Photovoltaic cell and method of manufacturing the same, stacked cell, photovoltaic module

Abstract

The present disclosure relates to the field of photovoltaics, and provides a photovoltaic cell, a manufacturing method thereof, a laminated cell, and a photovoltaic module. The photovoltaic cell comprises a cell substrate, a first conductive part on at least one surface side of the cell substrate, and a second conductive part extending in a first direction, with each second conductive part connected to a plurality of first conductive parts arranged at intervals in the first direction. The second conductive part comprises first parts and second parts alternately connected in the first direction, the first parts comprising portions of the second conductive part connected to the first conductive parts, and the second parts comprising portions of the second conductive part above the intervals between adjacent first conductive parts. In a direction perpendicular to the first direction, the width of the first parts is greater than the width of the second parts, which is conducive to reducing the contact resistance between the first conductive parts and the second conductive parts, and reducing the shading effect of the second conductive parts.

Description

Technical Field

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

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

[0003] Current photovoltaic cells mainly include BC cells (Back Contact cells), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and real cell) cells, and heterojunction cells (Heterojunction with Intrinsic Thin-film, abbreviated as HIT or HJT). Summary of the Invention

[0004] This disclosure provides a photovoltaic cell and its manufacturing method, a tandem cell, and a photovoltaic module, which at least helps to reduce the shading effect of the second conductive part while reducing the contact resistance of the first conductive part and the second conductive part.

[0005] This disclosure provides a photovoltaic cell, comprising: a cell substrate; a first conductive portion located on at least one surface side of the cell substrate; a second conductive portion extending along a first direction, wherein a single second conductive portion is connected to a plurality of first conductive portions spaced apart along the first direction; wherein the second conductive portion includes a first portion and a second portion alternately connected along the first direction, the first portion including a portion of the second conductive portion connected to the first conductive portion, and the second portion including a portion of the second conductive portion located above the interval between two adjacent first conductive portions; and in a direction perpendicular to the first direction, the width of the first portion is greater than the width of the second portion.

[0006] Optionally, along the second direction, the thickness of the first part is less than the thickness of the second part, the second direction is the thickness direction of the battery substrate, and the second direction intersects with the first direction.

[0007] Optionally, at least a portion of the second part is in contact with the battery substrate; and / or, along a second direction, at least a portion of the second part has a gap with the battery substrate, the second direction being the thickness direction of the battery substrate, and the second direction intersects the first direction.

[0008] Optionally, along the second direction, the first part and the first conductive part overlap or partially coincide, the second direction being the thickness direction of the battery substrate, and the second direction intersects with the first direction.

[0009] Optionally, the battery substrate includes a substrate and a passivation antireflection layer located on the substrate, wherein the first conductive portion and the second conductive portion are both located on the side of the passivation antireflection layer away from the battery substrate, and along the first direction, a portion of the thickness of the first conductive portion is embedded in the battery substrate.

[0010] Optionally, the materials of the first conductive part and the second conductive part are different.

[0011] Optionally, a single second conductive portion and a plurality of first conductive portions connected thereto constitute a first electrode.

[0012] Optionally, the photovoltaic cell further includes: a second electrode extending upward along a third direction; wherein, along the first direction, the second electrode is located between two partially adjacent first conductive portions, and the first portion further includes a portion of the second conductive portion connected to the second electrode, and the third direction intersects with the first direction; or, the second electrode is located on the side of the second conductive portion away from the first conductive portion, and the second electrode is connected to a plurality of second conductive portions spaced apart along the third direction.

[0013] Optionally, along the first direction, the ratio of the spacing between at least a portion of adjacent first conductive portions to the width of the first conductive portion is 1 to 20.

[0014] Optionally, along the first direction, the spacing between at least a portion of adjacent first conductive portions is 20 μm to 200 μm; and / or, along the first direction, the width of the first conductive portion is 10 μm to 100 μm.

[0015] Optionally, along a direction perpendicular to the first direction, the ratio of the width of the second part to the width of the first part is less than or equal to 0.7.

[0016] Optionally, the first part and the first conductive part have a first contact angle, and the second part and the battery substrate have a second contact angle, wherein the first contact angle is smaller than the second contact angle.

[0017] Optionally, the porosity of the first part is greater than that of the second part.

[0018] Optionally, along a direction perpendicular to the first direction, the outer contour of the first part has a first boundary point and a second boundary point; along a second direction, the outer contour of the first part has a first vertex farthest from the battery substrate, the second direction is the thickness direction of the battery substrate, and the second direction intersects the first direction; wherein, taking the surface side as a reference plane, along the second direction, the height difference between the first boundary point and the first vertex is a first height, the height difference between the second boundary point and the first vertex is a second height, the height difference between the first vertex and the reference plane is a first reference height, the ratio of the first height to the first reference height is greater than or equal to 0.75, and the ratio of the second height to the first reference height is greater than or equal to 0.75.

[0019] Optionally, along a direction perpendicular to the first direction, the outer contour of the second part has opposing third and fourth boundary points; along a second direction, the outer contour of the second part has a second vertex furthest from the battery substrate, the second direction being the thickness direction of the battery substrate, and the second direction intersecting the first direction; wherein, taking the surface side as a reference plane, along the second direction, the height difference between the third boundary point and the second vertex is the third height, the height difference between the fourth boundary point and the second vertex is the fourth height, the height difference between the second vertex and the reference plane is the second reference height, the ratio of the third height to the second reference height is less than 0.75, and the ratio of the fourth height to the second reference height is less than 0.75.

[0020] This disclosure also provides a method for manufacturing a photovoltaic cell, comprising: providing a cell substrate; forming a first conductive portion on at least one surface side of the cell substrate; forming a second conductive portion on a surface jointly formed by the cell substrate and the first conductive portion; wherein the second conductive portion extends along a first direction, a single second conductive portion is connected to a plurality of first conductive portions spaced apart along the first direction, and the second conductive portion includes a first portion and a second portion alternately connected along the first direction, the first portion including a portion of the second conductive portion connected to the first conductive portion, and the second portion including a portion of the second conductive portion located above the interval between two adjacent first conductive portions; and in a direction perpendicular to the first direction, the width of the first portion is greater than the width of the second portion.

[0021] Optionally, the step of forming the second conductive portion includes: printing a second paste on the surface jointly formed by the battery substrate and the first conductive portion, wherein the adhesion force between the second paste and the first conductive portion is greater than the adhesion force between the second paste and the battery substrate; and curing the second paste so that the second paste connected to the first conductive portion becomes the first portion, and the second paste in contact with the battery substrate becomes the second portion.

[0022] Optionally, the step of curing the second slurry includes: exposing the second slurry to a xenon lamp and / or irradiating it with a laser to heat the second slurry.

[0023] In another aspect, this disclosure provides a tandem solar cell, comprising: a base cell, which is a photovoltaic cell as described in any of the preceding claims, or a photovoltaic cell formed by a method for manufacturing a photovoltaic cell as described in any of the preceding claims; and a perovskite cell located on one side of the base cell.

[0024] This disclosure also provides a photovoltaic module, comprising: a battery string, which is formed by connecting a plurality of photovoltaic cells as described in any one of the above claims, or by connecting a plurality of photovoltaic cells formed by a method for manufacturing photovoltaic cells as described in any one of the above claims, or by connecting a plurality of stacked cells as described in the above claims; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film opposite to the battery string.

[0025] The technical solution provided in this disclosure has at least the following advantages: The width of the first part is greater than the width of the second part, so that different areas of the second conductive part are arranged with alternating thicknesses along the first direction. This is beneficial for increasing the contact area between the second conductive part and the first conductive part by using the wider first part, thereby reducing the contact resistance between the second conductive part and the first conductive part. It is also beneficial for reducing the projected area of ​​the second conductive part on the battery substrate by using the narrower second part, thereby reducing the light-blocking effect caused by the second conductive part on the battery substrate. Attached Figure Description

[0026] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. Figure 2 A partial top-view scanning electron microscope image of a photovoltaic cell provided in an embodiment of this disclosure; Figure 3 for Figure 1 A schematic diagram of a partial cross-sectional structure of the photovoltaic cell shown along the first cross-section direction AA1; Figure 4 for Figure 1 A schematic diagram of a partial cross-sectional structure of the photovoltaic cell shown along the second cross-section direction BB1; Figure 5 for Figure 1 A schematic diagram of a partial cross-sectional structure of the photovoltaic cell shown along the third section direction CC1; Figure 6 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the second cross-sectional direction BB1 provided in an embodiment of the present disclosure; Figure 7 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the third cross-sectional direction CC1 provided in an embodiment of the present disclosure; Figure 8 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure; Figure 9 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure; Figure 10 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure; Figure 11 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the third cross-section direction CC1 provided in an embodiment of the present disclosure; Figure 12 This is a partial top view of another photovoltaic cell provided in an embodiment of the present disclosure; Figure 13 for Figure 12 A schematic diagram of a partial cross-sectional structure of the photovoltaic cell shown along the third section direction CC1; Figure 14 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 15 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure; Figure 16 This is a partially enlarged cross-sectional view of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure. Figure 17 This is a partially enlarged cross-sectional view of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure. Figure 18 A process flow diagram of a method for manufacturing a photovoltaic cell according to another embodiment of this disclosure; Figure 19 This is a partial cross-sectional view of a photovoltaic cell manufacturing method according to another embodiment of the present disclosure after the formation of the first conductive portion; Figure 20 This is a partial top view of the structure after printing the second paste in a method for manufacturing a photovoltaic cell according to another embodiment of the present disclosure. Figure 21 A partial cross-sectional schematic diagram of a stacked battery provided in yet another embodiment of this disclosure; Figure 22 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 23 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0028] Explanation of reference numerals in the attached figures: 100. Battery substrate; 110. Surface side; 120. Substrate; 130. Passivation and antireflection layer; 101. First conductive part; 102. Second conductive part; 112. First part; 1121. First sub-part; 1122. Second sub-part; 122. Second part; 103. Gap; 104. First electrode; 114. Second electrode; 105. First vertex; 115. First boundary point; 125. Second boundary point; 106. Second vertex; 116. Third boundary point; 126. Fourth boundary point; 107. Second slurry; 119. Base cell; 129. Perovskite cell; 40. Photovoltaic cell; 41. Encapsulating film; 42. Cover plate; 43. Solder ribbon. Detailed Implementation

[0029] As can be seen from the background technology, the structure of photovoltaic cells needs further research.

[0030] This disclosure provides a photovoltaic cell and its manufacturing method, a tandem cell, and a photovoltaic module. In the photovoltaic cell, the width of the first part is designed to be greater than the width of the second part, so that different regions of the second conductive part are arranged with alternating thicknesses along the first direction. This is beneficial for increasing the contact area between the second conductive part and the first conductive part by using the wider first part, thereby reducing the contact resistance between the second conductive part and the first conductive part. It is also beneficial for reducing the projected area of ​​the second conductive part on the cell substrate by using the narrower second part, thereby reducing the shading effect caused by the second conductive part on the cell substrate.

[0031] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more (including two), unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0032] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0034] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0035] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0036] In the description of the embodiments of this disclosure, electrical connection between one component and another means that both components are made of conductive materials, and the two components are in direct contact and connected or connected via other conductive materials. Therefore, when the photovoltaic module is generating electricity, current flows between the two components. Electrical contact between one component and another means that the two components are not only in contact, but also, because both components are made of conductive materials, current flows between the two components when the photovoltaic module is generating electricity.

[0037] In the description of embodiments of this disclosure, the terms "about," "approximately," "roughly," or "about" for a numerical value referring to a specific parameter include the numerical value, and those skilled in the art will understand that the deviation from the numerical value is within acceptable tolerances of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0038] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a portion of the edge of the entire surface.

[0039] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. When a component (such as a layer, film, region, or substrate) is described as being on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be an intermediate component between the two components. Conversely, when a component is described as being on the surface of another component, or a component is "directly" on another component, or another component is formed or disposed on the surface of a component, it indicates that there is no intermediate component between the two components. For simplicity and clarity, various components may be drawn at any scale. In the drawings, some components may be omitted for simplicity.

[0040] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "the component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0041] The “components” mentioned above can refer to layers, films, regions, parts, structures, etc.

[0042] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0043] This disclosure provides a photovoltaic cell according to one embodiment. The photovoltaic cell provided by this disclosure will be described in detail below with reference to the accompanying drawings.

[0044] Reference Figure 1 and Figure 2 The photovoltaic cell includes: a cell substrate 100; a first conductive portion 101 located on at least one surface side 110 of the cell substrate 100; and a second conductive portion 102 extending along a first direction X, wherein a single second conductive portion 102 is connected to a plurality of first conductive portions 101 spaced apart along the first direction X; wherein the second conductive portion 102 includes a first portion 112 and a second portion 122 alternately connected along the first direction X, the first portion 112 including a portion of the second conductive portion 102 connected to the first conductive portion 101, and the second portion 122 including a portion of the second conductive portion 102 located above the interval between two adjacent first conductive portions 101; and in a direction perpendicular to the first direction X, the width W1 of the first portion 112 is greater than the width W2 of the second portion 122.

[0045] in, Figure 1 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. Figure 2 This is a partial top-view scanning electron microscope image of a photovoltaic cell provided in an embodiment of this disclosure. It should be noted that... Figure 1 This example uses four first conductive parts 101 connected to a single second conductive part 102. In practical applications, the number of first conductive parts connected to a single second conductive part is not limited and can be adjusted according to specific needs, such as 10, 50, or 100. Furthermore, to clearly highlight the width relationship of different areas within the second conductive part 102... Figure 1 The second conductive part 102 is divided into a first part 112 and a second part 122 by a dashed line.

[0046] It is worth noting that the plurality of first conductive portions 101 arranged at intervals along the first direction X are used to collect photogenerated carriers generated in the battery substrate 100. A single second conductive portion 102 is connected to the plurality of first conductive portions 101 arranged at intervals along the first direction X. Thus, the second conductive portion 102 can at least be used to collect the photogenerated carriers collected by the first conductive portions 101. Furthermore, a single second conductive portion 102 includes a plurality of first portions 112 connected to the first conductive portions 101, and a second portion 122 spaced apart from two adjacent first portions 112. Based on this, the width W1 of the first part 112 is designed to be greater than the width W2 of the second part 122, so that different regions of the second conductive part 102 are arranged with alternating thicknesses along the first direction X. This is beneficial for increasing the contact area between the second conductive part 102 and the first conductive part 101 by using the wider first part 112, thereby reducing the contact resistance between the second conductive part 102 and the first conductive part 101 and improving the collection efficiency of charge carriers in the first conductive part 101 by the second conductive part 102. It is also beneficial for reducing the projected area of ​​the second conductive part 102 on the battery substrate 100 by using the narrower second part 122, thereby reducing the light-shielding area on the battery substrate 100 caused by the second conductive part 102, so that more areas of the battery substrate 100 are exposed to light.

[0047] In some cases, the connection between a single second conductive part 102 and a plurality of first conductive parts 101 arranged at intervals along the first direction X means that the single second conductive part 102 is in contact with and electrically connected to the plurality of first conductive parts 101, that is, the first part 112 is in contact with and electrically connected to the first conductive parts 101. It is worth noting that the contact and electrical connection between the first part 112 and the first conductive parts 101 actually means that both are made of conductive materials and are directly in contact with each other; therefore, when the photovoltaic cell is generating electricity, there is an electrical connection between them. In other cases, the connection between a single second conductive part and a plurality of first conductive parts can also mean that both the second conductive part and the first conductive part are made of conductive materials and are connected via other conductive materials; therefore, when the photovoltaic cell is generating electricity, there is an electrical connection between them. It should be noted that the connection of two components mentioned later can include both of the above situations, that is, two components in contact and electrically connected or two components electrically connected.

[0048] It is worth noting that, for a single first part 112, the widths of different regions within the first part 112 may be the same or different. For example, along the direction of the first part 112 closer to the second part 122, the width of the portion of the first part 112 closer to the second part 122 may gradually decrease. Similarly, for a single second part 122, the widths of different regions within the second part 122 may be the same or different. For example, along the direction of the second part 122 closer to the first part 112, the width of the portion of the second part 122 closer to the first part 112 may gradually increase.

[0049] Based on this, the fact that the width W1 of the first part 112 is greater than the width W2 of the second part 122 can include at least the following two cases: In some cases, the average width of multiple regions in the first part 112 is greater than the average width of multiple regions in the second part 122. The width W1 of the first part 112 can be measured using a sampling method. For example, a partial electron microscope (SEM) image of the area where the first part 112 is located can be taken, and 3 to 5 sampling areas can be selected in the first part 112. The width of each sampling area along the direction perpendicular to the first direction X can be measured, and the average value can be calculated as the width W1 of the first part 112. Furthermore, the measurement method for the width W2 of the second part 122 is roughly the same as that for the width W1 of the first part 112, and will not be described further here.

[0050] In other cases, the width corresponding to the minimum width in the first part 112 is greater than the width corresponding to the maximum width in the second part 122. The width of each region in the first part 112 or the second part 122 can be measured by taking a partial electron microscope (SEM) image of the region where the first part 112 or the second part 122 is located.

[0051] The photovoltaic cell provided in one embodiment of this disclosure will be described in more detail below with reference to the accompanying drawings.

[0052] In some embodiments, in conjunction with reference Figure 3 and Figure 4 Along the second direction Y, the thickness T1 of the first part 112 can be less than the thickness T2 of the second part 122. The second direction Y is the thickness direction of the battery substrate 100, and the second direction Y intersects with the first direction X.

[0053] in, Figure 3 for Figure 1 A schematic diagram of a partial cross-sectional structure of the photovoltaic cell shown along the first cross-section direction AA1; Figure 4 for Figure 1 The diagram shows a partial cross-sectional structure of the photovoltaic cell along the second cross-section direction BB1.

[0054] It is worth noting that, given that the width W1 of the first part 112 is greater than the width W2 of the second part 122, and the thickness T1 of the first part 112 is less than the thickness T2 of the second part 122, along a cross-section perpendicular to the first direction X, the connection point between the second conductive part 102 and the first conductive part 101, i.e., the first part 112, has a wide and low cross-sectional shape, while the second part 122 has a narrow and high cross-sectional shape. Thus, with the combination of width and thickness, the contact area between the first part 112 and the first conductive part 101 is increased, and the light-blocking effect of the second part 122 is reduced, while the difference in cross-sectional area between the first part 112 and the second part 122 is reduced. This reduces the difference in conductivity between the first part 112 and the second part 122, thereby improving the overall conductivity of the second conductive part 102.

[0055] It should be noted that, for a single first part 112, the thickness of different regions in the first part 112 may be the same or different. For example, along the direction of the first part 112 near the second part 122, the thickness of the portion of the first part 112 near the second part 122 may gradually increase. For a single second part 122, the thickness of different regions in the second part 122 may be the same or different. For example, along the direction of the second part 122 near the first part 112, the thickness of the portion of the second part 122 near the first part 112 may gradually decrease.

[0056] Based on this, the fact that the thickness T1 of the first part 112 is less than the thickness T2 of the second part 122 can include at least the following two cases: In some cases, the average thickness of multiple regions in the first part 112 is less than the average thickness of multiple regions in the second part 122. The thickness T1 of the first part 112 can be measured using a sampling method. For example, a partial electron microscope (SEM) image of the area where the first part 112 is located can be taken, and 3 to 5 sampling areas can be selected in the first part 112. The thickness of each sampling area along the second direction Y is measured, and the average value is calculated as the thickness T1 of the first part 112. Furthermore, the method for measuring the thickness T2 of the second part 122 is roughly the same as that for measuring the thickness T1 of the first part 112, and will not be described further here.

[0057] In other cases, the thickness corresponding to the maximum thickness in the first part 112 is less than the thickness corresponding to the minimum thickness in the second part 122. The thickness of each region in the first part 112 or the second part 122 can be measured by taking a partial electron microscope (SEM) image of the region where the first part 112 or the second part 122 is located.

[0058] In some embodiments, in conjunction with reference Figure 4 and Figure 5 , Figure 5 for Figure 1 The diagram shows a partial cross-sectional structure of a photovoltaic cell along the third cross-section direction CC1, where at least a portion of the second part 122 can contact the cell substrate 100.

[0059] It is worth noting that the connection between the first part 112 and the first conductive part 101 refers to an electrical connection between the first part 112 and the first conductive part 101. The first part 112 and the first conductive part 101 can be directly connected or connected via other conductive materials. In contrast, the contact between at least a portion of the second part 122 and the battery substrate 100 only indicates physical contact, but there is no electrical connection between the second part 122 and the battery substrate 100. In other words, the battery substrate 100 is only used to support at least a portion of the second part 122. At this time, there is no height difference between the battery substrate 100 and at least a portion of the second part 122 along the first direction X. It should be noted that the subsequent mention of contact between two components also indicates physical contact between the two components, but no electrical connection.

[0060] In other embodiments, in conjunction with reference to Figure 6 and Figure 7Along the second direction Y, at least a portion of the second part 122 has a gap 103 between it and the battery substrate 100. The second direction Y is the thickness direction of the battery substrate 100, and it intersects with the first direction X. In other words, at least a portion of the second part 122 is suspended above the battery substrate 100. At this time, there is a height difference between the battery substrate 100 and at least a portion of the second part 122 along the first direction X.

[0061] in, Figure 6 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the second cross-sectional direction BB1 provided in an embodiment of the present disclosure; Figure 7 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the third cross-sectional direction CC1, provided in an embodiment of this disclosure.

[0062] It should be noted that, due to the manufacturing process of the second conductive part 102, the height difference between the second part 122 and the battery substrate 100 at different locations in a single second conductive part 102 along the first direction X can be the same or different; the height difference between different regions in a single second part 122 and the battery substrate 100 can be the same or different. For example, along the direction of the second part 122 closer to the first part 112, the height difference between the second part 122 and the battery substrate 100 gradually decreases.

[0063] Figure 5 The example shown is that the second part 122 is in contact with the battery substrate 100. Figure 7 The example shown here is that the entire second part 122 and the battery substrate 100 have a gap 103. In actual applications, a portion of a single second part may be in contact with the battery substrate, while the remaining portion may have a gap with the battery substrate.

[0064] Furthermore, the situations in which the second direction Y intersects with the first direction X include: the second direction Y and the first direction X are orthogonal, or the angle formed by the second direction Y and the first direction X is an obtuse angle, or the angle formed by the second direction Y and the first direction X is an acute angle.

[0065] In some examples, the angle between the second direction Y and the first direction X can be between 10° and 90°, such as 10°, 20°, 45°, 55°, 70°, 82°, or 90°. In some specific examples, the angle between the second direction Y and the first direction X can be between 45° and 90°, such as 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 90°.

[0066] In some embodiments, in conjunction with reference Figure 3 , Figures 8 to 10Along the second direction Y, the first part 112 and the first conductive part 101 overlap or partially coincide. The second direction Y is the thickness direction of the battery substrate 100, and the second direction Y intersects with the first direction X.

[0067] It should be noted that the overlap or partial overlap between the first part 112 and the first conductive part 101 can include at least the following situations: In some cases, refer to Figure 3 The orthographic projection of the first part 112 on the battery substrate 100 is located in the orthographic projection of the first conductive part 101 on the battery substrate 100.

[0068] In other cases, refer to Figure 8 , Figure 8 This is a schematic diagram of another partial cross-sectional structure of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure. The orthographic projection of the first conductive part 101 on the cell substrate 100 is located in the orthographic projection of the first part 112 on the cell substrate 100. This is beneficial to ensure that the surface of the first conductive part 101 exposed outside the cell substrate 100 is covered by the first part 112, thereby maximizing the contact area between the first part 112 and the first conductive part 101.

[0069] In some other cases, refer to Figure 9 , Figure 9 This is a partial cross-sectional view of a photovoltaic cell provided in an embodiment of the present disclosure along the first cross-sectional direction AA1. The orthographic projection of the first part 112 on the cell substrate 100 coincides with the orthographic projection of the first conductive part 101 on the cell substrate 100.

[0070] In some other cases, refer to Figure 10 , Figure 10 This is a partial cross-sectional view of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of the present disclosure. The orthographic projection of the first part 112 on the cell substrate 100 only partially overlaps with the orthographic projection of the first conductive part 101 on the cell substrate 100.

[0071] It should be noted that the cases in which different first portions 112 of a single second conductive portion 102 coincide or overlap with the first conductive portion 101 along the second direction Y can be the same or different, and each can be one of the four cases described above. Furthermore, the cases in which different first portions 112 of different second conductive portions 102 coincide or overlap with the first conductive portion 101 along the second direction Y can also be the same or different, and each can also be one of the four cases described above.

[0072] In some embodiments, reference Figure 11 , Figure 11This is a partial cross-sectional view of a photovoltaic cell provided in an embodiment of the present disclosure along the third cross-sectional direction CC1. The cell substrate 100 may include a substrate 120 and a passivation antireflection layer 130 located on the substrate 120. The first conductive part 101 and the second conductive part 102 are both located on the side of the passivation antireflection layer 130 away from the cell substrate 100, and along the first direction X, a portion of the thickness of the first conductive part 101 is embedded in the cell substrate 100.

[0073] It should be noted that, in addition to the substrate 120 including doped portions (not shown in the figure) for generating and collecting photogenerated carriers, the battery substrate 100 generally also has a passivation antireflection layer 130 formed on the doped portions. The passivation antireflection layer 130 serves both to passivate and protect the doped portions and to improve the absorption and utilization rate of incident light. Furthermore, for the first conductive portion 101 used to collect photogenerated carriers generated by the substrate 120, a portion of the first conductive portion 101 is embedded in the battery substrate 100, which helps to ensure good contact performance between the first conductive portion 101 and the substrate 120. Unlike the first conductive portion 101, the second conductive portion 102 is only located on the side of the passivation antireflection layer 130 away from the battery substrate 100 and is not embedded in the passivation antireflection layer 130, thus avoiding the risk of increased carrier recombination area caused by ohmic contact between the second conductive portion 102 and the substrate 120.

[0074] Furthermore, the embedding of the first conductive portion 101 of a certain thickness into the battery substrate 100 can include at least the following two scenarios: In some cases, reference Figure 11 In some cases, the first conductive portion 101 of a certain thickness is embedded only in the passivation and antireflection layer 130 and is in contact with and electrically connected to the substrate 120; in other cases, the first conductive portion of a certain thickness is not only embedded in the passivation and antireflection layer, but also further embedded in the substrate, for example, embedded in the doped portion included in the substrate, so as to be electrically connected to the substrate.

[0075] In some embodiments, reference Figure 1 The materials of the first conductive part 101 and the second conductive part 102 may be different.

[0076] In some cases, the first conductive part 101 is typically made of silver paste, which includes metallic components and glass powder, such that the material of the first conductive part 101 includes at least a metallic component. The metallic component is silver or an alloy containing silver and other metals.

[0077] In some examples, the first conductive part 101 may include silver particles or silver alloy particles.

[0078] In one example, the silver content of the silver alloy particles in the first conductive part 101 can be greater than 50%, for example, it can be 51%~60%, 60%~70%, or 70%~80%. Preferably, the silver content of the silver alloy particles in the first conductive part 101 can be 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, or 69%, etc.

[0079] In some cases, the second conductive part 102 is typically made from a slurry containing no glass powder or a small amount of glass powder.

[0080] In some examples, the second conductive part 102 may include at least one of silver-coated copper particles, silver-coated nickel particles, silver-nickel alloy particles, copper particles, nickel particles, or silver-tin alloy particles.

[0081] In one example, the silver content of the silver-coated copper particles, silver-coated nickel particles, or silver-nickel alloy particles in the second conductive part 102 may be less than 50%, for example, it may be 40%~49%, 30%~40%, or 20%~30%. Preferably, the silver content of the silver-coated copper particles, silver-coated nickel particles, or silver-nickel alloy particles in the second conductive part 102 may be 49%, 48%, 47%, 46%, 45%, 44%, 43%, 42%, 41%, 40%, 39%, 38%, 37%, 36%, 35%, 34%, 33%, 32%, 31%, or 30%, etc.

[0082] The positional relationship between the first conductive part and the second conductive part will be explained in detail below.

[0083] In some embodiments, reference Figure 12 , Figure 12 This is a partial top view of another photovoltaic cell provided in an embodiment of the present disclosure. A single second conductive part 102 and a plurality of first conductive parts 101 connected thereto constitute a first electrode 104. The first electrode 104 can be regarded as a fine grid in the photovoltaic cell.

[0084] In some cases, continue to refer to Figure 12 The orthographic projection shape of a single first conductive part 101 on the battery substrate 100 can be a circle, an ellipse, a rectangle with chamfers (rounded corners), etc.; the orthographic projection shape of a single second conductive part 102 on the battery substrate 100 can be a strip, and the strip can vary in thickness along the first direction X.

[0085] The following describes in detail another electrode included in a photovoltaic cell when a single second conductive part and a plurality of first conductive parts connected thereto constitute the first electrode.

[0086] In some cases, in conjunction with references Figure 12 and Figure 13 , Figure 13 for Figure 12 The diagram shows a partial cross-sectional structure of a photovoltaic cell along the third cross-sectional direction CC1. The photovoltaic cell may further include a second electrode 114 extending upwards along the third direction Z; wherein, along the first direction X, the second electrode 114 is located between two partially adjacent first conductive portions 101, and the first portion 112 also includes a portion of the second conductive portion 102 connected to the second electrode 114. Thus, the second electrode 114 can be considered as the main grid in the photovoltaic cell.

[0087] The first part 112 can be divided into a first sub-part 1121 and a second sub-part 1122. The first sub-part 1121 is the portion of the second conductive part 102 that is connected to the first conductive part 101, and the second sub-part 1122 is the portion of the second conductive part 102 that is connected to the second electrode 114. It is worth noting that a single second electrode 114 can be connected to a plurality of second conductive parts 102 arranged at intervals along the third direction Z, and a single second conductive part 102 can be connected to a plurality of second electrodes 114 arranged at intervals along the first direction X. Thus, although a single second electrode 114 is connected to one of the second sub-parts 1122 of a single second conductive part 102, a single second electrode 114 will also be connected to the second sub-parts 1122 of the plurality of second conductive parts 102.

[0088] In some examples, multiple first sub-parts 1121 may be spaced apart between two adjacent second sub-parts 1122 along the first direction X. In other words, the second sub-parts 1122 are interspersed among the multiple first sub-parts 1121.

[0089] It should be noted that, within the same second conductive portion 102, along the first direction X, the spacing between two adjacent first sub-portions 1121 can be equal to or unequal to the spacing between adjacent first sub-portions 1121 and second sub-portions 1122. Furthermore, Figure 12 The example only shows that there are 4 first conductive parts 101 connected to a single second conductive part 102, and one second electrode 114 is interspersed among them.

[0090] Furthermore, the third direction Z, the second direction Y, and the first direction X intersect each other pairwise. In one example, the third direction Z, the second direction Y, and the first direction X can be orthogonal to each other. In practical applications, the angle formed by any two of the first, second, and third directions can be either acute or obtuse. The cases where the second direction Y intersects the third direction Z, and the cases where the first direction X intersects the third direction Z, are similar to the cases where the first direction X intersects the second direction Y, and will not be elaborated further here. The following example uses the orthogonality of the first direction X and the third direction Z.

[0091] In other cases, refer to Figure 14 , Figure 14 This is a partial top view of another photovoltaic cell provided in an embodiment of the present disclosure. The photovoltaic cell may further include: a second electrode 114 extending upward along a third direction Z; the second electrode 114 is located on the side of the second conductive portion 102 away from the first conductive portion 101, and the second electrode 114 is connected to a plurality of second conductive portions 102 arranged at intervals along the third direction Z. Thus, the first portion 112 of the second conductive portion 102 is only the portion of the second conductive portion 102 connected to the first conductive portion 101; the second electrode 114 overlaps the second conductive portion 102, and has almost no contact with the first conductive portion 101. The second electrode 114 can be considered as the main grid in the photovoltaic cell.

[0092] It should be noted that, in order to clearly illustrate the positional relationship between the second electrode 114 and the second conductive part 102, Figure 14 The second electrode 114 is drawn using a perspective drawing method.

[0093] In both of the above scenarios, the positional relationship between the second electrode and the battery substrate includes at least the following two examples: In some examples, refer to Figure 13 The battery substrate 100 may include a substrate 120 and a passivation and antireflection layer 130 located on the substrate 120. Similar to the first conductive portion 101, a second electrode 114 of a certain thickness is embedded in the battery substrate 100 along the first direction X to contact and electrically connect with the battery substrate 100. In this way, the second electrode 114 can not only collect carriers in the second conductive portion 102 through the region connected to the second conductive portion 102, but also directly collect photogenerated carriers generated in the substrate 120 by itself.

[0094] In other examples, the second electrode may be located only on the battery substrate and not embedded in it, and the second electrode collects charge carriers in the second conductive portion through a region connected to the second conductive portion.

[0095] In other embodiments, reference is made to... Figure 15 , Figure 15 This is a partial top view of a photovoltaic cell provided in an embodiment of the present disclosure. The first conductive part 101 is a first electrode 104 extending along a third direction, and the second conductive part 102 is a second electrode 114. The third direction Z, the second direction Y, and the first direction X intersect each other. It is worth noting that the orthographic projection shape of the first conductive part 101 and the second conductive part 102 on the cell substrate 100 can both be elongated strips.

[0096] The specific structure of the first conductive part or the second conductive part will be described in detail below.

[0097] In some embodiments, reference Figure 7 or Figure 13 Along the first direction X, the ratio of the spacing D between at least a portion of adjacent first conductive portions 101 to the width W3 of the first conductive portion 101 can be 1 to 20, for example, 1 to 5, 5 to 10, 10 to 15, or 15 to 20. Optionally, the ratio of the spacing D between at least a portion of adjacent first conductive portions 101 to the width W3 of the first conductive portion 101 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, etc.

[0098] Along the first direction X, when the length of the second conductive portion 102 is constant, on the one hand, the spacing D between adjacent first conductive portions 101 has a decisive influence on the number of first conductive portions 101 connected to a single second conductive portion 102, and on the other hand, it has a decisive influence on the length of the second portion 122 located above the interval between two adjacent first conductive portions 101 in the second conductive portion 102. Based on this, if the ratio of the distance D between at least a portion of adjacent first conductive portions 101 to the width W3 of the first conductive portion 101 is less than 1, the number of first conductive portions 101 connected to a single second conductive portion 102 will be larger, which is not conducive to reducing the area of ​​electrical connection between the second conductive portion 102 and the battery substrate 100, and is not conducive to reducing the carrier recombination area; if the ratio of the distance D between at least a portion of adjacent first conductive portions 101 to the width W3 of the first conductive portion 101 is greater than 10, the length of a single second portion 122 will be longer, making it prone to breakage, and when at least a portion of the second portion 122 is suspended on the battery substrate 100, it is prone to collapse.

[0099] Thus, designing the ratio of the spacing D between at least a portion of the adjacent first conductive portions 101 to the width W3 of the first conductive portion 101 to be 1 to 20 is beneficial for controlling the number of first conductive portions 101 connected to a single second conductive portion 102 to be within a suitable range, ensuring a low recombination area of ​​charge carriers, and improving the structural stability of the second portion 122, thereby improving the yield of the second conductive portion 102.

[0100] It should be noted that in some cases, reference Figure 13Along the first direction X, a second electrode 114 is disposed between some adjacent first conductive portions 101, while no other conductive components are disposed between the remaining adjacent first conductive portions 101. Therefore, the spacing D between at least a portion of the adjacent first conductive portions 101 refers to the spacing between adjacent first conductive portions 101 along the first direction X that do not have a second electrode 114 inserted in between. In some examples, the spacing between the second electrode 114 and its adjacent first conductive portion 101 along the first direction X may also be equal to the spacing D between at least a portion of the adjacent first conductive portions 101. Figure 13 The spacing between two adjacent first conductive parts 101 and the spacing between the second electrode 114 and its adjacent first conductive part 101 are both marked as D.

[0101] In some cases, refer to Figure 7 Along the first direction X, no other conductive components are provided between adjacent first conductive parts 101. Based on this, the spacing D between at least a portion of adjacent first conductive parts 101 refers to the spacing between two adjacent first conductive parts 101 along the first direction X.

[0102] Furthermore, the spacing D between at least a portion of adjacent first conductive portions 101 can be measured using a sampling method. For example, partial top-view electron micrographs (SEM) of the area where multiple first conductive portions 101 are located can be taken, and 3 to 5 sampling points can be selected from each of two adjacent first conductive portions 101. The spacing between two adjacent sampling points along the first direction X can be measured, and the average value can be calculated as the spacing D between at least a portion of adjacent first conductive portions 101. Furthermore, the method for measuring the width W3 of the first conductive portion 101 is roughly the same as the method for measuring the spacing D between adjacent first conductive portions 101, and will not be described further here.

[0103] In some cases, refer to Figure 7 or Figure 13Along the first direction X, the spacing D between at least a portion of adjacent first conductive portions 101 can be 20μm to 200μm, for example, it can be 20μm to 50μm, 50μm to 100μm, 100μm to 150μm, or 150μm to 200μm. Optionally, the spacing D between at least a portion of adjacent first conductive portions 101 can be 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, or 200μm, etc. This allows the number of first conductive portions 101 connected to a single second conductive portion 102 to be within a suitable range on the limited layout area of ​​the currently widely used battery substrate 100, ensuring a low recombination area of ​​charge carriers and improving the structural stability of the second portion 122, thereby increasing the yield of the second conductive portion 102.

[0104] In some cases, the width W3 of the first conductive portion 101 along the first direction X can be 10μm to 100μm, for example, 10μm to 50μm or 50μm to 100μm. Optionally, the width W3 of the first conductive portion 101 can be 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm, etc. This helps to ensure that a suitable electrical connection area exists between the individual first conductive portion 101 and the battery substrate 100, and ensures that the first conductive portion 101 has good collection efficiency for photogenerated carriers in the battery substrate 100.

[0105] The first and second parts of the second conductive part will be described in detail below.

[0106] In some embodiments, reference Figure 1 Along the direction perpendicular to the first direction X, the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 is less than or equal to 0.7.

[0107] The width W1 of the first part 112 has a decisive influence on the contact resistance between the second conductive part 102 and the individual first conductive part 101, and the width W2 of the second part 122 has a decisive influence on the light-shielding area of ​​the second part 122 on the battery substrate 100. Therefore, if the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 is greater than 0.7, the difference in width between the second part 122 and the first part 112 is not significant, which is not conducive to balancing the small contact resistance between the second conductive part 102 and the individual first conductive part 101 and reducing the light-shielding area of ​​the second part 122 on the battery substrate 100.

[0108] In other words, by designing the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 to be less than or equal to 0.7, the second part 122 and the first part 112 can have a larger difference in width. This increases the contact area between the second conductive part 102 and the individual first conductive part 101, thereby reducing the contact resistance between the second conductive part 102 and the individual first conductive part 101, while also reducing the light-shielding area of ​​the second part 122 on the battery substrate 100.

[0109] In some cases, the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 can be greater than or equal to 0.3. This helps to avoid an excessive difference in width between the second part 122 and the first part 112, reducing the light-shielding area of ​​the second part 122 on the battery substrate 100 while ensuring sufficient contact area between the second conductive part 102 and the individual first conductive part 101, and preventing the second part 122 from breaking due to being too narrow. Thus, the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 is 0.3 to 0.7.

[0110] In some examples, the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 can be 0.3~0.4, 0.4~0.5, 0.5~0.6 or 0.6~0.7. Optionally, the ratio of the width W2 of the second part 122 to the width W1 of the first part 112 can be 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, or 0.7, etc.

[0111] In some examples, the width W1 of the first part 112 can be 5μm to 200μm, for example, it can be 5μm to 50μm, 50μm to 100μm, 100μm to 150μm or 150μm to 200μm. Optionally, the width W1 of the first part 112 can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, 140μm, 145μm, 150μm, 155μm, 160μm, 165μm, 170μm, 175μm, 180μm, 185μm, 190μm, 195μm, or 200μm, etc.

[0112] In some examples, the width W2 of the second part 122 can be 1.5μm to 140μm, for example, it can be 1.5μm to 30μm, 30μm to 60μm, 60μm to 90μm, 90μm to 110μm or 110μm to 140μm. Optionally, the width W1 of the first part 112 can be 1.5μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, or 140μm, etc.

[0113] In some embodiments, in conjunction with reference Figure 16 and Figure 17 The first part 112 and the first conductive part 101 have a first contact angle β1, and the second part 122 and the battery substrate 100 have a second contact angle β2. The first contact angle β1 is smaller than the second contact angle β2.

[0114] in, Figure 16 This is a partially enlarged cross-sectional view of a photovoltaic cell along the first cross-sectional direction AA1 provided in an embodiment of this disclosure. Figure 17 This is a partially enlarged cross-sectional view of a photovoltaic cell along the first cross-sectional direction AA1, provided in an embodiment of this disclosure.

[0115] It should be noted that, along a direction perpendicular to the first direction X, for example along the third direction Z, the first part 112 has two opposing side profiles. The first contact angle β1 between the first part 112 and the first conductive part 101 can be measured by sampling. For example, a partial electron microscope (SEM) schematic diagram of the contact area between the first part 112 and the first conductive part 101 can be taken, and 3 to 5 sampling points can be selected on the two opposing side profiles of the first part 112 respectively. The angle between the tangent at the profile where each sampling point is located and the plane approximately where the first conductive part 101 is located can be measured, and the average value can be calculated as the first contact angle β1.

[0116] Along a direction perpendicular to the first direction X, for example along the third direction Z, the second part 122 has two opposing side profiles. The second contact angle β2 between the second part 122 and the battery substrate 100 can be measured by sampling. For example, a partial electron microscope (SEM) schematic diagram of the contact area between the second part 122 and the battery substrate 100 can be taken, and 3 to 5 sampling points can be selected on the two opposing side profiles of the second part 122 respectively. The angle between the tangent at the profile where each sampling point is located and the plane approximately where the battery substrate 100 is located can be measured, and the average value can be calculated as the second contact angle β2.

[0117] Designing the first contact angle β1 to be smaller than the second contact angle β2 has two advantages. First, it helps the first part 112 to have a wide and low cross-sectional shape, thereby maximizing the contact area between the first part 112 and the first conductive part 101 while keeping the volume of the first part 112 constant. Second, it helps the second part 122 to have a narrow and high cross-sectional shape, thereby minimizing the light-shielding area of ​​the second part 122 on the battery substrate 100 while keeping the volume of the first part 112 constant.

[0118] In some cases, the first contact angle β1 is less than 90°. For example, the first contact angle β1 can be 80°~89°, 70°~80°, 60°~70°, 50°~60°, 40°~50°, 30°~40°, 20°~30°, or 10°~20°. Optionally, the first contact angle β1 can be 89°, 85°, 80°, 75°, 70°, 65°, 60°, 55°, 50°, 45°, 40°, 35°, 30°, 25°, 20°, 15°, or 10°, etc. In this way, along the cross-section perpendicular to the first direction X, it is beneficial to make the overall outer contour of the cross-sectional shape of the first part 112 approximately an inferior arc shape, a triangle, or a trapezoid, etc.

[0119] It should be noted that there are also metal particles inside the first part 112. Although the first contact angle β1 between the first part 112 as a whole and the first conductive part 101 is less than 90°, the contact angle between the metal particles inside the first part 112 and the first conductive part 101 can be greater than 90°.

[0120] In some cases, the second contact angle β2 is greater than or equal to 90°. For example, the second contact angle β2 can be 90°~100°, 100°~110°, 110°~120°, 120°~130°, 130°~140°, 140°~150°, 150°~160°, or 160°~170°. Optionally, the second contact angle β2 can be 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, or 170°, etc. In this way, along the cross-section perpendicular to the first direction X, it is beneficial to make the overall outer contour of the cross-sectional shape of the second part 122 approximately circular or elliptical.

[0121] In some embodiments, reference Figure 1 The porosity of the first part 112 can be greater than that of the second part 122. This results in a greater compactness within the second part 122, which, without affecting its conductivity, helps to further reduce the light-blocking area of ​​the second part 122 on the battery substrate 100 and improves the structural stability of the second part 122 to further prevent breakage or collapse. Furthermore, charge carriers are transported from the first conductive part 101 to the second part 122 via the first part 112. The first part 112 acts as an intermediate bridge for charge carrier transport from the first conductive part 101 to the second part 122. Appropriately increasing the porosity of the first part 112 helps to provide more transport paths for charge carriers, such as a mesh-like transport network.

[0122] It should be noted that the porosity of the first part 112 can be measured in the following ways: the first part 112 can be cut by means of ion milling to obtain a sample of the first part 112; the cross-sectional morphology of the first part 112 can be obtained by SEM (scanning electron microscope) or TEM (transmission electron microscope); then the porosity of the first part 112 can be calculated by means of camera algorithm or area matting; or, the sample of the first part 112 can be reconstructed in three dimensions by X-ray microtomography to quantitatively analyze the porosity of the first part 112; or, the sample of the first part 112 can be cut and imaged layer by layer by using a combination of focused ion beam and scanning electron microscope, and finally the 3D pore network can be reconstructed to quantitatively analyze the porosity of the first part 112. Furthermore, the porosity of the first part 112 can be evaluated by utilizing the propagation characteristics of air-coupled ultrasonic waves in a porous medium layer; or, the porosity of the first part 112 can be evaluated by analyzing X-ray diffraction patterns, utilizing the phenomenon of X-ray scattering in a porous medium layer.

[0123] Furthermore, the method for measuring the porosity of the second part 122 is roughly the same as that for measuring the porosity of the first part 112, and will not be described again here.

[0124] In some cases, the porosity of the first part 112 can be greater than 20%, for example, it can be 21%~30%, 30%~40%, 40%~50%, 50%~60%, 60%~70%, 70%~80%, or 80%~90%. Optionally, the porosity of the first part 112 can be 21%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%, etc.

[0125] In some cases, the porosity of the second part 122 can be less than or equal to 20%, for example, it can be 15%~20%, 10%~15%, or 5%~10%. Optionally, the porosity of the second part 122 can be 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, or 5%, etc.

[0126] In some embodiments, reference Figure 16Along a direction perpendicular to the first direction X, the outer contour of the first part 112 has a first boundary point 115 and a second boundary point 125; along the second direction Y, the outer contour of the first part 112 has a first vertex 105 that is farthest from the battery substrate 100, the second direction Y is the thickness direction of the battery substrate 100, and the second direction Y intersects the first direction X; wherein, taking the surface side 110 as the reference plane, along the second direction Y, the height difference between the first boundary point 115 and the first vertex 105 is the first height H1, the height difference between the second boundary point 125 and the first vertex 105 is the second height H2, and the height difference between the first vertex 105 and the reference plane is the first reference height RH1.

[0127] It should be noted that, Figure 16 The reference plane is indicated by a dashed line. The first vertex 105, the first boundary point 115, and the second boundary point 125 are parallel to the reference plane.

[0128] The ratio of the first height H1 to the first reference height RH1 can be greater than or equal to 0.75, for example, it can be 0.75~0.8, 0.8~0.85, 0.85~0.9, or 0.9~0.95; optionally, the ratio of the first height H1 to the first reference height RH1 can be 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, or 0.95, etc.

[0129] The ratio of the second height H2 to the first reference height RH1 can be greater than or equal to 0.75, for example, it can be 0.75~0.8, 0.8~0.85, 0.85~0.9, or 0.9~0.95; optionally, the ratio of the second height H2 to the first reference height RH1 can be 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, or 0.95, etc.

[0130] This helps to ensure that the first contact angle β1 between the first part 112 and the first conductive part 101 is less than 90°, and to ensure that the outer contour of the cross-sectional shape of the first part 112 along the cross-section perpendicular to the first direction X is approximately circular or elliptical.

[0131] It is worth noting that the cross-sectional shape of the second conductive part 102 along the cross-section perpendicular to the first direction X is actually irregular, but it can be approximated as a partially regular shape. For example, the outer contour of the cross-sectional shape of the first part 112 is approximately circular or elliptical, and the cross-sectional shape of the second conductive part 102 is different at different locations. Based on this, when the width W1 of the first part 112 is measured by sampling, the sampling area in the first part 112 includes the first boundary point 115 and the second boundary point 125 of the outer contour of the cross-section of the first part 112. The width of the sampling area along the direction perpendicular to the first direction X refers to the distance between the first boundary point 115 and the second boundary point 125 along the direction perpendicular to the first direction X.

[0132] It should be noted that the reference Figure 12 or Figure 14 When a single second conductive part 102 and a plurality of first conductive parts 101 connected thereto form a first electrode 104, the relevant dimensions of the outer contour of the first part 112 have the above-mentioned characteristics not only in the direction perpendicular to the first direction X, but also in the direction along the first direction X.

[0133] In some embodiments, reference Figure 17 Along the first direction X, the outer contour of the second part 122 has a relative third boundary point 116 and a fourth boundary point 126; along the second direction Y, the outer contour of the second part 122 has a second vertex 106 that is farthest from the battery substrate 100, the second direction Y is the thickness direction of the battery substrate 100, and the second direction Y intersects the first direction X; wherein, with the surface side 110 as the reference plane, along the second direction Y, the height difference between the third boundary point 116 and the second vertex 106 is the third height H3, the height difference between the fourth boundary point 126 and the second vertex 106 is the fourth height H4, and the height difference between the second vertex 106 and the reference plane is the second reference height RH2.

[0134] It should be noted that, Figure 17 The reference plane is indicated by a dashed line. The second vertex 106, the third boundary point 116, and the fourth boundary point 126 are parallel to the reference plane.

[0135] The ratio of the third height H3 to the second reference height RH2 can be less than 0.75, for example, it can be 0.7~0.74, 0.65~0.7, 0.6~0.65, 0.55~0.6, 0.5~0.55, 0.45~0.5, or 0.4~0.45; optionally, the ratio of the third height H3 to the second reference height RH2 can be 0.74, 0.73, 0.72, 0.71, or 0.7. 0.69, 0.68, 0.67, 0.66, 0.65, 0.64, 0.63, 0.62, 0.61, 0.6, 0.59, 0.58, 0.57, 0.56, 0.55, 0.54, 0.53, 0.52, 0.51, 0.5, 0.49, 0.48, 0.47, 0.46, 0.45, 0.44, 0.43, 0.42, 0.41, or 0.4, etc.

[0136] The ratio of the fourth height H4 to the second reference height RH2 can be less than 0.75, for example, it can be 0.7~0.74, 0.65~0.7, 0.6~0.65, 0.55~0.6, 0.5~0.55, 0.45~0.5, or 0.4~0.45; optionally, the ratio of the fourth height H4 to the second reference height RH2 can be 0.74, 0.73, 0.72, 0.71, 0.7, ... 0.69, 0.68, 0.67, 0.66, 0.65, 0.64, 0.63, 0.62, 0.61, 0.6, 0.59, 0.58, 0.57, 0.56, 0.55, 0.54, 0.53, 0.52, 0.51, 0.5, 0.49, 0.48, 0.47, 0.46, 0.45, 0.44, 0.43, 0.42, 0.41, or 0.4, etc.

[0137] This helps to ensure that the second contact angle β2 between the second part 122 and the battery substrate 100 is greater than or equal to 90°, and to ensure that the overall outer contour of the cross-sectional shape of the second part 122 along the cross-section perpendicular to the first direction X is approximately circular or elliptical.

[0138] It is worth noting that the cross-sectional shape of the second conductive part 102 along the section perpendicular to the first direction X is actually irregular, but it can be approximated as a partially regular shape. For example, the outer contour of the cross-sectional shape of the second part 122 is approximately circular or elliptical, and the cross-sectional shape is different at different locations of the second conductive part 102. Based on this, when measuring the width W2 of the second part 122 by sampling, the sampling area in the second part 122 includes the third boundary point 116 and the fourth boundary point 126 of the outer contour of the cross-section of the second part 122. The width of the sampling area along the direction perpendicular to the first direction X refers to the distance between the third boundary point 116 and the fourth boundary point 126 along the direction perpendicular to the first direction X.

[0139] It should be noted that the reference Figure 12 or Figure 14 When a single second conductive part 102 and a plurality of first conductive parts 101 connected thereto form a first electrode 104, the relevant dimensions of the outer contour of the second part 122 have the above-mentioned characteristics not only in the direction perpendicular to the first direction X, but also in the direction along the first direction X.

[0140] In summary, the width W1 of the first part 112 is greater than the width W2 of the second part 122, so that different regions of the second conductive part 102 are arranged with alternating thicknesses along the first direction X. This is beneficial for increasing the contact area between the second conductive part 102 and the first conductive part 101 by using the wider first part 112, thereby reducing the contact resistance between the second conductive part 102 and the first conductive part 101. It is also beneficial for reducing the projected area of ​​the second conductive part 102 on the battery substrate 100 by using the narrower second part 122, thereby reducing the light-blocking effect of the second conductive part 102 on the battery substrate 100.

[0141] Another embodiment of this disclosure provides a method for manufacturing a photovoltaic cell, used to form the photovoltaic cell provided in the foregoing embodiment. The manufacturing method of the photovoltaic cell provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0142] refer to Figure 18 , Figure 18 This is a process flow diagram of a method for manufacturing a photovoltaic cell according to another embodiment of the present disclosure. The method for manufacturing a photovoltaic cell includes at least the following steps: S1: Provides battery substrate 100.

[0143] S2: A first conductive portion 101 is formed on at least one surface side 110 of the battery substrate 100.

[0144] S3: A second conductive portion 102 is formed on the surface jointly formed by the battery substrate 100 and the first conductive portion 101.

[0145] The second conductive portion 102 extends along the first direction X. Each second conductive portion 102 is connected to a plurality of first conductive portions 101 arranged at intervals along the first direction X. The second conductive portion 102 includes a first portion 112 and a second portion 122 that are alternately connected along the first direction X. The first portion 112 includes the portion of the second conductive portion 102 that is connected to the first conductive portion 101. The second portion 122 includes the portion of the second conductive portion 102 that is located above the interval between two adjacent first conductive portions 101. In a direction perpendicular to the first direction X, the width W1 of the first portion 112 is greater than the width W2 of the second portion 122.

[0146] The method for forming the first conductive part 101 will be described in detail below.

[0147] In some embodiments, reference Figure 19 , Figure 19 This is a partial cross-sectional view of a photovoltaic cell manufacturing method according to another embodiment of the present disclosure, after the first conductive portion has been formed.

[0148] A first paste (not shown) is printed on at least one surface side 110 of the battery substrate 100; the first paste is then dried and sintered, or directly sintered, to transform the first paste into a first conductive portion 101. Thus, after sintering, the metal particles in the first paste melt and recrystallize to form a blocky and dense first conductive portion 101.

[0149] In some cases, the first paste can be silver paste.

[0150] The method for forming the second conductive part 102 will be described in detail below.

[0151] In some embodiments, in conjunction with reference Figure 20 and Figure 1 , Figure 20 This is a partial top view of a photovoltaic cell manufacturing method provided in another embodiment of the present disclosure after printing a second paste. The step of forming the second conductive part 102 may include: printing a second paste 107 on the surface jointly formed by the cell substrate 100 and the first conductive part 101, wherein the adhesion force between the second paste 107 and the first conductive part 101 is greater than the adhesion force between the second paste 107 and the cell substrate 100; and performing a curing treatment on the second paste 107, such that the second paste 107 connected to the first conductive part 101 is transformed into a first part 112, and the second paste 107 in contact with the cell substrate 100 is transformed into a second part 122.

[0152] It should be noted that, in order to clearly illustrate the positional relationship between the second slurry 107 and the first conductive part 101, Figure 20 The second slurry 107 is drawn using a perspective drawing method.

[0153] It is worth noting that the adhesion force between the second slurry 107 and the first conductive part 101 is greater than the adhesion force between the second slurry 107 and the battery substrate 100. Based on this, in the step of curing the second slurry 107, the resistance to shrinkage and curing caused by the first conductive part 101 is greater than the resistance caused by the battery substrate 100, resulting in a greater degree of shrinkage in the portion of the second slurry 107 in contact with the first conductive part 101 than in the portion in contact with the battery substrate 100. In other words, by utilizing the difference in adhesion force between the second slurry 107 and the first conductive part 101 and the battery substrate 100, the portion of the second slurry 107 in contact with the battery substrate 100 undergoes significant shrinkage during the curing process, resulting in a smaller light-blocking area on the battery substrate 100, while the portion of the second slurry 107 in contact with the first conductive part 101 does not undergo significant shrinkage, ensuring a good contact area between the second slurry 107 and the first conductive part 101. Furthermore, it is advantageous to form a second conductive portion 102 in which the width W1 of the first portion 112 is greater than the width W2 of the second portion 122.

[0154] In some cases, the printed second paste 107 can be dried before curing.

[0155] It should be noted that, regardless of whether the printed second paste 107 is dried beforehand, before the curing process, the width of the second paste 107 in contact with the first conductive part 101 along the direction perpendicular to the first direction X is not significantly different from the width of the second paste 107 in contact with the battery substrate 100. The metal particles in the second paste 107 are independent of each other, or multiple metal particles are interconnected. During the curing process of the second paste 107, the metal particles melt upon heating and reconnect or fuse based on mechanisms such as surface diffusion or grain boundary diffusion. During this process, the portion of the second paste 107 in contact with the first conductive part 101 experiences stronger adhesion, thus limiting the narrowing of its width. Conversely, the portion of the second paste 107 in contact with the battery substrate 100 experiences weaker adhesion, thus allowing for significant narrowing of its width, and this portion may detach from the battery substrate 100. In this way, it is easy to make the first contact angle β1 between the first part 112 and the first conductive part 101 smaller than the second contact angle β2 between the second part 122 and the battery substrate 100.

[0156] In some cases, the step of curing the second slurry 107 may include exposing the second slurry 107 to a xenon lamp and / or laser irradiation to heat the second slurry 107.

[0157] In some examples, while the second slurry 107 is exposed to xenon lamps or lasers, at least one of the following heating methods can be used to supplement the heating of the second slurry 107: contact heating, hot air heating, resistance wire thermal radiation heating, or infrared radiation heating.

[0158] In some examples, the second slurry 107 includes at least one of silver-coated copper particles, silver-coated nickel particles, or silver-nickel alloy particles.

[0159] It is worth noting that, for the second slurry 107, which is a low-temperature slurry, the purpose of curing the second slurry 107 includes: evaporation of organic solvents in the second slurry 107, causing volume shrinkage of the second slurry 107; curing of the resin in the second slurry 107; and contact between metal particles in the second slurry 107, such as the melting of metal particles to form a sintering neck. Based on this, the slurry is cured using conventional thermal radiation or thermal conduction methods, resulting in a slow temperature rise and a relatively low maximum temperature (typically 150℃~250℃). There is only a weak mechanical engagement between the metal particles and the first conductive part 101 or the battery substrate 100, mainly relying on resin adhesion for fixation. Throughout the curing process, the internal and external temperature differences are small, and the accumulated shrinkage stress is easily released through weak points such as microcracks or pores, and the morphology of the second slurry 107 does not change significantly.

[0160] In another embodiment of the photovoltaic cell manufacturing method provided in this disclosure, the second slurry 107 is exposed to xenon lamp and / or irradiated by laser. On the one hand, at the contact point between the second slurry 107 and the first conductive part 101, the first conductive part 101 will not undergo further significant shrinkage during the solidification process after sintering. The first conductive part 101 contains glass powder, and the metal in the first conductive part 101, such as silver, can form a strong chemical bond with the battery substrate 100 through the glass powder. Furthermore, the metal particles in the second slurry 107 can form a metal bond with the first conductive part 101, making it difficult for the second slurry 107 to detach from the first conductive part 101.

[0161] On the other hand, at the contact point between the second slurry 107 and the battery substrate 100, xenon lamp exposure or laser irradiation causes a rapid temperature rise and a high instantaneous temperature. Photon energy can be instantly absorbed by the metal particles in the second slurry 107, causing the local temperature to far exceed the resin decomposition temperature and the metal melting point within milliseconds. This allows the surface of the metal particles to melt instantaneously, and the resulting liquid phase forms liquid bridges between the particles. Through a large capillary force in the liquid phase, adjacent metal particles are pulled together, resulting in significant densification and shrinkage of the second slurry 107. Furthermore, the vapor from the vaporization of organic matter in the battery substrate 100 also helps the second slurry 107 detach from the battery substrate 100.

[0162] In some cases, in conjunction with references Figure 19 and Figure 20 The battery substrate 100 may include a substrate 120 and a passivation antireflection layer 130 located on the substrate 120. The material of the passivation antireflection layer 130 may be silicon nitride. The metal bonding force between the metal particles in the second paste 107 and the first conductive part 101 is greater than the van der Waals force between the metal particles in the second paste 107 and the silicon nitride.

[0163] Another embodiment of this disclosure provides a tandem battery, which includes the photovoltaic cell provided in the foregoing embodiments, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the foregoing embodiments. The tandem battery provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0164] refer to Figure 21 , Figure 21 This is a partial cross-sectional schematic diagram of a tandem solar cell provided in another embodiment of the present disclosure. The tandem solar cell includes: a bottom cell 119, which is a photovoltaic cell provided in the aforementioned embodiment, or a photovoltaic cell formed by the manufacturing method of the photovoltaic cell provided in the aforementioned embodiment; and a perovskite cell 129, which is located on one side of the bottom cell 119.

[0165] In some embodiments, the perovskite solar cell 129 may include: a first transport layer, a perovskite substrate, a second transport layer, a transparent conductive layer, and an antireflection layer stacked together. The first transport layer is directly opposite the base cell 119.

[0166] In some examples, the first transport layer can be either an electron transport layer or a hole transport layer, and the second transport layer can be either an electron transport layer or a hole transport layer.

[0167] In some embodiments, the bandgap width of the perovskite cell 129 is wider than that of the bottom cell 119. Therefore, stacking the perovskite cell 129 on top of the bottom cell 119 can give the stacked cell a wider spectral response range, thereby maximizing the utilization of solar energy and improving the efficiency of the photovoltaic cell.

[0168] In some embodiments, the stacked cell may further include an intermediate connecting layer (not shown in the figure), which connects the bottom cell 119 and the perovskite cell 129.

[0169] In some cases, the intermediate connecting layer is typically a tunnel junction or a very thin metal or transparent electrode composite layer. Optionally, the intermediate connecting layer can be a transparent conductive oxide, which has good photoelectric properties, high photon transmittance, and high conductivity, thereby enabling the perovskite solar cell 129 and the bottom cell 119 to maintain good ohmic contact.

[0170] In other cases, the back grid, back main grid, front grid, and front main grid of the photovoltaic cell serving as the bottom cell 119 can also serve as an intermediate connection layer to achieve electrical connection with the perovskite cell 129. It should be noted that electrical connection between the two actually means that both are made of conductive materials and are directly connected in contact or connected through other conductive materials. Therefore, when the photovoltaic cell is generating electricity, there is an electrical connection between the two.

[0171] Another embodiment of this disclosure provides a photovoltaic module, which includes multiple photovoltaic cells as provided in the foregoing embodiments, or photovoltaic cells formed by the manufacturing method of multiple photovoltaic cells as provided in the foregoing embodiments, or multiple tandem cells as provided in the foregoing embodiments. The photovoltaic module is used to convert received light energy into electrical energy. It should be noted that the parts that are the same as or corresponding to the foregoing embodiments can be referred to the corresponding descriptions of the foregoing embodiments, and will not be repeated below.

[0172] Reference Figure 22 and Figure 23 The photovoltaic module includes: a photovoltaic cell 40 connected by multiple photovoltaic cells 40 provided in the foregoing embodiments, or a photovoltaic cell 40 formed by the manufacturing method of multiple photovoltaic cells provided in the foregoing embodiments, or a photovoltaic cell 40 connected by multiple stacked cells provided in the foregoing embodiments; an encapsulating film 41 for covering the surface of the cell string; and a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the cell string.

[0173] in, Figure 22 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 23 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0174] In some embodiments, the photovoltaic cell 40 includes, but is not limited to, one or any combination of BC cells, TOPCON cells, PERC cells, HIT / HJT cells, and thin-film solar cells. 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; BC cells include, but are not limited to, IBC cells (Interdigitated Back Contact), HBC cells (Heterojunction Back Contact), TBC cells (TOPCon BackContact), HTBC cells (Heterojunction Tunnel Oxide Passivated Back Contact), or HPBC cells (Hybrid Passivated Back Contact).

[0175] In some embodiments, the photovoltaic cell 40 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0176] In some cases, multiple photovoltaic cells 40 can be electrically connected via solder ribbons 43. It is worth noting that electrical connection actually means that both are made of conductive materials and are directly connected or connected via other conductive materials. Therefore, when the photovoltaic cells 40 are generating electricity, there is an electrical connection between them.

[0177] It should be noted that, Figure 22 and Figure 23 This illustration only shows one positional relationship between photovoltaic cells 40, where electrodes of different polarities in each photovoltaic cell 40 are located on the same surface, and the side of each photovoltaic cell 40 with electrodes faces the same direction. Solder ribbons 43 connect the same side of two adjacent photovoltaic cells 40 respectively. In other embodiments, the photovoltaic cells may also be arranged such that the sides of two adjacent photovoltaic cells with electrodes are located on different sides, in which case solder ribbons connect the different sides of the two adjacent photovoltaic cells.

[0178] In some embodiments, the photovoltaic cells 40 are electrically connected in the form of a single cell or multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. The photovoltaic cells 40 can be a single cell or a sliced ​​cell, where a sliced ​​cell refers to a cell formed by cutting a complete single cell.

[0179] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the photovoltaic cell 40, and the second encapsulating layer covers the other of the front or back sides of the photovoltaic cell 40. Specifically, at least one of the first encapsulating layer or the second encapsulating layer may be an organic encapsulating film such as polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin thermoplastic elastomer (POE), or polyethylene glycol terephthalate (PET). Alternatively, at least one of the first encapsulating layer or the second encapsulating layer may also be an EP film, an EPE film, or a PVP film. Among them, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film, POE film, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0180] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0181] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0182] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic cell, characterized in that, include: Battery substrate; A first conductive portion is located on at least one surface side of the battery substrate; A second conductive portion extending along a first direction, wherein a single second conductive portion is connected to a plurality of first conductive portions spaced apart along the first direction; The second conductive portion includes a first portion and a second portion that are alternately connected along the first direction. The first portion includes a part of the second conductive portion that is connected to the first conductive portion. The second portion includes a part of the second conductive portion that is located above the interval between two adjacent first conductive portions. Along a direction perpendicular to the first direction, the width of the first part is greater than the width of the second part.

2. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, the thickness of the first part is less than the thickness of the second part, the second direction is the thickness direction of the battery substrate, and the second direction intersects with the first direction.

3. The photovoltaic cell according to claim 1, characterized in that, At least a portion of the second part is in contact with the battery substrate; and / or, along a second direction, at least a portion of the second part has a gap with the battery substrate, the second direction being the thickness direction of the battery substrate, and the second direction intersects the first direction.

4. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, the first part and the first conductive part overlap or partially coincide, the second direction is the thickness direction of the battery substrate, and the second direction intersects with the first direction.

5. The photovoltaic cell according to claim 1, characterized in that, The battery substrate includes a substrate and a passivation and antireflection layer located on the substrate. The first conductive portion and the second conductive portion are both located on the side of the passivation and antireflection layer away from the battery substrate, and along the first direction, a portion of the thickness of the first conductive portion is embedded in the battery substrate.

6. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, The materials of the first conductive part and the second conductive part are different.

7. The photovoltaic cell according to any one of claims 1 to 5, characterized in that, A single second conductive part and a plurality of first conductive parts connected thereto constitute a first electrode.

8. The photovoltaic cell according to claim 7, characterized in that, Also includes: A second electrode extending upward along a third side; Wherein, along the first direction, the second electrode is located between two partially adjacent first conductive portions, and the first portion further includes a portion of the second conductive portion connected to the second electrode, and the third direction intersects with the first direction; or... The second electrode is located on the side of the second conductive portion away from the first conductive portion, and the second electrode is connected to a plurality of second conductive portions arranged at intervals along the third direction.

9. The photovoltaic cell according to claim 1, characterized in that, Along the first direction, the ratio of the spacing between at least a portion of adjacent first conductive portions to the width of the first conductive portion is 1 to 20.

10. The photovoltaic cell according to claim 9, characterized in that, Along the first direction, the spacing between at least a portion of adjacent first conductive portions is 20 μm to 200 μm; and / or, along the first direction, the width of the first conductive portion is 10 μm to 100 μm.

11. The photovoltaic cell according to claim 1, characterized in that, Along a direction perpendicular to the first direction, the ratio of the width of the second part to the width of the first part is less than or equal to 0.

7.

12. The photovoltaic cell according to claim 1, characterized in that, The first part and the first conductive part have a first contact angle, and the second part and the battery substrate have a second contact angle, wherein the first contact angle is smaller than the second contact angle.

13. The photovoltaic cell according to claim 1, characterized in that, The porosity of the first part is greater than that of the second part.

14. The photovoltaic cell according to claim 1, characterized in that, Along a direction perpendicular to the first direction, the outer contour of the first part has a first boundary point and a second boundary point; along a second direction, the outer contour of the first part has a first vertex farthest from the battery substrate, the second direction is the thickness direction of the battery substrate, and the second direction intersects the first direction; Wherein, taking the surface side as the reference plane, along the second direction, the height difference between the first boundary point and the first vertex is the first height, the height difference between the second boundary point and the first vertex is the second height, the height difference between the first vertex and the reference plane is the first reference height, the ratio of the first height to the first reference height is greater than or equal to 0.75, and the ratio of the second height to the first reference height is greater than or equal to 0.

75.

15. The photovoltaic cell according to claim 1, characterized in that, Along a direction perpendicular to the first direction, the outer contour of the second part has a relative third boundary point and a fourth boundary point; along a second direction, the outer contour of the second part has a second vertex farthest from the battery substrate, the second direction being the thickness direction of the battery substrate, and the second direction intersecting the first direction; Wherein, taking the surface side as the reference plane, along the second direction, the height difference between the third boundary point and the second vertex is the third height, the height difference between the fourth boundary point and the second vertex is the fourth height, the height difference between the second vertex and the reference plane is the second reference height, the ratio of the third height to the second reference height is less than 0.75, and the ratio of the fourth height to the second reference height is less than 0.

75.

16. A method for manufacturing a photovoltaic cell, characterized in that, include: Provide battery substrate; A first conductive portion is formed on at least one surface side of the battery substrate; A second conductive portion is formed on the surface jointly formed by the battery substrate and the first conductive portion; Wherein, the second conductive portion extends along a first direction, a single second conductive portion is connected to a plurality of first conductive portions arranged at intervals along the first direction, and the second conductive portion includes a first portion and a second portion alternately connected along the first direction, the first portion includes a portion of the second conductive portion connected to the first conductive portion, and the second portion includes a portion of the second conductive portion located above the interval between two adjacent first conductive portions; Along a direction perpendicular to the first direction, the width of the first part is greater than the width of the second part.

17. The method for manufacturing a photovoltaic cell according to claim 16, characterized in that, The step of forming the second conductive portion includes: A second paste is printed on the surface formed by the battery substrate and the first conductive part, wherein the adhesion force between the second paste and the first conductive part is greater than the adhesion force between the second paste and the battery substrate. The second slurry is cured so that the second slurry connected to the first conductive part is transformed into the first part, and the second slurry in contact with the battery substrate is transformed into the second part.

18. The method for manufacturing a photovoltaic cell according to claim 17, characterized in that, The step of curing the second slurry includes: exposing the second slurry to a xenon lamp and / or laser irradiation to heat the second slurry.

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

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

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