Solar cell, tandem solar cell and photovoltaic module

Abstract

Solar cell comprising the following: a substrate (100) having a first surface (110) and a second surface (120) opposite each other, each being substantially perpendicular to a thickness direction (Z) of the substrate (100); and Grid lines (101) arranged at intervals on at least one of the first surface (110) and the second surface (120) along a first direction (X), wherein each grid line (101) of at least some of the grid lines (101) has a respective contact structure (102) and a respective connecting layer (103) electrically connected to the substrate (100), the respective contact structure (102) having a plurality of contact sections (112) arranged at intervals along a second direction (Y), the respective connecting layer (103) being an elongated strip structure extending along the second direction (Y), and the first direction (X) intersecting the second direction (Y); wherein the respective interconnect layer (103) is electrically connected to the plurality of contact sections (112) and contains a material that differs from a material of the plurality of contact sections (112), and an orthographic projection of the respective connection layer (103) onto the substrate (100) partially overlaps with orthographic projections of the multitude of contact sections (112) onto the substrate (100); wherein the plurality of contact sections (112) includes first contact sections (122) and second contact sections (132) arranged alternately along the second direction (Y), and the respective connecting layer (103) includes a first side extending along the second direction (Y), a opposite second side extending along the second direction (Y), a first side section (113) extending along the second direction (Y) on the first side, and a second side section (123) extending along the second direction (Y) on the second side; and wherein the first contact sections (122) penetrate at least the first side section (113) and the second contact sections (132) penetrate at least the second side section (123).

Description

TECHNICAL AREA

[0001] The present application relates to the technical field of photovoltaic technology and in particular to a solar cell, a tandem solar cell and a photovoltaic module. STATE OF THE ART

[0002] With the gradual depletion of fossil fuels, solar cells are increasingly being used as a new energy alternative. A solar cell is a device for converting sunlight into electrical energy. Using the photovoltaic principle, the solar cell generates charge carriers, which are then carried out through grid lines, thus efficiently utilizing electrical energy. Currently, solar cells mainly include back-contact solar cells (BC solar cells, BC = back contact), solar cells with tunnel oxide passivated contacts (TOPCON solar cells, TOPCON = tunnel oxide passivated contact), PERC solar cells (PERC = passivated emitter and rear cells), and heterojunction solar cells. SUMMARY

[0003] Embodiments of the present disclosure provide for a solar cell, a method for manufacturing solar cells, a tandem solar cell and a photovoltaic module, which at least contribute to improving the performance of the electrical connection between grid lines and substrate of a solar cell and to reducing the manufacturing costs of grid lines.

[0004] In one aspect, some embodiments of the present disclosure provide for a solar cell comprising: a substrate having a first surface and a second surface, which are opposite each other and each is substantially perpendicular to a thickness direction of the substrate, and grid lines arranged at intervals on at least one of the first surface and the second surface along a first direction. Each grid line of at least some of the grid lines has a respective contact structure and a respective interconnect layer that are electrically connected to the substrate, wherein the respective contact structure includes a plurality of contact sections arranged at intervals along a second direction, the respective interconnect layer is an elongated strip structure extending along the second direction, and the first direction intersects the second direction.The respective interconnect layer is electrically connected to the plurality of contact sections and contains a material different from a material of the plurality of contact sections. An orthographic projection of the respective interconnect layer onto the substrate partially overlaps with orthographic projections of the plurality of contact sections onto the substrate. The plurality of contact sections includes first contact sections and second contact sections arranged alternately along the second direction. The respective interconnect layer has a first side extending along the second direction, a opposite second side extending in the second direction, a first side section extending along the second direction on the first side, and a second side section extending along the second direction on the second side.The first contact sections penetrate at least the first side section, and the second contact sections penetrate at least the second side section.

[0005] In some embodiments, the first contact sections are not aligned with the second contact sections in the second direction.

[0006] In some embodiments, segments of the first contact sections are aligned with segments of the second contact sections in the second direction.

[0007] In some embodiments, each first contact section of the first contact sections includes a first segment that is oriented towards the segments of the second contact sections in the second direction, and has a segment of the respective first contact section that is different from the first segment having a width of less than or equal to 25 µm in the first direction.

[0008] In some embodiments, the orthographic projections of the plurality of contact sections onto the substrate have the form of circles, ellipses, triangles, rectangles, trapezoids or N-sided polygons, where N is a positive integer greater than 4.

[0009] In some embodiments, the orthographic projections of the plurality of contact sections onto the substrate have the form of circles or ellipses, and each first contact section of the first contact sections is tangential to a second contact section of the second contact sections, which is adjacent to the respective first contact section in the second direction.

[0010] In some embodiments, an orthographic projection of a respective contact section of the plurality of contact sections onto the substrate has an area in the range of 100 µm2 to 5000 µm2.

[0011] In some embodiments, the respective bonding layer has a width in the range of 10 µm to 70 µm in the first direction.

[0012] In some embodiments, in the second direction, the distance between a respective first contact section of the first contact sections and a second contact section of the second contact sections, which is adjacent to the respective first contact section, is less than or equal to 200 µm.

[0013] In some embodiments, the multitude of contact sections in the thickness direction have thicknesses in the range of 1 µm to 10 µm and / or the respective bonding layer has a thickness in the range of 4 µm to 20 µm.

[0014] In some embodiments, the solar cell has finger electrodes and busbars. The grid lines are finger electrodes and the busbars are formed in the form of elongated strip structures extending along the first direction; or the grid lines are busbars and the finger electrodes are formed in the form of elongated strip structures extending along the first direction.

[0015] In some embodiments, the grid lines are finger electrodes, and the solar cell further comprises: busbars arranged at intervals on at least one of the first surface and the second surface along the second direction. Each busbar of at least some of the busbars has a respective interconnection structure and an respective intermediate interconnection layer that are electrically connected to the substrate, wherein the respective interconnection structure includes a plurality of interconnection sections arranged at intervals along the first direction, and the respective intermediate interconnection layer is an elongated strip structure extending along the first direction.The respective intermediate interconnection layer is electrically connected to the plurality of interconnection sections, the plurality of interconnection sections includes first interconnection sections and second interconnection sections arranged alternately along the second direction, and the respective intermediate interconnection layer has a third side extending along the second direction, a opposite fourth side extending in the second direction, a third side section extending along the second direction on the third side, and a fourth side section extending along the second direction on the fourth side.The first connecting sections penetrate at least the third side section, the second connecting sections penetrate at least the fourth side section, and a material of the multitude of connecting sections differs from a material of the respective intermediate connecting layer.

[0016] In some embodiments, the multitude of contact sections contains silver particles and the respective bonding layer contains copper particles or silver-coated copper particles.

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

[0018] In another aspect, some embodiments of the present disclosure provide a method for manufacturing solar cells, comprising: providing a substrate having a first surface and a second surface, wherein the first surface and the second surface are opposite each other and each is substantially perpendicular to a thickness direction of the substrate; and forming grid lines arranged at intervals on at least one of the first surface and the second surface along a first direction.Each grid line of at least some of the grid lines has a respective contact structure and a respective interconnection layer that are electrically connected to the substrate. The respective contact structure includes a plurality of contact segments arranged at intervals along a second direction. The respective interconnection layer is an elongated strip structure extending along the second direction, and the first direction intersects the second direction. The respective interconnection layer is electrically connected to the plurality of contact segments and contains a material different from a material of the plurality of contact segments. An orthographic projection of the respective interconnection layer onto the substrate partially overlaps with orthographic projections of the plurality of contact segments onto the substrate.The plurality of contact sections includes first contact sections and second contact sections arranged alternately along the second direction, and each bonding layer has a first side extending along the second direction, a contrasting second side extending in the second direction, a first side section extending along the second direction on the first side, and a second side section extending along the second direction on the second side. The first contact sections penetrate at least the first side section, and the second contact sections penetrate at least the second side section.

[0019] In some embodiments, the grid lines are finger electrodes, and the second surface includes first print areas and second print areas that partially overlap with the first. Forming the grid lines involves: printing a first paste onto the first print areas using a first screen printing process; performing sintering on the first paste to form the respective contact structure on the first print areas; printing a second paste onto the second print areas using a second screen printing process; and curing the second paste to form the respective bonding layer on the second print areas. The first paste is a heat-curing paste, the second paste is a non-heat-curing paste, and the process temperature for performing sintering is higher than the process temperature for curing.

[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 solids content in the silver paste ranges from 75% to 92%.

[0022] In some embodiments, the second surface further comprises third printing areas. The method further includes: printing the first paste onto the third printing areas using the first screen printing process and performing sintering on the first paste to form busbars on the third printing areas; or printing the second paste onto the third printing areas using the second screen printing process and curing the second paste to form the busbars on the third printing areas.

[0023] In some embodiments, the finger electrodes formed on the second surface are backside finger electrodes, the busbars formed on the second surface are backside busbars, and the first surface has fourth print areas extending along the first direction and fifth print areas extending along the second direction. Prior to performing sintering, the method further includes: printing a third paste onto the fourth print areas using a second screen-printing process; and printing a fourth paste onto the fifth print areas using a fourth screen-printing process. Performing sintering includes: performing sintering on the third paste to form frontside finger electrodes on the fourth print areas; and performing sintering on the fourth paste to form frontside busbars on the fifth print areas.

[0024] In yet another aspect, some embodiments of the present disclosure provide for a tandem solar cell comprising a lower solar cell and an upper solar cell arranged on one side of the lower solar cell. The lower solar cell encloses the solar cells as illustrated above, or the lower solar cell is manufactured using the method illustrated above.

[0025] In yet another aspect, some embodiments of the present disclosure provide for a photovoltaic module comprising: at least one solar cell string, wherein the at least one solar cell string is formed by joining a plurality of solar cells as illustrated above, or by joining a plurality of solar cells produced using the method as illustrated above, or by joining a plurality of tandem solar cells as illustrated above; at least one encapsulation adhesive film configured to cover a surface of the at least one solar cell string; and at least one cover plate configured to cover a surface of the at least one encapsulation adhesive film facing away from the at least one cell string. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Exemplary illustrations of one or more embodiments are provided as images in the corresponding accompanying drawings. These exemplary illustrations do not constitute a limitation of the embodiments. The drawings do not represent a scale limitation unless otherwise indicated. For a clearer illustration of the technical solutions in related technologies or in the embodiments of this disclosure, the drawings to be used in the embodiments are briefly described below. It is evident that the drawings mentioned in the following illustration represent only some embodiments of this disclosure. Persons skilled in the art can derive other drawings from these drawings without inventive effort. Fig. 1 is a schematic top view of a section of a first grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. 2 is a schematic top view of a section of a solar cell, which is provided in some embodiments of the present disclosure; Fig. 3 is a schematic cross-sectional view along a first section direction AA1 in Fig. 2; Fig. Figure 4 is a schematic top view of a section of a second grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 5 is a schematic top view of a section of a third grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 6 is a schematic top view of a section of a fourth grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 7 is a schematic top view of a section of a fifth grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 8 is a partially enlarged schematic representation of two adjacent contact sections of the solar cell, which is provided in some embodiments of the present disclosure; Fig. Figure 9 is a schematic top view of a section of a sixth grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 10 is a schematic top view of a section of a seventh grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 11 is a schematic top view of a section of an eighth grid line of a solar cell, which is provided in some embodiments of the present invention; Fig. Figure 12 is a schematic top view of a section of another solar cell provided in some embodiments of the present disclosure; Fig. Figure 13 is a schematic top view of a section of a busbar of the solar cell, which is provided in some embodiments of the present disclosure; Fig. Figure 14 is a schematic cross-sectional view of a section of a tandem solar cell, which is provided in some embodiments of the present disclosure; Fig. Figure 15 is a schematic perspective view of a section of a cell string of a photovoltaic module, which is provided in some embodiments of the present disclosure; and Fig. Figure 16 is a schematic cross-sectional view of a section of the photovoltaic module provided in some embodiments of the present disclosure. Description of reference symbols: 100 substrate; 110 first surface; 120 second surface; 101 grid line; 102 Contact structure; 112 Contact section; 122 first contact section; 122a first edge; 1221 first segment; 1222 second segment; 132 second contact section; 132a second edge; 103 Compound layer; 113 first page section; 123 second page section; 104 Finger electrode; 105 busbar; 115 Connection structure; 125 Interconnect layer; 135 Connecting section; 145 first connecting section; 155 second connecting section; 165 third page section; 175 fourth section; 106 lower solar cell; 107 upper solar cell; 40 solar cells; 41 Encapsulation adhesive film; 42 Cover plate; 43 conductive strips. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0027] Analysis revealed that for both solar cells with grid lines on both surfaces and back-contact solar cells with grid lines on a single surface, the grid line formation process consumes a large amount of silver paste for printing, resulting in high metallization costs and a desire to reduce grid line manufacturing costs. Furthermore, back-contact solar cells with grid lines on a single surface require a greater quantity of silver paste compared to solar cells with grid lines on both surfaces.

[0028] In practice, for solar cells that have grid lines formed on both surfaces, for example TOPCON solar cells, the amount of silver paste used for one solar cell is up to 80 mg, and the amount of silver paste used for a single surface of the solar cell is up to 40 mg.

[0029] In the solar cell, the method for manufacturing solar cells, the tandem solar cell and the photovoltaic module provided in the embodiments of the present disclosure, the first contact sections are electrically connected to at least the first side section and the second contact sections are electrically connected to the second side section, or the second contact sections are electrically connected to at least the second side section and the first contact sections are electrically connected to the first side section, such that a respective first contact section of the first contact sections cannot be arranged in the first direction oriented towards a second contact section that is adjacent to the respective first contact section in the second direction.Thus, on the one hand, with unchanged dimensions of the respective interconnect layer, the arrangement in which the first contact sections are not aligned with the second contact sections contributes to reducing the material consumption of the respective contact structure, while at the same time ensuring sufficient contact areas between the respective contact structure and the respective interconnect layer compared to manufacturing the respective contact structure so that it has an elongated strip structure similar to the respective interconnect layer, which contributes to improving the performance of the electrical connection between the grid lines and the substrate and to reducing the manufacturing costs of the grid lines.On the other hand, the arrangement in which the first contact sections are not aligned with the second contact sections contributes to increasing a maximum distance between an edge of a respective first contact section of the first contact sections and an edge of a respective second contact section of the second contact sections in the first direction, which, with unchanged dimensions of the respective bonding layer, contributes to reducing the requirement for alignment accuracy between the respective contact structure and the respective bonding layer compared to producing the respective contact structure so that it has an elongated strip structure similar to the respective bonding layer.In this way, the difficulty of manufacturing the respective interconnect layer, and therefore the difficulty of producing the grid lines, can be reduced, while ensuring good electrical contact performance between the respective contact structure and the respective interconnect layer. Furthermore, because the material of the multiple contact sections differs from the material of the respective interconnect layer, the manufacturing costs of the respective contact structure can be further reduced by matching the material of the multiple contact sections and the material of the respective interconnect layer.

[0030] In the description of the embodiments of this disclosure, the technical terms "first," "second," and the like serve only to distinguish different objects and are not to be understood as indicating or implying the relative importance or as an implicit reference to the number, specific order, or dominant-subordinate relationship of the specified technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless expressly stated otherwise.

[0031] The term "embodiment" as used herein means that certain features, structures, or properties described in combination with the embodiments may be present in at least one embodiment of this disclosure. This term, which appears at various points in the description, refers neither to the same embodiment nor to separate or alternative embodiments that are mutually exclusive with other embodiments. Persons skilled in the art understand, both expressly and implicitly, that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the embodiments of the present disclosure, the term "and / or" herein merely denotes an associative relationship that describes related objects and indicates that three relationships are possible. For example, A and / or B indicates that there are three cases: A alone, A and B together, and B alone. Furthermore, the symbol " / " herein generally indicates an "or" relationship between the related objects.

[0033] In the description of the embodiments of the present disclosure, “a plurality of” means two or more (including two). Similarly, “a plurality of groups” means two or more groups (including two groups), and “a plurality of parts” means two or more parts (including two parts).

[0034] In the description of the embodiments of the present disclosure, the orientation or position relationships indicated by the technical terms "central", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or position relationships shown in the accompanying drawings and serve only to facilitate and simplify the description of the present disclosure, rather than indicating or implying that the device or element in question must have a particular orientation or be designed and operated in a particular orientation, and are therefore not to be interpreted as limiting the embodiments of the present disclosure.

[0035] In illustrating the embodiments of this disclosure, technical terms such as "installation," "coupling," "connection," or "fastening" are to be understood in a broad sense unless otherwise specified and limited. For example, "connection" may refer to fixed connections, detachable connections, integrated connections, mechanical or electrical connections, direct connections or indirect connections via an intermediate medium, internal connections between two components, or an interaction relationship between two components. Those skilled in the art will understand the specific meanings of the aforementioned terms in the embodiments of the present invention according to the specific circumstances.

[0036] In the drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​a layer are exaggerated for clarity and to simplify the description. When a component is described as being on top of another component or on a surface of another component, the component may be "directly" on the surface of the other component, or a third component may be present between the two components. Conversely, when a component is described as being on the surface of another component, or when the other component is formed or provided on a surface of a component, no third component is present between the two components.Furthermore, if one component is described as being formed “essentially” on the other component, this indicates that the component is formed neither on the entire surface (or a front surface) of the other component nor on part of an edge of the entire surface.

[0037] If, in the description of the embodiments of the present disclosure, one component “includes” another component, other components are not excluded and may, unless otherwise stated, also be included.

[0038] Furthermore, when components such as layers, films, regions, or plates are referred to as "on / arranged on" another component, this can mean that they are "directly on" another component (i.e., there are no other components between them) or that other components may be present between them. It also indicates that if a component such as a layer, film, region, or plate is "directly on" another component, or if the component such as a layer, film, region, or plate is on a surface of another component, there are no other components between them.

[0039] The terms used in the description of the embodiments described herein serve only to describe certain embodiments and are not to be understood as limiting. In the sense used in the description of the described embodiments and in the accompanying claims, "the component" is intended to include the plural form, unless the context clearly indicates otherwise. Herein, a component includes a layer, a film, a region, a plate, or the like.

[0040] Various embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are provided in the embodiments of the present disclosure to facilitate readers' understanding of these embodiments. Nevertheless, the claimed technical solutions of the present disclosure can also be implemented without these technical details and with various changes and modifications based on the following embodiments.

[0041] Some embodiments of the present disclosure provide a solar cell. A detailed illustration of the solar cell is provided below in conjunction with the accompanying drawings.

[0042] How Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. As can be seen from Figure 7, the solar cell comprises the following: a substrate 100 having a first surface 110 and a second surface 120, which are opposite each other and each is substantially perpendicular to a thickness direction Z of the substrate 100, and grid lines 101 arranged at intervals on at least one of the first surface 110 and the second surface 120 along a first direction X. Each grid line of at least some of the grid lines 101 has a respective contact structure 102 and a respective interconnect layer 103, which are electrically connected to the substrate 100, wherein the respective contact structure 102 includes a plurality of contact sections 112 arranged along a second direction Y, the respective interconnect layer 103 is an elongated strip structure extending along the second direction Y, and the first direction X intersects the second direction Y.Each interconnect layer 103 is electrically connected to the plurality of contact sections 112. The material of the plurality of contact sections 112 differs from the material of the respective interconnect layer 103. An orthographic projection of the respective interconnect layer 103 onto the substrate partially overlaps orthographic projections of the plurality of contact sections 112 onto the substrate. The plurality of contact sections 112 includes first contact sections 122 and second contact sections 132, which are arranged alternately along the second direction Y. Each interconnect layer 103 includes a first side section 113 and a second side section 123, which extend along the second direction Y.The first contact sections 122 are electrically connected to at least the first side section 113 and the second contact sections 132 are electrically connected to at least the second side section 123.

[0043] In this context, the phrase “essentially perpendicular to” refers to the fact that each of the first surface 110 and the second surface 120 may be strictly perpendicular to the thickness direction Z of the substrate 100, or an included angle between the thickness direction Z and each of the first surface 110 and the second surface 120 may be slightly larger or smaller than a right angle, for example, the included angle may be 87°, 88°, 89°, 91°, 92°, 93° or the like.

[0044] Fig. Figure 1 is a schematic top view of a section of a first grid line of a solar cell, which is provided in some embodiments of the present invention. Fig. Figure 2 is a schematic top view of a section of a solar cell, which is provided in some embodiments of the present disclosure. Fig. 3 is a schematic cross-sectional view along a first section direction AA1 in Fig. 2. Fig. Figure 4 is a schematic top view of a section of a second grid line of a solar cell, which is provided in some embodiments of the present invention. Fig. Figure 5 is a schematic top view of a section of a third grid line of a solar cell, which is provided in some embodiments of the present invention. Fig. Figure 6 is a schematic top view of a section of a fourth grid line of a solar cell, which is provided in some embodiments of the present invention. Fig. Figure 7 is a schematic top view of a section of a fifth grid line of a solar cell, which is provided in some embodiments of the present invention.

[0045] It should be noted that, to clearly illustrate the positional relationship between the respective connection layer 103 and the multitude of contact sections 112, both Fig. 1 as well Fig. 2. Use a perspective drawing method for the respective bonding layer 103. In addition, Fig. Figure 1 shows only one example of a positional relationship between the respective compound layer 103 and the plurality of contact sections 112, and a further detailed illustration of the positional relationship between the respective compound layer 103 and the plurality of contact sections 112 is provided in conjunction with other drawings. Fig. Figure 3 shows the grid lines 101 as being formed on the second surface 120 as an example. In practice, the grid lines can be formed on the first surface or on both the first and second surfaces.

[0046] It should be noted that in some embodiments, such as Fig. 1, Fig. 4, Fig. 5 or Fig. As can be seen from Figure 6, the first contact sections 122 are electrically connected to at least the first side section 113, and the second contact sections 132 are electrically connected to at least the second side section 123 in such a way that a respective first contact section of the first contact sections 122 cannot be aligned in the first direction X with a second contact section 132 that is adjacent to the respective first contact section 122 in the second direction Y. In this case, the first contact sections 122 are electrically connected to at least the first side section 113, and the second contact sections 132 are electrically connected to the second side section 123, or the second contact sections 132 are electrically connected to at least the second side section 123, and the first contact sections 122 are electrically connected to the first side section 113.A detailed illustration of the positional relationship between the respective connection layer 103 and the multitude of contact sections 112 of the respective contact structure 102 is provided below.

[0047] Thus, on the one hand, with unchanged dimensions of the respective interconnection layer 103, the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 contributes to reducing the material consumption of the respective contact structure 102, while at the same time ensuring sufficient contact areas between the respective contact structure 102 and the respective interconnection layer 103 compared to producing the respective contact structure so that it has an elongated strip structure similar to the respective interconnection layer 103, which contributes to improving the performance of the electrical connection between the grid lines 101 and the substrate 100 and to reducing the manufacturing costs of the grid lines 101.On the other hand, each first contact section 122 has a third edge facing away from the second contact sections 132 in the first direction X, and each second contact section 132 has a fourth edge facing away from the first contact sections 122, wherein the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 contributes to increasing a maximum distance between the respective third edge and the respective fourth edge in the first direction X, which, with unchanged dimensions of the respective interconnection layer 103, contributes to reducing the requirement for alignment accuracy between the respective contact structure 102 and the respective interconnection layer 103 compared to manufacturing the respective contact structure such that it has an elongated strip structure similar to the respective interconnection layer 103.In other words, the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 allows for a larger misalignment error between the respective contact structure 102 and the respective interconnection layer 103 in the first direction X. As long as the error is not larger than this misalignment error, the contact area between the respective interconnection layer 103 and the respective contact structure 102 remains unchanged. In this way, the difficulty of manufacturing the respective interconnection layer 103, and therefore the difficulty of manufacturing the grid lines 101, can be reduced, while ensuring good electrical contact performance between the respective contact structure 102 and the respective interconnection layer 103.

[0048] In some embodiments, as Fig. 1, Fig. 4 or Fig. 5 can be seen, the first contact sections 122 are electrically connected to at least the first side section 113 and the second contact sections 132 are electrically connected only to the second side section 123 and are not electrically connected to the first side section 113.

[0049] In some other embodiments, such as Fig. 1, Fig. 4 or Fig. 6 can be seen, the second contact sections 132 are electrically connected at least to the second side section 123 and the first contact sections 122 are electrically connected only to the first side section 113 and are not electrically connected to the second side section 123.

[0050] In some other embodiments, such as Fig. As can be seen from Figure 7, the first contact sections 122 are electrically connected to at least the first side section 113, the second contact sections 132 are electrically connected to at least the second side section 123, and the first contact sections 122 and the second contact sections 132 are arranged such that they are spaced apart from each other along the second direction Y. In particular, each first contact section 122 is electrically connected to both the first side section 113 and the second side section 123, and each second contact section 132 is electrically connected to both the first side section 113 and the second side section 123.In this way, with unchanged dimensions of the respective interconnection layer 103, the arrangement in which the first contact sections 122 and the second contact sections 132 are arranged so that they are spaced apart from each other along the second direction Y contributes to reducing the material consumption of the respective contact structure 102, while at the same time ensuring sufficient contact areas between the respective contact structure 102 and the respective interconnection layer 103 compared to producing the respective contact structure so that it has an elongated strip structure similar to the respective interconnection layer 103, which contributes to improving the performance of the electrical connection between the grid lines 101 and the substrate 100 and to reducing the manufacturing costs of the grid lines 101.

[0051] Furthermore, the material of the multitude of contact sections 112 differs from the material of the respective connecting layer 103, thus preventing the grid lines 101 from being produced using the same material.By adapting the material of the plurality of contact sections 112 and the material of the respective connecting layer 103, for example, by adapting the material of the respective connecting layer 103 so that it has costs that are lower than the costs of the material of the plurality of contact sections 112, in addition to the reduction in the manufacturing costs of the respective contact structure 102 resulting from the reduction in the amount of material required for the respective contact structure 102 by designing the plurality of contact sections 112 as distributed, the manufacturing costs of the respective contact structure 102 can be further reduced due to the reduction in the cost of the material of the respective connecting layer 103.

[0052] It should be noted that in some embodiments, such as in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7, with a single grid line 101, the interconnect layer 103 can be electrically connected to each contact section 112 of the contact structure 102. In practice, due to limitations in printing technology, if the orthographic projection of the interconnect layer onto the substrate overlaps with a respective orthographic projection of each contact section, poor electrical connection(s) between the interconnect layer and individual contact section(s) may occur, such as in a case where significant errors occur in the print thickness of individual contact section(s) or significant errors occur in the print thickness of some areas of the interconnect layer.Alternatively, due to limitations in printing technology, if a finished pattern of individual contact section(s) differs significantly from a designed pattern, poor electrical connection(s) may also occur between the bonding layer and individual contact section(s).

[0053] A more detailed illustration of the solar cell provided in some embodiments of the present disclosure is provided below in conjunction with the accompanying drawings.

[0054] In some embodiments, as Fig. As can be seen from Figure 4, for a grid line 101, the first contact segments 122 are not aligned with the second contact segments 132 in the second direction Y. In other words, orthographic projections of the first contact segments 122 on a plane perpendicular to the second direction Y and orthographic projections of the second contact segments 132 on the plane perpendicular to the second direction Y do not overlap.

[0055] In this case, the connection between the multitude of contact sections 112 and the interconnection layer 103 is as follows: The first contact sections 122 are electrically connected only to the first side section 113 and the second contact sections 132 are electrically connected only to the second side section 123.

[0056] In some other embodiments, such as Fig. 1, Fig. 5 or Fig. As can be seen from Figure 6, with a grid line 101, segments of the first contact sections 122 are aligned with segments of the second contact sections 132 in the second direction Y. In other words, orthographic projections of the first contact sections 122 on the plane perpendicular to the second direction Y partially overlap with orthographic projections of the second contact sections 132 on the plane perpendicular to the second direction Y.

[0057] In this case, the connection between the plurality of contact sections 112 and the connection layer 103 includes at least three arrangements as follows.

[0058] Order one: How Fig. As can be seen from Figure 1, the first contact sections 122 are electrically connected only to the first side section 113, and the second contact sections 132 are electrically connected only to the second side section 123. It should be noted that, in order to reduce the dimensions of the contact sections 112, thereby lowering manufacturing costs and increasing the contact area between the contact sections 112 and the interconnect layer 103, compared to those in Figure 1, the following dimensions were used: Fig. 4 contact sections shown 112 which are in Fig. The contact sections 112 shown in Figure 1 can have larger widths in the first direction X and smaller extension lengths in the second direction Y, thereby ensuring, as far as possible, that more than half of the area of ​​the contact structure 102 can be electrically connected to the connection layer 103.

[0059] Arrangement two: How Fig. As can be seen from Figure 5, the first contact sections 122 are electrically connected to both the first side section 113 and the second side section 123, while the second contact sections 132 are electrically connected only to the second side section 123. It should be noted that, in order to reduce the dimensions of the contact sections 112, thereby lowering manufacturing costs and increasing the contact area between the contact sections 112 and the compound layer 103 in the first direction X, a first contact section 122 can have a width greater than the width of a second contact section 132, thus ensuring, as far as possible, that more than half the area of ​​the contact structure 102 can be electrically connected to the compound layer 103. Furthermore, the Fig. 5 contact sections 112 shown compared to those in Fig. The contact sections 112 shown in Figure 1 have larger widths in the first direction X and smaller extension lengths in the second direction Y in order to reduce the amount of material required for the contact structure 102 as much as possible.

[0060] Arrangement three: How Fig. As can be seen from Figure 6, the first contact sections 122 are electrically connected only to the first side section 113, and the second contact sections 132 are electrically connected to both the first side section 113 and the second side section 123. It should be noted that, in order to reduce the dimensions of the contact sections 112, thereby lowering manufacturing costs and increasing the contact area between the contact sections 112 and the compound layer 103 in the first direction X, a second contact section 132 can have a width greater than that of a first contact section 122, thus ensuring, as far as possible, that more than half the area of ​​the contact structure 102 can be electrically connected to the compound layer 103. Furthermore, the Fig. 6 contact sections 112 shown compared to those in Fig. The contact sections 112 shown in Figure 1 have larger widths in the first direction X and smaller extension lengths in the second direction Y in order to reduce the amount of material required for the contact structure 102 as much as possible.

[0061] How Fig. As can be seen from point 8, the three aforementioned orders are relevant. Fig. Figure 8 shows a partially enlarged schematic representation of two adjacent contact sections of the solar cell, which is provided in some embodiments of the present disclosure. Each first contact section of the first contact sections 122 includes a first segment 1221 that is oriented towards the segments of the second contact sections 132 in the second direction Y, and a segment of the respective first contact section 122 that is different from the first segment 1221 has a width S of less than or equal to 25 µm in the first direction X.In other words, a misalignment area between a first contact section 122 and a second contact section 132, adjacent to the first contact section 122 in 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, 1 µm, or the like. amount to.

[0062] The segment of the respective first contact section 122 that differs from the first segment 1221 can be designated as the second segment 1222, and the second segment 1222 has a width S of less than or equal to 25 µm in the first direction X. Fig. 8 is the first contact section 122 divided by a dashed line into the first segment 1221 and the second segment 1222.

[0063] It should be noted that if the first segments of the first contact sections 122 are aligned in the second direction Y to the segments of the second contact sections 132 and the widths S of the second segments 1222 in the first direction X are greater than 25 µm, the misalignment between a first contact section 122 and a second contact section 132 adjacent to this first contact section in the first direction X is relatively large, and the distance between the third edge and the fourth edge in the first direction X is too large, which does not help to ensure a large contact area between the compound layer 103 and the contact structure 102 with unchanged dimensions of the compound layer 103.Thus, the misalignment area between a first contact section 122 and a second contact section 132, which is adjacent to this first contact section in the second direction Y, is set to be less than or equal to 25 µm, which helps to provide a reasonable misalignment between a first contact section 122 and a second contact section 132, which is adjacent to this first contact section in the first direction X, thereby reducing the dimensions of the contact sections 112 as much as possible and ensuring, as far as possible, that more than half of the area of ​​the contact structure 102 can be electrically connected to the interconnection layer 103.

[0064] In some other embodiments, such as Fig. As can be seen from Figure 7, for a grid line 101, the first contact segments 122 are aligned with the second contact segments 132 in the second direction Y. In other words, orthographic projections of the first contact segments 122 onto the plane perpendicular to the second direction Y overlap with orthographic projections of the second contact segments 132 onto the plane perpendicular to the second direction Y. That is, the misalignment area between a first contact segment 122 and a second contact segment 132 adjacent to this first contact segment in the second direction Y is 0.

[0065] In this case, the connection between the multitude of contact sections 112 and the interconnection layer 103 is as follows: The first contact sections 122 are electrically connected to both the first side section 113 and the second side section 123, and the second contact sections 132 are electrically connected to both the first side section 113 and the second side section 123.

[0066] The following is a detailed illustration of the multitude of contact sections 112.

[0067] In some embodiments, as the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8 shows that the orthographic projections of the multitude of contact sections 112 onto the substrate 100 have the form of rectangles.

[0068] How Fig. As can be seen in 9, this is the case with some other embodiments. Fig. 9 A schematic top view of a section of a sixth grid line of the solar cell, which is provided in some embodiments of the present disclosure, wherein the orthographic projections of the plurality of contact sections 112 onto the substrate 100 may have the form of circles. It should be noted that, due to accuracy limitations of the process for forming the plurality of contact sections 112, if the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have circular shapes, the circles may also be approximately circular and need not necessarily be geometrically standard circles.

[0069] How Fig. As can be seen in 10, this is the case with some other embodiments. Fig. 10 A schematic top view of a section of a seventh grid line of the solar cell, which is provided in some embodiments of the present disclosure, wherein the orthographic projections of the plurality of contact sections 112 onto the substrate 100 may have the shape of ellipses. It should be noted that, due to accuracy limitations of the process for forming the plurality of contact sections 112, if the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have elliptical shapes, the ellipses may also be approximately elliptical and need not necessarily be geometrically standard ellipses.

[0070] How Fig. As can be seen in 11, this is the case with some other embodiments. Fig. 11 a schematic top view of a section of an eighth grid line of the solar cell, which is provided in some embodiments of the present disclosure, wherein the orthographic projections of the plurality of contact sections 112 onto the substrate 100 may have the form of triangles.

[0071] It should be noted that in practice the orthographic projections of the multitude of contact sections 112 onto the substrate 100 may also have the form of trapezoids or N-sided polygons, where N is a positive integer greater than 4.

[0072] In some embodiments, as Fig. As can be seen from Figure 9, the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have the form of circles or ellipses, and each first contact section of the first contact sections 122 is tangential to a second contact section of the second contact sections 132 that is adjacent to the respective first contact section 122 in the second direction Y. In this way, although a first contact section 122 and a second contact section 132 that is adjacent to this first contact section 122 are partially connected, most of the surface areas of the first contact section 122 and the second contact section 132 are spaced apart from each other in the second direction Y, which helps to reduce the amount of material required for the contact structure 102 as much as possible without altering the dimensions of the bonding layer 103.

[0073] It should be noted that Fig. Figure 9 shows an exemplary arrangement in which the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have circular shapes, and a first contact section 122 is tangential to a second contact section 132, which is adjacent to this first contact section 122 in the second direction Y. In practice, if the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have circular shapes, the first contact sections 122 and the second contact section 132 can be spaced apart from each other in the second direction Y.

[0074] Furthermore, if the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have the form of ellipses, a first contact section 122 can also be tangential to a second contact section 132, which is adjacent to this first contact section 122 in the second direction Y. Fig. Figure 10 shows only an exemplary arrangement in which the orthographic projections of the plurality of contact sections 112 onto the substrate 100 have the form of ellipses and the first contact sections 122 and the second contact section 132 are spaced apart from each other in the second direction Y.

[0075] In some embodiments, as Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. As can be seen from Figure 11, an orthographic projection of a respective contact section of the plurality of contact sections 112 onto the substrate 100 has an area in the range of 100 µm2 to 5000 µm2, for example it can be 300 µm2, 500 µm2, 800 µm2, 1000 µm2, 1200 µm2, 1500 µm2, 1700 µm2, 2000 µm2, 2300 µm2, 2500 µm2, 2800 µm2, 3000 µm2, 3300 µm2, 3500 µm2, 3800 µm2, 4000 µm2, 4200 µm2, 4500 µm2, 4800 µm2 or similar.

[0076] It should be noted that if the area of ​​an orthographic projection of a contact section 112 onto the substrate 100 is less than 100 µm², the contact area between a single contact section 112 and the compound layer 103 is too small, which does not contribute to improving either the performance of electrical connections between the contact sections 112 and the substrate 100 or the contact performance between the contact sections 112 and the compound layer 103. If the area of ​​an orthographic projection of a contact section 112 onto the substrate 100 is greater than 5000 µm², the effect of reducing the amount of material required for the contact structure 102 based solely on the distance between adjacent contact sections 112 is limited.Thus, the design is such that an orthographic projection of a respective contact section 112 onto the substrate 100 has an area in the range of 100 µm2 to 5000 µm2, which helps to improve the performance of the electrical connections between the contact sections 112 and the substrate 100, to improve the contact performance between the contact sections 112 and the connection layer 103 and to reduce the amount of material required for the contact structure 102 as much as possible.

[0077] In some embodiments, as Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 or Fig. 9, Fig. 10 to Fig. As can be seen from 11, the connection layer 103 has a width in the range of 10 µm to 70 µm in the first direction X, for example it can be 15 µm, 20 µm, 25 µm, 30 µm, 35 µm, 40 µm, 45 µm, 50 µm, 55 µm, 60 µm or 65 µm.

[0078] In some embodiments, as Fig. As can be seen from Figure 1, in the first direction X the width of the connecting layer 103 is essentially equal to the width of the contact structure 102, with the difference that the first contact sections are not aligned with the second contact sections of the contact structure 102 in the first direction X, while the connecting layer 103 is an elongated strip structure extending along the second direction Y.

[0079] In some embodiments, as Fig. 8 can be seen in the second direction Y, in each first contact section of the first contact sections 122 has a first edge 122a which is directly facing a second contact section of the second contact sections 132 which is adjacent to the respective first contact section 122, the second contact section 132 has a second edge 132a which is directly facing the respective first contact section 122, and there is a distance D between the first edge 122a and the second edge 132a less than or equal to 200 µm.

[0080] If the distance D between the first edge 122a and the second edge 132a is greater than 200 µm, the spacing between the respective first contact section 122 and the second contact section 132 is too large, resulting in an excessively low arrangement density of the contact sections 112 of the contact structure 102, so that most of the interconnection layer 103 (see Fig. 1) not electrically compatible with contact structure 102 (see Fig. 1) is connected. Thus, the distance D between the first edge 122a and the second edge 132a is set to less than or equal to 200 µm, which helps to ensure a high arrangement density of the contact sections 112 of the contact structure 102, thereby ensuring as far as possible that the majority of the interconnection layer 103 can be electrically connected to the contact structure 102, and ensuring a sufficient contact area between the interconnection layer 103 and the contact structure 102.

[0081] It should be noted that in Fig. 8 The contact sections 112, whose orthographic projections onto the substrate 100 have the shape of rectangles, are used as an example, and the distance D between the first edge 122a and the second edge 132a is specified based on the exemplary contact sections 112. In practice, if the orthographic projections of the contact sections 112 onto the substrate 100 have other shapes, the distance between the first edge and the second edge can also be less than or equal to 200 µm.

[0082] In some embodiments in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 can have a multitude of contact sections 112 thicknesses in the range of 1 µm to 10 µm in the thickness direction Z, for example 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm or the like.

[0083] In some embodiments in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 the compound layer 103 can have a thickness in the range of 4 µm to 20 µm, for example 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, 19 µm or the like.

[0084] The following is a detailed illustration of the materials of the contact sections 112 and the interconnection layer 103.

[0085] In some embodiments, as Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11, the material of the multitude of contact sections 112 contains silver particles and the material of the compound layer 103 may contain copper particles or silver-coated copper particles.

[0086] For a unit mass, the cost of silver particles is higher than that of copper particles and also higher than that of silver-coated copper particles. Furthermore, the electrical contact efficiency between silver particles and the substrate 100 is higher than that between copper particles and the substrate 100 and also higher than that between silver-coated copper particles and the substrate 100. Thus, only the material of the contact structure of a grid line 101 consists of silver particles, which, on the one hand, contributes to a significant reduction in the silver particle content in the grid lines 101 and, on the other hand, ensures the highest possible electrical contact efficiency between the grid lines 101 and the substrate 100, thereby guaranteeing that the solar cell has a high photoelectric conversion efficiency.On the other hand, compared to the amount of paste required for the contact structure 102, designing the interconnection layer 103, which requires a larger amount of paste, such that it contains copper particles or silver-coated copper particles, can ensure a sufficient amount of paste for the interconnection layer 103 so that the interconnection layer 103 can effectively collect charge carriers from the multitude of contact sections 112 of the contact structure 102 and the manufacturing costs of the interconnection layer 103 can be reduced.

[0087] In some embodiments, compared to simply using silver paste to form the grid lines on the first or second surface, only the material of the contact sections 112 of the grid lines 101 contains silver particles; that is, only the contact sections 112 are formed using silver paste. In this way, the amount of silver paste required to form the contact sections 112 can be reduced, for example, to 3 mg to 15 mg. If silver paste is simply used to form the grid lines on the first or second surface, the amount of silver paste used for a single surface of the solar cell is up to 40 mg. For the grid lines 101 in some embodiments of the present disclosure, the amount of silver paste used for a single surface of the solar cell can be reduced to 3 mg to 15 mg.

[0088] It should be noted that in some embodiments of the present disclosure, in addition to the arrangement in which the first contact sections are not aligned with the second contact sections of the contact structure 102 in the first direction X in order to reduce the amount of silver paste required to form the contact sections 112, the amount of silver paste required to form the contact sections 112 can be further reduced by reducing the thicknesses of the contact sections 112 in the thickness direction Z.

[0089] In some embodiments in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 the material of the compound layer 103 may contain copper particles and the copper particles may have diameters in the range of 50 nm to 1500 nm, for example they 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, 1400 nm or the like.

[0090] In some other embodiments in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 the material of the compound layer 103 may contain silver-coated copper particles and the silver-coated copper particles may have diameters in the range of 1 µm to 10 µm, for example they may be 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm or the like.

[0091] It should be noted that the diameters of the silver-coated copper particles refer to the outer diameters of the silver-coated copper particles, i.e., the diameters of the outer contours of the silver-coated copper particles.

[0092] In some embodiments, the proportion of silver in the silver-coated copper particles is in the range of 15% to 50%, for example 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%, 49% or the like.

[0093] The following is a detailed illustration of the types of grid lines 101.

[0094] How Fig. As can be seen from 12, in some embodiments Fig. Figure 12 shows a schematic top view of a section of another solar cell provided in some embodiments of the present disclosure. The grid lines 101 are finger electrodes 104 and the busbars 105 are formed in the form of elongated strip structures extending along the first direction X; or the grid lines are busbars 105 and the finger electrodes 104 are formed in the form of elongated strip structures extending along the first direction X. It should be noted that Fig. Figure 12 shows, by way of example, that the grid lines 101 are finger electrodes 104 and the busbars 105 are formed in the form of elongated strip structures extending along the first direction X. In practice, the grid lines can also be busbars and the finger electrodes are formed in the form of elongated strip structures extending along the first direction.

[0095] It should be noted that the embodiments of the grid lines 101 illustrated above, regardless of whether the grid lines 101 are finger electrodes 104 or busbars 105, contribute to improving the performance of the electrical connection between the grid lines 101 and the substrate 100 and to reducing the manufacturing costs of the grid lines 101. Furthermore, the arrangement of the grid lines 101 in which the first contact sections are not aligned with the second contact sections contributes to reducing the manufacturing difficulty of the grid lines 101.

[0096] Furthermore, the arrangement density of the finger electrodes 104 on the substrate 100 is higher than that of the busbars 105. Therefore, compared to the total amount of material required to fabricate the busbars 105 on a single surface, the total amount of material required to fabricate the finger electrodes 104 on a single surface is generally higher. Thus, compared to the busbars 105, applying the configurations of the grid lines 101 illustrated above to the finger electrodes 104 contributes more to reducing the total length of material required to fabricate the grid lines 101, thereby reducing the manufacturing costs of the solar cell.

[0097] Furthermore, in some cases an electrical connection between the finger electrodes 104 and the substrate 100 is required, and the busbars 105 can be electrically connected only to the finger electrodes 104 without being electrically connected to the substrate 100. The charge carriers in the substrate 100 can first be collected by the finger electrodes 104 and then by the busbars 105, which are electrically connected to the finger electrodes 104. In this way, it is not necessary to form a direct electrical connection between the busbars 105 and the substrate 100. For example, the material used to form the busbars 105 does not need to be embedded in a passivation layer on the substrate 100.Therefore, the busbars 105 can be formed using a lower-cost material, as long as the electrical connection between the busbars 105 and the finger electrodes 104 can be achieved. Based on this, applying the above-illustrated configurations of the grid lines 101 to the finger electrodes 104 not only improves the performance of the electrical contact between the finger electrodes 104 and the substrate 100 by means of the contact structure 102, but also reduces the manufacturing costs of the finger electrodes 104 by means of the interconnect layer 103. Furthermore, the busbars 105 can be formed using a lower-cost material to further reduce the manufacturing costs of the solar cell.

[0098] It should be noted that each of the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11 to Fig. Figure 12 shows, for example, that in the second direction Y there is only one first contact section 122 between two adjacent second contact sections 132. In other words, in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11 to Fig. In the examples shown in Figure 12, with the multitude of contact sections 112 that are electrically connected to the same bonding layer 103, in the second direction Y between two adjacent first contact sections 122 only a second contact section 132 is present.

[0099] In practice, there is no limit to the number of second contact sections that can be arranged between two adjacent first contact sections; for example, there can be two or three second contact sections. Likewise, there is no limit to the number of first contact sections that can be arranged between two adjacent second contact sections; for example, there can be two or three first contact sections. In other words, in practice, in the second direction, there can be no second contact section between two adjacent first contact sections, or there can be no first contact section between two adjacent second contact sections. For example, one first contact section and three second contact sections are arranged as a set, and a plurality of sets are arranged repeatedly along the second direction.

[0100] How Fig. 1 and Fig. As can be seen from 13, in some embodiments Fig. 13 A schematic top view of a section of a busbar of the solar cell, which is provided in some embodiments of the present disclosure. The grid lines 101 are finger electrodes and the solar cell may further comprise: busbars 105 arranged at intervals on at least one of the first surfaces 110 (see Fig. 3) and the second surface 120 (see Fig. 3) are arranged along the second direction Y. Each busbar of at least some of the busbars 105 has a respective connection structure 115 and a respective intermediate connection layer 125 that are electrically connected to the substrate 100, wherein the respective connection structure 115 includes a plurality of connection sections 135 that are arranged along the first direction X, and the respective intermediate connection layer 125 is an elongated strip structure that extends along the first direction X.Each intermediate interconnection layer 125 is electrically connected to a plurality of interconnection sections 135. The plurality of interconnection sections 135 includes first interconnection sections 145 and second interconnection sections 155, which are arranged alternately along the second direction Y. Each intermediate interconnection layer 125 includes a third side section 165 and a fourth side section 175, which extend along the second direction Y. The first interconnection sections 145 are electrically connected to at least the third side section 165, the second interconnection sections 155 are electrically connected to at least the fourth side section 175, and one material of the plurality of interconnection sections 135 differs from a material of the respective intermediate interconnection layer 125.

[0101] It should be noted that in addition to the contact structures 102, which are configured for electrical connection between the finger electrodes and the substrate 100, the busbars 105 also include connection structures 115, which are configured for electrical connection between the busbars and the substrate 100. In other words, in addition to some sections of the finger electrodes that are electrically directly connected to the substrate 100, the busbars 105 also include some sections that are electrically directly connected to the substrate 100.Therefore, the charge carriers in the substrate 100 can be collected not only via the finger electrodes and then via the busbars 105, but can also be collected directly via the busbars 105 through the connecting structures 115. This helps to shorten the transport distance of some charge carriers in the substrate 100 to the busbars 105, thereby reducing the transport loss of charge carriers and improving the charge carrier collection efficiency through the busbars 105. In this way, the photoelectric conversion efficiency of the solar cell can be improved.

[0102] It should be noted that the connecting structures 115 of the busbars 105 are similar to the contact structures 102 of the finger electrodes, the connecting sections 135 of the connecting structures 115 are similar to the contact sections 112 of the contact structure 102, the first connecting sections 145 are similar to the first contact sections 122, the second connecting sections 155 are similar to the second contact sections 132, the intermediate connecting layer 125 is similar to the connecting layer 103, the third side section 165 is similar to the first side section 113, and the fourth side section 175 is similar to the second side section 123, with the difference that the dimensions of the connecting sections 135 are different from those of the contact sections 112, and the dimensions of the intermediate connecting layer 125 are different from those of the connecting layer 103.Therefore, the connection structures 115 and the intermediate connection layers 125 of the busbars 105 are not discussed in detail here. Furthermore, shows... Fig. 13 shows only an exemplary arrangement of the busbars 105, in which the connecting structure 115 is electrically connected to the intermediate connecting layer 125. For other arrangements of the connection between the connecting structure 115 and the intermediate connecting layer 125, reference is made to the aforementioned arrangements of the connection between the contact structure and the connecting layer.

[0103] The following is a detailed illustration of the types of solar cells.

[0104] In some embodiments, the solar cell has grid lines formed on both surfaces. The solar cell can be a PERC cell, a TOPCON solar cell, a HIT / HJT (hetero-transition technology) solar cell, a thin-film solar cell, or any combination thereof. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide thin-film solar cells, gallium arsenide thin-film solar cells, and cadmium sulfide thin-film solar cells.

[0105] Based on this, in Fig. 3. The first surface 110 of the substrate 100 can be the front surface. On the first surface 110, a plurality of front finger electrodes (not shown) are provided at intervals along the first direction X, and a plurality of front busbars (not shown) are provided at intervals along the second direction Y. The second surface 120 of the substrate 100 can be the back surface. On the second surface 120, a plurality of back finger electrodes are provided at intervals along the first direction X, and a plurality of back busbars (not shown) are provided at intervals along the second direction Y.

[0106] It should be noted that the solar cells can be single-sided cells, in which the first surface 110 serves as the light-receiving surface for receiving incident light, and the second surface 120 serves as the back surface. Alternatively, the solar cells can be double-sided cells, in which both the first surface 110 and the second surface 120 can serve as light-receiving surfaces for receiving incident light. In this case, the back surface can also receive incident light, but its reception of incident light is weaker than that of the light-receiving surface, and it is therefore considered the back surface.

[0107] In some embodiments, in Fig. 3. The rear finger electrodes can be implemented as the grid lines 101 illustrated in the preceding embodiments, and each of the rear busbars, front finger electrodes, and front busbars can be implemented as a single-layer, elongated strip structure. In this way, the manufacturing costs of the solar cells can be reduced by forming the grid lines 101 on the second surface 120, and excessive obstruction of the substrate 100 by the front busbars and rear busbars formed on the first surface can be prevented to ensure that the solar cell has a sufficient light-receiving surface.

[0108] In some other embodiments, the posterior finger electrodes and the anterior finger electrodes can be designated as grid lines 101 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) be implemented, which are illustrated in the foregoing embodiments. Each of the rear busbars and the front busbars can be implemented as a single-layer and elongated strip structure, or the rear busbars and the front busbars can be implemented as the busbars 105 (see Fig. 13) be implemented, as illustrated in the foregoing embodiments.

[0109] In some other embodiments, the rear finger electrodes can be configured as grid lines 101 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) implemented, which are illustrated in the above embodiments, the rear busbars can be the busbars 105 (see Fig. 13) be implemented as illustrated in the foregoing embodiments, and each of the front finger electrodes and front busbars may be implemented as a single-layer and elongated strip structure.

[0110] In some other embodiments, the front finger electrodes can be configured as the grid lines 101 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) be implemented, which are illustrated in the above embodiments, the front busbars can be considered the busbars 105 (see Fig. 13) be implemented as illustrated in the foregoing embodiments, and each of the rear finger electrodes and rear busbars may be implemented as a single-layer and elongated strip structure.

[0111] In some embodiments, the solar cell is a back-contact solar cell, also known as a BC solar cell. BC solar cells include, but are not limited to, interdigitated back-contact solar cells (IBC solar cells, IBC = interdigitated back contact), heterojunction back-contact solar cells (HBC solar cells, HBC = heterojunction back contact), TOPCon back-contact solar cells (TBC solar cells), or solar cells with hybrid passivated back contacts (HPBC solar cells, HPBC = hybrid passivated back contacts). Thus, in Fig. 3 the first surface 110 or the second surface 120 can be considered as the rear surface of the finally formed solar cell.

[0112] Based on this, the rear finger electrodes and the rear busbars are provided on the rear surface of the solar cell.

[0113] In some embodiments, the rear finger electrodes provided on the first surface or the second surface can be designated as the grid lines 101 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) be implemented as illustrated in the foregoing embodiments, and each of the rear busbars may be implemented as a single-layer and elongated strip structure.

[0114] In some other embodiments, the rear finger electrodes provided on the first surface or the second surface can be configured as grid lines 101 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) be implemented, which are illustrated in the foregoing embodiments, and each of the rear busbars provided on the first surface or the second surface can be referred to as the busbars 105 (see Fig. 13) be implemented, as illustrated in the foregoing embodiments.

[0115] In the contact structure 102 of the solar cell, each first contact section of the first contact sections 122 in the first direction X is not aligned to a second contact section 132, which is adjacent to the respective first contact section 122 in the second direction Y.Thus, on the one hand, with unchanged dimensions of the respective interconnection layer 103, the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 contributes to reducing the material consumption of the contact structure 102, while at the same time ensuring sufficient contact areas between the contact structure 102 and the interconnection layer 103 compared to producing the contact structure so that it has an elongated strip structure similar to the interconnection layer 103, which contributes to improving the performance of the electrical connection between the grid lines 101 and the substrate 100 and to reducing the manufacturing costs of the grid lines 101.On the other hand, in the first direction X, each first contact section 122 has a respective third edge facing away from the second contact sections 132, and each second contact section 132 has a respective fourth edge facing away from the first contact sections 122, wherein the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 contributes to increasing a maximum distance between the respective third edge and the respective fourth edge in the first direction X, which, with unchanged dimensions of the respective interconnection layer 103, contributes to reducing the requirement for alignment accuracy between the contact structure 102 and the interconnection layer 103 compared to manufacturing the contact structure so that it has an elongated strip structure similar to the interconnection layer 103.In other words, the arrangement in which the first contact sections 122 are not aligned with the second contact sections 132 allows for a larger misalignment error between the contact structure 102 and the interconnection layer 103 in the first direction X. As long as the error is not larger than this misalignment error, the contact area between the interconnection layer 103 and the contact structure 102 remains unchanged. In this way, the difficulty of manufacturing the interconnection layer 103, and therefore the difficulty of manufacturing the grid lines 101, can be reduced, while ensuring good electrical contact performance between the contact structure 102 and the interconnection layer 103.

[0116] Some embodiments of the present disclosure provide a method for manufacturing the solar cells described in the preceding embodiments. A detailed illustration of the method for manufacturing solar cells is provided below in conjunction with the accompanying drawings. It should be noted that parts identical or corresponding to those in the preceding embodiments are not repeated here.

[0117] The process for manufacturing solar cells Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11 includes the following: providing a substrate 100 having a first surface 110 and a second surface 120, wherein the first surface 110 and the second surface 120 are opposite each other and each is substantially perpendicular to a thickness direction Z of the substrate 100; and forming grid lines 101 arranged at intervals on at least one of the first surface 110 and the second surface 120 along a first direction X.Each grid line of at least some of the grid lines 101 has a respective contact structure 102 and a respective interconnection layer 103 that are electrically connected to the substrate 100, wherein the respective contact structure 102 includes a plurality of contact sections 112 arranged along a second direction Y, the respective interconnection layer 103 is an elongated strip structure extending along the second direction Y, and the first direction X intersects the second direction Y. The respective interconnection layer 103 is electrically connected to the plurality of contact sections 112. The plurality of contact sections 112 includes first contact sections 122 and second contact sections 132 arranged alternately along the second direction Y, and the respective interconnection layer 103 includes a first side section 113 and a second side section 123 extending along the second direction Y.The first contact sections 122 are electrically connected to at least the first side section 113, the second contact sections 132 are electrically connected to at least the second side section 123 and a material of the plurality of contact sections 112 differs from a material of the respective connection layer 103.

[0118] In some embodiments in Fig. 1, Fig. 4, Fig. 5 or Fig. 6. The first contact sections 122 are electrically connected to at least the first side section 113, and the second contact sections 132 are electrically connected to at least the second side section 123, such that each first contact section of the first contact sections 122 is not aligned in the first direction X with a second contact section 132 that is adjacent to the respective first contact section 122 in the second direction Y. In this case, the first contact sections 122 are electrically connected to at least the first side section 113, and the second contact sections 132 are electrically connected to the second side section 123, or the second contact sections 132 are electrically connected to at least the second side section 123, and the first contact sections 122 are electrically connected to the first side section 113.

[0119] In some other embodiments, such as Fig. As can be seen from Figure 7, the first contact sections 122 are electrically connected to at least the first side section 113, the second contact sections 132 are electrically connected to at least the second side section 123, and the first contact sections 122 and the second contact sections 132 are arranged such that they are spaced apart from each other along the second direction Y. In particular, each first contact section 122 is electrically connected to both the first side section 113 and the second side section 123, and each second contact section 132 is electrically connected to both the first side section 113 and the second side section 123.

[0120] It should be noted that subdividing the contact sections 112 of the contact structure 102 into the first contact sections 122, which are electrically connected to at least the first side section 113, and the second contact sections 132, which are electrically connected to at least the second side section 123, helps to reduce the amount of material required for the contact structure 102 by adjusting the positional relationship between the compound layer 103 and the first contact sections 122 and the second contact sections 132, while simultaneously ensuring that sufficient contact areas are present between the contact structure 102 and the compound layer 103. In this way, the performance of the electrical connection between the grid lines 101 and the substrate 100 can be improved, and the manufacturing costs of the grid lines 101 can be reduced.

[0121] The following is a detailed illustration of the manufacturing process of grid lines 101.

[0122] In some embodiments in Fig. 2 and Fig. 3. The grid lines 101 can be finger electrodes, and the second surface 120 includes first pressure areas (not shown) and second pressure areas (not shown), which partially overlap with the first pressure areas. It should be noted that the first pressure areas correspond to the subsequently formed contact structure 102, and the second pressure areas correspond to the subsequently formed compound layer 103. In other words, the first pressure areas essentially overlap with the orthographic projection of the subsequently formed contact structure 102 onto the substrate 100, and the second pressure areas essentially overlap with the orthographic projection of the subsequently formed compound layer 103 onto the substrate 100.

[0123] In Fig. 2 and Fig. 3. The operation of forming the grid lines can involve the following: printing a first paste onto the first print areas using a first screen printing process, performing sintering on the first paste to form the respective contact structure 102 on the first print areas, printing a second paste onto the second print areas using a second screen printing process, and curing the second paste to form the respective bonding layer 103 on the second print areas. The first paste is a baked-on paste, the second paste is a non-baked-on paste, and the process temperature for performing sintering is higher than the process temperature for curing.

[0124] Because the first paste is a baking paste and the second paste is a non-baking paste, the contact structure 102 that is ultimately formed is electrically connected to the substrate 100; for example, it is embedded in a passivation layer on the substrate 100. However, the connection layer 103 is formed above the surface of the substrate 100; that is, it is not embedded in the passivation layer on the substrate 100 and is also not in direct electrical contact with the substrate 100.

[0125] In some embodiments, the first paste can be silver paste and the second paste can be copper paste or silver-coated copper paste. In practice, due to the arrangement of the contact structure 102, in which the first contact sections 122 and the second contact sections 132 are arranged alternately, the amount of the first paste consumed for a single surface 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, 14 mg, or the like.

[0126] In some embodiments, the solids content in the silver paste can range from 75% to 92%, for example it can be 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91% or the like.

[0127] It should be noted that the solids in the silver paste include not only silver particles but also at least glass particles. The solids content of the silver paste refers to the total content of all solids, including silver particles, in the silver paste.

[0128] In some situations, during the printing process of grid lines using only silver paste, the solids content of the silver paste is generally high, such as higher than 90%. In comparison to the process of printing grid lines using only silver paste, the solids content of the silver paste used in the method for manufacturing solar cells provided for in some other embodiments of the present disclosure can be lower, resulting in a thinner silver paste used to form the contact structure 102. In other words, the viscosity of the silver paste used to form the contact structure 102 is lower.In this way, when the silver paste is printed onto the first printing areas of the substrate 100, it can spread to a certain extent on the substrate 100, which helps to increase the contact area between the contact structure 102 subsequently formed using the silver paste and the substrate 100.

[0129] It should be noted that the second surface 120 can be considered the back surface of the solar cell. By combining the first and second screen printing processes, a grid line 101, which includes the contact structure 102 and the bonding layer 103, can be formed on the second surface 120. Furthermore, in practice, taking the formation of the grid lines 101 on the second surface 120 as an example, the first and second screen printing processes can also be applied to the first surface to form the grid lines, which will not be repeated here.Furthermore, in practice, where the grid lines 101 formed on the second surface 120 are taken as an example as finger electrodes, the grid lines formed using the first screen printing process and the second screen printing process can also be busbars formed on the first surface or the second surface, which is not repeated here.

[0130] In Fig. 13 is the formation process of the connection structure 115 when the busbars 105 have the connection structure 115 and the intermediate connection layer 125, which are electrically connected to the substrate 100 (see Fig. 2), similar to that of contact structure 102 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11) and the formation process of the intermediate layer 125 is similar to that of the intermediate layer 103 (see Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. 11), which will not be repeated here.

[0131] The following is a detailed illustration of the manufacturing process of the busbars 105 formed on the second surface 120, excluding the grid lines 101.

[0132] In some embodiments in Fig. 2 includes the second surface 120 and further third printing areas (not shown). The process further involves: printing the first paste onto the third printing areas using the first screen printing process and performing sintering on the first paste to form busbars on the third printing areas. It should be noted that the third printing areas correspond to the busbars subsequently formed. In other words, the third printing areas essentially overlap with the orthographic projection of the busbars subsequently formed onto the substrate 100.

[0133] It should be noted that the production of the contact structures 102 of the grid lines 101 and the production of the busbars can be carried out in the same process, which helps to reduce a printing process and further reduce the manufacturing costs of solar cells.

[0134] In some other embodiments in Fig. 2 includes the second surface 120 and third printing areas (not shown). The process further includes: printing the second paste on the third printing areas using the second screen printing process and curing the second paste (see Fig. 12) to form the busbars 105 on the third printing areas. It should be noted that the third printing areas correspond to the busbars 105 subsequently formed. In other words, the third printing areas essentially overlap with the orthographic projection of the subsequently formed busbars 105 onto the substrate 100.

[0135] It should be noted that the production of the interconnection layers 103 of the grid lines 101 and the production of the busbars 105 can be carried out in the same process, which also helps to reduce a printing process and further reduce the manufacturing costs of solar cells.

[0136] In some other embodiments, the first screen printing and sintering processes are used exclusively to form the contact structures of the grid lines, and the second screen printing and curing processes are used exclusively to form the bonding layers of the grid lines. Subsequently, the busbars on the second surface are formed using a different process.

[0137] In some embodiments in Fig. 3 and Fig. 12. The finger electrodes 104 formed on the second surface 120 can be posterior finger electrodes, the busbars 105 formed on the second surface 120 are posterior busbars, and the first surface 110 includes fourth pressure areas (not shown) extending along the first direction X, and fifth pressure areas (not shown) extending along the second direction Y. It should be noted that the fourth pressure areas correspond to the subsequently formed anterior finger electrodes and the fifth pressure areas correspond to the subsequently formed anterior busbars.In other words, the fourth pressure areas essentially overlap with the orthographic projection of the subsequently formed front finger electrodes onto the substrate 100, and the fifth pressure areas essentially overlap with the orthographic projection of the subsequently formed front busbars onto the substrate 100.

[0138] Prior to performing sintering, the process may further include: printing a third paste onto the fourth print areas using a second screen printing process; and printing a fourth paste onto the fifth print areas using a fourth screen printing process. Performing sintering may include: performing sintering on the third paste to form front-side finger electrodes on the fourth print areas; and performing sintering on the fourth paste to form front-side busbars on the fifth print areas.

[0139] In some embodiments, the third paste and the fourth paste can be the same, that is, the material of the front finger electrodes and the material of the front busbars can be the same.

[0140] It should be noted that the order of the third and fourth screen printing processes can be reversed.

[0141] Based on the above, it is known that if the grid lines 101 are backside finger electrodes, the printing process of the solar cell includes at least the following situations: In some situations, the backside busbars, the contact structures 102 of the grid lines 101, the frontside busbars and the frontside finger electrodes can be formed using four printing processes and then sintered together, and finally, the printing process and curing treatment of the interconnect layers 103 of the grid lines 101 can be carried out.In some other situations, the rear busbars and the contact structures 102 of the grid lines 101 are formed using the same printing process; the front busbars and the front finger electrodes can be formed using two printing processes each, followed by a common sintering; and finally, the printing process and curing treatment of the interconnection layers 103 of the grid lines 101 are carried out. In some other situations, the contact structures 102 of the grid lines 101, the front busbars, and the front finger electrodes can be formed using three printing processes each, followed by a common sintering; then, the interconnection layers 103 of the grid lines 101 and the rear busbars can be formed using the same printing process; and finally, a curing treatment is carried out.

[0142] Some embodiments of the present disclosure provide for a tandem solar cell that includes the solar cell as illustrated in the preceding embodiments, or the solar cell formed using the method for manufacturing solar cells illustrated in the preceding embodiments. A detailed illustration of the tandem solar cell is provided below in conjunction with the accompanying drawings. It should be noted that parts that are identical or equivalent to those in the preceding embodiments are not repeated here.

[0143] Fig. As can be seen from page 14, Fig. Figure 14 shows a schematic cross-sectional view of a section of a tandem solar cell provided in some embodiments of the present disclosure. The tandem solar cell comprises a lower solar cell 106 and an upper solar cell 107 arranged on one side of the lower solar cell 106. The lower solar cell 106 encloses the solar cell as illustrated in the preceding embodiments, or the lower solar cell 106 is manufactured using the method illustrated in the preceding embodiments.

[0144] In some embodiments, the upper solar cell 107 can be made of perovskite solar cells, donor-acceptor solar cells, cadmium telluride solar cells (CdTe solar cells), copper indium gallium diselenide solar cells (CIGS solar cells) or gallium arsenide solar cells (GaAs solar cells).

[0145] In some embodiments, the upper solar cell 107 may comprise the following: a first transport layer, a perovskite substrate, a second transport layer, a transparent conductive layer, and an antireflection layer, stacked together. The first transport layer faces directly towards the lower solar cell 106.

[0146] In some embodiments, the first transport layer can be either an electron transport layer or a hole transport layer, and the second transport layer can be either the electron transport layer or the hole transport layer.

[0147] In some embodiments, the upper solar cell 107 has a band gap width that is larger than that of the lower solar cell 106. Therefore, stacking the upper solar cell 107 on top of the lower solar cell 106 can allow the tandem solar cell to have a wider spectral response range, thereby maximizing the use of solar energy and improving the efficiency of the solar cell.

[0148] In some embodiments, a back-contact tandem solar cell may further include an intermediate interconnect layer (not shown) which is arranged between the lower solar cell 106 and the upper solar cell 107 and is electrically connected to them.

[0149] In some embodiments, the interlinking layer is generally a tunnel junction or a very thin metal or transparent electrode recombination layer. In some embodiments, the interlinking layer can be a transparent conductive oxide exhibiting good optoelectronic properties, high photon transmission, and high conductivity, thereby maintaining good ohmic contact between the upper solar cell 107 and the lower solar cell 106.

[0150] In some other embodiments, the rear finger electrodes, the rear busbars, the front finger electrodes and the front busbars of the solar cell functioning as the lower solar cell 106 can also be used as intermediate connection layers for the electrical connection with the upper solar cell 107.

[0151] Some embodiments of the present disclosure provide for a photovoltaic module. The photovoltaic module includes a plurality of solar cells, as illustrated in the preceding embodiments, or includes a plurality of solar cells formed using the method for manufacturing solar cells, as illustrated in the preceding embodiments, or is formed by connecting a plurality of tandem solar cells, as illustrated in the preceding embodiments. The photovoltaic module is configured to convert received light energy into electrical energy. It should be noted that for parts that are the same as or correspond to those in the preceding embodiments, reference may be made to the corresponding illustration in the preceding embodiments, which are not repeated here.

[0152] How Fig. 15, Fig. 16 and Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12 to Fig. As can be seen from Figure 13, the photovoltaic module comprises the following: at least one solar cell string, at least one encapsulation adhesive film 41 configured to cover a surface of the at least one solar cell string, and at least one cover plate 42 configured to cover a surface of the at least one encapsulation adhesive film 41 facing away from the at least one solar cell string. The at least one solar cell string is formed by electrically connecting a plurality of solar cells 40 as illustrated in the preceding embodiments, or by electrically connecting a plurality of solar cells 40 formed using the method for manufacturing solar cells as illustrated in the preceding embodiments, or by electrically connecting a plurality of tandem solar cells as illustrated in the preceding embodiments.

[0153] Fig. Figure 15 is a schematic perspective view of a section of a cell string of a photovoltaic module, which is provided in some embodiments of the present disclosure, and Fig. Figure 16 is a schematic cross-sectional view of a section of the photovoltaic module provided in some embodiments of the present disclosure.

[0154] In some embodiments, solar cells 40 are electrically connected, either as a whole or as segments, to form a plurality of solar cell strings, and the plurality of solar cell strings are electrically connected in series and / or parallel. Each solar cell 40 can be a whole cell or a segmented cell, a segmented cell referring to a cell formed by cutting a whole cell.

[0155] In some embodiments, as Fig. 15 and Fig. 16 shows that the multitude of solar cells 40 are electrically connected using conductive strips 43. Fig. 15 and Fig.Figure 16 schematically shows a positional relationship between solar cells 40, that is, the grid lines of solar cells 40 with the same polarity are arranged in the same direction; in other words, the grid lines of each solar cell 40 with positive polarity are arranged so that they point in the same direction, such that a conductive strip 43 is connected to opposite sides of two adjacent solar cells 40. In some other embodiments, the electrodes of each solar cell with different polarities can be arranged so that they point in the same direction; that is, the electrodes of adjacent solar cells are arranged in the sequence of first polarity, second polarity, first polarity, and so on, and a conductive strip is connected to opposite sides of two adjacent solar cells.

[0156] In some embodiments, the at least one encapsulation adhesive film 41 comprises a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers one of the front and rear surfaces of the solar cell 40, and the second encapsulation layer covers the other of the front and rear surfaces of the solar cell 40. In particular, at least one of the first and second encapsulation layers can be an organic encapsulation film, such as a polyvinyl butyral adhesive film (PVB adhesive film), an ethylene vinyl acetate copolymer adhesive film (EVA adhesive film), a polyethylene octene elastomer adhesive film (POE adhesive film), or a polyethylene terephthalate adhesive film (PET adhesive film). Alternatively, at least one of the first and second encapsulation layers can also be an EP adhesive film, an EPE adhesive film, or a PVP adhesive film.EP adhesive film refers to a co-extruded adhesive film composed of stacked EVA and POE adhesive films. EPE adhesive film refers to a co-extruded adhesive film formed by sequentially stacked EVA, POE, and EVA adhesive films. PVP adhesive film refers to a co-extruded adhesive film formed by stacked POE, EVA, and POE adhesive films. The process for manufacturing co-extruded adhesive films may involve, during the production of the adhesive films, the sequential extrusion of one or more raw materials onto another type of adhesive film that has already been manufactured, or the joining of different types of adhesive films that have already been manufactured together.

[0157] In some cases, an interface exists between the first and second encapsulation layers prior to lamination. After lamination, the resulting photovoltaic module no longer has a first and second encapsulation layer; that is, the first and second encapsulation layers have formed an integrated encapsulation adhesive film 41.

[0158] In some embodiments, the cover plate 42 can be a transparent cover plate, such as a glass cover plate or a plastic cover plate. The surface of the cover plate 42 facing the encapsulation adhesive film 41 can be an uneven surface or a textured surface having a variety of protruding structures, thereby increasing the utilization rate of incident light. The at least one cover plate 42 includes a first cover plate and a second cover plate. The first cover plate faces the first encapsulation layer, and the second cover plate faces the second encapsulation layer.

[0159] Those skilled in the art will understand that the embodiments mentioned above are specific examples for implementing the present disclosure. In practice, various changes to the form and details can be made without altering the scope of protection of the present disclosure. Therefore, the scope of patent protection of the present disclosure is subject to the scope of protection defined in the accompanying claims.

Claims

Solar cell comprising: a substrate (100) having a first surface (110) and a second surface (120) opposite each other and each substantially perpendicular to a thickness direction (Z) of the substrate (100); and grid lines (101) arranged at intervals on at least one of the first surface (110) and the second surface (120) along a first direction (X), each grid line (101) having at least some of the grid lines (101) a respective contact structure (102) and a respective interconnect layer (103) electrically connected to the substrate (100), the respective contact structure (102) having a plurality of contact sections (112) arranged at intervals along a second direction (Y), the respective interconnect layer (103) being an elongated strip structure extending along the second direction (Y), and the first direction (X) intersecting the second direction (Y);wherein the respective interconnect layer (103) is electrically connected to the plurality of contact sections (112) and contains a material that differs from a material of the plurality of contact sections (112), and an orthographic projection of the respective interconnect layer (103) onto the substrate (100) partially overlaps with orthographic projections of the plurality of contact sections (112) onto the substrate (100);wherein the plurality of contact sections (112) includes first contact sections (122) and second contact sections (132) arranged alternately along the second direction (Y), and the respective connecting layer (103) includes a first side extending along the second direction (Y), a opposite second side extending along the second direction (Y), a first side section (113) extending along the second direction (Y) on the first side, and a second side section (123) extending along the second direction (Y) on the second side; and wherein the first contact sections (122) penetrate at least the first side section (113) and the second contact sections (132) penetrate at least the second side section (123). Solar cell according to claim 1, wherein in the second direction (Y) the first contact sections (122) are not aligned to the second contact sections (132). Solar cell according to claim 1, wherein in the second direction (Y) segments of the first contact sections (122) are aligned to segments of the second contact sections (132). Solar cell according to claim 3, wherein each first contact section of the first contact sections (122) includes a first segment (1221) and a second segment (1222), the first segment (1221) being oriented to the segments of the second contact sections (132) in the second direction (Y) and the second segment (1222) having a width of less than or equal to 25 µm in the first direction (X). Solar cell according to one of claims 1 to 4, wherein the orthographic projections of the plurality of contact sections (112) onto the substrate (100) have the form of circles, ellipses, triangles, rectangles, trapezoids or N-sided polygons, wherein N is a positive integer greater than 4. Solar cell according to one of claims 1 to 5, comprising finger electrodes (104) and busbars (105), wherein: the grid lines (101) are finger electrodes (104) and the busbars (105) are formed in the form of elongated strip structures extending along the first direction (X); or the grid lines (101) are busbars (105) and the finger electrodes (104) are formed in the form of elongated strip structures extending along the first direction (X). Solar cell according to one of claims 1 to 5, wherein the grid lines (101) are finger electrodes (104) and the solar cell further comprises: busbars (105) arranged at intervals on at least one of the first surface (110) and the second surface (120) along the second direction (Y), wherein each busbar of at least some of the busbars (105) comprises a respective connection structure (115) and a respective intermediate connection layer (125) that are in electrical contact with the substrate (100), the respective connection structure (115) comprising a plurality of connection sections (135) arranged at intervals along the first direction (X), and the respective intermediate connection layer (125) being an elongated strip structure extending along the first direction (X);wherein the respective intermediate interconnection layer (125) is in electrical connection with the plurality of interconnection sections (135), the plurality of interconnection sections (135) including first interconnection sections (145) and second interconnection sections (155) arranged alternately along the second direction (Y), and the respective intermediate interconnection layer (125) including a third side extending along the second direction, a opposite fourth side extending in the second direction, a third side section (165) extending along the second direction (Y) on the third side, and a fourth side section (175) extending along the second direction (Y) on the fourth side;and wherein the first connecting sections (145) penetrate at least the third side section (165), the second connecting sections (155) penetrate at least the fourth side section (175), and a material of the plurality of connecting sections (135) differs from a material of the respective intermediate connecting layer (125). Solar cell according to one of claims 1 to 7, wherein the plurality of contact sections (112) contains silver particles and the respective connecting layer (103) contains copper particles or silver-coated copper particles; and wherein the copper particles have diameters in the range of 50 nm to 1500 nm or the silver-coated copper particles have diameters in the range of 1 µm to 10 µm or a proportion of silver in the silver-coated copper particles is in the range of 15% to 50%. Tandem solar cell comprising: a lower solar cell (106), wherein the lower solar cell (106) comprises the solar cell according to any one of claims 1 to 8; and an upper solar cell (107) arranged on one side of the lower solar cell (106). Photovoltaic module comprising: at least one solar cell string, wherein the at least one solar cell string is formed by connecting a plurality of solar cells (40) according to any one of claims 1 to 8 or by connecting a plurality of tandem solar cells according to claim 9; at least one encapsulation adhesive film (41) covering the surface of the at least one cell string; and the at least one cover plate (42) configured to cover a surface of the at least one encapsulation adhesive film (41) facing away from the at least one cell string.

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