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

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a photovoltaic cell and a manufacturing method thereof, a laminated cell and a photovoltaic module, and the photovoltaic cell comprises a cell substrate which is provided with a first surface and a second surface which are opposite to each other; the grid lines are located on the first face and / or the second face and arranged at intervals in the first direction, each grid line comprises a contact structure and a connecting layer which are electrically connected with the battery substrate, each contact structure comprises a plurality of contact parts, and each connecting layer is of a long-strip-shaped structure extending in the second direction; the contact part comprises a first contact part and a second contact part which are alternately arranged in the second direction, the connecting layer is provided with a first side part and a second side part which are opposite in the first direction, the first contact part is at least in contact connection with the first side part, and the second contact part is in contact connection with the second side part; the second contact part is at least in contact connection with the second side part, and the first contact part is in contact connection with the first side part, thereby at least facilitating the improvement of the electrical connection performance of the grid line and the battery substrate and the reduction of the manufacturing cost of the grid line.

Description

Technical Field

[0001] The present disclosure relates to the field of photovoltaics, and particularly to a photovoltaic cell, a manufacturing method thereof, a tandem cell, and a photovoltaic module. Background Art

[0002] With the gradual depletion of fossil energy, photovoltaic cells, as a new energy alternative, are used more and more widely. A photovoltaic cell is a device that converts the light energy of the sun into electrical energy. The photovoltaic cell utilizes the photovoltaic effect to generate carriers, and then uses grid lines to lead out the carriers, thereby facilitating the effective utilization of electrical energy. Currently, the main types of photovoltaic cells include BC cells (Back Contact), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and real cell), and heterojunction cells, etc. Summary of the Invention

[0003] Embodiments of the present disclosure provide a photovoltaic cell, a manufacturing method thereof, a tandem cell, and a photovoltaic module, which are at least beneficial to improving the electrical connection performance between the grid lines and the cell substrate and reducing the manufacturing cost of the grid lines.

[0004] According to some embodiments of the present disclosure, on the one hand, an embodiment of the present disclosure provides a photovoltaic cell, including: a cell substrate having a first surface and a second surface opposite to each other in the thickness direction; a plurality of grid lines located on the first surface and / or the second surface and arranged at intervals in a first direction, the grid lines including a contact structure electrically connected to the cell substrate and a connection layer, the contact structure including a plurality of contact portions arranged in sequence in a second direction, the connection layer being a strip-shaped structure extending in the second direction, the first direction and the second direction intersecting; wherein, the connection layer is in contact connection with the plurality of contact portions in the contact structure, the material of the contact portion is different from the material of the connection layer, and the orthographic projection portions of the contact portion and the connection layer on the cell substrate partially overlap; the contact portion includes a first contact portion and a second contact portion arranged alternately in the second direction, the connection layer has a first side portion and a second side portion opposite to each other in the first direction, the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or, the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion.

[0005] In some embodiments, in the same grid line, the first contact portion and the second contact portion are not directly opposite to each other in the second direction.

[0006] In some embodiments, in the same gate line, a partial region of the first contact portion and a partial region of the second contact portion face each other along the second direction.

[0007] In some embodiments, along the second direction, the portion of the first contact portion that faces the second contact portion is the first portion, and the width of the portion of the first contact portion other than the first portion in the first direction is less than or equal to 25 μm.

[0008] In some embodiments, along the thickness direction, the shape of the orthographic projection of the contact portion on the battery substrate is circular, oval, triangular, rectangular, trapezoidal, or N-sided, where N is a positive integer greater than 4.

[0009] In some embodiments, along the thickness direction, the shape of the orthographic projection of the contact portion on the battery substrate is circular or oval, and the adjacent first contact portion and second contact portion along the second direction are tangent to each other.

[0010] In some embodiments, along the thickness direction, the orthographic projection area of the contact portion on the battery substrate is 100 μm 2 ~5000 μm 2 。

[0011] In some embodiments, along the first direction, the width of the connection layer is 10 μm to 70 μm.

[0012] In some embodiments, among the adjacent first contact portion and second contact portion along the second direction, the edge of the first contact portion closest to the second contact portion is the first edge, the edge of the second contact portion closest to the first contact portion is the second edge, and the distance between the first edge and the second edge is less than or equal to 200 μm.

[0013] In some embodiments, along the thickness direction, the thickness of the contact portion is 1 μm to 10 μm; and / or, the thickness of the connection layer is 4 μm to 20 μm.

[0014] In some embodiments, the gate line is one of a fine grid and a main grid, and the other of the fine grid and the main grid is a long strip structure extending along the first direction.

[0015] In some embodiments, the grid line is a fine grid, and the photovoltaic cell further includes: a plurality of main grids located on at least one of the first surface and the second surface and arranged at intervals along the second direction, the main grid including a connection structure electrically connected to the cell substrate and an interconnection layer, the connection structure including a plurality of connection portions arranged in sequence along the first direction, and the interconnection layer being a strip-shaped structure extending along the first direction; wherein, the interconnection layer is in contact connection with the plurality of connection portions in the connection structure, the connection portion includes a first connection portion and a second connection portion arranged alternately along the second direction, the interconnection layer has a third side portion and a fourth side portion opposite to each other along the first direction, the first connection portion is at least in contact connection with the third side portion, the second connection portion is at least in contact connection with the fourth side portion, and the material of the connection portion is different from the material of the interconnection layer.

[0016] In some embodiments, the material of the contact portion includes silver particles, and the material of the connection layer includes copper particles or silver-coated copper particles.

[0017] In some embodiments, the diameter of the copper particles is 50 nm to 1500 nm; or, the diameter of the silver-coated copper particles is 1 μm to 10 μm; or, the proportion of silver in the silver-coated copper particles is 15% to 50%.

[0018] According to some embodiments of the present disclosure, on the other hand, the present disclosure also provides a manufacturing method of a photovoltaic cell, including: providing a cell substrate having a first surface and a second surface opposite to each other in the thickness direction; forming a plurality of grid lines arranged at intervals along a first direction on the first surface and / or the second surface, the grid line including a contact structure electrically connected to the cell substrate and a connection layer, the contact structure including a plurality of contact portions arranged in sequence along a second direction, the connection layer being a strip-shaped structure extending along the second direction, and the first direction and the second direction intersect; wherein, the connection layer is in contact connection with the plurality of contact portions in the contact structure, the material of the contact portion is different from the material of the connection layer, and the orthographic projections of the contact portion and the connection layer on the cell substrate partially overlap; the contact portion includes a first contact portion and a second contact portion arranged alternately along the second direction, the connection layer has a first side portion and a second side portion opposite to each other along the first direction, the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or, the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion.

[0019] In some embodiments, the gate line is a fine gate; the second surface has a first printing area and a second printing area that at least partially overlaps with the first printing area; the steps of forming the gate line include: using a first screen printing process to print a first paste on the first printing area; performing a sintering process on the first paste to form the contact structure corresponding to the first printing area; using a second screen printing process to print a second paste on the second surface; performing a curing process on the second paste to form the connection layer corresponding to the second printing area; wherein, the first paste is a burn-through paste, and the second paste is a non-burn-through paste; the process temperature of the sintering process is higher than the process temperature of the curing process.

[0020] In some embodiments, the first paste is a silver paste, and the second paste is a copper paste or a silver-coated copper paste.

[0021] In some embodiments, the solid content in the silver paste is 75% - 92%.

[0022] In some embodiments, the second surface further has a third printing area; in the step of performing the first screen printing process, the first paste is also printed on the third printing area, and in the step of performing the sintering process, the main gate corresponding to the third printing area is also formed; alternatively, in the step of performing the second screen printing process, the second paste is also printed on the third printing area, and in the step of performing the curing process, the main gate corresponding to the third printing area is also formed.

[0023] In some embodiments, the fine gate formed on the second surface is a back fine gate, and the main gate formed on the second surface is a back main gate; the first surface has a fourth printing area extending along the first direction and a fifth printing area extending along the second direction; before performing the sintering process, the manufacturing method of the photovoltaic cell further includes: using a third screen printing process to print a third paste on the fourth printing area; in the step of performing the sintering process, the third paste is also subjected to the sintering process to form the front fine gate corresponding to the fourth printing area; using a fourth screen printing process to print a fourth paste on the fifth printing area; in the step of performing the sintering process, the fourth paste is also subjected to the sintering process to form the front main gate corresponding to the fifth printing area.

[0024] According to some embodiments of the present disclosure, yet another aspect of the embodiments of the present disclosure further provides a tandem cell, including: a bottom cell, the bottom cell being the photovoltaic cell as described in any one of the above, or a photovoltaic cell formed by the manufacturing method of multiple photovoltaic cells as described in any one of the above; a top cell, the top cell being located on one side of the bottom cell.

[0025] According to some embodiments of the present disclosure, on the other hand, an embodiment of the present disclosure further provides a photovoltaic module, including: a battery string, which is formed by connecting a plurality of photovoltaic cells as described in any one of the above, or formed by connecting photovoltaic cells formed by the manufacturing method of a plurality of photovoltaic cells as described in any one of the above, or formed by connecting a plurality of the above-described tandem cells; an encapsulation film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulation film facing away from the battery string.

[0026] The technical solutions provided by the embodiments of the present disclosure have at least the following advantages: Designing that the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or, the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion, can make the adjacent first contact portion and second contact portion in the second direction be arranged in a staggered manner in the first direction. In this way, on the one hand, on the premise that the size of the connection layer is the same, compared with the contact structure whose preparation and connection layer are both strip-shaped structures, with the help of the staggered first contact portion and second contact portion, it is beneficial to reduce the amount of materials required for the contact structure while ensuring that the contact structure and the connection layer have sufficient contact area, thereby being beneficial to improving the electrical connection performance between the grid line and the battery substrate and reducing the manufacturing cost of the grid line; on the other hand, with the help of the staggered first contact portion and second contact portion, it is beneficial to widen the distance between the two edges of the first contact portion and the second contact portion that are farthest apart in the first direction. Therefore, on the premise that the size of the connection layer is the same, compared with the contact structure whose preparation and connection layer are both strip-shaped structures, it is beneficial to reduce the requirement for the alignment accuracy between the connection layer and the contact structure, thereby being beneficial to reducing the preparation difficulty of the connection layer to reduce the preparation difficulty of the grid line while ensuring a high contact performance between the contact structure and the connection layer.

[0027] In addition, designing that the material of the contact portion is different from the material of the connection layer can further reduce the preparation cost of the contact structure by adjusting the costs of the material of the contact portion and the material of the connection layer. Description of the Drawings

[0028] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the figures in the drawings do not constitute a proportional limitation; in order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the traditional technology, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1The first partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 2 A partial top view schematic diagram of the photovoltaic cell provided by an embodiment of the present disclosure; Figure 3 For Figure 2 A cross-sectional schematic diagram along the first cross-section direction AA1; Figure 4 The second partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 5 The third partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 6 The fourth partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 7 The fifth partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 8 A partial enlarged schematic diagram of two adjacent contact parts in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 9 The sixth partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 10 The seventh partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 11 The eighth partial top view schematic diagram of the grid lines in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 12 Another partial top view schematic diagram of the photovoltaic cell provided by an embodiment of the present disclosure; Figure 13 A partial top view schematic diagram of the main grid in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 14 A partial cross-sectional schematic diagram of the stacked cell provided by another embodiment of the present disclosure; Figure 15 A partial three-dimensional schematic diagram of the battery string in the photovoltaic module provided by yet another embodiment of the present disclosure; Figure 16 A partial cross-sectional schematic diagram of the photovoltaic module provided by yet another embodiment of the present disclosure.

[0030] Explanation of reference numerals: 100, Battery substrate; 110, First side; 120, Second side; 101, Grid line; 102, Contact structure; 112, Contact portion; 122, First contact portion; 122a, First edge; 1221, First part; 1222, Second part; 132, Second contact portion; 132a, Second edge; 103, Connection layer; 113, First side portion; 123, Second side portion; 104, Fine grid; 105, Main grid; 115, Connection structure; 125, Interconnection layer; 135, Connection portion; 145, First connection portion; 155, Second connection portion; 165, Third side portion; 175, Fourth side portion; 106, Bottom cell; 107, Top cell; 40, Photovoltaic cell; 41, Encapsulation adhesive film; 42, Cover plate; 43, Conductive strip. Detailed implementation manner

[0031] Through analysis, it is found that in the process of forming grid lines by printing silver paste, whether it is for photovoltaic cells with grid lines on both sides or back-contact cells with grid lines on one side, the amount of silver paste used is relatively large, the metallization cost is high, and the preparation cost of grid lines needs to be reduced. Moreover, compared with photovoltaic cells with grid lines on both sides, the amount of silver paste used in back-contact cells with grid lines on one side is even larger.

[0032] In practical applications, for photovoltaic cells with grid lines on both sides, such as TOPCON cells, the amount of silver paste used for the whole photovoltaic cell is as high as 80 mg, and the amount of silver paste used for one side is as high as 40 mg.

[0033] Embodiments of the present disclosure provide a photovoltaic cell, a manufacturing method thereof, a stacked cell, and a photovoltaic module. In the photovoltaic cell, it is designed that the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion, so that the adjacent first contact portion and second contact portion in the second direction are arranged in a staggered manner in the first direction. In this way, on the one hand, on the premise that the size of the connection layer is the same, compared with the contact structure whose preparation and connection layer are both strip-shaped structures, with the help of the staggered first contact portion and second contact portion, it is beneficial to reduce the material consumption of the contact structure while ensuring that the contact structure and the connection layer have sufficient contact area, thereby being beneficial to improving the electrical connection performance between the grid line and the cell substrate and reducing the manufacturing cost of the grid line; on the other hand, with the help of the staggered first contact portion and second contact portion, it is beneficial to widen the distance between the two edges of the first contact portion and the second contact portion that are farthest apart in the first direction. Therefore, on the premise that the size of the connection layer is the same, compared with the contact structure whose preparation and connection layer are both strip-shaped structures, it is beneficial to reduce the requirement for the alignment accuracy between the connection layer and the contact structure, thereby being beneficial to reducing the preparation difficulty of the connection layer to reduce the preparation difficulty of the grid line while ensuring a high contact performance between the contact structure and the connection layer. In addition, by designing that the material of the contact portion is different from that of the connection layer, the preparation cost of the contact structure can be further reduced by adjusting the costs of the materials of the contact portion and the connection layer.

[0034] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "a plurality" is more than two, unless otherwise clearly and specifically defined.

[0035] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0036] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: there is A, there is both A and B, and there is B. In addition, the character " / " in this article generally represents an "or" relationship between the front and rear associated objects.

[0037] In the description of the embodiments of the present disclosure, the term "plurality" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0038] In the description of the embodiments of the present disclosure, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present disclosure.

[0039] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0040] In the corresponding drawings of the embodiments of the present disclosure, for better understanding and convenience of description, the thickness and area of the layer are enlarged. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component "substantially" 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 partial edge of the entire surface.

[0041] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise stated, other components are not excluded, and other components may further be included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components therebetween), or there may be other components therebetween. In addition, when a component such as a layer, film, region, or plate is "directly located on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located therebetween.

[0042] The terms used in the description of the various embodiments herein are only for the purpose of describing specific embodiments and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, "the component" is also intended to include the plural form unless the context clearly indicates otherwise. Among them, the component includes components such as a layer, film, region, or plate.

[0043] The following will elaborate on the embodiments of the present disclosure in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present disclosure, many technical details are provided to help the reader better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can still be implemented.

[0044] An embodiment of the present disclosure provides a photovoltaic cell. The following will detail the photovoltaic cell provided by an embodiment of the present disclosure in conjunction with the accompanying drawings.

[0045] With reference to Figures 1 to 7, a photovoltaic cell includes: a cell substrate 100 having a first surface 110 and a second surface 120 opposite to each other in the thickness direction Z; a plurality of grid lines 101 disposed at intervals along the first direction X on the first surface 110 and / or the second surface 120, the grid lines 101 including a contact structure 102 electrically connected to the cell substrate 100 and a connection layer 103, the contact structure 102 including a plurality of contact portions 112 arranged in sequence along the second direction Y, the connection layer 103 being a strip-shaped structure extending along the second direction Y, and the first direction X intersecting the second direction Y; wherein, the connection layer 103 is in contact connection with the plurality of contact portions 112 in the contact structure 102, the material of the contact portion 112 is different from the material of the connection layer 103, and the orthographic projections of the contact portion 112 and the connection layer 103 on the cell substrate 100 partially overlap; the contact portion 112 includes a first contact portion 122 and a second contact portion 132 arranged alternately along the second direction Y, the connection layer 103 has a first side portion 113 and a second side portion 123 opposite to each other along the first direction X, and the first contact portion 122 is at least in contact connection with the first side portion 113, and the second contact portion 132 is at least in contact connection with the second side portion 123.

[0046] Wherein, Figure 1 is the first partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 2 is a partial top view schematic diagram of the photovoltaic cell provided by an embodiment of the present disclosure; Figure 3 is Figure 2 a cross-sectional schematic diagram along the first cross-section direction AA1; Figure 4 is the second partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 5 is the third partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 6 is the fourth partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure; Figure 7 is the fifth partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure.

[0047] It should be noted that, for clearly showing the positional relationship between the connection layer 103 and the contact portion 112, Figure 1 and Figure 2 both adopt a perspective drawing method for the connection layer 103. In addition, Figure 1 is only an example of a positional relationship between the connection layer 103 and the contact portion 112, and the positional relationship between the connection layer 103 and the contact portion 112 will be further described in detail in combination with other drawings later; Figure 3 takes the grid line 101 located on the second surface 120 as an example. In practical applications, the grid line can be located on the first surface, or can be located on both the first surface and the second surface at the same time.

[0048] It should be noted that in some cases, referring to Figure 1 , Figure 4 , Figure 5 or Figure 6 , by designing that the first contact portion 122 is at least in contact connection with the first side portion 113 and the second contact portion 132 is at least in contact connection with the second side portion 123, the first contact portion 122 and the second contact portion 132 adjacent to each other in the second direction Y can be arranged in a staggered manner in the first direction X. Among them, the first contact portion 122 is at least in contact connection with the first side portion 113 and the second contact portion 132 is in contact connection with the second side portion 123, or the second contact portion 132 is at least in contact connection with the second side portion 123 and the first contact portion 122 is in contact connection with the first side portion 113. It should be noted that the positional relationship between the contact portion 112 in the contact structure 102 and the connection layer 103 will be described in detail later.

[0049] In this way, on the one hand, on the premise that the size of the connection layer 103 is the same, compared with the contact structure that is also a strip-shaped structure like the connection layer 103, by means of the staggered arrangement of the first contact portion 122 and the second contact portion 132, it is beneficial to reduce the amount of material required for the contact structure 102 while ensuring that the contact structure 102 and the connection layer 103 have a sufficient contact area, thereby being beneficial to improving the electrical connection performance between the gate line 101 and the battery substrate 100 and reducing the manufacturing cost of the gate line 101; on the other hand, along the first direction X, the first contact portion 122 has a third edge away from the second contact portion 132, and the second contact portion 132 has a fourth edge away from the first contact portion 122. By means of the staggered arrangement of the first contact portion 122 and the second contact portion 132, it is beneficial to widen the distance between the third edge and the fourth edge in the first direction X. Therefore, on the premise that the size of the connection layer 103 is the same, compared with the contact structure that is also a strip-shaped structure like the connection layer 103, it is beneficial to reduce the requirement for the alignment accuracy between the connection layer 103 and the contact structure 102. In other words, based on the staggered arrangement of the first contact portion 122 and the second contact portion 132, a larger offset error between the connection layer 103 and the contact structure 102 in the first direction X can be tolerated, and within this offset error, the contact area between the connection layer 103 and the contact structure 102 will not change, thereby being beneficial to further ensuring a high contact performance between the contact structure 102 and the connection layer 103, and reducing the manufacturing difficulty of the connection layer 103 to reduce the manufacturing difficulty of the gate line 101.

[0050] In some examples, referring to Figure 1 , Figure 4 or Figure 5 , the first contact portion 122 is at least in contact connection with the first side portion 113 and the second contact portion 132 is only in contact connection with the second side portion 123, and the second contact portion 132 is not in contact connection with the first side portion 113.

[0051] In some other examples, referring to Figure 1 , Figure 4 or Figure 6 , the second contact portion 132 is at least in contact connection with the second side portion 123, and the first contact portion 122 is only in contact connection with the first side portion 113, and the first contact portion 122 is not in contact connection with the second side portion 123.

[0052] In some other cases, referring to Figure 7 , the first contact portion 122 is designed to be at least in contact connection with the first side portion 113, and the second contact portion 132 is at least in contact connection with the second side portion 123. It can also be arranged such that the adjacent first contact portion 122 and second contact portion 132 in the second direction Y are spaced apart in the second direction Y, and the first contact portion 122 is in contact connection with both the first side portion 113 and the second side portion 123, and the second contact portion 132 is also in contact connection with both the first side portion 113 and the second side portion 123. Thus, on the premise that the size of the connection layer 103 is the same, compared with the contact structure that is also a strip-shaped structure like the preparation and connection layer 103, with the first contact portion 122 and the second contact portion 132 spaced apart in the second direction Y, it is beneficial to reduce the amount of material required for the contact structure 102 while ensuring that the contact structure 102 and the connection layer 103 have sufficient contact area, thereby being beneficial to improving the electrical connection performance between the gate line 101 and the battery substrate 100 and reducing the manufacturing cost of the gate line 101.

[0053] In addition, designing the material of the contact portion 112 to be different from the material of the connection layer 103 can avoid using the same material for preparing the gate line 101. By adjusting the costs of the material of the contact portion 112 and the material of the connection layer 103, for example, designing the cost of the material of the connection layer 103 to be lower than the cost of the material of the contact portion 112, thus while reducing the amount of material required for the contact structure 102 with the help of the dispersed multiple contact portions 112 to reduce the manufacturing cost of the contact structure 102, it can also further reduce the manufacturing cost of the contact structure 102 based on the reduction of the cost of the material of the connection layer 103.

[0054] It should be noted that in some cases, referring to Figures 1 to 7, for a single gate line 101, the connection layer 103 can be in contact connection with each contact part 112 in the contact structure 102. In practical applications, due to the limitations of the printing process, when the positive projections of the connection layer and each contact part on the battery substrate overlap, there may be no good contact connection between the connection layer and some individual contact parts. For example, there are large errors in the printing thickness of some individual contact parts or large errors in the printing thickness of some areas of the connection layer; or, due to the limitations of the printing process, when the pattern finally formed by some individual contact parts is quite different from the designed pattern, there may also be no good contact connection between the connection layer and this contact part.

[0055] The following will describe the photovoltaic cell provided by an embodiment of the present disclosure in more detail with reference to the accompanying drawings.

[0056] In some embodiments, referring to Figure 4 , in the same gate line 101, the first contact part 122 and the second contact part 132 are not directly opposite in the second direction Y. In other words, with a plane perpendicular to the second direction Y as the projection plane, the positive projections of the first contact part 122 and the second contact part 132 on the projection plane do not overlap.

[0057] In this case, the contact connection between the contact part 112 and the connection layer 103 is as follows: the first contact part 122 is only in contact connection with the first side part 113, and the second contact part 132 is only in contact connection with the second side part 123.

[0058] In some other embodiments, referring to Figure 1 , Figure 5 or Figure 6 , in the same gate line 101, some areas of the first contact part 122 and some areas of the second contact part 132 are directly opposite in the second direction Y. In other words, with a plane perpendicular to the second direction Y as the projection plane, the positive projections of the first contact part 122 and the second contact part 132 on the projection plane partially overlap.

[0059] Thus, the contact connection between the contact part 112 and the connection layer 103 includes at least the following three situations: In some situations, referring to Figure 1 , the contact connection between the contact part 112 and the connection layer 103 is as follows: the first contact part 122 is only in contact connection with the first side part 113, and the second contact part 132 is only in contact connection with the second side part 123. It should be noted that in order to reduce the size of the contact part 112 itself to reduce the manufacturing cost while increasing the contact area between the contact part 112 and the connection layer 103, compared with the contact part 112 shown in Figure 4 , Figure 1The width of the contact portion 112 shown in the first direction X can be larger, and the extension length in the second direction Y can be smaller, so as to ensure that more than half of the area in the contact structure 102 can be in contact and connection with the connection layer 103 as much as possible.

[0060] In some other cases, referring to Figure 5 , the contact and connection situation between the contact portion 112 and the connection layer 103 is as follows: The first contact portion 122 is in contact and connection not only with the first side portion 113 but also with the second side portion 123, and the second contact portion 132 is only in contact and connection with the second side portion 123. It should be noted that, in order to reduce the size of the contact portion 112 itself to reduce the manufacturing cost while increasing the contact area between the contact portion 112 and the connection layer 103, the width of the first contact portion 122 in the first direction X can be greater than the width of the second contact portion 132 in the first direction X, so as to ensure that more than half of the area in the contact structure 102 can be in contact and connection with the connection layer 103 as much as possible. In addition, compared with Figure 1 the contact portion 112 shown, Figure 5 the width of the contact portion 112 shown in the first direction X can be larger, and the extension length in the second direction Y can be smaller, so as to reduce the amount of material required for the contact structure 102 as much as possible.

[0061] In some other cases, referring to Figure 6 , the contact and connection situation between the contact portion 112 and the connection layer 103 is as follows: The first contact portion 122 is only in contact and connection with the first side portion 113, and the second contact portion 132 is in contact and connection not only with the second side portion 123 but also with the first side portion 113. It should be noted that, in order to reduce the size of the contact portion 112 itself to reduce the manufacturing cost while increasing the contact area between the contact portion 112 and the connection layer 103, the width of the second contact portion 132 in the first direction X can be greater than the width of the first contact portion 122 in the first direction X, so as to ensure that more than half of the area in the contact structure 102 can be in contact and connection with the connection layer 103 as much as possible. In addition, compared with Figure 1 the contact portion 112 shown, Figure 6 the width of the contact portion 112 shown in the first direction X can be larger, and the extension length in the second direction Y can be smaller, so as to reduce the amount of material required for the contact structure 102 as much as possible.

[0062] In the above various cases, referring to Figure 8 , Figure 8FIG. 0 is a partially enlarged schematic view of two adjacent contact portions in a photovoltaic cell provided by an embodiment of the present disclosure. Along the second direction Y, the portion of the first contact portion 122 facing the second contact portion 132 is the first portion 1221. The width S of the portion of the first contact portion 122 other than the first portion 1221 in the first direction X is less than or equal to 25 μm. In other words, the misalignment range between the adjacent first contact portion 122 and the second contact portion 132 along the second direction Y is less than or equal to 25 μm. For example, it can be 24 μm, 23 μm, 22 μm, 21 μm, 20 μm, 19 μm, 18 μm, 17 μm, 16 μm, 15 μm, 14 μm, 13 μm, 12 μm, 11 μm, 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm or 1 μm, etc.

[0063] It should be noted that the portion of the first contact portion 122 other than the first portion 1221 may be the second portion 1222, and the width S of the second portion 1222 in the first direction X is less than or equal to 25 μm. Figure 8 The first portion 1221 and the second portion 1222 in the first contact portion 122 are divided by a dotted line in FIG.

[0064] It is worth noting that on the premise that a partial area of the first contact portion 122 and a partial area of the second contact portion 132 face each other along the second direction Y, if the width S of the second portion 1222 in the first direction X is greater than 25 μm, the misalignment degree between the adjacent first contact portion 122 and the second contact portion 132 in the first direction X will be relatively large, and the distance between the third edge and the fourth edge in the first direction X will be too large. In the case where the size of the connection layer 103 remains unchanged, it is not conducive to ensuring a large contact area between the connection layer 103 and the contact structure 102. Therefore, designing the misalignment range between the adjacent first contact portion 122 and the second contact portion 132 along the second direction Y to be less than or equal to 25 μm is beneficial to controlling the misalignment degree between the adjacent first contact portion 122 and the second contact portion 132 in the first direction X to be appropriate, so as to minimize the size of the contact portion 112 itself while ensuring that more than half of the area in the contact structure 102 can be in contact connection with the connection layer 103 as much as possible.

[0065] In still other embodiments, referring to Figure 7 , in the same grid line 101, the first contact portion 122 and the second contact portion 132 face each other along the second direction Y. In other words, with a plane perpendicular to the second direction Y as the projection plane, the orthographic projections of the first contact portion 122 and the second contact portion 132 on the projection plane coincide, that is, the misalignment range between the adjacent first contact portion 122 and the second contact portion 132 along the second direction Y is 0.

[0066] In this case, the contact connection between the contact portion 112 and the connection layer 103 is as follows: The first contact portion 122 is in contact connection with both the first side portion 113 and the second side portion 123, and the second contact portion 132 is in contact connection with both the first side portion 113 and the second side portion 123.

[0067] The contact portion 112 will be described in detail below.

[0068] In some embodiments, referring to Figures 1 to 8 , in the thickness direction Z, the orthographic projection shape of the contact portion 112 on the battery substrate 100 may be a rectangle.

[0069] In some other embodiments, referring to Figure 9 , Figure 9 is the sixth partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure. In the thickness direction Z, the orthographic projection shape of the contact portion 112 on the battery substrate 100 may be a circle. It should be noted that due to the influence of the process accuracy of forming the contact portion 112, when the orthographic projection shape of the contact portion 112 on the battery substrate 100 is a circle, the circle may also be an approximate circle, and it is not necessarily a standard circle in the geometric sense.

[0070] In still some other embodiments, referring to Figure 10 , Figure 10 is the seventh partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure. In the thickness direction Z, the orthographic projection shape of the contact portion 112 on the battery substrate 100 may be an ellipse. It should be noted that due to the influence of the process accuracy of forming the contact portion 112, when the orthographic projection shape of the contact portion 112 on the battery substrate 100 is an ellipse, the ellipse may also be an approximate ellipse, and it is not necessarily a standard ellipse in the geometric sense.

[0071] In yet some other embodiments, referring to Figure 11 , Figure 11 is the eighth partial top view schematic diagram of the grid line in the photovoltaic cell provided by an embodiment of the present disclosure. In the thickness direction Z, the orthographic projection shape of the contact portion 112 on the battery substrate 100 may be a triangle.

[0072] It should be noted that in practical applications, the orthographic projection shape of the contact portion on the battery substrate may also be a trapezoid or an N-sided polygon, where N is a positive integer greater than 4.

[0073] In some embodiments, referring to Figure 9, in the thickness direction Z, the orthographic projection shape of the contact portion 112 on the battery substrate 100 is circular or elliptical, and the first contact portion 122 and the second contact portion 132 adjacent along the second direction Y are tangent to each other. Thus, based on the special morphology of the contact portion 112, although for the adjacent first contact portion 122 and second contact portion 132, some regions are in contact connection, most regions are spaced apart along the second direction Y, which also helps to minimize the amount of material required for the contact structure 102 on the premise that the size of the connection layer 103 is the same.

[0074] It should be noted that Figure 9 Taking the orthographic projection shape of the contact portion 112 on the battery substrate 100 as circular and the first contact portion 122 and the second contact portion 132 adjacent along the second direction Y being tangent to each other as an example. In practical applications, when the orthographic projection shape of the contact portion on the battery substrate is circular, the first contact portion and the second contact portion adjacent along the second direction can also be spaced apart from each other.

[0075] In addition, when the orthographic projection shape of the contact portion on the battery substrate is elliptical, the first contact portion and the second contact portion adjacent along the second direction can also be tangent to each other, Figure 10 Taking only the orthographic projection shape of the contact portion 112 on the battery substrate 100 as elliptical and the first contact portion 122 and the second contact portion 132 adjacent along the second direction Y being spaced apart from each other as an example.

[0076] In some embodiments, with reference to Figures 1 to 11 , in the thickness direction Z, the orthographic projection area of the contact portion 112 on the battery substrate 100 can be 100 μm 2 ~5000 μm 2 , for example, it can be 300 μm 2 , 500 μm 2 , 800 μm 2 , 1000 μm 2 , 1200 μm 2 , 1500 μm 2 , 1700 μm 2 , 2000 μm 2 , 2300 μm 2 , 2500 μm 2 , 2800 μm 2 , 3000 μm 2 , 3300 μm 2 , 3500 μm 2 , 3800 μm 2 , 4000 μm 2 , 4200 μm 2 , 4500 μm 2 or 4800 μm 2 etc.

[0077] It is worth noting that if the orthographic projection area of ​​the contact portion 112 on the battery substrate 100 is less than 100 μm 2 If the contact area between a single contact portion 112 and the connecting layer 103 is too small, it is not conducive to improving the electrical connection performance between the contact portion 112 and the battery substrate 100, nor is it conducive to improving the contact performance between the contact portion 112 and the connecting layer 103; if the orthographic projection area of ​​the contact portion 112 on the battery substrate 100 is greater than 5000 μm 2 The effect of reducing the amount of material required for the contact structure 102 by simply relying on the spacing between adjacent contact portions 112 is limited. In this way, the orthographic projection area of ​​the contact portion 112 on the battery substrate 100 can be designed to be 100 μm 2 ~5000μm 2 This is beneficial for improving the electrical connection performance between the contact portion 112 and the battery substrate 100 and the contact performance between the contact portion 112 and the connection layer 103 while reducing the amount of material required for the contact structure 102 as much as possible.

[0078] In some embodiments, reference Figures 1 to 7 or Figures 9 to 11 Along the first direction X, the width of the connection layer 103 can be 10μm~70μm, for example, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm or 65μm, etc.

[0079] In some cases, reference Figure 1 Along the first direction X, the width of the connecting layer 103 can be substantially the same as the width of the contact portion 112 . The difference is that the multiple contact portions 112 in the contact structure 102 along the second direction Y are staggered in the first direction X, and the connecting layer 103 is a long strip structure extending along the second direction Y.

[0080] In some embodiments, reference Figure 8 In the first contact portion 122 and the second contact portion 132 adjacent to each other along the second direction Y, the edge of the first contact portion 122 closest to the second contact portion 132 is the first edge 122a, the edge of the second contact portion 132 closest to the first contact portion 122 is the second edge 132a, and the distance D between the first edge 122a and the second edge 132a is less than or equal to 200 μm.

[0081] It is worth noting that if the distance D between the first edge 122a and the second edge 132a is greater than 200 μm, the arrangement spacing between adjacent first contact portions 122 and second contact portions 132 is large, so that the arrangement density of the contact portions 112 in the contact structure 102 is too low, which will cause the connection layer 103 (refer toFigure 1 ), most regions of which are not in contact connection with the contact structure 102 (refer to Figure 1 ). Thus, designing the distance D between the first edge 122a and the second edge 132a to be less than or equal to 200 μm is beneficial to ensuring a relatively high arrangement density of the contact portions 112 in the contact structure 102, so as to ensure that most regions in the connection layer 103 can be in contact connection with the contact structure 102 as much as possible, and to ensure a sufficient contact area between the connection layer 103 and the contact structure 102.

[0082] It should be noted that Figure 8 the distance D between the first edge 122a and the second edge 132a is schematically shown by taking the shape of the orthographic projection of the contact portion 112 on the battery substrate 100 as a rectangle as an example. In practical applications, when the shape of the orthographic projection of the contact portion on the battery substrate is other shapes, the distance between the first edge and the second edge can also be less than or equal to 200 μm.

[0083] In some embodiments, with reference to Figures 1 to 11 , along the thickness direction Z, the thickness of the contact portion 112 can be 1 μm to 10 μm. For example, it can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm or 9 μm, etc.

[0084] In some embodiments, with reference to Figures 1 to 11 , the thickness of the connection layer 103 can be 4 μm to 20 μm. For example, it can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm or 19 μm, etc.

[0085] The materials of the contact portion 112 and the connection layer 103 will be described in detail below.

[0086] In some embodiments, with reference to Figures 1 to 11 , the material of the contact portion 112 can include silver particles, and the material of the connection layer 103 can include copper particles or silver-coated copper particles.

[0087] It should be noted that, per unit mass, the cost of silver particles is higher than that of copper particles and also higher than that of silver-coated copper particles. In addition, the electrical connection performance of silver particles with the battery substrate 100 is higher than that of copper particles with the battery substrate 100 and also higher than that of silver-coated copper particles with the battery substrate 100. Based on this, the material of only the contact structure in the grid line 101 is designed to be silver particles. On the one hand, it is beneficial to greatly reduce the content of silver particles in the grid line 101 while ensuring the electrical connection performance between the grid line 101 and the battery substrate 100 to ensure that the photovoltaic cell has a high photoelectric conversion efficiency. On the other hand, compared with the demand for the paste of the contact structure 102, the connection layer 103 with a greater demand for the paste is designed to include copper particles or silver-coated copper particles, which can not only ensure sufficient usage of the connection layer 103 so that the connection layer 103 can effectively collect the carriers of the multiple contact parts 112 in the contact structure 102, but also reduce the preparation cost of forming the connection layer 103.

[0088] In some cases, compared with simply using silver paste to form grid lines on the first side or the second side, the material of only the contact part 112 in the grid line 101 is designed to include silver particles, that is, only silver paste is used to form the contact part 112, and the amount of silver paste required to form the contact part 112 can be lower, for example, it can be reduced to 3 mg - 15 mg. In other words, compared with when simply using silver paste to form grid lines on the first side or the second side, where the amount of single-sided silver paste is as high as 40 mg, in the grid line 101 designed in an embodiment of the present disclosure, the amount of single-sided silver paste can be reduced to 3 mg - 15 mg.

[0089] It should be noted that in the grid line 101 designed in an embodiment of the present disclosure, in addition to designing the first contact part 122 and the second contact part 132 to be staggeredly arranged in the first direction X to reduce the amount of silver paste required to form the contact part 112, the thickness of the contact part 112 in the thickness direction Z can also be reduced to further reduce the amount of silver paste required to form the contact part 112.

[0090] In some cases, with reference to Figures 1 to 11 , the material of the connection layer 103 can include copper particles, and the diameter of the copper particles can be 50 nm - 1500 nm. For example, it can be 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm or 1400 nm, etc.

[0091] In other cases, with reference to Figures 1 to 11, the material of the connection layer 103 may include silver-coated copper particles, and the diameter of the silver-coated copper particles may be 1 μm to 10 μm. For example, it may be 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, or 1400 nm, etc.

[0092] It should be noted that the diameter of the silver-coated copper particles refers to the outer diameter of the silver-coated copper particles, that is, the diameter of the overall outer contour of the silver-coated copper particles.

[0093] In some examples, the proportion of silver in the silver-coated copper particles is 15% to 50%. For example, it may be 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, or 49%, etc.

[0094] The types of the grid lines 101 are described in detail below.

[0095] In some embodiments, referring to Figure 12 , Figure 12 , which is another partial top view schematic diagram of a photovoltaic cell provided by an embodiment of the present disclosure. The grid line 101 is one of the fine grid 104 and the main grid 105, and the other of the fine grid 104 and the main grid 105 is a long strip structure extending along the first direction X. It should be noted that Figure 12 takes the grid line 101 as the fine grid 104 and the main grid 105 as a long strip structure extending along the first direction X as an example. In practical applications, it may also be that the grid line is the main grid and the fine grid is a long strip structure extending along the first direction.

[0096] It should be noted that whether the fine grid 104 or the main grid 105 adopts the design of the grid line 101 described in the above various embodiments, it is beneficial to improve the electrical connection performance between the grid line 101 and the battery substrate 100 and reduce the manufacturing cost of the grid line 101. Moreover, based on the misalignment design of the contact portion 112 in the grid line 101, it is beneficial to reduce the preparation difficulty of the grid line 101.

[0097] In addition, on the battery substrate 100, the arrangement density of the fine grid 104 is greater than that of the main grid 105. Therefore, generally, the total amount of materials required to fabricate all the fine grids 104 on a single side is greater than the total amount of materials required to fabricate all the main grids 105 on the single side. On this basis, compared with the design of the grid line 101 described in the above various embodiments for the main grid 105, the design of the grid line 101 described in the above various embodiments for the fine grid 104 is more conducive to reducing the total amount of materials required to fabricate the grid line 101, so as to reduce the manufacturing cost of the photovoltaic cell.

[0098] Moreover, in some cases, the fine grid 104 needs to be electrically connected to the battery substrate 100, and the main grid 105 can be only in contact connection with the fine grid 104, without the main grid 105 being electrically connected to the battery substrate 100. The carriers in the battery substrate 100 can be first collected by the fine grid 104 and then collected by the main grid 105 in contact connection with the fine grid 104. Thus, the material used to form the main grid 105 does not need to achieve a direct electrical connection between the main grid 105 and the battery substrate 100. For example, the material used to form the main grid 105 does not need to be embedded in the passivation layer in the battery substrate 100. Then, the main grid 105 can select a material with a lower cost to achieve the contact connection between the main grid 105 and the fine grid 104. On this basis, the design of the grid line 101 described in the above various embodiments for the fine grid 104 is not only conducive to promoting the electrical contact performance between the fine grid 104 and the battery substrate 100 by means of the contact structure 102, but also conducive to reducing the manufacturing cost of the fine grid 104 by means of the connection layer 103. Moreover, the main grid 105 can select a material with a lower cost to further reduce the manufacturing cost of the photovoltaic cell.

[0099] It should be noted that Figures 1 to 12 in all of them, taking the example that along the second direction Y, a single first contact part 122 and a single second contact part 132 are arranged in a staggered manner in the first direction X. In other words, Figures 1 to 12 in the illustrated example, among the multiple contact parts 112 in contact connection with the same connection layer 103, along the second direction Y, only one second contact part 132 is spaced between two adjacent first contact parts 122, and only one first contact part 122 is spaced between two adjacent second contact parts 132.

[0100] In practical applications, when designing the staggered arrangement of the first contact portion and the second contact portion adjacent in the second direction in the first direction, the number of second contact portions spaced between two adjacent first contact portions is not limited. For example, it can be 2 or 3. The number of first contact portions spaced between two adjacent second contact portions is also not limited. For example, it can be 2 or 3. In other words, in practical applications, there may be no second contact portion between two adjacent first contact portions along the second direction, or there may be no first contact portion between two adjacent second contact portions along the second direction. For example, 1 first contact portion and 3 second contact portions are arranged as a group, and multiple groups are repeatedly arranged along the second direction.

[0101] In some other embodiments, with reference to Figure 1 and Figure 13 , Figure 13 FIG. is a partial top view schematic diagram of the main grid in a photovoltaic cell provided by an embodiment of the present disclosure. The grid line 101 is a fine grid. The photovoltaic cell may further include: a plurality of main grids 105 arranged at intervals along the second direction Y on at least one of the first surface 110 (refer to Figure 3 ) and the second surface 120 (refer to Figure 3 ). The main grid 105 includes a connection structure 115 electrically connected to the battery substrate 100 and an interconnection layer 125. The connection structure 115 includes a plurality of connection portions 135 arranged in sequence along the first direction X. The interconnection layer 125 is a strip-shaped structure extending along the first direction X. Among them, the interconnection layer 125 is in contact connection with the plurality of connection portions 135 in the connection structure 115. The connection portion 135 includes a first connection portion 145 and a second connection portion 155 arranged alternately along the second direction Y. The interconnection layer 125 has opposite third side portions 165 and fourth side portions 175 along the first direction X. The first connection portion 145 is at least in contact connection with the third side portion 165, and the second connection portion 155 is at least in contact connection with the fourth side portion 175, and the material of the connection portion 135 is different from the material of the interconnection layer 125.

[0102] It should be noted that not only does the fine grid include a contact structure 102 electrically connected to the battery substrate 100, but also the main grid 105 includes a connection structure 115 electrically connected to the battery substrate 100. In other words, not only some regions in the fine grid are directly electrically connected to the battery substrate 100, but also some regions in the main grid 105 are directly electrically connected to the battery substrate 100. Then, the carriers in the battery substrate 100 can not only be collected by the main grid 105 via the fine grid first, but also be directly collected by the main grid 105 through the connection structure 115, which is beneficial to shortening the transmission distance of some carriers in the battery substrate 100 to the main grid 105, thereby reducing the transmission loss of the carriers, and thus being beneficial to improving the collection efficiency of the main grid 105 for the carriers to improve the photoelectric conversion efficiency of the photovoltaic cell.

[0103] It should be noted that the connection structure 115 in the main grid 105 is similar to the contact structure 102 in the fine grid. The connection part 135 included in the connection structure 115 is similar to the contact part 112 in the contact structure 102. The first connection part 145 is similar to the first contact part 122, and the second connection part 155 is similar to the second contact part 132. The interconnection layer 125 is similar to the connection layer 103. The third side part 165 is similar to the first side part 113, and the fourth side part 175 is similar to the second side part 123. The difference lies in that the specific dimensions of the connection part 135 and the contact part 112 are different, and the specific dimensions of the interconnection layer 125 and the connection layer 103 are different. Here, no more details will be given about the connection structure 115 and the interconnection layer 125 included in the main grid 105. In addition, Figure 13 Only one case of the contact connection between the connection structure 115 and the interconnection layer 125 in the main grid 105 is schematically shown. Other cases of the contact connection between the connection structure 115 and the interconnection layer 125 can refer to the contact connection cases of the aforementioned contact structure and the connection layer.

[0104] The types of photovoltaic cells will be described in detail below.

[0105] In some embodiments, the photovoltaic cell is a photovoltaic cell with grid lines on both sides, such as a PERC cell, a TOPCON cell, a HIT / HJT cell (Heterojunction Technology), or a solar thin film cell, or any combination thereof. Among them, the solar thin film cell includes, but is not limited to, a perovskite solar thin film cell, a copper indium selenide solar thin film cell, a gallium arsenide solar thin film cell, and a cadmium sulfide solar thin film cell.

[0106] On this basis, referring to Figure 3 , the first surface 110 of the cell substrate 100 can be the front surface, and there are a plurality of front fine grids (not shown in the figure) arranged at intervals along the first direction X and a plurality of front main grids (not shown in the figure) arranged at intervals along the second direction Y on the first surface 110; the second surface 120 of the cell substrate 100 can be the back surface, and there are a plurality of back fine grids arranged at intervals along the first direction X and a plurality of back main grids (not shown in the figure) arranged at intervals along the second direction Y on the second surface 120.

[0107] It should be noted that the photovoltaic cell can be a single-sided cell, i.e., the first side 110 can be used as the light-receiving surface for receiving incident light, and the second side 120 can be used as the backlight surface; or, the photovoltaic cell can be a double-sided cell, then both the first side 110 and the second side 120 can be used as the light-receiving surfaces and can be used to receive incident light. It can be understood that the backlight surface described in an embodiment of the present disclosure can also receive incident light, but the degree of receiving incident light is weaker than that of the light-receiving surface, so it is defined as the backlight surface.

[0108] In some cases, referring to Figure 3 , the back fine grid can be the grid line 101 described in the above various embodiments, and the back main grid, the front fine grid, and the front main grid can all be single-layer strip-shaped structures. In this way, while reducing the manufacturing cost of the photovoltaic cell by means of the grid line 101 located on the second side 120, it is possible to avoid excessive shielding of the cell substrate 100 by the front main grid and the back main grid located on the first side, so as to ensure that the photovoltaic cell has a sufficient light-receiving surface.

[0109] In other cases, both the back fine grid and the front fine grid can be the grid line 101 described in the above various embodiments (refer to Figures 1 to 11 ), both the back main grid and the front main grid can be single-layer strip-shaped structures, or both the back main grid and the front main grid can be the main grid 105 described above (refer to Figure 13 ).

[0110] In still other cases, the back fine grid can be the grid line 101 described in the above various embodiments (refer to Figures 1 to 11 ), the back main grid can be the main grid 105 described above (refer to Figure 13 ), and both the front fine grid and the front main grid can be single-layer strip-shaped structures.

[0111] In yet other cases, the front fine grid can be the grid line 101 described in the above various embodiments (refer to Figures 1 to 11 ), the front main grid can be the main grid 105 described above (refer to Figure 13 ), and both the back fine grid and the back main grid can be single-layer strip-shaped structures.

[0112] In some other embodiments, the photovoltaic cell is a back-contact cell, i.e., a BC cell. The BC cell includes, but is not limited to, an IBC cell (Interdigitated Back Contact), an HBC cell (Heterojunction Back Contact), a TBC cell (TOPCon Back Contact), an HPBC cell (Hybrid Passivated Back Contact), etc. Thus, referring to Figure 3 , the first surface 110 or the second surface 120 can be regarded as the back surface of the finally formed photovoltaic cell.

[0113] On this basis, the back surface of the photovoltaic cell includes back surface fine grids and back surface main grids.

[0114] In some cases, the back surface fine grids located on the first surface or the second surface can be the grid lines 101 described in the above various embodiments (refer to Figures 1 to 11 ), and the back surface main grids can be a single-layer strip-like structure.

[0115] In some other cases, the back surface fine grids located on the first surface or the second surface can be the grid lines 101 described in the above various embodiments (refer to Figures 1 to 11 ), and the back surface main grids located on the first surface or the second surface can be the main grids 105 described above (refer to Figure 13 ).

[0116] In summary, the first contact portion 122 and the second contact portion 132 adjacent to each other in the second direction Y in the contact structure 102 can be arranged in a staggered manner in the first direction X. In this way, on the one hand, on the premise that the size of the connection layer 103 is the same, compared with the contact structure which is also a strip-shaped structure like the connection layer 103, by means of the staggered arrangement of the first contact portion 122 and the second contact portion 132, it is beneficial to reduce the amount of material required for the contact structure 102 while ensuring that the contact structure 102 and the connection layer 103 have a sufficient contact area, thereby being beneficial to improving the electrical connection performance between the gate line 101 and the battery substrate 100 and reducing the manufacturing cost of the gate line 101; on the other hand, in the first direction X, the first contact portion 122 has a third edge away from the second contact portion 132, and the second contact portion 132 has a fourth edge away from the first contact portion 122. By means of the staggered arrangement of the first contact portion 122 and the second contact portion 132, it is beneficial to widen the distance between the third edge and the fourth edge in the first direction X. Therefore, on the premise that the size of the connection layer 103 is the same, compared with the contact structure which is also a strip-shaped structure like the connection layer 103, it is beneficial to reduce the requirement for the alignment accuracy between the connection layer 103 and the contact structure 102. In other words, based on the staggered arrangement of the first contact portion 122 and the second contact portion 132, a larger offset error in the first direction X can be allowed between the connection layer 103 and the contact structure 102, and within this offset error, the contact area between the connection layer 103 and the contact structure 102 will not change, thereby being beneficial to further ensuring a high contact performance between the contact structure 102 and the connection layer 103, and reducing the manufacturing difficulty of the connection layer 103 to reduce the manufacturing difficulty of the gate line 101.

[0117] Another embodiment of the present disclosure further provides a manufacturing method of a photovoltaic cell for preparing the photovoltaic cell provided in the foregoing embodiment. The manufacturing method of the photovoltaic cell provided in another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the same or corresponding parts as those in the foregoing embodiment will not be elaborated here.

[0118] With reference to Figures 1 to 11, A method for manufacturing a photovoltaic cell includes: providing a cell substrate 100 having a first surface 110 and a second surface 120 opposite to each other in the thickness direction Z; forming a plurality of grid lines 101 spaced apart along a first direction X on the first surface 110 and / or the second surface 120, the grid lines 101 including a contact structure 102 electrically connected to the cell substrate 100 and a connection layer 103, the contact structure 102 including a plurality of contact portions 112 arranged in sequence along a second direction Y, the connection layer 103 being a strip-shaped structure extending along the second direction Y, and the first direction X intersecting the second direction Y; wherein, the connection layer 103 is in contact connection with the plurality of contact portions 112 in the contact structure 102, the contact portions 112 include a first contact portion 122 and a second contact portion 132 arranged alternately along the second direction Y, the connection layer 103 has a first side portion 113 and a second side portion 123 opposite to each other in the first direction X, the first contact portion 122 is at least in contact connection with the first side portion 113, the second contact portion 132 is at least in contact connection with the second side portion 123, and the material of the contact portion 112 is different from the material of the connection layer 103.

[0119] In some cases, referring to Figure 1 , Figure 4 , Figure 5 or Figure 6 , designing the first contact portion 122 to be at least in contact connection with the first side portion 113 and the second contact portion 132 to be at least in contact connection with the second side portion 123 can cause the adjacent first contact portion 122 and second contact portion 132 along the second direction Y to be arranged in a staggered manner in the first direction X. Among them, the first contact portion 122 is at least in contact connection with the first side portion 113 and the second contact portion 132 is in contact connection with the second side portion 123, or, the second contact portion 132 is at least in contact connection with the second side portion 123 and the first contact portion 122 is in contact connection with the first side portion 113.

[0120] In other cases, referring to Figure 7 , designing the first contact portion 122 to be at least in contact connection with the first side portion 113 and the second contact portion 132 to be at least in contact connection with the second side portion 123 can also cause the adjacent first contact portion 122 and second contact portion 132 along the second direction Y to be arranged at intervals in the second direction Y, and the first contact portion 122 is in contact connection with both the first side portion 113 and the second side portion 123, and the second contact portion 132 is also in contact connection with both the first side portion 113 and the second side portion 123.

[0121] It should be noted that dividing the contact portion 112 in the contact structure 102 into a first contact portion 122 that is at least in contact and connected to the first side portion 113 and a second contact portion 132 that is at least in contact and connected to the second side portion 123 is beneficial for adjusting the positional relationship between both the first contact portion 122 and the second contact portion 132 and the connection layer 103. While ensuring that the contact structure 102 and the connection layer 103 have a sufficient contact area, it reduces the amount of material required for the contact structure 102, thereby being beneficial for improving the electrical connection performance between the gate line 101 and the battery substrate 100 and reducing the manufacturing cost of the gate line 101.

[0122] The following details the preparation process of the gate line 101.

[0123] In some embodiments, with reference to Figure 2 and Figure 3 , the gate line 101 can be a fine grid; the second surface 120 has a first printing area (not marked in the figure), and a second printing area (not marked in the figure) that at least partially overlaps with the first printing area. It should be noted that the first printing area corresponds to the subsequent formed contact structure 102, and the second printing area corresponds to the subsequent formed connection layer 103. In other words, the first printing area is basically the orthographic projection of the subsequent formed contact structure 102 on the battery substrate 100, and the second printing area is basically the orthographic projection of the subsequent formed connection layer 103 on the battery substrate 100.

[0124] Continuing with reference to Figure 2 and Figure 3 , the steps of forming the gate line 101 can include: using a first screen printing process to print a first paste on the first printing area; performing a sintering treatment on the first paste to form a contact structure 102 corresponding to the first printing area; using a second screen printing process to print a second paste on the second surface 120; performing a curing treatment on the second paste to form a connection layer 103 corresponding to the second printing area; wherein, the first paste is a burn-through type paste, the second paste is a non-burn-through type paste; the process temperature of the sintering treatment is higher than the process temperature of the curing treatment.

[0125] It should be noted that since the first paste is a burn-through type paste and the second paste is a non-burn-through type paste, the finally formed contact structure 102 will be electrically connected to the battery substrate 100, for example, embedded in the passivation layer of the battery substrate 100, but the connection layer 103 is only located on the surface of the battery substrate 100, that is, it will not be embedded in the passivation layer of the battery substrate 100 and will not be directly electrically connected to the battery substrate 100.

[0126] In some cases, the first paste may be a silver paste, and the second paste may be a copper paste or a silver-coated copper paste. In practical applications, based on the alternating design of the first contact portion 122 and the second contact portion 132 in the contact structure 102, the single consumption of the large-area first paste can be reduced to 3 mg to 15 mg. For example, it can be 4 mg, 5 mg, 6 mg, 7 mg, 8 mg, 9 mg, 10 mg, 11 mg, 12 mg, 13 mg, or 14 mg, etc.

[0127] In some examples, the solid content in the silver paste can be 75% to 92%. For example, it can be 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, or 91%, etc.

[0128] It should be noted that the solids in the silver paste include at least glass bodies in addition to silver particles, and the solid content in the silver paste refers to the total content of all solids including silver particles in the silver paste.

[0129] In some cases, in the process of using a silver paste to print and form the entire grid line, the solid content in the used silver paste is generally large, for example, greater than 90%. Based on this, compared with the process of using a silver paste to print and form the entire grid line, the solid content of the silver paste used in the manufacturing method of the photovoltaic cell provided in another embodiment of the present disclosure can be lower. Then, the silver paste used to form the contact structure 102 is thinner. In other words, the viscosity of the silver paste used to form the contact structure 102 is lower. Thus, when the silver paste is printed on the first printing area of the battery substrate 100, the silver paste can have a certain degree of spreading on the battery substrate 100, which is convenient for increasing the contact area between the subsequent contact structure 102 formed based on the silver paste and the battery substrate 100.

[0130] It should be noted that the above-mentioned second surface 120 can be understood as the back surface of the photovoltaic cell. Combining the first screen printing process and the second screen printing process, the grid line 101 including the contact structure 102 and the connection layer 103 can be formed on the second surface 120. In addition, taking the formation of the grid line 101 on the second surface 120 as an example, in practical applications, the first screen printing process and the second screen printing process can also be applied on the first surface to form a grid line, which will not be elaborated here. Moreover, taking the grid line 101 formed on the second surface 120 as a fine grid as an example, in practical applications, the grid line combined with the first screen printing process and the second screen printing process can also be a main grid, and the grid line serving as the main grid can be formed on the first surface or the second surface, which will not be elaborated here.

[0131] It should be noted that referring to Figure 13 , in the design where the main grid 105 includes the battery substrate 100 (referring to Figure 2When forming the connection structure 115 and the interconnection layer 125 that are electrically connected, the forming process of the connection structure 115 is similar to that of the contact structure 102 (refer to Figures 1 to 11 ), and the forming process of the interconnection layer 125 is similar to that of the connection layer 103 (refer to Figures 1 to 11 ), which will not be elaborated here.

[0132] The preparation process of the main grid 105 located on the second side 120 except for the grid line 101 will be described in detail below.

[0133] In some cases, refer to Figure 2 , the second side 120 also has a third printing area (not shown in the figure); in the step of performing the first screen printing process, a first paste is also printed on the third printing area, and in the step of performing the sintering treatment, a main grid corresponding to the third printing area is also formed. It should be noted that the third printing area corresponds to the main grid formed subsequently. In other words, the third printing area is basically the orthographic projection of the main grid formed subsequently on the cell substrate 100.

[0134] It is worth noting that the preparation of the contact structure 102 in the grid line 101 can be completed in the same step as the preparation of the main grid, which is beneficial to reducing one printing process and further reducing the preparation cost of the photovoltaic cell.

[0135] In other cases, refer to Figure 2 , the second side 120 also has a third printing area (not shown in the figure); in the step of performing the second screen printing process, a second paste is also printed on the third printing area, and in the step of performing the curing treatment, a main grid 105 corresponding to the third printing area is also formed (refer to Figure 12 ). It should be noted that the third printing area corresponds to the main grid 105 formed subsequently. In other words, the third printing area is basically the orthographic projection of the main grid 105 formed subsequently on the cell substrate 100.

[0136] It is worth noting that the preparation of the connection layer 103 in the grid line 101 can be completed in the same step as the preparation of the main grid 105, which is also beneficial to reducing one printing process and further reducing the preparation cost of the photovoltaic cell.

[0137] In still other cases, combining the first screen printing process and the sintering treatment, only the contact structure in the grid line is formed; combining the second screen printing process and the curing treatment, only the connection layer in the grid line is formed, and other processes are used subsequently to form the main grid located on the second side.

[0138] In the above various cases, combining reference Figure 3 and Figure 12, the fine grid 104 formed on the second surface 120 can be the back fine grid, and the main grid 105 formed on the second surface 120 is the back main grid; the first surface 110 has a fourth printing area (not shown in the figure) extending along the first direction X and a fifth printing area (not shown in the figure) extending along the second direction Y. It should be noted that the fourth printing area corresponds to the front fine grid formed subsequently, and the fifth printing area corresponds to the front main grid formed subsequently. In other words, the fourth printing area is basically the orthographic projection of the front fine grid formed subsequently on the battery substrate 100, and the fifth printing area is basically the orthographic projection of the front main grid formed subsequently on the battery substrate 100.

[0139] Before the sintering process, the manufacturing method of the photovoltaic cell may further include: using a third screen printing process to print a third paste on the fourth printing area; in the step of the sintering process, the third paste is also sintered to form a front fine grid corresponding to the fourth printing area; using a fourth screen printing process to print a fourth paste on the fifth printing area; in the step of the sintering process, the fourth paste is also sintered to form a front main grid corresponding to the fifth printing area.

[0140] In some examples, the third paste and the fourth paste can be the same, that is, the materials of the front fine grid and the front main grid can be the same.

[0141] It should be noted that the order of the third screen printing process and the fourth screen printing process can be reversed.

[0142] Based on the foregoing description, when the back fine grid is the grid line 101, the printing process of the photovoltaic cell at least includes the following situations: in some cases, the back main grid, the contact structure 102 in the grid line 101, the front main grid, and the front fine grid can be formed by four printing processes respectively, and then sintered uniformly, and finally the printing process and curing process of the connection layer 103 in the grid line 101 are carried out; in other cases, the back main grid and the contact structure 102 in the grid line 101 are formed by the same printing process, the front main grid and the front fine grid can be formed by two printing processes respectively, and then sintered uniformly, and finally the printing process and curing process of the connection layer 103 in the grid line 101 are carried out; in still other cases, the contact structure 102 in the grid line 101, the front main grid, and the front fine grid can be formed by three printing processes respectively, and then sintered uniformly, the back main grid and the connection layer 103 in the grid line 101 are formed by the same printing process, and finally the curing process is carried out.

[0143] Another embodiment of the present disclosure further provides a tandem solar cell, which includes the 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. The tandem solar cell provided in another embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the same or corresponding parts as those in the foregoing embodiment will not be described herein again.

[0144] Reference Figure 14 , Figure 14 FIG. is a partial cross-sectional schematic diagram of a tandem solar cell provided in another embodiment of the present disclosure. The tandem solar cell (andem solar cell) includes: a bottom cell 106, which is the 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; a top cell 107, which is located on one side of the bottom cell 106.

[0145] In some embodiments, the top cell 107 can be one of a perovskite solar cell, a donor-acceptor cell, a cadmium telluride (CdTe) solar cell, a copper indium gallium selenide (CIGS) solar cell, or a gallium arsenide (GaAs) solar cell.

[0146] In some embodiments, the top cell 107 may include: a stacked first transport layer, a perovskite substrate, a second transport layer, a transparent conductive layer, and an antireflection layer. Among them, the first transport layer faces the bottom cell 106.

[0147] In some examples, the first transport layer can be one of an electron transport layer or a hole transport layer, and the second transport layer can be the other of an electron transport layer or a hole transport layer.

[0148] In some embodiments, the bandgap width of the top cell 107 is wider than that of the bottom cell 106. Therefore, stacking the top cell 107 above the bottom cell 106 can enable the tandem solar cell to have a wider spectral response range, thereby maximizing the utilization of solar energy and improving the efficiency of the solar cell.

[0149] In some embodiments, the back-contact tandem solar cell may further include: an intermediate connection layer (not shown in the figure), which is connected between the bottom cell 106 and the top cell 107.

[0150] In some cases, the intermediate connection layer is generally a tunnel junction or a very thin metal or transparent electrode composite layer. Optionally, the intermediate connection layer can be a transparent conductive oxide, which has good optoelectronic properties, high photon transmittance, and high conductivity, so that the top cell 107 and the bottom cell 106 can maintain good ohmic contact.

[0151] In other cases, the back fine grids, back main grids, front fine grids, and front main grids in the photovoltaic cell serving as the bottom cell 106 can also be used as the intermediate connection layer to achieve electrical connection with the top cell 107.

[0152] Another embodiment of the present disclosure further provides a photovoltaic module. The photovoltaic module includes a plurality of photovoltaic cells provided in the foregoing embodiments, or a plurality of photovoltaic cells formed by the manufacturing method of the photovoltaic cells provided in the foregoing embodiments, or a plurality of tandem cells provided in the foregoing embodiments connected together. The photovoltaic module is used to convert the received light energy into electrical energy. It should be noted that for the same or corresponding parts as those in the foregoing embodiments, reference may be made to the corresponding descriptions in the foregoing embodiments, which will not be elaborated hereinafter.

[0153] With reference to Figure 15 、 Figure 16 and Figures 1 to 13 , the photovoltaic module includes: a battery string, which is formed by connecting a plurality of photovoltaic cells 40 provided in the foregoing embodiments, or a plurality of photovoltaic cells 40 formed by the manufacturing method of the photovoltaic cells provided in the foregoing embodiments, or a plurality of tandem cells provided in the foregoing embodiments connected together; an encapsulation adhesive film 41, which is used to cover the surface of the battery string; and a cover plate 42, which is used to cover the surface of the encapsulation adhesive film 41 facing away from the battery string.

[0154] Among them, Figure 15 is a partial three-dimensional schematic diagram of the battery string in the photovoltaic module provided in another embodiment of the present disclosure; Figure 16 is a partial cross-sectional schematic diagram of the photovoltaic module provided in another embodiment of the present disclosure.

[0155] In some embodiments, the photovoltaic cells 40 are electrically connected in the form of a whole piece or multiple sub-pieces to form a plurality of battery strings, and the plurality of battery strings are electrically connected in series and / or in parallel. The photovoltaic cell 40 can be a whole-piece cell or a sliced cell, and the sliced cell refers to a cell formed by cutting a complete whole-piece cell through a cutting process.

[0156] In some embodiments, with reference to Figure 15 and Figure 16 , a plurality of photovoltaic cells 40 can be electrically connected through a conductive strip 43. Figure 15 and Figure 16Only the positional relationship between a plurality of photovoltaic cells 40 is schematically shown, that is, the arrangement directions of the grid lines of the photovoltaic cells 40 with the same polarity are the same, or in other words, the grid lines with the positive polarity of each photovoltaic cell 40 are arranged towards the same side, so that the conductive strips 43 are respectively connected to different sides of two adjacent photovoltaic cells 40. In other embodiments, the electrodes of the photovoltaic cells may also face the same side according to different polarities, that is, the electrodes of a plurality of adjacent photovoltaic cells are sequentially arranged in the order of the first polarity, the second polarity, and the first polarity, then the conductive strip connects two adjacent photovoltaic cells on the same side.

[0157] In some embodiments, the encapsulation adhesive film 41 includes a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers one of the front or back surfaces of the photovoltaic cell 40, and the second encapsulation layer covers the other of the front or back surfaces of the photovoltaic cell 40. Specifically, at least one of the first encapsulation layer or the second encapsulation layer may be an organic encapsulation adhesive film such as a polyvinyl butyral (PVB) adhesive film, an ethylene-vinyl acetate copolymer (EVA) adhesive film, a polyethylene octene co-elastic body (POE) adhesive film, or a polyethylene terephthalate (PET) adhesive film. Alternatively, at least one of the first encapsulation layer or the second encapsulation layer may also be an adhesive film such as an EP adhesive film, an EPE adhesive film, or a PVP adhesive film. Among them, the EP adhesive film refers to a co-extruded adhesive film composed of an EVA adhesive film and a POE adhesive film stacked, the EPE adhesive film refers to a co-extruded adhesive film formed by sequentially stacking an EVA adhesive film + a POE adhesive film + an EVA adhesive film, and the PVP adhesive film refers to a co-extruded adhesive film formed by stacking a POE adhesive film + an EVA adhesive film + a POE adhesive film. The co-extruded adhesive film can be prepared by extruding one or more raw materials onto another already formed adhesive film in sequence during the adhesive film processing, or by bonding different types of already formed adhesive films together.

[0158] In some cases, there is a demarcation line between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination treatment, there will no longer be the concept of the first encapsulation layer and the second encapsulation layer in the formed photovoltaic module, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation adhesive film 41.

[0159] In some embodiments, the cover plate 42 may be a cover plate with a light-transmitting function such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 42 facing the encapsulation adhesive film 41 may be a concave-convex surface or a velvet surface including a plurality of convex structures, so as to increase the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate. The first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer.

[0160] Those of ordinary skill in the art will understand that the above embodiments are specific embodiments for implementing the present disclosure. In actual applications, various changes can be made to them in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the protection scope of the embodiments of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A photovoltaic cell, characterized in that, Comprising: A battery substrate having a first surface and a second surface opposite to each other in the thickness direction; A plurality of grid lines located on the first surface and / or the second surface and spaced apart in a first direction, the grid lines including a contact structure electrically connected to the battery substrate and a connection layer, the contact structure including a plurality of contact portions arranged in sequence in a second direction, the connection layer being a strip-shaped structure extending in the second direction, the first direction and the second direction intersecting; Wherein, the connection layer is in contact connection with the plurality of contact portions in the contact structure, the material of the contact portion is different from the material of the connection layer, and a part of the positive projection of the contact portion and the connection layer on the battery substrate overlaps; the contact portion includes a first contact portion and a second contact portion arranged alternately in the second direction, the connection layer has a first side portion and a second side portion opposite to each other in the first direction, the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or, the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion.

2. The photovoltaic cell according to claim 1, wherein, In the same grid line, the first contact portion and the second contact portion are not directly opposite to each other in the second direction.

3. The photovoltaic cell according to claim 1, characterized in that, In the same grid line, a partial region of the first contact portion and a partial region of the second contact portion are directly opposite to each other in the second direction.

4. The photovoltaic cell according to claim 3, characterized in that, In the second direction, the part of the first contact portion opposite to the second contact portion is the first part, and the width of the part of the first contact portion other than the first part in the first direction is less than or equal to 25 μm.

5. The photovoltaic cell according to any one of claims 1 to 4, characterized in that, In the thickness direction, the positive projection shape of the contact portion on the battery substrate is circular, elliptical, triangular, rectangular, trapezoidal or N-sided, where N is a positive integer greater than 4.

6. The photovoltaic cell according to any one of claims 1 to 4, characterized in that, In the thickness direction, the positive projection shape of the contact portion on the battery substrate is circular or elliptical, and the adjacent first contact portion and second contact portion in the second direction are tangent to each other.

7. The photovoltaic cell according to any one of claims 1 to 4, characterized in that, In the thickness direction, the orthographic projection area of the contact part on the battery substrate is 100μm 2 ~5000μm 2 .

8. The photovoltaic cell according to claim 1, characterized in that, In the first direction, the width of the connection layer is 10 μm to 70 μm.

9. The photovoltaic cell according to claim 1, characterized in that, Among the adjacent first contact portion and second contact portion in the second direction, the edge of the first contact portion closest to the second contact portion is the first edge, the edge of the second contact portion closest to the first contact portion is the second edge, and the distance between the first edge and the second edge is less than or equal to 200 μm.

10. The photovoltaic cell according to claim 1, characterized in that, In the thickness direction, the thickness of the contact portion is 1 μm to 10 μm; and / or, the thickness of the connection layer is 4 μm to 20 μm.

11. The photovoltaic cell according to claim 1, characterized in that, The grid line is one of a fine grid and a main grid, and the other of the fine grid and the main grid is a strip-shaped structure extending in the first direction.

12. The photovoltaic cell according to claim 1, wherein, The grid line is a fine grid, and the photovoltaic cell further includes: A plurality of main grids located on at least one of the first surface and the second surface and spaced apart along the second direction, the main grid including a connection structure electrically connected to the battery substrate and an interconnection layer, the connection structure including a plurality of connection portions arranged in sequence along the first direction, and the interconnection layer being a strip-shaped structure extending along the first direction; Wherein, the interconnection layer is in contact connection with the plurality of connection portions in the connection structure, the connection portion includes a first connection portion and a second connection portion arranged alternately along the second direction, the interconnection layer has a third side portion and a fourth side portion opposite to each other along the first direction, the first connection portion is at least in contact connection with the third side portion, the second connection portion is at least in contact connection with the fourth side portion, and the material of the connection portion is different from the material of the interconnection layer.

13. The photovoltaic cell according to claim 1, characterized in that, The material of the contact portion includes silver particles, and the material of the connection layer includes copper particles or silver-coated copper particles.

14. The photovoltaic cell according to claim 13, wherein The diameter of the copper particles is 50 nm to 1500 nm; or, the diameter of the silver-coated copper particles is 1 μm to 10 μm; or, the proportion of silver in the silver-coated copper particles is 15% to 50%.

15. A manufacturing method of a photovoltaic cell, characterized in that, Including: Providing a battery substrate having a first surface and a second surface opposite to each other in the thickness direction; Forming a plurality of grid lines spaced apart along the first direction on the first surface and / or the second surface, the grid line including a contact structure electrically connected to the battery substrate and a connection layer, the contact structure including a plurality of contact portions arranged in sequence along the second direction, the connection layer being a strip-shaped structure extending along the second direction, and the first direction and the second direction intersect; Wherein, the connection layer is in contact connection with the plurality of contact portions in the contact structure, the material of the contact portion is different from the material of the connection layer, and the orthographic projections of the contact portion and the connection layer on the battery substrate partially overlap; the contact portion includes a first contact portion and a second contact portion arranged alternately along the second direction, the connection layer has a first side portion and a second side portion opposite to each other along the first direction, the first contact portion is at least in contact connection with the first side portion and the second contact portion is in contact connection with the second side portion, or, the second contact portion is at least in contact connection with the second side portion and the first contact portion is in contact connection with the first side portion.

16. The manufacturing method of the photovoltaic cell according to claim 15, characterized in that, The grid line is a fine grid; the second surface has a first printing area and a second printing area at least partially overlapping with the first printing area; The steps of forming the grid line include: printing a first paste on the first printing area by using a first screen printing process; sintering the first paste to form the contact structure corresponding to the first printing area; printing a second paste on the second surface by using a second screen printing process; curing the second paste to form the connection layer corresponding to the second printing area; Wherein, the first paste is a burn-through paste, the second paste is a non-burn-through paste; the process temperature of the sintering process is higher than the process temperature of the curing process.

17. The manufacturing method of a photovoltaic cell according to claim 16, characterized in that, The first paste is a silver paste, and the second paste is a copper paste or a silver-coated copper paste.

18. The manufacturing method of a photovoltaic cell according to claim 17, characterized in that, The solid content in the silver paste is 75% - 92%.

19. The manufacturing method of a photovoltaic cell according to claim 16, characterized in that, The second surface further has a third printing area; In the step of performing the first screen printing process, the first paste is also printed on the third printing area, and in the step of performing the sintering treatment, a main grid corresponding to the third printing area is also formed; or, In the step of performing the second screen printing process, the second paste is also printed on the third printing area, and in the step of performing the curing treatment, a main grid corresponding to the third printing area is also formed.

20. The manufacturing method of a photovoltaic cell according to claim 19, characterized in that, The fine grid formed on the second surface is a back fine grid, and the main grid formed on the second surface is a back main grid; the first surface has a fourth printing area extending along the first direction and a fifth printing area extending along the second direction; Before performing the sintering treatment, the manufacturing method of the photovoltaic cell further includes: Using a third screen printing process to print a third paste on the fourth printing area; in the step of performing the sintering treatment, the third paste is also sintered to form a front fine grid corresponding to the fourth printing area; using a fourth screen printing process to print a fourth paste on the fifth printing area; in the step of performing the sintering treatment, the fourth paste is also sintered to form a front main grid corresponding to the fifth printing area.

21. A stacked battery, characterized in that, Comprising: A bottom cell, which is the photovoltaic cell according to any one of claims 1 to 14, or a photovoltaic cell formed by the manufacturing method of a plurality of photovoltaic cells according to any one of claims 15 to 20; A top cell, which is located on one side of the bottom cell.

22. A photovoltaic module, characterized in that, Comprising: A battery string, which is connected by a plurality of photovoltaic cells according to any one of claims 1 to 14, or a photovoltaic cell formed by the manufacturing method of a plurality of photovoltaic cells according to any one of claims 15 to 20, or a plurality of tandem cells according to claim 21; An encapsulation adhesive film for covering the surface of the battery string; A cover plate for covering the surface of the encapsulation adhesive film facing away from the battery string.

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