Photovoltaic cell, manufacturing method thereof and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a photovoltaic cell and a manufacturing method thereof, and a photovoltaic module, and the manufacturing method comprises the steps: providing a substrate, the substrate comprises a first surface and a second surface which are oppositely arranged, and at least one of the first surface and the second surface comprises metal regions and non-metal regions which are alternately arranged along a first direction; forming a seed film on at least one of the first surface and the second surface by using a physical vapor deposition process; forming a mask layer on one side, far away from the substrate, of the seed film, wherein the mask layer is only located on the metal region; taking the mask layer as an etching barrier layer, performing graphical processing on the seed film to form a seed layer only located in the metal region, and removing the mask layer; and forming a conductive layer on the seed layer by adopting an electroplating process. The embodiment of the invention is at least beneficial to improving the preparation efficiency of the photovoltaic cell and reducing the preparation cost of the photovoltaic cell.

Description

Technical Field

[0001] The present disclosure relates to the photovoltaic field, and in particular to a photovoltaic cell and a manufacturing method thereof, and a photovoltaic module. Background Art

[0002] As fossil energy is gradually depleted, photovoltaic cells are increasingly used as a new energy alternative. Photovoltaic cells are devices that convert sunlight into electrical energy. Photovoltaic cells use the photovoltaic principle to generate photogenerated carriers, and then use electrodes to lead out the carriers, thereby facilitating the effective use of electrical energy. The electrode generally includes a main grid and a sub-grid. The sub-grid is mainly used to collect photogenerated carriers, and the main grid is mainly used to lead out the photogenerated carriers collected by the sub-grid.

[0003] However, the electrode is only located on a very small part of the surface of the photovoltaic cell to ensure that the photovoltaic cell has a larger light-receiving surface. Based on this, in the process of preparing the electrode, it is necessary to control the electrode to be formed on the local surface of the photovoltaic cell. The conventional method is to form the electrode by screen printing the silver-coated slurry and then sintering it at high temperature. On the one hand, the unit price of silver is relatively high, and the resistivity of the electrode has an important influence on the photoelectric conversion efficiency of the photovoltaic cell, which makes the amount of silver in the electrode remain high; on the other hand, based on the fluidity of the slurry, it is easy to have poor uniformity of the formed electrode, which affects the preparation efficiency of the electrode.

[0004] Therefore, it is necessary to seek an electrode manufacturing method with lower preparation cost and higher preparation efficiency. Summary of the invention

[0005] The embodiments of the present disclosure provide a photovoltaic cell and a method for manufacturing the same, and a photovoltaic module, which are at least beneficial to improving the preparation efficiency of the photovoltaic cell and reducing the preparation cost of the photovoltaic cell.

[0006] According to some embodiments of the present disclosure, on the one hand, the embodiments of the present disclosure provide a method for manufacturing a photovoltaic cell, comprising: providing a substrate, the substrate comprising a first surface and a second surface arranged opposite to each other, at least one of the first surface and the second surface comprising metal areas and non-metal areas alternately arranged along a first direction; forming a seed film on at least one of the first surface and the second surface using a physical vapor deposition process; forming a mask layer on a side of the seed film away from the substrate, the mask layer being located only on the metal area; using the mask layer as an etching barrier layer, patterning the seed film to form a seed layer located only in the metal area, and removing the mask layer; and forming a conductive layer on the seed layer using an electroplating process.

[0007] In some embodiments, after providing the substrate and before forming the seed film, the method for manufacturing the photovoltaic cell further includes: forming a passivation layer on at least one of the first surface and the second surface, the passivation layer having an opening exposing at least a portion of the metal area; in the step of forming the seed film, the seed film is not only located in the opening, but also located on a side of the passivation layer away from the substrate.

[0008] In some embodiments, after forming the passivation layer and before forming the seed film, the method for manufacturing the photovoltaic cell further includes: performing a high-temperature activation treatment on the substrate and the passivation layer.

[0009] In some embodiments, the step of forming the seed film includes: forming a transition film on at least one of the first surface and the second surface, the material of the transition film and the material of the substrate containing the same semiconductor element; forming a main film on the side of the transition film away from the substrate, the material of the main film and the material of the transition film both containing metal elements.

[0010] In some embodiments, the steps of patterning the seed film and removing the mask layer include: using the mask layer as an etching barrier layer, and using a first etching solution to remove the main film located on the non-metallic area; using a second etching solution to remove the mask layer and the transition film located on the non-metallic area; wherein the remaining transition film located in the metal area serves as a transition layer, and the remaining main film located in the metal area serves as a main layer.

[0011] In some embodiments, after forming the transition film and before forming the main film, the step of forming the seed film also includes: forming a diffusion barrier film on a side of the transition film away from the substrate; and the step of forming the seed film includes forming the main film on a side of the diffusion barrier film away from the transition film.

[0012] In some embodiments, the step of patterning the seed film includes: using the mask layer as an etching barrier layer, using a third etching solution to remove the main film located on the non-metallic area, and removing the diffusion barrier film located on the non-metallic area; using a second etching solution to remove the mask layer and the transition film located on the non-metallic area; wherein the remaining transition film located in the metal area serves as a transition layer, the remaining diffusion barrier film located in the metal area serves as a diffusion barrier layer, and the remaining main film located in the metal area serves as a main layer.

[0013] In some embodiments, the step of forming the mask layer includes: using a screen printing process to form the mask layer on the side of the seed film located on the metal area away from the substrate; or, forming an initial mask layer on the side of the seed film away from the substrate, exposing and developing the initial mask layer to finally form the mask layer located on the metal area.

[0014] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a photovoltaic cell, comprising: a substrate, the substrate comprising a first surface and a second surface arranged opposite to each other, at least one of the first surface and the second surface comprising metal areas and non-metal areas alternately arranged along a first direction; a seed layer, located only on the metal area; and a conductive layer, located on a side of the seed layer away from the substrate.

[0015] In some embodiments, the photovoltaic cell further includes: a passivation layer located on at least one of the first surface and the second surface, and the passivation layer has an opening exposing at least a portion of the metal region, and the seed layer is at least located in the opening.

[0016] In some embodiments, along the direction from the seed layer to the conductive layer, the seed layer includes a transition layer and a main layer stacked in sequence; or, along the direction from the seed layer to the conductive layer, the seed layer includes the transition layer, a diffusion barrier layer and the main layer stacked in sequence.

[0017] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a photovoltaic assembly, comprising: a cell string, formed by connecting a plurality of photovoltaic cells formed by the photovoltaic cell manufacturing method as described in any one of the above items, or formed by connecting a plurality of photovoltaic cells as described in any one of the above items; a packaging film for covering the surface of the cell string; and a cover plate for covering the surface of the packaging film facing away from the cell string.

[0018] The technical solution provided by the embodiments of the present disclosure has at least the following advantages: The seed layer and the conductive layer finally formed together constitute the electrode of the photovoltaic cell. In order to form the electrode only on the metal area, the seed layer and the conductive layer are prepared in batches. On the one hand, the combination of physical vapor deposition process and patterning treatment is used to prepare a seed layer with a thinner thickness. Compared with the patterning treatment of the entire electrode, it is beneficial to reduce the thickness of the electrode to be etched by the patterning treatment. Only the seed film needs to be patterned, which effectively reduces the etching cost and the total time consumption of the patterning treatment; on the other hand, based on the seed layer located only in the metal area, the electroplating process can be directly used so that the conductive layer will only be formed on the metal area with the seed layer. There is no need to pattern the conductive layer, so that a conductive layer with uniform thickness can be formed, which is beneficial to reduce the amount of the conductive layer and ensure the yield of the formed conductive layer. In other words, with the help of the combination of physical vapor deposition process and patterning treatment, a seed layer adapted to the electroplating process is formed. There is no need to overcome the characteristics of the whole surface deposition of the electroplating process, and the selective deposition of the conductive layer can be achieved with the help of the seed layer, which is beneficial to improve the preparation efficiency of photovoltaic cells and reduce the preparation cost of photovoltaic cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A partial cross-sectional schematic diagram of a substrate in a method for manufacturing a photovoltaic cell provided in an embodiment of the present disclosure; Figure 2 A first partial cross-sectional schematic diagram after a seed film is formed in a method for manufacturing a photovoltaic cell provided by an embodiment of the present disclosure; Figure 3 For Figure 2 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Figure 4 For Figure 3 A schematic diagram of a partial cross section after the structure shown is patterned and a conductive layer is formed; Figure 5 A partial cross-sectional schematic diagram after forming a passivation layer and a seed film in a method for manufacturing a photovoltaic cell provided by an embodiment of the present disclosure; Figure 6 A second partial cross-sectional schematic diagram after a seed film is formed in the method for manufacturing a photovoltaic cell provided by an embodiment of the present disclosure; Figure 7 For Figure 6 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Figure 8 For Figure 7 A schematic diagram of a partial cross section formed after the structure shown is etched using the first etching solution; Fig. 9 For Figure 8 A schematic diagram of a partial cross section formed after etching the structure shown using the second etching solution; Fig.10 A third partial cross-sectional schematic diagram after a seed film is formed in the method for manufacturing a photovoltaic cell provided in one embodiment of the present disclosure; Fig.11 For Fig.10 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Fig.12 For Fig.11 A schematic diagram of a partial cross section formed after the structure shown is etched using a third etching solution; Fig.13 For Fig.12 A schematic diagram of a partial cross section formed after etching the structure shown using the second etching solution; Fig.14 A schematic diagram of a partial cross-sectional structure of a photovoltaic cell formed by a method for manufacturing a photovoltaic cell provided according to an embodiment of the present disclosure; Fig.15 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure; Fig.16 for Fig.15 A schematic diagram of a cross-sectional structure along the cross-sectional direction MM1. DETAILED DESCRIPTION

[0021] As can be seen from the background technology, the preparation efficiency of photovoltaic cells needs to be improved, and the preparation cost of photovoltaic cells needs to be reduced.

[0022] After analysis, it was found that when using the screen printing process to form electrodes, not only the silver content and fluidity of the slurry need to be considered, but also the photovoltaic cell as a whole needs to be subjected to high-temperature sintering to sinter the slurry into electrodes. During the sintering process, it is necessary to avoid the risk of slurry burn-through, the possibility of increasing internal defects of the photovoltaic cell due to high temperature, the problem of large differences in the size of the electrodes formed in different areas, and the problem of poor contact between the electrodes formed in some areas and the substrate in the photovoltaic cell.

[0023] In order to form an electrode located on part of the surface of a photovoltaic cell, that is, to form an electrode in a localized manner, it is impossible to achieve this by simply using a deposition process. Generally, a deposition process, such as an electroplating process, is first used to form an initial electrode on the entire surface of the photovoltaic cell, and then the entire initial electrode is patterned. However, in the step of patterning, most of the entire initial electrode needs to be removed, resulting in high etching costs, and the thickness of the initial electrode required for electroplating is relatively large, which will also affect the thickness uniformity of the entire initial electrode, and cause the subsequent etching of the initial electrode to be uneven.

[0024] The present disclosure provides a photovoltaic cell and a manufacturing method thereof, and a photovoltaic module. In the manufacturing method, the seed layer and the conductive layer finally formed together constitute the electrode of the photovoltaic cell. In order to form the electrode only on the metal area, the seed layer and the conductive layer are prepared in batches. On the one hand, the combination of physical vapor deposition process and patterning treatment is used to prepare a seed layer with a thinner thickness. Compared with the patterning treatment of the entire electrode, it is beneficial to reduce the thickness of the electrode required for etching by the patterning treatment. Only the seed film needs to be patterned, which effectively reduces the etching cost and reduces the total time consumption of the patterning treatment; on the other hand, based on the seed layer only located in the metal area, the electroplating process can be directly used, so that the conductive layer will only be formed on the metal area with the seed layer, and there is no need to pattern the conductive layer, so that a conductive layer with uniform thickness can be formed, which is beneficial to reduce the amount of the conductive layer and ensure the yield of the formed conductive layer. In other words, with the help of the combination of physical vapor deposition process and patterning treatment, a seed layer adapted to the electroplating process is formed, and there is no need to overcome the characteristics of the whole surface deposition of the electroplating process, and the selective deposition of the conductive layer can be achieved with the help of the seed layer, which is beneficial to improve the preparation efficiency of the photovoltaic cell and reduce the preparation cost of the photovoltaic cell.

[0025] In the description of the embodiments of the present disclosure, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] In the description of the embodiments of the present disclosure, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0028] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0029] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0030] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to the specific circumstances.

[0031] In the accompanying drawings corresponding to the embodiments of the present disclosure, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or a third component may exist between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0032] In the description of the embodiments of the present disclosure, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist in between. In addition, when a component such as a layer, film, region, or plate is "directly located on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located in between.

[0033] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0034] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0035] An embodiment of the present disclosure provides a method for manufacturing a photovoltaic cell. The method for manufacturing a photovoltaic cell provided by an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. Figures 1 to 14 A partial cross-sectional schematic diagram corresponding to each step in a method for manufacturing a photovoltaic cell provided in an embodiment of the present disclosure.

[0036] refer to Figures 1 to 14 , the manufacturing method of the photovoltaic cell comprises at least the following steps: Figure 1 or Fig.14 , providing a substrate 100, the substrate 100 includes a first surface 110 and a second surface 120 disposed opposite to each other, at least one of the first surface 110 and the second surface 120 includes metal areas 130 and non-metal areas 140 alternately arranged along a first direction X; referring to Figure 2 , Figure 5 , Figure 6 or Fig.10 , a seed film 101 is formed on at least one of the first surface 110 and the second surface 120 by a physical vapor deposition process; Figure 3 , Figure 7 or Fig.11 , a mask layer 102 is formed on the side of the seed film 101 away from the substrate 100, and the mask layer 102 is only located on the metal area 130; Figure 3 and Figure 4 , combined with reference Figures 7 to 9 , or combined with reference Figures 11 to 13 , using the mask layer 102 as an etching barrier layer, the seed film 101 is patterned to form a seed layer 103 located only in the metal region 130, and the mask layer 102 is removed; continue to refer to Figure 4 , a conductive layer 104 is formed on the seed layer 103 by an electroplating process.

[0037] It should be noted that Figure 1 A partial cross-sectional schematic diagram of a substrate in a method for manufacturing a photovoltaic cell provided in an embodiment of the present disclosure; Figure 2 A first partial cross-sectional schematic diagram after a seed film is formed in a method for manufacturing a photovoltaic cell provided by an embodiment of the present disclosure; Figure 3 For Figure 2 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Figure 4 For Figure 3 A partial cross-sectional schematic diagram after the structure shown in FIG. is patterned and a conductive layer is formed. Figures 5 to 14 Provide detailed explanation.

[0038] It is worth noting that the seed layer 103 and the conductive layer 104 formed in the end are both components of the electrode of the photovoltaic cell. In order to form the electrode only on the metal area 130, the electrode to be prepared is first divided into two parts, namely the seed layer 103 and the conductive layer 104, and then the seed layer 103 and the conductive layer 104 are prepared in batches. On the one hand, a combination of physical vapor deposition process and graphic treatment is adopted to prepare a seed layer 103 with a relatively thin thickness. Compared with graphic treatment of the entire electrode, this is beneficial to reducing the thickness of the electrode that needs to be etched for graphic treatment. Only the seed film 101 needs to be graphic treated, which effectively reduces the etching cost and the total time consumption of graphic treatment. On the other hand, based on the seed layer 103 located only in the metal area 130, the electroplating process can be directly used to realize the selective deposition of the conductive layer 104, that is, the conductive layer 104 will only be formed on the metal area 130 with the seed layer 103, and there is no need to graphic treatment the conductive layer 104, so that a conductive layer 104 with uniform thickness can be formed, which is beneficial to reduce the amount of conductive layer 104 used and ensure the yield of the formed conductive layer 104. In other words, by combining physical vapor deposition technology and graphical processing, a seed layer 103 adapted to the electroplating process is formed. There is no need to overcome the characteristics of full-surface deposition in the electroplating process. The conductive layer 104 can be selectively deposited with the help of the seed layer 103, which is beneficial to improving the preparation efficiency of photovoltaic cells and reducing the preparation cost of photovoltaic cells.

[0039] It is worth emphasizing that the seed layer 103 is mainly used to improve the contact performance between the final electrode and the substrate 100, and the conductive layer 104 is mainly used to reduce the resistivity of the final electrode. Therefore, along the second direction Y, the thickness of the seed layer 103 is less than the thickness of the conductive layer 104. Only the seed layer 103 is patterned, which is conducive to significantly reducing the proportion of the etching thickness required for the patterning process in the entire electrode thickness, that is, significantly reducing the proportion of the etching amount of the etched seed film 101 to the entire electrode, which can reduce the amount of etching solution used in the patterning process and the total time consumption of the patterning process, thereby improving the preparation efficiency of the seed layer 103 and reducing the preparation cost of the seed layer 103. In addition, the second direction Y is the direction from the second surface 120 to the first surface 110; the seed layer 103 and the conductive layer 104 will be described in detail later.

[0040] To facilitate the description of the positional relationship between the finally formed electrode and the substrate 100, for those skilled in the art, the first surface 110 and / or the second surface 120 can be divided into a metal area 130 and a non-metal area 140, wherein the metal area 130 is generally used to refer to the relative area where the electrode is formed in the subsequent metallization process, and the non-metal area 140 is generally used to refer to other areas except the metal area 130. Take the second surface 120 including the metal area 130 and the non-metal area 140 arranged alternately along the first direction X as an example, wherein the metal area 130 at least includes the area where the orthographic projection of the seed layer 103 on the substrate 100 is located, and the area on the second surface 120 except the metal area 130 is the non-metal area 140. Among them, in order to ensure that the film layer contacted by the seed layer 103 has a large doping concentration or the area contacted by the seed layer 103 is a high concentration area, thereby reducing the contact resistance, the orthographic projection area of ​​the metal area 130 is generally set to be greater than or equal to the orthographic projection area of ​​the seed layer 103. In other words, the orthographic projection area of ​​the seed layer 103 on the substrate 100 is smaller than the area of ​​the metal region 130, and the orthographic projection position must be within the metal region 130. It should be noted that the number of metal regions 130 and the number of non-metal regions 140 can both be multiple, and the metal regions 130 and non-metal regions 140 are alternately arranged along the first direction X. In other words, the metal region 130 can be located in the interval between adjacent non-metal regions 140, and the non-metal region 140 can also be located in the interval between adjacent metal regions 130.

[0041] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0042] In some embodiments, reference Figures 1 to 14, the second surface 120 includes metal areas 130 and non-metal areas 140 arranged alternately along the first direction X, and the seed layer 103 and the conductive layer 104 are both formed on the second surface 120. In other embodiments, the first surface may include metal areas and non-metal areas arranged alternately along the first direction, and the seed layer and the conductive layer are both formed on the first surface; or, the first surface and the second surface both include metal areas and non-metal areas arranged alternately along the first direction, the first surface includes the first metal area and the first non-metal area arranged alternately along the first direction, the second surface includes the second metal area and the second non-metal area arranged alternately along the first direction, and the seed layer and the conductive layer are formed not only on the first metal area, but also on the second metal area. In addition, the seed layer formed on the first metal area and the seed layer formed on the second metal area can be formed in the same preparation process, or they can be formed in different preparation processes using the same manufacturing method; the conductive layer formed on the first metal area and the conductive layer formed on the second metal area can be formed in the same preparation process, or they can be formed in different preparation processes using the same manufacturing method.

[0043] It should be noted that Figure 4 or Fig.14 In the figure, the seed layer 103 and the conductive layer 104 are both formed on the second surface 120 as an example, and the following description will be given by taking the example of forming the seed layer 103 and the conductive layer 104 on the second surface 120 as an example.

[0044] In some examples, reference Figures 1 to 14 , the photovoltaic cell can be a single-sided cell, the first surface 110 can be regarded as the light-receiving surface of the photovoltaic cell, which is used to receive incident light, and the second surface 120 can be used as the back surface, that is, the backlight surface. In other examples, the photovoltaic cell can be a double-sided cell, then both the first surface 110 and the second surface 120 can be used as light-receiving surfaces, both can be used to receive incident light, and the first surface 110 can be one of the front surface or the back surface. In other words, the electrode formed in the manufacturing method of the photovoltaic cell improved in one embodiment of the present disclosure is suitable for various types of photovoltaic cells. It can be understood that the backlight surface described in one embodiment of the present disclosure can also receive incident light, but the degree of receiving the incident light is weaker than the degree of receiving the incident light by the light-receiving surface, and therefore it is defined as the backlight surface. The second surface 120 is used as the backlight surface as an example for explanation below.

[0045] In some examples, the photovoltaic cell is an IBC cell (Interdigitated Back Contact), the electrodes of the IBC cell include a main grid and a fine grid. The photovoltaic cell manufacturing method provided in an embodiment of the present disclosure can be used to form a main grid and can be used to form a fine grid.

[0046] In some embodiments, the physical vapor deposition (PVD) process includes but is not limited to electron beam evaporation or vacuum evaporating (vacuum evaporation).

[0047] In some embodiments, reference Figure 5 , Figure 5 A partial cross-sectional schematic diagram after forming a passivation layer and a seed film in a method for manufacturing a photovoltaic cell provided for an embodiment of the present disclosure, after providing a substrate 100 and before forming a seed film 101, the method for manufacturing a photovoltaic cell may further include: forming a passivation layer 105 on at least one of a first surface 110 and a second surface 120, the passivation layer 105 having an opening 115 exposing at least a portion of a metal region 130; in the step of forming the seed film 101, the seed film 101 is not only located in the opening 115, but also located on a side of the passivation layer 105 away from the substrate 100.

[0048] It is worth noting that the passivation layer 105 is used to passivate the surface of the substrate 100 to reduce the defect state density on the surface of the entire substrate 100 and reduce the probability of carrier recombination in the substrate 100, so that more carriers can be collected by the finally formed electrode. On this basis, the finally formed electrode needs to pass through the passivation layer 105 to make ohmic contact with the substrate 100, and the seed film 101 used to prepare the seed layer 103 needs to be located in the opening 115 of the passivation layer 105, so that the seed film 101 is in ohmic contact with the substrate 100.

[0049] Thus, on the one hand, compared with the electrode formed by screen printing and high-temperature sintering, the slurry may cause excessive corrosion to the passivation layer and the substrate. In the photovoltaic cell manufacturing method provided by an embodiment of the present disclosure, a deposition process is used to form the seed film 101, which is beneficial to avoid excessive corrosion of the passivation layer 105 and the substrate 100 by the seed film 101; on the other hand, before forming the seed film 101, a passivation layer 105 having an opening 115 is first formed, and the seed film 101 is formed by a deposition process, which is beneficial to make the morphology of the contact interface between the formed seed film 101 and the passivation layer 105 controllable. For example, the side wall of the opening 115 is flat, and the contact between the finally formed electrode and the passivation layer 105 is smooth. The edge is also relatively smooth, and the electrode will not have too large a difference in conductivity in different regions due to too large a difference in edge morphology, which is conducive to improving the stability of the overall conductivity of the electrode and avoiding the loss of carriers caused by sudden changes in conductivity in some regions of the electrode, which is conducive to promoting the formation of a good ohmic contact between the seed film 101 and the substrate 100, and improving the collection efficiency of the carriers of the final electrode; on the other hand, there is no need to use the passivation layer 105 to block excessive erosion of the slurry, so the thickness of the passivation layer 105 in the second direction Y can be reduced to reduce the preparation cost of the passivation layer 105 and reduce the parasitic absorption of light by the passivation layer 105, so that the substrate 100 can receive more incident light. Based on improvements in many aspects, the method for manufacturing a photovoltaic cell provided in another embodiment of the present disclosure is conducive to reducing the preparation cost of the photovoltaic cell while improving the photoelectric conversion efficiency of the photovoltaic cell.

[0050] In some cases, the passivation layer 105 may be a single-layer structure or a stacked-layer structure, and the material of the passivation layer 105 may include at least one of aluminum oxide, silicon nitride, silicon oxide, or silicon oxynitride.

[0051] In some cases, continue to refer to Figure 5 , a single opening 115 may only expose a portion of a single metal region 130, so that the final electrode can fill the opening 115 to ensure sufficient ohmic contact area between the electrode and the metal region 130, and the electrode portion can be located on the surface of the passivation layer 105 away from the substrate 100, thereby increasing the cross-sectional area of ​​the electrode as a whole, reducing the resistance of the electrode as a whole, and further improving the photogenerated carrier collection capability of the electrode. In other cases, a single opening may also expose the entire area of ​​a single metal region.

[0052] In some cases, continue to refer to Figure 5The step of forming a passivation layer 105 having an opening 115 exposing at least a portion of the metal area 130 may include: forming an initial passivation layer (not shown in the figure) on at least one of the first surface 110 and the second surface 120, wherein the initial passivation layer covers at least one of the first surface 110 and the second surface 120; performing a laser opening treatment on a portion of the initial passivation layer to form an opening 115 exposing at least a portion of the metal area 130, and the remaining initial passivation layer serves as the passivation layer 105.

[0053] In some embodiments, continue to refer to Figure 5 After forming the passivation layer 105 and before forming the seed film 101, the method for manufacturing the photovoltaic cell may further include: performing a high temperature activation treatment on the substrate 100 and the passivation layer 105. In this way, it is beneficial to enhance the passivation effect of the passivation layer 105 on the substrate 100 by means of high temperature, further reduce the probability of carrier recombination, and increase the life of minority carriers, thereby facilitating the improvement of the open circuit voltage and photoelectric conversion efficiency of the photovoltaic cell.

[0054] The steps of forming the seed film 101 and the seed layer 103 include at least the following two embodiments: In some embodiments, reference Figure 6 , Figure 6 The second partial cross-sectional schematic diagram after the seed film is formed in the manufacturing method of the photovoltaic cell provided in one embodiment of the present disclosure, the step of forming the seed film 101 may include: forming a transition film 111 on at least one of the first surface 110 and the second surface 120, the material of the transition film 111 and the material of the substrate 100 contain the same semiconductor element; forming a main body film 121 on the side of the transition film 111 away from the substrate 100, and the material of the main body film 121 and the material of the transition film 111 both contain metal elements.

[0055] It is worth noting that the material of the transition film 111 and the material of the substrate 100 contain the same semiconductor elements, so that the lattice of the transition film 111 and the lattice of the substrate 100 are more adapted, which is beneficial to avoid the problem of large lattice mismatch between the transition film 111 and the substrate 100, so as to avoid the problem of increased surface defects caused by lattice mismatch, and it is also beneficial to improve the adhesion between the transition film 111 and the substrate 100, and enhance the contact performance between the finally formed electrode and the substrate 100.

[0056] It should be noted that the metal elements contained in the main film 121 and the transition film 111 may be the same or different. Both the main film 121 and the transition film 111 may be formed by a physical vapor deposition process. In practical applications, the main film and the transition film may also be formed by different preparation processes.

[0057] In some examples, the semiconductor element may be silicon, the material of the substrate 100 may be silicon, the material of the transition film 111 may be aluminum silicon material, and the material of the main film 121 may be copper.

[0058] In some cases, in conjunction with reference Figures 7 to 9 The steps of patterning the seed film 101 and removing the mask layer 102 may include: Figure 7 and Figure 8 , using the mask layer 102 as an etching barrier layer, using a first etching solution to remove the main film 121 located on the non-metallic area 140; Figure 8 and Fig. 9 , using a second etching solution to remove the mask layer 102 and the transition film 111 located on the non-metallic area 140; wherein the remaining transition film 111 located in the metal area 130 serves as the transition layer 113, and the remaining main film 121 located in the metal area 130 serves as the main layer 123.

[0059] in, Figure 7 For Figure 6 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Figure 8 For Figure 7 A schematic diagram of a partial cross section formed after the structure shown is etched using the first etching solution; Fig. 9 For Figure 8 A schematic diagram of a partial cross section of the structure shown after etching with the second etching solution.

[0060] It is worth noting that in order to form the seed layer 103 including the transition layer 113 and the main layer 123, the main film 121 and the transition film 111 are etched step by step, which is beneficial to improving the dimensional accuracy of the newly formed seed layer 103; moreover, the mask layer 102 can be removed simultaneously in the step of etching the transition film 111, and there is no need to use additional processes to remove the mask layer 102 subsequently, which is beneficial to simplify the preparation process of photovoltaic cells and reduce the preparation cost of photovoltaic cells.

[0061] In some examples, the first etching solution may be a mixed solution including sulfuric acid and hydrogen peroxide. In one example, the concentration of sulfuric acid in the first etching solution may be in the range of 100 g / L to 300 g / L, for example, 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, 160 g / L, 170 g / L, 180 g / L, 190 g / L, 120 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, 250 g / L, 260 g / L, 270 g / L, 280 g / L or 290 g / L, etc.; the concentration of hydrogen peroxide in the first etching solution may be in the range of 100 g / L to 300 g / L, for example, 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, 160 g / L, 170 g / L, 180 g / L, 190 g / L, 120 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, 250 g / L, 260 g / L, 270 g / L, 280 g / L or 290 g / L, etc. It can be 20g / L ~ 50g / L, for example, it can be 21g / L, 22g / L, 23g / L, 24g / L, 25g / L, 26g / L, 27g / L, 28g / L, 29g / L, 30g / L, 31g / L, 32g / L, 33g / L, 34g / L, 35g / L, 36g / L, 37g / L, 38g / L, 39g / L, 40g / L, 41g / L, 42g / L, 43g / L, 44g / L, 45g / L, 46g / L, 47g / L, 48g / L or 49g / L.

[0062] In some examples, the second etching solution may be a solution including potassium hydroxide.

[0063] In other embodiments, reference Fig.10 , Fig.10 The third partial cross-sectional schematic diagram after forming a seed film in the manufacturing method of a photovoltaic cell provided in one embodiment of the present disclosure, after forming the transition film 111 and before forming the main film 121, the step of forming the seed film 101 may also include: forming a diffusion barrier film 131 on the side of the transition film 111 away from the substrate 100; the step of forming the seed film 101 includes forming the main film 121 on the side of the diffusion barrier film 131 away from the transition film 111. It should be noted that the steps of forming the transition film 111 and the main film 121 are the same or corresponding to the above embodiments and are not repeated here.

[0064] It is worth noting that the diffusion barrier film 131 can block the diffusion of metal elements in the main film 121 into the transition film 111, further reducing the probability of metal elements in the main film 121 diffusing into the substrate 100, so as to avoid the problem of increased probability of carrier recombination caused by the diffusion of metal elements in the main film 121 into the substrate 100, thereby helping to improve the conductivity of the finally formed electrode itself with the help of the main film 121, while improving the contact performance between the finally formed electrode and the substrate 100.

[0065] It should be noted that the main film 121 , the diffusion barrier film 131 and the transition film 111 can all be formed by a physical vapor deposition process. In practical applications, the main film, the diffusion barrier film and the transition film can also be formed by different preparation processes.

[0066] In some examples, the material of the diffusion barrier film 131 may be a titanium tungsten material.

[0067] In some examples, along the second direction Y, the thickness of the diffusion barrier film 131 can be 15nm~30nm, for example, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm or 29nm, etc.

[0068] In some cases, in conjunction with reference Figures 11 to 13 The step of patterning the seed film 101 may include: Fig.11 and Fig.12 , using the mask layer 102 as an etching barrier layer, using a third etching solution to remove the main film 121 located on the non-metallic area 140, and removing the diffusion barrier film 131 located on the non-metallic area 140; combined with reference Fig.12 and Fig.13 , use a second etching solution to remove the mask layer 102 and the transition film 111 located on the non-metallic area 140; wherein the remaining transition film 111 located in the metal area 130 serves as the transition layer 113, the remaining diffusion barrier film 131 located in the metal area 130 serves as the diffusion barrier layer 133, and the remaining main film 121 located in the metal area 130 serves as the main layer 123.

[0069] in, Fig.11 For Fig.10 A schematic diagram of a local cross section after a mask layer is formed on the structure shown; Fig.12 For Fig.11 A schematic diagram of a partial cross section formed after the structure shown is etched using a third etching solution; Fig.13 For Fig.12 A schematic diagram of a partial cross section of the structure shown after etching with the second etching solution.

[0070] It is worth noting that in order to form the seed layer 103 including the transition layer 113, the diffusion barrier layer 133 and the main layer 123, the third etching solution is first used to remove the main film 121 located on the non-metallic area 140 and the diffusion barrier film 131 located on the non-metallic area 140, and then the second etching solution is used to remove the transition film 111 and the mask layer 102 located on the non-metallic area 140, which is beneficial to improve the dimensional accuracy of the newly formed seed layer 103; moreover, the mask layer 102 can be removed simultaneously in the step of etching the transition film 111, and there is no need to use an additional process to remove the mask layer 102 subsequently, which is beneficial to simplify the preparation process of photovoltaic cells and reduce the preparation cost of photovoltaic cells.

[0071] In some examples, the third etching solution may also be a mixed solution including sulfuric acid and hydrogen peroxide. Compared with using the first etching solution to only remove the main film 121 located on the non-metallic area 140, using the third etching solution needs to remove both the main film 121 located on the non-metallic area 140 and the diffusion barrier film 131 located on the non-metallic area 140. The concentration of hydrogen peroxide in the third etching solution is higher than the concentration of hydrogen peroxide in the first etching solution to ensure the graphical processing of both the main film 121 and the diffusion barrier film 131.

[0072] In one example, the material of the main film 121 is copper, and the material of the diffusion barrier film 131 is titanium tungsten. The etching of copper requires the joint corrosion of sulfuric acid and hydrogen peroxide, while the etching of titanium tungsten can only rely on the corrosion of hydrogen peroxide.

[0073] In one example, the concentration range of sulfuric acid in the third etching solution can be 100 g / L~300 g / L, for example, it can be 110 g / L, 120 g / L, 130 g / L, 140 g / L, 150 g / L, 160 g / L, 170 g / L, 180 g / L, 190 g / L, 120 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, 250 g / L, 260 g / L, 270 g / L, 280 g / L or 290 g / L; the concentration range of hydrogen peroxide in the third etching solution can be 30 g / L~80 g / L, for example, it can be 30 g / L, 31 g / L, 32 g / L, 33 g / L, 34 g / L, 35 g / L, 36 g / L, 37 g / L 7g / L, 38g / L, 39g / L, 40g / L, 41g / L, 42g / L, 43g / L, 44g / L, 45g / L, 46g / L, 47g / L , 48g / L, 49g / L, 50g / L, 51g / L, 52g / L, 53g / L, 54g / L, 55g / L, 56g / L, 57g / L, 58g / L, 59g / L, 60g / L, 61g / L, 62g / L, 63g / L, 64g / L, 65g / L, 66g / L, 67g / L, 68g / L, 69 g / L, 70g / L, 71g / L, 72g / L, 73g / L, 74g / L, 75g / L, 76g / L, 77g / L, 78g / L or 79g / L, etc.

[0074] In the above two embodiments, along the second direction Y, the thickness of the transition film 111 can be 5nm~100nm, for example, it can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm or 95nm, etc.; along the second direction Y, the thickness of the main film 121 can be 250nm~1000nm, for example, it can be 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm or 950nm, etc.

[0075] The steps of forming the mask layer 102 are described in detail below.

[0076] In some embodiments, reference Figure 3 , Figure 7 or Fig.11The step of forming the mask layer 102 may include: using a screen printing process to form the mask layer 102 on a side of the seed film 101 located on the metal region 130 away from the substrate 100. In some examples, the material of the mask layer 102 may be ink.

[0077] In other embodiments, reference Figure 3 , Figure 7 or Fig.11 , the step of forming the mask layer 102 may include: forming an initial mask layer on the side of the seed film 101 away from the substrate 100, exposing and developing the initial mask layer to finally form the mask layer 102 located on the metal region 130. In some examples, the material of the initial mask layer may be a positive photoresist or a negative photoresist, wherein the positive photoresist is characterized in that after being exposed to ultraviolet light, the exposed portion becomes more soluble, that is, the irradiated portion after exposure will be retained; the negative photoresist is characterized in that after being exposed to ultraviolet light, the exposed portion undergoes a cross-linking reaction, making the portion insoluble, that is, the irradiated portion after exposure will be removed.

[0078] In some embodiments, reference Fig.14 , Fig.14 A schematic diagram of a partial cross-sectional structure of a photovoltaic cell formed by a method for manufacturing a photovoltaic cell provided in accordance with an embodiment of the present disclosure is provided, wherein the second surface 120 may be a back surface, the base 100 may include a substrate 150, a tunneling layer 160 and a first doped semiconductor layer 170 stacked in sequence, and the second surface 120 is a surface of the first doped semiconductor layer 170 away from the tunneling layer 160. The tunneling layer 160 and the first doped semiconductor layer 170 constitute a passivation contact structure, and the passivation contact structure provides good surface passivation for the surface of the substrate 150, which is beneficial to reducing the metal contact recombination current and improving the open circuit voltage and short circuit current of the photovoltaic cell.

[0079] In other embodiments, the first surface may be the front surface, the substrate includes a second doped semiconductor layer, and the first surface includes a surface of the second doped semiconductor layer. It should be noted that the second doped semiconductor layer may be formed based on the substrate, so the second doped semiconductor layer may be considered to be embedded in the substrate, and the remaining substrate may serve as a substrate. In addition, the second doped semiconductor layer may be a selective emitter directly opposite to the metal region along the second direction; or, the second doped semiconductor layer may be embedded in the entire first surface of the substrate; or, the substrate includes a substrate and an emitter, and the emitter is additionally formed on the surface of the substrate.

[0080] In some cases, reference Fig.14, the material of the substrate 150 may be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, for example, silicon or germanium. Among them, the elemental semiconductor material may be single crystalline, polycrystalline, amorphous or microcrystalline (a state having both single crystalline and amorphous states is called microcrystalline), for example, silicon may be at least one of single crystalline silicon, polycrystalline silicon, amorphous silicon or microcrystalline silicon. In other embodiments, the material of the substrate 150 may also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanium, silicon carbide, gallium arsenide, indium gallium, perovskite, cadmium telluride, copper indium selenide and other materials.

[0081] In some cases, reference Fig.14 , the substrate 150 may be an N-type semiconductor substrate doped with an N-type doping element, the first doped semiconductor layer 170 may be polysilicon doped with an N-type doping element, and the second doped semiconductor layer 180 may be silicon doped with a P-type doping element. In other cases, the substrate may also be a P-type semiconductor substrate doped with a P-type doping element, the first doped semiconductor layer may be polysilicon doped with a P-type doping element, and the second doped semiconductor layer may be silicon doped with an N-type doping element.

[0082] In some examples, the N-type doping element may be at least one of Group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As); the P-type doping element may be at least one of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In).

[0083] In summary, the seed layer 103 and the conductive layer 104 finally formed together constitute the electrode of the photovoltaic cell. In order to form the electrode only on the metal area 130, the seed layer 103 and the conductive layer 104 are prepared in batches. On the one hand, the combination of physical vapor deposition process and patterning process is used to prepare a seed layer 103 with a thinner thickness. Compared with the patterning process of the entire electrode, it is beneficial to reduce the thickness of the electrode to be etched for the patterning process. Only the seed film 101 needs to be patterned, which effectively reduces the etching cost and reduces the total time consumption of the patterning process; on the other hand, based on the seed layer 103 located only in the metal area 130, the electroplating process can be directly used, so that the conductive layer 104 will only be formed on the metal area 130 with the seed layer 103, and there is no need to pattern the conductive layer 104, so that a conductive layer 104 with uniform thickness can be formed, which is beneficial to reduce the amount of the conductive layer 104 and ensure the yield of the formed conductive layer 104. In other words, by combining physical vapor deposition technology and graphical processing, a seed layer 103 adapted to the electroplating process is formed. There is no need to overcome the characteristics of full-surface deposition in the electroplating process. The conductive layer 104 can be selectively deposited with the help of the seed layer 103, which is beneficial to improving the preparation efficiency of photovoltaic cells and reducing the preparation cost of photovoltaic cells.

[0084] Another embodiment of the present disclosure further provides a photovoltaic cell, which is formed by the method for manufacturing the photovoltaic cell provided in the above embodiment. The photovoltaic cell provided in another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiment will not be repeated here.

[0085] refer to Figure 4 , Fig. 9 , Fig.13 or Fig.14 The photovoltaic cell includes: a substrate 100, the substrate 100 includes a first surface 110 and a second surface 120 arranged opposite to each other, at least one of the first surface 110 and the second surface 120 includes metal areas 130 and non-metal areas 140 alternately arranged along a first direction X; a seed layer 103, which is only located on the metal area 130; and a conductive layer 104, which is located on a side of the seed layer 103 away from the substrate 100.

[0086] It should be noted that Figure 4 , Fig. 9 , Fig.13 and Fig.14 In the example, it is only taken that the second surface 120 includes the metal areas 130 and the non-metal areas 140 arranged alternately along the first direction X. The seed layer 103 and the conductive layer 104 together constitute the electrode of the photovoltaic cell.

[0087] In some embodiments, in conjunction with reference Figure 4 and Figure 5The photovoltaic cell may further include: a passivation layer 105, which is located on at least one of the first surface 110 and the second surface 120, and the passivation layer 105 has an opening 115 that exposes at least a portion of the metal area 130, and the seed layer 103 is at least located in the opening 115. In this way, it is beneficial to control the morphology of the contact interface between the seed layer 103 and the passivation layer 105 by means of the opening 115. For example, if the side wall of the opening 115 is flat, the edge where the seed layer 103 and the passivation layer 105 contact is also relatively flat, and the seed layer 103 will not have too large a difference in conductivity in different regions due to too large a difference in edge morphology, thereby facilitating the stability of the overall conductivity of the seed layer 103, avoiding the loss of carriers caused by the sudden change in conductivity of a portion of the seed layer 103, thereby facilitating the formation of a good ohmic contact between the seed layer 103 and the substrate 100, and improving the carrier collection efficiency of the finally formed electrode.

[0088] In some embodiments, reference Fig. 9 , along the direction from the seed layer 103 to the conductive layer 104 , the seed layer 103 may include a transition layer 113 and a main layer 123 stacked in sequence.

[0089] In other embodiments, reference Fig.13 , along the direction from the seed layer 103 to the conductive layer 104, the seed layer 103 may include a transition layer 113, a diffusion barrier layer 133 and a main layer 123 stacked in sequence. In this way, the diffusion barrier layer 133 is used to block the diffusion of metal elements in the main layer 123 into the transition layer 113, further reducing the probability of metal elements in the main layer 123 diffusing into the substrate 100, thereby avoiding the problem of increased carrier recombination probability caused by the diffusion of metal elements in the main layer 123 into the substrate 100, thereby facilitating the improvement of the conductivity of the final electrode itself with the help of the main layer 123, and improving the contact performance between the final electrode and the substrate 100.

[0090] In some examples, the material of the diffusion barrier layer 133 may be titanium tungsten material. In some examples, along the second direction Y, the thickness of the diffusion barrier layer 133 may be 15 nm to 30 nm, for example, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm or 29 nm, etc.

[0091] In the above-mentioned various embodiments, the material of the transition layer 113 and the material of the substrate 100 contain the same semiconductor elements, so that the lattice of the transition layer 113 and the lattice of the substrate 100 are more adapted, which is beneficial to avoid the problem of large lattice mismatch between the transition layer 113 and the substrate 100, so as to avoid the problem of increased surface defects caused by lattice mismatch, and it is also beneficial to improve the adhesion between the transition layer 113 and the substrate 100, and enhance the contact performance between the finally formed electrode and the substrate 100; the material of the main layer 123 and the material of the transition layer 113 both contain metal elements.

[0092] In some examples, the material of the transition layer 113 may be an aluminum silicon material, and the material of the main layer 123 may be copper. In some examples, along the second direction Y, the thickness of the transition layer 113 may be 5nm-100nm, for example, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm or 95nm, etc.; along the second direction Y, the thickness of the main layer 123 may be 250nm-1000nm, for example, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm or 950nm, etc.

[0093] In summary, the seed layer 103 in the electrode is beneficial to improving the contact performance between the electrode and the substrate 100, and the seed layer 103 is formed by the photovoltaic cell manufacturing method provided in an embodiment of the present disclosure, which is beneficial to improving the dimensional accuracy of the formed seed layer 103, so as to improve the thickness uniformity of the seed layer 103 in the second direction Y, thereby improving the conductivity uniformity of each area in the electrode, so as to improve the photoelectric conversion efficiency of the photovoltaic cell.

[0094] Another embodiment of the present disclosure further provides a photovoltaic module, which is used to convert received light energy into electrical energy. The photovoltaic module provided by another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiments are not repeated here.

[0095] Combined with reference Fig.15 , Fig.16 and Figure 4The photovoltaic module includes: a cell string, which is formed by connecting a plurality of photovoltaic cells 40 formed by the manufacturing method of the photovoltaic cell provided in the above embodiment, or by connecting a plurality of photovoltaic cells 40 provided in the above embodiment; a packaging film 41, which is used to cover the surface of the cell string; and a cover plate 42, which is used to cover the surface of the packaging film 41 away from the cell string. The photovoltaic cells 40 are electrically connected in the form of a whole piece or multiple pieces to form a plurality of cell strings, and the plurality of cell strings are electrically connected in series and / or in parallel.

[0096] in, Fig.15 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure; Fig.16 for Fig.15 A schematic diagram of a cross-sectional structure along the cross-sectional direction MM1.

[0097] In some embodiments, the photovoltaic cell 40 includes, but is not limited to, one or any combination of PERC cells (Passivated Emitter Rear Cell), IBC cells (Interdigitated Back Contact), TOPCon cells (Tunnel Oxide Passivated Contact), HIT / HJT cells (Heterojunction Technology heterojunction cells), solar thin-film cells, and stacked cells. Among them, solar thin-film cells include, but are not limited to, perovskite solar thin-film cells, copper indium selenide solar thin-film cells, gallium arsenide solar thin-film cells, and cadmium sulfide solar thin-film cells. Stacked cells include, but are not limited to, perovskite cells superimposed on crystalline silicon cells, perovskite cells superimposed on perovskite cells, and perovskite cells superimposed on thin-film cells.

[0098] In some embodiments, the photovoltaic cell 40 may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell, and the multi-compound solar cell may be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell or a perovskite solar cell. In addition, the photovoltaic cell 40 may be a whole cell or a sliced ​​cell, and a sliced ​​cell refers to a cell formed by a complete whole cell through a cutting process.

[0099] In some embodiments, reference Fig.15 , multiple battery strings can be electrically connected through the conductive tape 402. Fig.15Only one positional relationship between photovoltaic cells is illustrated, that is, the arrangement direction of the electrodes with the same polarity of the cells is the same, or the electrodes with positive polarity of each cell are arranged toward the same side, so that the conductive strips connect different sides of two adjacent cells. In other embodiments, the cells can also be arranged in the order of electrodes with different polarities facing the same side, that is, the electrodes of multiple adjacent cells are arranged in the order of the first polarity, the second polarity, and the first polarity, and the conductive strips connect two adjacent cells on the same side.

[0100] In some embodiments, no intervals are set between the battery cells, that is, the battery cells overlap each other.

[0101] In some embodiments, the encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer, the first encapsulation layer covers one of the front or back sides of the photovoltaic cell 40, and the second encapsulation layer covers the other of the front or back sides of the photovoltaic cell 40. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film or polyethylene terephthalate (PET) film, or at least one of the first encapsulation layer or the second encapsulation layer can also be an EP film, EPE film or 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 stacking EVA film + POE film + EVA film in sequence, and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. The co-extruded film can be prepared by sequentially extruding one or more raw materials onto another already manufactured film during the film processing, or by bonding different types of already manufactured films together.

[0102] In some cases, there is a boundary between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0103] In some embodiments, the cover plate 42 may be a glass cover plate, a plastic cover plate or the like with a light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may be a concave-convex surface or a velvet surface including a plurality of convex structures, thereby increasing the utilization rate of the incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer.

[0104] In some embodiments, the photovoltaic cell 40 may be a busbar cell or a busbar-less cell.

[0105] In some cases, when the photovoltaic cell 40 is a main grid cell, the surface of the photovoltaic cell 40 has a plurality of main grids arranged at intervals along the third direction and a plurality of sub-grids arranged at intervals along the fourth direction, and the first direction can be set to one of the third direction or the fourth direction according to actual needs. In the process of constructing a battery string using the photovoltaic cell 40, the conductive tape 402 is electrically connected to at least one main grid on each of the two adjacent photovoltaic cells 40. The conductive tape 402 can be electrically connected to the main grid by welding with a pad, or the conductive tape 402 can be fixed on the main grid by glue points in advance, and the conductive tape 402 can be electrically connected to the main grid by using the fusion of the glue points and the deformation of the conductive tape 402 during the lamination process.

[0106] In other cases, when the photovoltaic cell 40 is a main grid-free cell, the surface of the photovoltaic cell 40 has a plurality of sub-grids arranged at intervals along the fourth direction, and the first direction is set as the fourth direction. In the process of constructing a battery string using the photovoltaic cell 40, the conductive tape 402 is electrically connected to the plurality of sub-grids on each of the two adjacent photovoltaic cells 40. The conductive tape 402 can be fixed at a specific position above the photovoltaic cell 40 by glue dots, and then the electrical connection between the conductive tape 402 and the sub-grids is achieved by utilizing the fusion of the glue dots and the deformation of the conductive tape 402 during the lamination process.

[0107] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A method for manufacturing a photovoltaic cell, characterized in that: include: Providing a substrate, the substrate comprising a first surface and a second surface arranged opposite to each other, at least one of the first surface and the second surface comprising metal areas and non-metal areas alternately arranged along a first direction; forming a seed film on at least one of the first surface and the second surface by a physical vapor deposition process; forming a mask layer on a side of the seed film away from the substrate, wherein the mask layer is only located on the metal region; Using the mask layer as an etching barrier, patterning the seed film to form a seed layer located only in the metal region, and removing the mask layer; An electroplating process is adopted to form a conductive layer on the seed layer.

2. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that: After providing the substrate and before forming the seed film, the method for manufacturing the photovoltaic cell further includes: forming a passivation layer on at least one of the first surface and the second surface, the passivation layer having an opening exposing at least a portion of the metal region; In the step of forming the seed film, the seed film is not only located in the opening, but also located on a side of the passivation layer away from the substrate.

3. The method for manufacturing a photovoltaic cell according to claim 2, characterized in that: After forming the passivation layer and before forming the seed film, the method for manufacturing the photovoltaic cell further includes: performing a high-temperature activation treatment on the substrate and the passivation layer.

4. The method for manufacturing a photovoltaic cell according to claim 1 or 2, characterized in that: The step of forming the seed film comprises: forming a transition film on at least one of the first surface and the second surface, wherein a material of the transition film and a material of the substrate contain the same semiconductor element; A main body film is formed on a side of the transition film away from the substrate, and materials of the main body film and the transition film both contain metal elements.

5. The method for manufacturing a photovoltaic cell according to claim 4, characterized in that: The steps of patterning the seed film and removing the mask layer include: Using the mask layer as an etching barrier layer, and using a first etching solution to remove the main film located on the non-metallic area; Using a second etching solution to remove the mask layer and the transition film located on the non-metallic area; The transition film remaining in the metal area serves as a transition layer, and the main film remaining in the metal area serves as a main layer.

6. The method for manufacturing a photovoltaic cell according to claim 4, characterized in that: After forming the transition film and before forming the main film, the step of forming the seed film further includes: forming a diffusion barrier film on a side of the transition film away from the substrate; The step of forming the seed film includes forming the main film on a side of the diffusion barrier film away from the transition film.

7. The method for manufacturing a photovoltaic cell according to claim 6, characterized in that: The step of patterning the seed film comprises: Using the mask layer as an etching barrier layer, and using a third etching solution to remove the main film located on the non-metallic area, and to remove the diffusion barrier film located on the non-metallic area; Using a second etching solution to remove the mask layer and the transition film located on the non-metallic area; The transition film remaining in the metal region serves as a transition layer, the diffusion barrier film remaining in the metal region serves as a diffusion barrier layer, and the main film remaining in the metal region serves as a main layer.

8. The method for manufacturing a photovoltaic cell according to claim 1, characterized in that: The step of forming the mask layer comprises: Using a screen printing process to form the mask layer on a side of the seed film located on the metal region away from the substrate; or, An initial mask layer is formed on a side of the seed film away from the substrate, and the initial mask layer is exposed and developed to finally form the mask layer located on the metal region.

9. A photovoltaic cell, characterized in that: include: A substrate, the substrate comprising a first surface and a second surface arranged opposite to each other, at least one of the first surface and the second surface comprising metal areas and non-metal areas alternately arranged along a first direction; A seed layer, located only on the metal region; The conductive layer is located on a side of the seed layer away from the substrate.

10. The photovoltaic cell according to claim 9, characterized in that: Also includes: A passivation layer is located on at least one of the first surface and the second surface, and the passivation layer has an opening exposing at least a portion of the metal region, and the seed layer is at least located in the opening.

11. The photovoltaic cell according to claim 9, characterized in that: In the direction from the seed layer to the conductive layer, the seed layer includes a transition layer and a main layer stacked in sequence; or, in the direction from the seed layer to the conductive layer, the seed layer includes the transition layer, the diffusion barrier layer and the main layer stacked in sequence.

12. A photovoltaic module, characterized in that: include: A cell string, formed by connecting a plurality of photovoltaic cells formed by the method for manufacturing a photovoltaic cell according to any one of claims 1 to 8, or formed by connecting a plurality of photovoltaic cells according to any one of claims 9 to 11; A packaging film, used to cover the surface of the battery string; The cover plate is used to cover the surface of the packaging film facing away from the battery string.

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