Solar cell and method of manufacturing the same, photovoltaic module, and photovoltaic system

Abstract

The application is suitable for the technical field of solar cells, and provides a solar cell, a preparation method thereof, a photovoltaic module and a photovoltaic system, which comprise: a silicon substrate comprising opposite first and second surfaces; a doped layer arranged on at least one of the first and second surfaces; a passivation layer arranged on a side of the doped layer away from the silicon substrate and comprising a through hole; a seed layer connected with the doped layer through the through hole; the passivation layer comprises a first injection part at least partially in contact with the seed layer; the injection material corresponding to the first injection part comprises a main preparation material of the seed layer; and the main preparation material is a preparation material with the largest mass ratio.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and in particular relates to a solar cell and its preparation method, photovoltaic module and photovoltaic system. Background Technology

[0002] In related technologies, electroplating is commonly used to fabricate the grid lines of solar cells. The seed layer is a crucial foundational layer in the electroplating process, its core function being to provide a conductive substrate for subsequent metal plating. However, the adhesion between the seed layer and the passivation layer is typically poor, and strong adhesion between the seed layer and the silicon substrate is also difficult to achieve. Therefore, improving the adhesion between the seed layer and the passivation film or to the silicon substrate has become an urgent problem to be solved. Summary of the Invention

[0003] This application provides a solar cell and its preparation method, a photovoltaic module and a photovoltaic system, which aims to solve the problems that the seed layer usually has poor adhesion to the silicon substrate and that it is difficult to form strong adhesion between the passivation layer and the seed layer.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] In a first aspect, a solar cell is provided, comprising: a silicon substrate including opposing first and second surfaces; a doped layer disposed on at least one of the first and second surfaces; a passivation layer disposed on the side of the doped layer away from the silicon substrate, including vias; a seed layer, the seed layer passing through the vias and connected to the doped layer; the passivation layer including a first injection portion, the first injection portion being at least partially in contact with the seed layer; the injection material corresponding to the first injection portion including the main preparation material of the seed layer; the main preparation material being the preparation material with the largest mass percentage.

[0006] In some embodiments, the first injection portion is disposed at the contact position between the passivation layer and the seed layer, including at least a first injection portion disposed on the top of the passivation layer that contacts the seed layer.

[0007] In some embodiments, the first injection portion is disposed at the contact position between the passivation layer and the seed layer, and the first injection portion further includes a first injection portion disposed on the sidewall of the passivation layer that contacts the seed layer.

[0008] In some embodiments, the first injection portion is further disposed at a position where the passivation layer and the seed layer are not in contact, including at least a first injection portion disposed on the top of the passivation layer that is not in contact with the seed layer.

[0009] In some embodiments, the first injection portion is further disposed at a position where the passivation layer and the seed layer are not in contact, including at least a first injection portion disposed on the top of the passivation layer that is not in contact with the seed layer.

[0010] In some embodiments, the first injection portion is disposed on the entire surface of the passivation layer.

[0011] In some embodiments, the size of the first implantation portion in the thickness direction of the silicon substrate is 3 nm to 200 nm.

[0012] In some embodiments, the doped layer includes a second injection portion; the injection material of the second injection portion includes the main preparation material of the seed layer; and the location of the via corresponds at least partially to the second injection portion.

[0013] In some embodiments, the size of the implanted portion in the thickness direction of the silicon substrate is 3 nm to 300 nm.

[0014] In some embodiments, the second injection portion includes a third injection portion and a fourth injection portion; the third injection portion corresponds to the passivation layer covered area in the second injection portion; and the fourth injection portion corresponds to the passivation layer not covered area in the second injection portion.

[0015] In some embodiments, the dimension of the third implantation portion in the silicon substrate thickness direction is greater than or equal to the dimension of the fourth implantation portion in the silicon substrate thickness direction.

[0016] In some embodiments, the main preparation material is one of Al, Ag, Cu, and Mg.

[0017] In some embodiments, the mass percentage of the main preparation material is greater than 50%.

[0018] In some embodiments, in addition to the main preparation material, the seed layer preparation material may also include one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V.

[0019] In some embodiments, the injection material of the first injection portion or the second injection portion further includes one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V.

[0020] In some embodiments, the system further includes a first alloy layer and a metal layer; the first alloy layer and the metal layer are stacked sequentially on the side of the seed layer away from the silicon substrate.

[0021] In some embodiments, the materials used to prepare the metal layer include one or more of Cu, Al, and Ag.

[0022] In some embodiments, the first alloy layer includes an Al-Cu alloy layer and / or an Al-Cu-Ti alloy layer.

[0023] In some embodiments, the material composition of the Al-Cu alloy layer includes Al2Cu, , One or more of Al4Cu9.

[0024] In some embodiments, a first protective layer is further included, which is disposed on the side of the metal layer away from the silicon substrate; the material composition of the first protective layer includes one or more of Sn, Ni, Ag, and Zn.

[0025] In some embodiments, a second protective layer is further included; the second protective layer is disposed on the side of the first protective layer away from the silicon substrate; the material used to prepare the second protective layer includes an oxide corresponding to the material used to prepare the first protective layer.

[0026] In some embodiments, a second alloy layer is further included; the second alloy layer is disposed between the first protective layer and the metal layer; the second alloy layer includes a Sn-Cu alloy layer.

[0027] In some embodiments, the doped layer includes a first doped layer and a second doped layer, which are alternately disposed on a first surface of a silicon substrate; a passivation layer is disposed on the side of the first and second doped layers away from the silicon substrate, and includes vias corresponding to the first and second doped layers; a seed layer passes through the vias corresponding to the first and second doped layers and is connected to the corresponding doped layers; a first implantation portion is disposed on the passivation layer on at least one of the first and second doped layers and contacts a portion of the seed layer disposed thereon.

[0028] In some embodiments, an isolation region is further provided between the first doped layer and the second doped layer.

[0029] In some embodiments, the doped layer includes a first doped layer and a second doped layer, the first doped layer being disposed on a first surface of a silicon substrate and the second doped layer being disposed on a second surface of the silicon substrate; a passivation layer being disposed on the side of the first and second doped layers away from the silicon substrate, including vias corresponding to the first and second doped layers; a seed layer passing through the vias corresponding to the first and second doped layers and connecting to the corresponding doped layers; and a first implantation portion being disposed on the passivation layer on at least one of the first and second doped layers and in contact with a portion of the seed layer disposed thereon.

[0030] In a second aspect, a method for fabricating a solar cell is provided, comprising: providing a silicon substrate, the silicon substrate including opposing first and second surfaces; forming a doped layer on at least one of the first and second surfaces; forming a passivation layer on a side of the doped layer away from the silicon substrate; the passivation layer including vias; forming a seed layer on the doped layer based on the vias; the passivation layer including a first implantation portion; the implantation material corresponding to the first implantation portion including the main preparation material of the seed layer; the main preparation material being the preparation material with the largest mass percentage.

[0031] In some embodiments, before forming the seed layer, the method further includes: injecting implantation material into the doped layer through a via to form a second implantation portion; the implantation material of the second implantation portion includes the main preparation material of the seed layer; the location of the via at least partially corresponds to the second implantation portion.

[0032] In some embodiments, the method further includes: forming a metal layer on the side of the seed layer opposite to the silicon substrate; and performing an annealing process to form a first alloy layer between the metal layer and the seed layer.

[0033] Thirdly, the present invention provides a solar cell, which is made by the solar cell preparation method described above.

[0034] Fourthly, the present invention provides a photovoltaic module, which includes any of the possible solar cells described above.

[0035] Fifthly, the present invention provides a photovoltaic system, which includes the photovoltaic modules described above.

[0036] The beneficial effects of this invention are as follows:

[0037] The solar cells, their fabrication methods, photovoltaic modules, and photovoltaic systems of this application embodiment, since the passivation layer includes a first injection portion and the injection material corresponding to the first injection portion includes the main fabrication material of the seed layer, can improve the bonding force between the passivation layer and the seed layer. External stress is mainly applied to the edge between the electrode and the seed layer. In actual implementation, the seed layer and the electrode are wider than the vias on the passivation layer. Therefore, increasing the bonding force between the seed layer and the passivation layer, so that they do not detach under applied stress, can prevent stress that may cause failure from being transmitted to the contact interface between the seed layer and the silicon substrate, thereby protecting the contact interface between the seed layer and the silicon substrate. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0042] Figure 5 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0043] Figure 6 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0044] Figure 7 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0045] Figure 8 This is a schematic flowchart of a method for fabricating a solar cell according to an embodiment of this application;

[0046] Figure 9 This is a schematic flowchart of a method for preparing a solar cell according to another embodiment of this application;

[0047] Figure 10 This is a schematic flowchart of a method for preparing a solar cell according to another embodiment of this application.

[0048] Explanation of key component symbols: Solar cell 10; Silicon substrate 11; Doped layer 12; First implantation layer 13; Passivation layer 14; Seed layer 15; First doped layer 121; Second doped layer 122; Tunneling layer 16; First tunneling layer 161; Second tunneling layer 162; First alloy layer 17; Metal layer 18; First protective layer 19; Second protective layer 20; Second alloy layer 21; Second implantation layer 22; Third implantation layer 23; Fourth implantation layer 24. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0050] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and 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 of this application.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0054] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0055] According to one aspect of this application, a solar cell 10 is provided, such as... Figure 1 As shown, it includes: a silicon substrate 11; including opposing first and second surfaces;

[0056] A doped layer 12 is disposed on at least one of the first surface and the second surface;

[0057] Passivation layer 14 is disposed on the side of doped layer 12 away from silicon substrate 11 and includes vias;

[0058] Seed layer 15 passes through a via and is connected to doped layer 12; passivation layer 14 includes first injection portion 13, which is at least partially in contact with seed layer 15; the injection material corresponding to first injection portion 13 includes the main preparation material of seed layer 15; the main preparation material is the preparation material with the largest mass percentage.

[0059] In the solar cells, their fabrication methods, photovoltaic modules, and photovoltaic systems of this application embodiment, since the passivation layer 14 includes a first injection portion 13 and the injection material corresponding to the first injection portion 13 includes the main fabrication material of the seed layer 15, the bonding force between the passivation layer 14 and the seed layer 15 can be improved. External stress is mainly applied to the edge between the electrode and the seed layer 15. In actual implementation, the seed layer 15 and the electrode are wider than the vias on the passivation layer. Therefore, increasing the bonding force between the seed layer 15 and the passivation layer 14, so that they do not detach under applied stress, can prevent stress that may cause failure from being transmitted to the contact interface between the seed layer 15 and the silicon substrate 11, thereby protecting the contact interface between the seed layer 15 and the silicon substrate 11.

[0060] It should be noted that the first injection portion 13 may exist in the entire passivation layer 14 or in a portion of the passivation layer 14. The specific location of the first injection portion 13 will be described below based on the following embodiments:

[0061] In one embodiment, as described above Figure 1 As shown, the first injection section 13 is disposed at the contact position between the passivation layer 14 and the seed layer 15, and includes at least the first injection section 13 disposed on the top of the passivation layer 14 that contacts the seed layer 15.

[0062] Specifically, the first injection portion 13 exists only at the contact position between the top of the passivation layer 14 and the seed layer 15, while the first injection portion 13 does not exist at the non-contact position between the top of the passivation layer 14 and the seed layer 15, and the first injection portion 13 exists at the partial contact position between the sidewall of the passivation layer 14 and the seed layer 15. The thickness of the first injection portion 13 can be less than the thickness of the passivation layer 14, or the thickness of the first injection portion 13 can be equal to the thickness of the passivation layer 14.

[0063] Thus, the first injection section 13 exists only at the contact position between the top of the passivation layer 14 and the seed layer 15, and the injection material corresponding to the first injection section 13 includes the main preparation material of the seed layer. In this way, the bonding force between the passivation layer 14 and the seed layer 15 can be improved, and the use of injection material can be reduced, thereby reducing the manufacturing cost of solar cells.

[0064] In some embodiments, such as Figure 2 As shown, in Figure 1Based on this, the first injection section 13 is disposed at the contact position between the passivation layer 14 and the seed layer 15, and the first injection section 13 also includes a first injection section 13 disposed on the side wall of the passivation layer 14 that contacts the seed layer 15.

[0065] Specifically, the first injection portion 13 exists at the contact position between the top of the passivation layer 14 and the seed layer 15, and also exists at the contact position between the sidewall of the passivation layer 14 and the seed layer 15, while the first injection portion 13 does not exist at the non-contact position between the top of the passivation layer 14 and the seed layer 15.

[0066] Thus, the first injection portion 13 exists at the contact position between the top of the passivation layer 14 and the seed layer 15, and at the contact position between the sidewall of the passivation layer 14 and the seed layer 15. The injection material corresponding to the first injection portion 13 includes the main preparation material of the seed layer. In this way, the bonding force between the sidewall of the passivation layer 14 and the seed layer 15 can be improved, further enhancing the bonding force between the passivation layer 14 and the seed layer 15, and reducing the use of injection material, thereby reducing the manufacturing cost of solar cells.

[0067] In one embodiment, such as Figure 3 As shown, in Figure 1 Based on this, the first injection section 13 is also provided at a non-contact position between the passivation layer 14 and the seed layer 15, including at least a first injection section 13 provided on the top of the passivation layer 14 that does not contact the seed layer 15.

[0068] Specifically, the first injection portion 13 exists at the contact position between the top of the passivation layer 14 and the seed layer 15, and also exists at the non-contact position between the top of the passivation layer 14 and the seed layer 15. The first injection portion 13 exists at a partial contact position between the sidewall of the passivation layer 14 and the seed layer 15, or the first injection portion 13 does not exist at the contact position between the sidewall of the passivation layer 14 and the seed layer 15.

[0069] Thus, the first injection portion 13 exists at the contact and non-contact positions between the top of the passivation layer 14 and the seed layer 15. The injection material corresponding to the first injection portion 13 includes the main preparation material of the seed layer. This can improve the bonding force between the passivation layer 14 and the seed layer 15, reduce the use of injection material, and lower the manufacturing cost of solar cells.

[0070] In some embodiments, such as Figure 4 As shown, in Figure 3 Based on this, the first injection section 13 is also provided at a non-contact position between the passivation layer 14 and the seed layer 15, including at least a first injection section 13 provided on the top of the passivation layer 14 that does not contact the seed layer 15.

[0071] Specifically, the first injection portion 13 exists at the contact position between the top of the passivation layer 14 and the seed layer 15, as well as at the non-contact position between the top of the passivation layer 14 and the seed layer 15, and at the contact position between the sidewall of the passivation layer 14 and the seed layer 15.

[0072] Thus, the first injection portion 13 exists at the contact and non-contact positions between the top of the passivation layer 14 and the seed layer 15, and at the contact positions between the sidewall of the passivation layer 14 and the seed layer 15. The injection material corresponding to the first injection portion 13 includes the main preparation material of the seed layer. This can improve the bonding force between the sidewall and top of the passivation layer 14 and the seed layer 15, further improve the bonding force between the passivation layer 14 and the seed layer 15, and reduce the use of injection material, thereby reducing the manufacturing cost of the solar cell. In addition, since the top of the passivation layer 14 is at the contact and non-contact positions with the seed layer 15, it is easier to prepare the first injection portion 13, saving process steps.

[0073] In some embodiments, such as Figure 5 As shown, the first injection portion 13 is disposed on the entire surface of the passivation layer 14.

[0074] Specifically, the entire surface of the passivation layer 14 may include P-regions, N-regions, and an isolation region between the P-regions and N-regions.

[0075] Thus, the first injection portion 13 is disposed on the entire surface of the passivation layer 14, which can improve the bonding force between the sidewalls and top of the passivation layer 14 and the seed layer 15, further improving the bonding force between the passivation layer 14 and the seed layer 15. It also eliminates the need to prepare the first injection portion 13 in separate regions, simplifying the preparation process of the first injection portion 13 and improving the preparation efficiency of the solar cell.

[0076] In some embodiments, the size of the first implantation portion 13 in the thickness direction of the silicon substrate is 3nm to 200nm. For example, it can be any value between 3nm, 50nm, 100nm, 150nm, 200nm or 3nm to 200nm, and is not limited herein.

[0077] Thus, the size of the first injection portion 13 in the thickness direction of the silicon substrate 11 is within a suitable range, which can avoid the first injection portion 13 being too large in the thickness direction of the silicon substrate 11, thus affecting the passivation effect, and can also avoid the first injection portion 13 being too small in the thickness direction of the silicon substrate 11, thus preventing it from forming a strong bonding force between the seed layer 15 and the silicon substrate 11.

[0078] In some embodiments, the doped layer 12 includes a second injection portion 22; the injection material of the second injection portion 22 includes the main preparation material of the seed layer 15; the location of the via corresponds at least partially to the second injection portion 22.

[0079] Understandably, since the doped layer 12 includes a second injection portion 22, that is, the seed layer 15 passes through the via and is connected to the second injection portion 22 of the doped layer 12, and the injection material of the second injection portion 22 includes the main preparation material of the seed layer 15, the second injection portion 22 of the doped layer 12 forms a connection bridge between the seed layer 15 and the silicon substrate 11, thereby improving the bonding force between the seed layer 15 and the silicon substrate 11.

[0080] In one embodiment of the present invention, the first surface is a light-receiving surface, and the second surface is disposed on the other side of the silicon substrate 11 relative to the first surface; that is, the first surface and the second surface are located on different sides and opposite sides of the silicon substrate 11. In this embodiment, the silicon substrate 11 is an N-type monocrystalline silicon wafer. It is understood that in other embodiments, the silicon substrate 11 may also be other types of silicon wafers such as polycrystalline silicon wafers or quasi-monocrystalline silicon wafers. The type of the silicon substrate 11 may also be set to P-type. The silicon substrate 11 is set according to the actual use needs, and no specific limitation is made here.

[0081] In one embodiment of the present invention, the passivation layer 14 is one or more combinations of an oxide layer, a silicon carbide layer, and an amorphous silicon layer. As examples of the present invention, the passivation layer 14 can be an oxide layer of a single material, a combination of oxide layers of multiple materials and amorphous silicon layers, or a combination of multiple layers of amorphous silicon with different refractive indices of a single material. Furthermore, the passivation layer 14 can also be a silicon oxynitride layer, a silicon nitride layer, etc. It is understood that the specific structural arrangement of the passivation layer 14 includes, but is not limited to, the several arrangements listed above. The passivation layer 14 is configured according to actual usage needs and is not specifically limited here.

[0082] In one embodiment of the present invention, a passivation layer 14 exists between a portion of the seed layer 15 and the silicon substrate 11, while another portion of the seed layer 15 does not have a passivation layer 14 between it and the silicon substrate 11, but instead connects to the second injection portion 22 through a via.

[0083] It should be noted that the injection material of the first injection section 13 includes not only the main preparation material of the seed layer 15, but may also include other preparation materials of the seed layer 15, which is not limited here. The main preparation material of the first injection section 13 is different from the main preparation material of the seed layer 15. For example, the main preparation material of the first injection section 13 is silicon.

[0084] The doped layer 12 can be formed by diffusion into the silicon substrate 11 or by deposition of a film on the silicon substrate 11 through ion implantation or other methods.

[0085] The doped layer 12 may include a first doped layer 121 and a second doped layer 122 with different doping polarities.

[0086] The first doped layer 121 and the second doped layer 122 are respectively a P-doped layer 12 and an N-doped layer 12.

[0087] The P-doped layer 12 and the N-doped layer 12 can be doped polycrystalline silicon layers. The N-doped layer 12 is doped with an N-type element, specifically a group VA element of the periodic table, for example, phosphorus. The P-doped layer 12 is doped with a P-type element, specifically a group IIIA element of the periodic table, for example, boron.

[0088] In some embodiments, a tunneling layer 16 is further included between the silicon substrate 11 and the doped layer 12.

[0089] In some embodiments, the second implantation portion 22 has a dimension of 3 nm to 300 nm in the thickness direction of the silicon substrate 11. For example, it can be any value between 3 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm or 3 nm to 300 nm, and there is no specific limitation here.

[0090] Thus, the size of the second injection portion 22 in the thickness direction of the silicon substrate 11 is within a suitable range, which can avoid the second injection portion 22 being too large in the thickness direction of the silicon substrate 11, which would affect the conductivity of the doped layer 12. It can also avoid the second injection portion 22 being too small in the thickness direction of the silicon substrate 11, which would result in the connection bridge between the seed layer 15 formed therein being too narrow, making it impossible to form a strong bonding force between the seed layer 15 and the silicon substrate 11.

[0091] In some embodiments, the second injection portion 22 includes a third injection portion 23 and a fourth injection portion 24; the third injection portion 23 corresponds to the passivation layer covered area in the second injection portion 22; and the fourth injection portion corresponds to the passivation layer not covered area in the second injection portion 22.

[0092] In this way, the passivation layer 14 can shield part of the second injection portion 22, thereby improving the adhesion between the second injection portion 22 and the silicon substrate 11. Since the injection material of the second injection portion 22 includes the main preparation material of the seed layer 15, the adhesion between the seed layer 15 and the silicon substrate 11 is also improved.

[0093] In some embodiments, the dimension of the third implantation portion 23 in the thickness direction of the silicon substrate 11 is greater than or equal to the dimension of the fourth implantation portion 24 in the thickness direction of the silicon substrate 11.

[0094] It needs to be explained, such as Figures 1-5 As shown, the doped layer 12 may include grooves corresponding to the vias, meaning the doped layer 12 is in a relatively uneven state; of course, as Figure 6As shown, the doped layer 12 may also not include the groove corresponding to the through hole, that is, the doped layer 12 is in a relatively flat state. When the doped layer 12 does not include the groove corresponding to the through hole, the arrangement of the first injection part 13 can be referred to as follows. Figures 1-5 The corresponding explanations will not be elaborated here.

[0095] Specifically, when the doped layer 12 does not include the groove corresponding to the via, the dimension of the third implantation portion 23 in the thickness direction of the silicon substrate 11 is equal to the dimension of the fourth implantation portion 24 in the thickness direction of the silicon substrate 11.

[0096] When the doped layer 12 includes a groove corresponding to a via, the dimension of the third implantation portion 23 in the thickness direction of the silicon substrate 11 is larger than the dimension of the fourth implantation portion 24 in the thickness direction of the silicon substrate 11. In this case, the sidewalls of the seed layer 15 are connected to the passivation layer 14 and the third implantation portion 23 of the doped layer 12, respectively, which increases the contact area between the seed layer 15 and the doped layer 12, increases the friction between the seed layer 15 and the doped layer 12, and thus improves the bonding force between the seed layer 15 and the silicon substrate 11.

[0097] In practical applications, the grooves corresponding to the vias in the doped layer 12 can be formed when the vias in the passivation layer 14 are formed.

[0098] In some embodiments, the main material for preparing the seed layer 15 is one of Al, Ag, Cu, and Mg.

[0099] Understandably, Al, Ag, Cu, and Mg have good electrical conductivity, which can effectively reduce series resistance and improve carrier collection efficiency.

[0100] In some embodiments, the mass percentage of the main preparation material is greater than 50%. For example, it can be any value between 60%, 70%, 80%, 90%, 100% or 50%-100%, and there is no specific limitation here.

[0101] This ensures the stable performance of the main material properties; for example, high-purity silicon can improve photoelectric conversion efficiency; reduce impurity interference and enhance material uniformity and stability; simplify the preparation process and reduce control difficulty; improve the bonding force with subsequent layers and ensure the overall performance and lifespan of the battery; and at the same time optimize the cost structure and reduce the overall cost while ensuring performance.

[0102] In some embodiments, the solar cell 10 further includes a tunneling layer 16 located between the silicon substrate 11 and the doped layer 12.

[0103] The tunneling layer 16 and the doped layer 12 are stacked together.

[0104] For example, the material used to prepare the tunneling layer 16 can be one or more of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride.

[0105] This reduces interfacial recombination losses, increases the open-circuit voltage and fill factor of the battery, and thus improves the photoelectric conversion efficiency of the battery.

[0106] In some embodiments, the seed layer 15 is an alloy material. Besides the main preparation material, the seed layer 15 may also include one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V. Preferably, the content of the main preparation material in the seed layer 15 is >50%. More preferably, the main preparation material of the seed layer 15 is Al, with a content ≥70%; the auxiliary preparation material is Ti, with a content ≤30%; or, the main preparation material is Al, with a content ≥70%; the auxiliary preparation material is W, with a content ≤30%; or, the main preparation material is Al, with a content ≥70%; the auxiliary preparation material is Ti, with a content ≤30%; or, the main preparation material is Al, with a content ≥70%; the auxiliary preparation material is Mo, with a content ≤30%.

[0107] Understandably, Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V and their nitrides exhibit strong oxidation resistance and good thermal stability. Overall, these metals can optimize the conductivity, adhesion, and thermal stability of the seed layer 15.

[0108] In some embodiments, the injection material of the first injection section 13 or the second injection section 22 may further include one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V.

[0109] In some embodiments, the solar cell 10 further includes a first alloy layer 17 and a metal layer 18; the first alloy layer 17 and the metal layer 18 are stacked sequentially on the side of the seed layer 15 away from the silicon substrate 11.

[0110] In this way, a functionally layered composite electrode structure can be constructed, which effectively blocks the diffusion of metal layer 18 atoms into seed layer 15, prevents contamination and performance degradation, and enhances the long-term stability and reliability of the electrode.

[0111] In some embodiments, the material used to prepare the metal layer 18 includes one or more of Cu, Al, and Ag.

[0112] In this way, Cu, Al, and Ag can give metal layer 18 good conductivity, reduce series resistance, and improve battery efficiency.

[0113] In some embodiments, the first alloy layer 17 includes an Al-Cu alloy layer and / or an Al-Cu-Ti alloy layer.

[0114] In this way, the properties of multiple metals can be combined to improve the thermal stability of the alloy layer and enhance its bonding with the upper and lower layers (seed layer 15 and metal layer 18).

[0115] In some embodiments, the material composition of the Al-Cu alloy layer includes Al2Cu (θ phase). (η2 phase) One or more of the following: (ζ2 phase) and Al4Cu9 (γ1 phase).

[0116] In this way, a deterministic compound phase can provide stable contact resistance and excellent thermodynamic stability, effectively suppressing element interdiffusion, thereby improving the electrode's conductivity reliability, mechanical strength and long-term service performance.

[0117] In some embodiments, the solar cell 10 further includes a first protective layer 19, which is disposed on the side of the metal layer 18 away from the silicon substrate 11; the material composition of the first protective layer 19 includes one or more of Sn, Ni, Ag, and Zn.

[0118] Understandably, this protective layer provides an antioxidant and corrosion-resistant barrier in exposed environments, effectively preventing moisture, oxygen, and pollutants from eroding the underlying metal electrode, thereby significantly improving the long-term environmental stability and reliability of the electrode.

[0119] In some embodiments, the solar cell 10 further includes a second protective layer 20; the second protective layer 20 is disposed on the side of the first protective layer 19 away from the silicon substrate 11; the material for the preparation of the second protective layer 20 includes an oxide corresponding to the material for the preparation of the first protective layer 19.

[0120] For example, the material composition of the first protective layer 19 includes Sn, and the material used to prepare the second protective layer 20 includes an oxide of Sn; or, for example, the material composition of the first protective layer 19 includes Ni, Ag, and Zn, and the material used to prepare the second protective layer 20 includes an oxide of Ni, an oxide of Ag, and an oxide of Zn.

[0121] In some embodiments, the solar cell 10 further includes a second alloy layer 21; the second alloy layer 21 is disposed between the first protective layer 19 and the metal layer 18; the second alloy layer 21 includes a Sn-Cu alloy layer.

[0122] The second alloy layer 21, the first protective layer 19, and the metal layer 18 are stacked together.

[0123] In this way, a functionally layered composite electrode structure can be constructed, effectively blocking the diffusion of atoms from the first protective layer 19 to the metal layer 18, preventing contamination and performance degradation, and enhancing the long-term stability and reliability of the electrode.

[0124] It should be noted that the embodiments of this application provide a solar cell 10, which can be a bifacial solar cell, a back-contact solar cell, etc., and is not limited thereto.

[0125] In some embodiments, the solar cell 10 is a back-contact solar cell, the doped layer 12 includes a first doped layer 121 and a second doped layer 122, the first doped layer 121 and the second doped layer 122 are alternately disposed on the first surface of the silicon substrate 11; a passivation layer 14 is disposed on the side of the first doped layer 121 and the second doped layer 122 away from the silicon substrate 11, including through holes corresponding to the first doped layer 121 and the second doped layer 122; a seed layer 15 passes through the through holes corresponding to the first doped layer 121 and the second doped layer 122 and is connected to the corresponding doped layer; a first injection portion 13 is disposed on the passivation layer 14 on at least one of the first doped layer 121 and the second doped layer 122, and partially contacts the seed layer 15 disposed thereon.

[0126] Specifically, the first implantation portion 13 can be disposed on the passivation layer 14 on the first doped layer 121 and partially contact the seed layer 15 disposed thereon. Alternatively, the first implantation portion 13 can be disposed on the passivation layer 14 on the second doped layer 122 and partially contact the seed layer 15 disposed thereon. Alternatively, the first implantation portion 13 can be disposed on the passivation layer 14 corresponding to the first doped layer 121 and the passivation layer 14 on the second doped layer 122, and partially contact the seed layer 15 disposed thereon.

[0127] This increases the flexibility of the preparation process for the first injection section 13.

[0128] When both the P-region and the N-region are located on the first surface (i.e., the back side) of the silicon substrate 11, the P-region and the N-region are isolated by an isolation region. A first doped layer 121 and a second doped layer 122 are alternately arranged on the back side of the silicon substrate 11; the tunneling layer 16 may include a first tunneling layer 161 and a second tunneling layer 162. The second tunneling layer 162 may be a P-tunneling layer, and the first tunneling layer 161 may be an N-tunneling layer. One of the first doped layer 121 and the second doped layer 122 is a P-doped layer, and the other is an N-doped layer.

[0129] For example, when both the P-region and the N-region are located on the back side of the silicon substrate 11, the second doped layer 122 can be a P-doped layer 12, and the first doped layer 121 can be an N-doped layer; the second tunneling layer 162 can be a P-tunneling layer, and the first tunneling layer 161 can be an N-tunneling layer. The P-region and the N-region are isolated by an isolation region.

[0130] In some embodiments, an isolation region is further provided between the first doped layer 121 and the second doped layer 122.

[0131] This effectively prevents lateral diffusion and electrical crosstalk between the two. The isolation structure improves the electrical isolation of the doped regions, ensuring independent and stable electrical characteristics in each region, thereby enhancing the consistency and reliability of device performance.

[0132] In some embodiments, the solar cell 10 is a bifacial solar cell, such as Figure 6 As shown, the doped layer 12 includes a first doped layer 121 and a second doped layer 122. The first doped layer 121 is disposed on a first surface of the silicon substrate 11, and the second doped layer 122 is disposed on a second surface of the silicon substrate 11. A passivation layer 14 is disposed on the side of the first doped layer 121 and the second doped layer 122 away from the silicon substrate 11, and includes vias corresponding to the first doped layer 121 and the second doped layer 122. A seed layer 15 passes through the vias corresponding to the first doped layer 121 and the second doped layer 122 and is connected to the corresponding doped layer 12. A first implantation portion 13 is disposed on the passivation layer on at least one of the first doped layer 121 and the second doped layer 122, and partially contacts the seed layer 15 disposed thereon.

[0133] Specifically, the first implantation portion 13 can be disposed on the passivation layer 14 on the first doped layer 121 and partially contact the seed layer 15 disposed thereon. Alternatively, the first implantation portion 13 can be disposed on the passivation layer 14 on the second doped layer 122 and partially contact the seed layer 15 disposed thereon. Alternatively, the first implantation portion 13 can be disposed on the passivation layer 14 corresponding to the first doped layer 121 and the passivation layer 14 on the second doped layer 122, and partially contact the seed layer 15 disposed thereon.

[0134] When the solar cell 10 is a bifacial solar cell, the P-region and the N-region are located on opposite sides of the silicon substrate 11. One of the P-regions is located on the first surface of the silicon substrate 11, and the other is located on the second surface of the silicon substrate 11. When the P-region and the N-region are located on opposite sides of the silicon substrate 11, a P-doped layer 12 is disposed on one of the first surface and the N-doped layer 12 is disposed on the other.

[0135] With the P-region located on the front side of the silicon substrate 11 and the N-region located on the back side of the silicon substrate 11, the P-region can completely cover the front side of the silicon substrate 11 or only cover a portion of the front side; the N-region can completely cover the back side of the silicon substrate 11 or only cover a portion of the back side. There can also be multiple P-regions and N-regions. For example, if the P-regions cover a portion of the front side of the silicon substrate 11, with adjacent P-regions spaced apart, and the N-regions only cover a portion of the back side of the silicon substrate 11, with adjacent N-regions spaced apart, parasitic photoabsorption can be reduced.

[0136] This increases the flexibility of the preparation process for the first injection section 13.

[0137] According to one aspect of this application, a method for preparing a solar cell 10 is provided, such as... Figure 7 As shown, the preparation method for preparing the above-mentioned solar cell 10 includes:

[0138] S201, Provides silicon substrate 11.

[0139] The silicon substrate 11 includes a first surface and a second surface opposite to each other.

[0140] In one embodiment of the present invention, the first surface is a light-receiving surface, and the second surface is disposed on the other side of the silicon substrate 11 relative to the first surface; that is, the first surface and the second surface are located on different sides and opposite sides of the silicon substrate 11. In this embodiment, the silicon substrate 11 is an N-type monocrystalline silicon wafer. It is understood that in other embodiments, the silicon substrate 11 may also be other types of silicon wafers such as polycrystalline silicon wafers or quasi-monocrystalline silicon wafers. The type of the silicon substrate 11 may also be set to P-type. The silicon substrate 11 is set according to the actual use needs, and no specific limitation is made here.

[0141] As one possible approach, after obtaining the original silicon substrate 11, the original silicon substrate 11 can be cleaned to remove organic matter, metal impurities, and particles from its surface, thus obtaining the silicon substrate 11.

[0142] In one example, the raw silicon substrate 11 can be cleaned using the RCA standard cleaning method.

[0143] S202, a doped layer 12 is formed on at least one of the first surface and the second surface.

[0144] The doped layer 12 includes a second implantation portion 22.

[0145] As one possible implementation, the silicon substrate 11 can be placed in a deposition apparatus and silane gas can be introduced into the deposition apparatus to deposit a doped polysilicon layer on at least one surface of the silicon substrate 11 to form a doped layer 12.

[0146] In one example, the deposition equipment can be LPCVD or PECVD.

[0147] Specifically, a doped layer 12 can be formed through phosphorus diffusion.

[0148] For example, after setting the relevant process parameters for phosphorus diffusion, phosphorus source gas can be introduced into the reaction chamber of the deposition equipment to form the doped layer 12.

[0149] For example, the phosphorus source gas can be POCl3, etc.

[0150] The relevant process parameters for phosphorus diffusion may include temperature, time, gas flow rate, etc. Specific values ​​for temperature, time, and gas flow rate can be found in existing technologies and will not be elaborated upon here.

[0151] Alternatively, the doped layer 12 can be formed by boron diffusion.

[0152] For example, after setting the relevant process parameters for boron diffusion, a boron diffusion source can be introduced into the reaction chamber of the deposition equipment to form a doped layer 12.

[0153] For example, boron diffusion sources can include BCl3, etc.

[0154] In some embodiments, an inert gas may be introduced into the deposition apparatus during the period in which silane gas is introduced into the deposition apparatus.

[0155] In one example, the inert gas can be one or more of argon, nitrogen, and helium.

[0156] As another possible implementation, a tunneling layer 16 may be formed on at least one surface of the silicon substrate 11, and a doped layer 12 may be formed on the side of the tunneling layer 16 opposite to the silicon substrate 11.

[0157] Specifically, the silicon substrate 11 can be wet-processed, and an oxide layer (such as silicon oxide) can be grown on the wet-processed silicon substrate 11 to prepare a tunneling layer 16 on the silicon substrate 11.

[0158] For example, a tunneling layer 16 can be prepared by reacting silicon substrate 11 with oxygen or water vapor in a high-temperature environment using thermal oxidation to generate silicon dioxide. This allows an oxide layer (such as silicon oxide) to be grown on the wet-processed silicon substrate 11.

[0159] For example, silicon oxide can be generated by decomposing a gas-phase precursor on the surface of the silicon substrate 11 to grow an oxide layer (such as silicon oxide) on the wet-processed silicon substrate 11 to prepare the tunneling layer 16.

[0160] The wet processing can include a pretreatment stage and a main etching stage.

[0161] For example, organic matter, metallic impurities, and natural oxide layers on the surface of the silicon substrate 11 can be removed during the pretreatment stage, and the silicon substrate 11 can be etched during the main etching stage. It should be noted that the specific processes for removing organic matter, metallic impurities, and natural oxide layers from the surface of the silicon substrate 11, as well as the specific processes for etching the silicon substrate 11 during the main etching stage, can be referred to existing technologies and will not be elaborated here.

[0162] Understandably, by preparing the tunneling layer 16, the interfacial recombination loss can be reduced, the open-circuit voltage and fill factor of the cell can be improved, thereby enhancing the photoelectric conversion efficiency of the cell.

[0163] In some embodiments, the solar cell 10 can be a back-contact cell or a bifacial solar cell 10 (e.g., a TOPCon cell). Since the P-region and N-region of the back-contact cell are both formed on the back side of the cell, when preparing the tunneling layer 16, corresponding tunneling layers 16 are formed in the regions corresponding to the P-region and N-region, respectively. Then, corresponding doped layers 12, passivation layers 14, seed layers 15, and metal layers 18 are formed on them. Generally, the P-region and N-region are isolated by an isolation region to avoid direct contact between the two regions and cause a short circuit. The structure of the back-contact cell can refer to the prior art and will not be described in detail here.

[0164] When the solar cell 10 is a bifacial solar cell 10, such as a TOPCon cell, the P region and N region are generally on the front and back sides of the cell, respectively. Then, a tunneling layer 16 is generally formed on the entire back side of the cell. Then, a corresponding doped layer 12, passivation layer 14, seed layer 15 and metal layer 18 are formed on the tunneling layer 16. The structure of the TOPCon cell can refer to the existing technology, and will not be described in detail here.

[0165] S203. A passivation layer 14 is formed on the side of the doped layer 12 away from the silicon substrate 11.

[0166] The passivation layer 14 includes through holes. The passivation layer 14 includes a first injection section 13; the injection material corresponding to the first injection section 13 includes the main preparation material of the seed layer 15; the main preparation material is the preparation material with the largest mass percentage.

[0167] As one possible implementation, one or more of silicon nitride films, silicon nitride films, and aluminum nitride films can be deposited on the doped layer 12 to form a passivation layer 14 on the side of the doped layer 12 opposite to the silicon substrate 11.

[0168] Furthermore, vias can be formed in the area to be metallized in the passivation layer 14 by laser or etching to expose the doped layer 12.

[0169] S204. A seed layer 15 is formed on the doped layer 12 based on the via.

[0170] As one possible implementation, at least one of the following processes can be used to form a seed layer 15 on the doped layer 12: PVD, ALD, screen printing, vapor deposition, sputtering, etc.

[0171] For example, seed layers of Al, Co, Ta, W, Ti, etc. can be deposited using PVD / ALD, etc. 15.

[0172] In the solar cells, their fabrication methods, photovoltaic modules, and photovoltaic systems of this application embodiment, since the passivation layer 14 includes a first injection portion 13 and the injection material corresponding to the first injection portion 13 includes the main fabrication material of the seed layer 15, the bonding force between the passivation layer 14 and the seed layer 15 can be improved. External stress is mainly applied to the edge between the electrode and the seed layer 15. In actual implementation, the seed layer 15 and the electrode are wider than the vias on the passivation layer. Therefore, increasing the bonding force between the seed layer 15 and the passivation layer 14, so that it will not detach under stress, can prevent stress that may cause failure from being transmitted to the contact interface between the seed layer 15 and the silicon substrate 11, thereby protecting the contact interface between the seed layer 15 and the silicon substrate 11.

[0173] In some embodiments, Figure 9 This is a schematic flowchart of a method for fabricating a solar cell 10 according to another embodiment of this application, as shown below. Figure 9 As shown, prior to forming the seed layer 15, this application further includes the following steps:

[0174] S301. Material is injected into the doped layer 12 through the through-hole to form the second injection section 22.

[0175] As one possible implementation, the second implantation section 22 can be formed by implanting material into the doped layer 12 through a via via by ion implantation or sputtering.

[0176] In some embodiments, Figure 10 This is a schematic flowchart of a method for fabricating a solar cell 10 according to another embodiment of this application, as shown below. Figure 10 As shown, after forming the seed layer 15, this application further includes the following steps:

[0177] S401. A metal layer 18 is formed on the side of the seed layer 15 away from the silicon substrate 11.

[0178] As one possible implementation, metal can be deposited on the seed layer 15 to form the metal layer 18 by electroplating.

[0179] For example, at least one of the following equipment can be used for electroplating: horizontal electroplating machine, vertical electroplating machine, and tank electroplating machine. The electroplating solution can be at least one of copper sulfate, copper plating additive, stannous sulfate, and tin plating additive.

[0180] Understandably, by depositing metal on the seed layer 15 through an electroplating process to form the metal layer 18, the seed layer 15 can reduce contact resistance, improve adhesion, and ensure long-term stable operation of the battery.

[0181] S402. Perform annealing treatment to form a first alloy layer 17 between the metal layer 18 and the seed layer 15.

[0182] The annealing temperature is between 100℃ and 400℃. For example, it can be any value between 100℃, 200℃, 300℃, 400℃ or 100℃ and 400℃, and there is no restriction here.

[0183] In this way, the annealing temperature is within a suitable range, which allows for precise control of the formation of the alloy phase and the interface structure, while avoiding thermal damage to the solar cell 10 caused by excessively high temperatures. This ensures the overall performance and reliability of the solar cell 10 while achieving excellent ohmic contact and adhesion.

[0184] It is understood that in such embodiments, the photovoltaic module corresponding to the solar cell 10 may further include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the front and back of the solar cell 10, the photovoltaic glass, adjacent cells, etc. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film can be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0185] Photovoltaic glass can be applied to the encapsulating film on the front side of the solar cell 10. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell 10 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell 10 together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell 10.

[0186] The backsheet can be attached to the encapsulant film on the back of the solar cell 10. The backsheet provides protection and support for the solar cell 10, offering reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulant film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell 10, encapsulant film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire photovoltaic module, providing stable support and installation. For example, the photovoltaic module can be installed at the desired location using the metal frame.

[0187] The photovoltaic system of this application embodiment includes the photovoltaic module described above.

[0188] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic modules; for example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0189] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0190] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A solar cell, characterized in that, include: A silicon substrate, comprising opposing first and second surfaces; A doped layer is disposed on at least one of the first surface and the second surface; A passivation layer is disposed on the side of the doped layer opposite to the silicon substrate, and includes vias; A seed layer, which passes through the via and is connected to the doped layer; The passivation layer includes a first injection portion, which is at least in contact with the seed layer; the injection material corresponding to the first injection portion includes the main preparation material of the seed layer; the main preparation material is the preparation material with the largest mass percentage. The doped layer includes a second injection section; the injection material of the second injection section includes the main preparation material of the seed layer; the location of the via corresponds at least partially to the second injection section.

2. The solar cell according to claim 1, characterized in that, The first injection portion is disposed at the contact position between the passivation layer and the seed layer, and includes at least the first injection portion disposed on the top of the passivation layer that contacts the seed layer.

3. The solar cell according to claim 2, characterized in that, The first injection portion is disposed at the contact position between the passivation layer and the seed layer, and the first injection portion further includes a first injection portion disposed on the sidewall of the passivation layer that contacts the seed layer.

4. The solar cell according to claim 2, characterized in that, The first injection portion is also disposed at a position where the passivation layer and the seed layer are not in contact, including at least the first injection portion disposed on the top of the passivation layer that is not in contact with the seed layer.

5. The solar cell according to claim 3, characterized in that, The first injection portion is also disposed at a position where the passivation layer and the seed layer are not in contact, including at least the first injection portion disposed on the top of the passivation layer that is not in contact with the seed layer.

6. The solar cell according to claim 1, characterized in that, The first injection portion is disposed on the entire surface of the passivation layer.

7. The solar cell according to claim 1, characterized in that, The size of the first implantation portion in the thickness direction of the silicon substrate is 3nm to 200nm.

8. The solar cell according to claim 1, characterized in that, The second implantation portion has a size of 3 nm to 300 nm in the thickness direction of the silicon substrate.

9. The solar cell according to claim 1, characterized in that, The second injection section includes a third injection section and a fourth injection section; The third injection section corresponds to the passivation layer covered area in the second injection section; the fourth injection section corresponds to the passivation layer not covered area in the second injection section.

10. The solar cell according to claim 9, characterized in that, The dimension of the third implantation portion in the thickness direction of the silicon substrate is greater than or equal to the dimension of the fourth implantation portion in the thickness direction of the silicon substrate.

11. The solar cell according to claim 1, characterized in that, The main preparation material is one of Al, Ag, Cu, and Mg.

12. The solar cell according to claim 1, characterized in that, The main preparation material accounts for more than 50% of the total mass.

13. The solar cell according to claim 1, characterized in that, In addition to the main preparation material, the seed layer preparation material also includes one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V.

14. The solar cell according to claim 1, characterized in that, The injection material of the first injection section or the second injection section may further include one or more of Mg, Mo, Ni, Ti, W, Cr, Mn, Pd, Bi, Nb, Ta, Pa, Si, and V.

15. The solar cell according to claim 1, characterized in that, It also includes a first alloy layer and a metal layer; the first alloy layer and the metal layer are stacked sequentially on the side of the seed layer away from the silicon substrate.

16. The solar cell according to claim 15, characterized in that, The materials used to prepare the metal layer include one or more of Cu, Al, and Ag.

17. The solar cell according to claim 15, characterized in that, The first alloy layer includes an Al-Cu alloy layer and / or an Al-Cu-Ti alloy layer.

18. The solar cell according to claim 17, characterized in that, The material composition of the Al-Cu alloy layer includes Al2Cu, , One or more of Al4Cu9.

19. The solar cell according to claim 15, characterized in that, It also includes a first protective layer, which is disposed on the side of the metal layer away from the silicon substrate; the material composition of the first protective layer includes one or more of Sn, Ni, Ag, and Zn.

20. The solar cell according to claim 19, characterized in that, It also includes a second protective layer; the second protective layer is disposed on the side of the first protective layer away from the silicon substrate; the material used to prepare the second protective layer includes an oxide corresponding to the material used to prepare the first protective layer.

21. The solar cell according to claim 19, characterized in that, It also includes a second alloy layer; the second alloy layer is disposed between the first protective layer and the metal layer; the second alloy layer includes a Sn-Cu alloy layer.

22. The solar cell according to claim 1, characterized in that, The doped layer includes a first doped layer and a second doped layer, wherein the first doped layer and the second doped layer are alternately disposed on the first surface of the silicon substrate; The passivation layer is disposed on the side of the first doped layer and the second doped layer away from the silicon substrate, and includes vias corresponding to the first doped layer and the second doped layer; The seed layer is connected to the corresponding doped layer through vias corresponding to the first doped layer and the second doped layer; The first injection portion is disposed on the passivation layer of at least one of the first doped layer and the second doped layer, and is in contact with the seed layer disposed thereon.

23. The solar cell according to claim 22, characterized in that, An isolation region is also provided between the first doped layer and the second doped layer.

24. The solar cell according to claim 1, characterized in that, The doped layer includes a first doped layer and a second doped layer, wherein the first doped layer is disposed on a first surface of the silicon substrate and the second doped layer is disposed on a second surface of the silicon substrate; The passivation layer is disposed on the side of the first doped layer and the second doped layer away from the silicon substrate, and includes vias corresponding to the first doped layer and the second doped layer; The seed layer is connected to the corresponding doped layer through vias corresponding to the first doped layer and the second doped layer; The first injection portion is disposed on the passivation layer of at least one of the first doped layer and the second doped layer, and is in contact with the seed layer disposed thereon.

25. A method for preparing a solar cell, characterized in that, include: A silicon substrate is provided, the silicon substrate including opposing first and second surfaces; A doped layer is formed on at least one of the first surface and the second surface; A passivation layer is formed on the side of the doped layer opposite to the silicon substrate; The passivation layer includes vias; A seed layer is formed on the doped layer based on the vias; The passivation layer includes a first injection portion; the injection material corresponding to the first injection portion includes the main preparation material of the seed layer. The main preparation material is the preparation material with the largest mass percentage; Before forming the seed layer, the method further includes: Material is injected into the doped layer through the via to form a second injection section; the injection material of the second injection section includes the main preparation material of the seed layer; the location of the via corresponds at least partially to the second injection section.

26. The method for preparing a solar cell according to claim 25, characterized in that, The method further includes: A metal layer is formed on the side of the seed layer opposite to the silicon substrate; An annealing process is performed to form a first alloy layer between the metal layer and the seed layer.

27. A solar cell, characterized in that, Made by the method of any one of claims 25-26.

28. A photovoltaic module, characterized in that, This includes the solar cell as described in any one of claims 1-24 or claim 27.

29. A photovoltaic system, characterized in that, Including the photovoltaic module as described in claim 28.

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