5 sampling areas can be selected in the second part 143. The width of each sampling area along the first direction X can be measured, and the average value can be calculated as the first width W1 of the second part 143 in the first fine grid 113.

[0135] In some cases, the second width W2 can be 15μm to 40μm, for example, it can be 15μm to 20μm, 20μm to 25μm, 25μm to 30μm, 30μm to 35μm or 35μm to 40μm.

[0136] On the one hand, designing the second width W2 to be greater than or equal to 15 μm helps to avoid the second width W2 being too small, thereby ensuring that the second part 143 in the second fine gate 123 has good transmission efficiency for all carriers. On the other hand, designing the second width W2 to be less than or equal to 40 μm helps to improve the transmission efficiency of the second part 143 in the second fine gate 123 for photogenerated carriers, while minimizing the second width W2 in the second part 143 in the second fine gate 123, so as to reduce the material cost of the second part 143 in the second fine gate 123.

[0137] Optionally, the second width W2 can be 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, or 40μm, etc.

[0138] In some examples, the second width W2 of the second portion 143 in the second fine grid 123 can be measured by sampling. For example, a partial electron microscope (SEM) image of the area where the second portion 143 of the second fine grid 123 is located can be taken, and 3 to 5 sampling areas can be selected in the second portion 143. The width of each sampling area along the first direction X can be measured, and the average value can be calculated as the second width W2 of the second portion 143 in the second fine grid 123.

[0139] In some cases, along the third direction Z, whether for the first fine gate 113 or the second fine gate 123, the thickness of the second part 143 is a third thickness H3, which can be 4μm to 20μm, for example, 4μm to 10μm, 10μm to 15μm or 15μm to 20μm.

[0140] Optionally, the third thickness H3 can be 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm or 20μm, etc.

[0141] In some embodiments, reference Figure 2Along the second direction Y, whether for the first fine gate 113 or the second fine gate 123, the width of the first part 133 can be a third width W3, which can be 5μm to 20μm, for example, 5μm to 10μm, 10μm to 15μm or 15μm to 20μm.

[0142] Optionally, the third width W3 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm or 20μm, etc.

[0143] The following provides a detailed explanation of the division of the first zone 111 and the second zone 121 in photovoltaic cells.

[0144] In some embodiments, reference Figure 10 , Figure 10 This is a sixth partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. The two corners of the first region 111 away from the second region 121 can be chamfered 104. Thus, the first region 111 is located at the edge of the photovoltaic cell with chamfered 104, making it susceptible to large external forces. When the first part 133 located on the first region 111 is manufactured using a printing screen, the area in the printing screen corresponding to the first region 111 is also prone to deformation.

[0145] In other words, the first surface 101 can be divided into two partitions 12 along the first direction X. The corner of at least one of the two opposite sides of the photovoltaic cell along the first direction X is a chamfer 104. One of the two partitions 12 is defined as the first partition 111 and the other is defined as the second partition 121. The first partition 111 is closer to the chamfer 104 than the second partition 121.

[0146] In some embodiments, reference Figure 11 , Figure 11 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. In addition to being divided into a first region 111 and a second region 121 along the first direction X, the first surface 101 can also be divided into a third region 131. The third region 131 is located on the side of the second region 121 away from the first region 111. The length of the first part 133 of the fine grid 103 located on the third region 131, the second region 121 and the first region 111 can be increased in each region.

[0147] In other words, the photovoltaic cell may also include: a third grid 153 located on the first surface 101, the third grid 153 being located on the side of the second grid 123 away from the first grid 113; the length of the first part 133 in the third grid 153 is a third length L3, the third length L3 being less than the second length L2.

[0148] Thus, the first surface 101 can be divided into three sections 12 along the first direction X: the third section 131, the second section 121, and the first section 111. The two corners of the first section 111 furthest from the second section 121 can be chamfered 104. Not only is the first length L1 greater than the second length L2, but the second length L2 is also greater than the third length L3.

[0149] In other embodiments, in conjunction with reference to Figure 10 and Figure 11 Without considering the third partition 12 in the first surface 101 as the third region 131, the first surface 101 along the first direction X can be considered to be divided into at least two partitions 12. The corner of at least one of the opposite sides of the photovoltaic cell along the first direction X is a chamfer 104. Of the at least two partitions 12, one of two adjacent partitions 12 is defined as the first region 111, and the other as the second region 121. The first region 111 is closer to the chamfer 104 than the second region 121. Based on this, along the first direction X, the length of the first part 133 of the fine grid 103 located in the first region 111 is a first length L1, and the length of the first part 133 of the fine grid 103 located in the second region 121 is a second length L2. The first length L1 is greater than the second length L2.

[0150] In some cases, refer to Figure 10 The first surface 101 can be divided into only the first zone 111 and the second zone 121; in other cases, refer to Figure 11 The first surface 101 can also be divided into at least 3 regions, that is, at least 3 partitions 12. Based on this, for any two adjacent partitions 12 among the multiple partitions 12, the one of the two partitions 12 that is closer to the chamfer 104 along the first direction X can be designated as the first region 111, and the other can be designated as the second region 121.

[0151] It should be noted that, Figure 11 The example only uses two adjacent partitions 12 near the chamfer 104 as the first partition 111 and the second partition 121, respectively; in addition, Figure 11 The example shown uses the first surface 101 divided into three partitions 12. In practical applications, the number of partitions 12 in the first surface 101 is not limited. For example, the first surface can be divided into four or five partitions, and the partition closer to the chamfer among any two adjacent partitions can be designated as the first partition and the other as the second partition. Based on this, the division of the fine grid 103 based on the partitions 12 can be not only divided into a first fine grid 113 and a second fine grid 123, or into a first fine grid 113, a second fine grid 123 and a third fine grid 153, but also into a first fine grid, a second fine grid, a third fine grid and a fourth fine grid, etc.

[0152] In some cases, provided that the first length L1 is greater than the second length L2, the length L of the first part 133 located on each partition 12 in the first direction X can be 5μm~100μm.

[0153] In some examples, the difference in length L of the first part 133 located on any two adjacent partitions 12 in the first direction X, that is, the difference between the first length L1 and the second length L2, can be 2μm to 30μm.

[0154] It should be noted that the division of the first region 111 and the second region 121 designed in the above two embodiments is applicable to the photovoltaic cell provided in an embodiment of this disclosure.

[0155] The following details the number of fine grids 103 set on a single partition 12.

[0156] In some cases, refer to Figure 10 In at least a portion of the partitions 12, at least two fine grids 103 are provided on each partition 12. Along the direction near the chamfer 104, the length L of the first part 133 on different partitions 12 increases in the first direction X.

[0157] It should be noted that, Figure 10 The diagram only shows two fine grids 103 on one partition 12. In actual applications, there is no limit to the number of fine grids set on a partition. For example, three, four or five fine grids can be set on a partition.

[0158] In other cases, at least a portion of the partitions have a fine grid on one partition. Thus, along the direction close to the chamfer, the length of the first part of each fine grid increases sequentially in the first direction.

[0159] In practical applications, each partition of a photovoltaic cell can be equipped with at least two fine grids; or, each partition can be equipped with one fine grid; or, a number of partitions can be equipped with at least two fine grids, while other partitions can be equipped with one fine grid.

[0160] The following uses a photovoltaic cell as an example to explain in detail the length of the first part located in different sections of the whole cell.

[0161] In some embodiments, reference Figure 12The photovoltaic cell can be a whole cell. The cell substrate 105 has two edge regions 115 opposite each other along a first direction X, and a central region 125 located between the two edge regions 115. The two corners of the edge regions 115 away from the central region 125 are chamfered 104. The edge regions 115 include at least one partition 12, and the central region 125 includes at least one partition 12. Along the direction from the central region 125 to the edge regions 115, the length L of the first part 133 of the fine grid 103 located on different partitions 12 increases zone by zone.

[0162] It should be noted that, Figure 12 This is a partial top view schematic diagram of an eighth type of photovoltaic cell structure provided in an embodiment of this disclosure. Furthermore, Figure 12 The example shown uses an edge area 115 comprising two partitions 12 and a center area 125 comprising one partition 12. In practical applications, there is no limit to the number of partitions included in the edge area; for example, the edge area may include only one partition, or it may include three, four, or five partitions. Similarly, there is no limit to the number of partitions included in the center area; for example, the center area may also include two, three, four, or five partitions.

[0163] The following uses photovoltaic cells as an example to explain in detail the length of the first part located in different sections of the cell.

[0164] In some embodiments, reference Figure 10 or Figure 11 The photovoltaic cell can be a segmented cell, which is 1 / N whole cells, where N is a positive integer greater than 1; the cell substrate 105 has a first edge 105a and a second edge 105b opposite to each other along the first direction X; the two corners of the first edge 105a away from the second edge 105b are chamfered 104; along the direction from the second edge 105b to the first edge 105a, the length of the first part 133 in the fine grid 103 located on different sections 12 increases zone by zone.

[0165] It should be noted that, Figure 10 The example shown uses a segmented battery comprising up to two partitions (12). Figure 11 The example shown here only includes up to 3 partitions in a chip battery. In actual applications, there is no limit to the number of partitions included in a chip battery. For example, a chip battery can include 4 or 5 partitions.

[0166] In some embodiments, the material of the first part 133 may include at least one of silver, silver-plated copper, silver-copper alloy, silver-plated nickel, or silver-nickel alloy, and the material of the second part 143 may include at least one of silver-plated copper, silver-copper alloy, silver-plated nickel, silver-nickel alloy, silver-plated tin, silver-tin alloy, copper, or nickel.

[0167] In some cases, when both the material of Part 133 and the material of Part 143 contain at least silver, the silver content in Part 133 may be higher than the silver content in Part 143.

[0168] In summary, the lengths of the first portion 133 in the first fine gate 113 and the first portion 133 in the second fine gate 123 are designed differently, with the first length L1 being greater than the second length L2. On one hand, the longer first portion 133 increases the alignment area between the first portion 133 and subsequent conductive portions and reduces alignment errors, thus ensuring the effective transmission of photogenerated carriers collected by the first portion 133 to the subsequent conductive portions. On the other hand, the longer first portion 133 increases the connection area between the first portion 133 and subsequent conductive portions, thereby increasing the connection strength and reducing the contact resistance. Thus, for the first fine gate 113, the transmission efficiency of photogenerated carriers collected by the first portion 133 to the subsequent conductive portions can be comprehensively improved, and the risk of subsequent conductive portions detaching from the first portion 133 can be reduced, thereby enhancing the structural stability of the first fine gate 113. Furthermore, even if the area corresponding to the first fine grid 113 in the printing screen is deformed to some extent, the longer first part 133 can ensure the connection between the first part 133 and other subsequent conductive parts, thereby helping to improve the service life of the printing screen and reduce the manufacturing cost of the first fine grid 113. In addition, the second fine grid 123 is generally subjected to less external force, and the area corresponding to the second fine grid 123 in the printing screen is not easily deformed. Designing the second length L2 of the first part 133 to be smaller can also ensure that the first part 133 and other subsequent conductive parts have sufficient connection area, thereby helping to reduce the material cost of the first part 133.

[0169] Another embodiment of this disclosure provides a printing screen, which can be used to form the fine grid in the photovoltaic cell provided in the foregoing embodiment. The printing screen provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0170] Reference Figure 13 , Figure 1 and Figure 2 , Figure 13 This is a partial top view of a printing screen provided in another embodiment of the present disclosure. The printing screen 106 may include: the printing screen 106 having a first opening 116 and a second opening 126; along the first direction X, the length of the first opening 116 is greater than the length of the second opening 126.

[0171] The length of the first opening 116 can be the fourth length L4, and the length of the second opening 126 can be the fifth length L5, with the fourth length L4 being greater than the fifth length L5.

[0172] In other words, the printing screen 106 is divided into at least a fourth zone 136 and a fifth zone 146 along the first direction X. The opening in the fourth zone 136 of the printing screen 106 can be regarded as the first opening 116, and the opening in the fifth zone 146 of the printing screen 106 can be regarded as the second opening 126.

[0173] It is worth noting that in the production line, a single printing screen 106 is reused to form the grids 103 in multiple photovoltaic cells. Based on this, as the usage time of the printing screen 106 increases, local areas of the printing screen 106, such as the edges of the printing screen 106, are prone to deformation, such as bending. This easily deformable area of ​​the printing screen 106 is designated as the fourth region 136. As the usage time of the printing screen 106 increases, when the portion of the printing screen 106 located in the fourth region 136 deforms, the first opening 116 located in the fourth region 136 will shift along the first direction X, causing the position of the first portion 133 formed based on the first opening 116 to shift. When other conductive portions, such as the second portion 143, are subsequently formed on the first portion 133 using other printing screens, the connection area between the second portion 143 and the first portion 133 will change.

[0174] Based on this, along the first direction X, the length of the first opening 116 is designed to be greater than the length of the second opening 126. Even if the portion of the printing screen 106 located in the fourth zone 136 undergoes slight deformation due to increased usage time, the first part 133 formed by the longer first opening 116 in the fourth zone 136 has more area for connection with the subsequently formed second part 143. Therefore, even if the formation position of the first part 133 is slightly offset, the sufficiently long first part 133 can tolerate a larger alignment error between the first part 133 and other subsequently formed conductive parts, still ensuring a sufficiently large connection area between the first part 133 and other subsequently formed conductive parts. In this way, the reduction in alignment accuracy between the first part 133 and other conductive parts caused by deformation of the printing screen 106 can be avoided, and the service life of the printing screen 106 can be improved.

[0175] In some embodiments, in conjunction with reference Figure 13 and Figure 1 The first opening 116 can correspond one-to-one with the first part 133.

[0176] In some embodiments, reference Figure 14 , Figure 14This is a partial top view of another embodiment of the printing screen provided in this disclosure. Along the first direction X, the spacing between adjacent first openings 116 along the second direction Y is the third spacing D3, and the spacing between adjacent second openings 126 along the second direction Y is the fourth spacing D4. The third spacing D3 can be greater than the fourth spacing D4. The first direction X intersects the second direction Y.

[0177] It is worth noting that, in conjunction with references Figure 14 and Figure 6 The fourth region 136 in the printing plate 106 can correspond to the first region 111 in the photovoltaic cell. The first opening 116 in the fourth region 136 can correspond to the first part 133 formed subsequently on the first region 111. Based on this, the parts of the fourth region 136 and the first region 111 that are the same or corresponding, and the parts of the first opening 116 in the fourth region 136 and the first part 133 formed subsequently on the first region 111 that are the same or corresponding, will not be described again here.

[0178] The fifth region 146 in the printing plate 106 can correspond to the second region 121 in the photovoltaic cell. The second opening 126 located in the fifth region 146 can correspond to the first part 133 subsequently formed on the second region 121. Based on this, the parts of the fifth region 146 that are the same as or corresponding to the second region 121, and the parts of the second opening 126 located in the fifth region 146 that are the same as or corresponding to the first part 133 subsequently formed on the second region 121, will not be described again here.

[0179] This disclosure provides another embodiment of a method for manufacturing a photovoltaic cell, used to form the photovoltaic cell provided in the foregoing embodiments. The manufacturing method of the photovoltaic cell provided in this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0180] Reference Figures 1 to 3 The method for manufacturing a photovoltaic cell includes at least the following steps: forming a photovoltaic cell including a first grid 113 and a second grid 123; the photovoltaic cell includes a cell substrate 105, the cell substrate 105 includes a first surface 101 and a second surface 102 disposed opposite to each other, the first grid 113 and the second grid 123 are located on the first surface 101, the first grid 113 and the second grid 123 include a plurality of first portions 133 arranged at intervals along a second direction Y; along the first direction X, the length of the first portion 133 in the first grid 113 is a first length L1, the length of the first portion 133 in the second grid 123 is a second length L2, the first length L1 is greater than the second length L2, and the first direction X intersects the second direction Y.

[0181] In some embodiments, in conjunction with reference Figure 15 and10 , Figure 15 This is a partial top view of the initial cell substrate in a method for manufacturing a photovoltaic cell according to another embodiment of the present disclosure. The photovoltaic cell is a segmented cell, and forming a photovoltaic cell including the fine grid 103 may include the following steps: refer to Figure 15 An initial battery substrate 135 is provided, and fine grids 103 are formed on the initial battery substrate 135 to form a complete battery. The initial battery substrate 135 has two sixth regions 1351 opposite each other along a first direction X, and a seventh region 1352 located between the two sixth regions 1351; the two corners of the sixth region 1351 away from the seventh region 1352 are chamfered 104; the sixth region 1351 includes at least one partition 12, and the seventh region 1352 includes at least one partition 12; along the direction from the seventh region 1352 to the sixth region 1351, the length of the first portion 133 of the fine grids 103 in different partitions 12 increases with each region.

[0182] Reference Figure 15 and Figure 10 Along the first direction X, the entire battery is divided into N sub-batteries, where N is a positive integer greater than 1.

[0183] It should be noted that, Figure 15 The example only uses the sixth zone 1351, which includes one partition 12, and the seventh zone 1352, which includes one partition 12. In actual applications, there is no limit to the number of partitions included in the sixth zone. For example, the sixth zone can also include 2, 3, 4, or 5 partitions. Similarly, there is no limit to the number of partitions included in the seventh zone. For example, the seventh zone can also include 2, 3, 4, or 5 partitions.

[0184] Another embodiment of this disclosure provides a tandem solar cell, which includes the photovoltaic cell provided in the foregoing embodiments, or a photovoltaic cell formed using the printing screen provided in the foregoing embodiments, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiments. The tandem solar cell provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0185] refer to Figure 16 , Figure 16 This is a partial cross-sectional structural diagram of a tandem solar cell provided in another embodiment of the present disclosure. The tandem solar cell includes: a bottom cell 117, which is a photovoltaic cell provided in the foregoing embodiment, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiment; and a perovskite cell 127, which is located on one side of the bottom cell 117.

[0186] In some embodiments, the perovskite solar cell 127 may include: a first transport layer, a perovskite substrate, a second transport layer, a transparent conductive layer, and an antireflection layer stacked together. The first transport layer is directly opposite the bottom cell 117.

[0187] In some examples, the first transport layer can be either an electron transport layer or a hole transport layer, and the second transport layer can be either an electron transport layer or a hole transport layer.

[0188] In some embodiments, the bandgap width of the perovskite cell 127 is wider than that of the bottom cell 117. Therefore, stacking the perovskite cell 127 on top of the bottom cell 117 can give the stacked cell a wider spectral response range, thereby maximizing the utilization of solar energy and improving the efficiency of the stacked cell.

[0189] In some embodiments, the stacked cell may further include an intermediate connecting layer (not shown in the figure), which connects the bottom cell 117 and the perovskite cell 127.

[0190] In some cases, the intermediate connecting layer is typically a tunnel junction or a very thin composite layer of metal or transparent electrode. Alternatively, the intermediate connecting layer can be a transparent conductive oxide, which has good optoelectronic properties, high photon transmittance, and high conductivity, thereby enabling the perovskite solar cell 127 and the bottom cell 117 to maintain good ohmic contact.

[0191] In other cases, the fine grid 103 in the photovoltaic cell serving as the bottom cell 117 (see reference) Figure 2 It can also serve as an intermediate connecting layer to achieve electrical connection with the perovskite solar cell 127. It should be noted that the electrical connection between the two actually means that both materials are conductive materials, and they are directly connected in contact or connected through other conductive materials. Therefore, when the tandem solar cell is generating electricity, there is an electrical connection between the two.

[0192] Another embodiment of this disclosure provides a photovoltaic module, which includes the photovoltaic cell provided in the foregoing embodiments, or a photovoltaic cell formed using the printing plate provided in the foregoing embodiments, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiments. The photovoltaic module is used to convert received light energy into electrical energy. The photovoltaic module provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the parts that are the same as or corresponding to the foregoing embodiments can be referred to the corresponding descriptions of the foregoing embodiments, and will not be repeated hereafter.

[0193] Reference Figure 17 , Figure 18 as well as Figures 1 to 3The photovoltaic module includes: a battery string, which is formed by connecting multiple photovoltaic cells 40 provided in the foregoing embodiments, or by connecting multiple photovoltaic cells 40 formed using a printing screen provided in the foregoing embodiments, or by connecting multiple photovoltaic cells 40 formed by the manufacturing method of photovoltaic cells provided in the foregoing embodiments, or by connecting multiple stacked cells provided in the foregoing embodiments; an encapsulation layer 41 for covering the surface of the battery string; and a cover plate 42 for covering the surface of the encapsulation layer 41 facing away from the battery string.

[0194] in, Figure 17 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of the present disclosure; Figure 18 This is a cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0195] In some embodiments, multiple photovoltaic cells 40 can be electrically connected via solder ribbons 43. It is worth noting that electrical connection actually means that both are made of conductive materials and are directly connected in contact or connected via other conductive materials. Therefore, when the photovoltaic cells 40 are generating electricity, there is an electrical connection between them.

[0196] It should be noted that, Figure 17 and Figure 18 This illustration only shows one positional relationship between photovoltaic cells 40, where electrodes of different polarities in each photovoltaic cell 40 are located on the same surface, and the side of each photovoltaic cell 40 with electrodes faces the same direction. Solder ribbons 43 connect the same side of two adjacent photovoltaic cells 40 respectively. In other embodiments, the photovoltaic cells may also be arranged such that the sides of two adjacent photovoltaic cells with electrodes are located on different sides, in which case solder ribbons connect the different sides of the two adjacent photovoltaic cells.

[0197] In some embodiments, the photovoltaic cells 40 are electrically connected in the form of a single cell or multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. The photovoltaic cells 40 can be a single cell or a sliced ​​cell, where a sliced ​​cell refers to a cell formed by cutting a complete single cell.

[0198] In some embodiments, the encapsulation layer 41 includes a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers one of the front or back sides of the photovoltaic cell 40, and the second encapsulation layer covers the other of the front or back sides of the photovoltaic cell 40. Specifically, at least one of the first encapsulation layer or the second encapsulation layer may be an organic encapsulation film such as polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin thermoplastic elastomer (POE), or polyethylene glycol terephthalate (PET). Alternatively, at least one of the first encapsulation layer or the second encapsulation layer may also be an EP film, an EPE film, or a PVP film. Among them, 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, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0199] 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 layer 41.

[0200] 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 encapsulation layer 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.

[0201] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic cell, characterized in that, include: A battery substrate, the battery substrate including a first surface and a second surface disposed opposite to each other; The first fine grid and the second fine grid are located on the first surface, and the first fine grid and the second fine grid include a plurality of first parts arranged at intervals along the second direction; Along the first direction, the length of the first part in the first fine grid is a first length, the length of the first part in the second fine grid is a second length, the first length is greater than the second length, and the first direction intersects the second direction.

2. The photovoltaic cell according to claim 1, characterized in that, The ratio of the first length to the second length is 1.02 to 20.

3. The photovoltaic cell according to claim 1 or 2, characterized in that, The first length is 7 μm to 100 μm; and / or, the second length is 5 μm to 98 μm.

4. The photovoltaic cell according to claim 1 or 2, characterized in that, The difference between the first length and the second length is 2μm~30μm.

5. The photovoltaic cell according to claim 1, characterized in that, The thickness of the first part in the first fine grid is a first thickness, and the thickness of the first part in the second fine grid is a second thickness, wherein the first thickness is greater than the second thickness.

6. The photovoltaic cell according to claim 5, characterized in that, The difference between the first thickness and the second thickness is 0.5 μm to 1.5 μm.

7. The photovoltaic cell according to claim 5 or 6, characterized in that, The first thickness is 1 μm to 6 μm; and / or the second thickness is 0.5 μm to 5 μm.

8. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, the spacing between adjacent first portions in the first fine grid is a first spacing, and the spacing between adjacent first portions in the second fine grid is a second spacing, wherein the first spacing is greater than the second spacing.

9. The photovoltaic cell according to claim 8, characterized in that, The ratio of the first spacing to the second spacing is 35 / 33 to 35 / 3.

10. The photovoltaic cell according to claim 8 or 9, characterized in that, The first spacing is 50μm to 350μm; and / or, the second spacing is 30μm to 330μm.

11. The photovoltaic cell according to claim 1, characterized in that, The first fine gate and the second fine gate further include a second portion extending along the second direction, the second portion being connected to a plurality of the first portions; along the first direction, the width of the second portion in the first fine gate is a first width, the width of the second portion in the second fine gate is a second width, and the first width is greater than the second width.

12. The photovoltaic cell according to claim 11, characterized in that, The ratio of the first width to the second width is 5 / 4 to 10 / 3.

13. The photovoltaic cell according to claim 11 or 12, characterized in that, The first width is 20μm to 50μm; and / or the second width is 15μm to 40μm.

14. The photovoltaic cell according to claim 11 or 12, characterized in that, The material of the first part includes at least one of silver, silver-plated copper, silver-copper alloy, silver-plated nickel, or silver-nickel alloy, and the material of the second part includes at least one of silver-plated copper, silver-copper alloy, silver-plated nickel, silver-nickel alloy, silver-plated tin, silver-tin alloy, copper, or nickel.

15. The photovoltaic cell according to claim 1, characterized in that, Also includes: A third fine grid is located on the first surface, the third fine grid being located on the side of the second fine grid away from the first fine grid; The length of the first part in the third fine grid is the third length, which is less than the second length.

16. A printing screen, characterized in that, include: The printing screen has a first opening and a second opening; Along the first direction, the length of the first opening is greater than the length of the second opening.

17. The printing screen according to claim 16, characterized in that, The spacing between adjacent first openings along the second direction is the third spacing, and the spacing between adjacent second openings along the second direction is the fourth spacing. The third spacing is greater than the fourth spacing, and the first direction intersects the second direction.

18. A method for manufacturing a photovoltaic cell, characterized in that, include: A photovoltaic cell comprising a first fine grid and a second fine grid is formed; The photovoltaic cell includes a cell substrate, the cell substrate includes a first surface and a second surface disposed opposite to each other, the first fine grid and the second fine grid are located on the first surface, and the first fine grid and the second fine grid include a plurality of first parts arranged at intervals along a second direction; Along the first direction, the length of the first part in the first fine grid is a first length, the length of the first part in the second fine grid is a second length, the first length is greater than the second length, and the first direction intersects the second direction.

19. A stacked battery, characterized in that, include: The bottom cell is a photovoltaic cell as described in any one of claims 1 to 15, or a photovoltaic cell formed using a printing screen as described in claim 16 or 17, or a photovoltaic cell formed by the manufacturing method of a photovoltaic cell as described in claim 18; A perovskite solar cell, wherein the perovskite solar cell is located on one side of the bottom solar cell.

20. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple photovoltaic cells as described in any one of claims 1 to 15, or by connecting multiple photovoltaic cells formed using a printing screen as described in claim 16 or 17, or by connecting multiple photovoltaic cells formed by the manufacturing method of photovoltaic cells as described in claim 18, or by connecting multiple stacked cells as described in claim 19. An encapsulation layer is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulation layer that faces away from the battery string.

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