Solar cell, preparation method thereof and photovoltaic module
By forming a recessed structure on the transparent conductive layer of the solar cell and setting up a conductive structure, the problem of large contact resistance between the electrode and the silicon substrate is solved, the series resistance is reduced, and the conversion efficiency of the solar cell is improved.
Patent Information
- Application Number
- CN202510123461.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-26
- Publication Date
- 2025-04-29
AI Technical Summary
In solar cells, the contact resistance between the electrode and the silicon substrate is large, resulting in a large series resistance of the battery, which seriously limits the improvement of the conversion efficiency of heterojunction batteries.
A recessed structure is provided on the surface of the transparent conductive layer that is far away from the silicon substrate, so that at least part of the conductive structure is disposed in the recessed structure, and electrically connects the conductive structure to the first electrode, increasing the contact area between the conductive structure and the transparent conductive layer, thereby reducing the contact resistance.
By reducing the contact resistance between the first electrode and the transparent conductive layer, the contact resistance between the electrode and the silicon substrate is reduced, the series resistance of the solar cell is reduced, and its conversion efficiency is improved.
Smart Images
Figure CN119907360A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic technology, and in particular to solar cells and methods for preparing the same, and photovoltaic modules. Background Art
[0002] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electrical energy. As they are green and environmentally friendly products that do not cause environmental pollution, and solar energy is a renewable resource, solar cells are a new type of battery with broad development prospects.
[0003] In the related art, the contact resistance between the electrode and the silicon substrate in the solar cell is relatively large, resulting in a large series resistance of the cell, which seriously limits the improvement of the conversion efficiency of the heterojunction cell. Summary of the invention
[0004] Based on this, the present application provides a solar cell and a method for preparing the same, and a photovoltaic module, which can improve the conversion efficiency of the solar cell.
[0005] An embodiment of the first aspect of the present application provides a solar cell, including a cell body, a first electrode and a conductive structure;
[0006] The battery body comprises a substrate, at least one side of which is provided with a doping layer and a transparent conductive layer;
[0007] The first electrode is disposed on a side of the transparent conductive layer away from the substrate;
[0008] A recessed structure is provided on the surface of the transparent conductive layer away from the substrate; at least a part of the conductive structure is provided in the recessed structure, and the conductive structure is electrically connected to the first electrode.
[0009] In one of the embodiments, the orthographic projection of the conductive structure on the substrate overlaps with the orthographic projection of the recessed structure on the substrate; the orthographic projection of the first electrode on the substrate overlaps with the orthographic projection of the conductive structure on the substrate.
[0010] In one embodiment, the conductive structure includes a first filling portion, the first filling portion is disposed in the recessed structure, and the first filling portion is electrically connected to the first electrode.
[0011] In one embodiment, the conductive structure further includes a first connecting portion connected to the first filling portion, the first connecting portion is disposed on a side of the transparent conductive layer away from the substrate; and the first connecting portion is electrically connected to the first electrode.
[0012] In one embodiment, the recessed structure includes a plurality of grooves arranged at intervals.
[0013] In one of the embodiments, the groove penetrates the transparent conductive layer along a first direction, and the conductive structure is electrically connected to the doping layer and the first electrode; the first direction is the thickness direction of the battery body.
[0014] In one of the embodiments, a dimension of the groove along a second direction is 1 nm to 500 nm, and the second direction is perpendicular to the first direction.
[0015] In one embodiment, the doping layer and the transparent conductive layer are stacked on two opposite surfaces of the substrate; and / or,
[0016] The solar cell further comprises an intrinsic amorphous silicon layer, and the intrinsic amorphous silicon layer is arranged between the substrate and the doping layer.
[0017] In one embodiment, the conductive structure includes any one of gold, silver, nickel, tin, and platinum.
[0018] An embodiment of the second aspect of the present application provides a method for preparing a solar cell, comprising:
[0019] Providing a battery body, the battery body comprising a substrate, at least one side of the substrate having a doping layer and a transparent conductive layer stacked on the surface;
[0020] A recessed structure and a conductive structure are formed on the transparent conductive layer; the recessed structure is disposed on a surface of the transparent conductive layer away from the substrate; and the conductive structure is at least partially disposed in the recessed structure;
[0021] A first electrode electrically connected to the conductive structure is formed on a side of the transparent conductive layer away from the substrate.
[0022] In one embodiment, the step of forming a recessed structure and a conductive structure on the transparent conductive layer includes:
[0023] The transparent conductive layer is etched with a first etching solution for a first preset time to form the recessed structure on the transparent conductive layer, wherein the recessed structure penetrates the transparent conductive layer along a first direction, wherein the first direction is a thickness direction of the battery body;
[0024] The recessed structure is filled with a metal precursor solution, and the metal precursor solution is dried and thermally reduced at a first preset temperature for a second preset time to obtain a conductive structure at least partially disposed within the recessed structure, wherein the conductive structure is electrically connected to the doping layer; the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
[0025] In one embodiment, the first preset duration is between 30s and 600s;
[0026] and / or, the first preset temperature is between 80°C and 200°C;
[0027] And / or, the second preset time length is between 3 minutes and 10 minutes.
[0028] In one embodiment, the step of forming a recessed structure and a conductive structure on the transparent conductive layer includes:
[0029] A first solution is used to cover a portion of the surface of the transparent conductive layer away from the substrate side for a third preset time; the first solution is dried and thermally reduced at a second preset temperature for a fourth preset time to form a recessed structure and a conductive structure on the transparent conductive layer, wherein the recessed structure penetrates the transparent conductive layer along a first direction, and the first direction is the thickness direction of the battery body; the conductive structure is at least partially arranged in the recessed structure, and the conductive structure is electrically connected to the doping layer; the first solution includes a first etching solution and a metal precursor solution, and the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
[0030] In one embodiment, the third preset time length is between 30s and 600s;
[0031] and / or, the second preset temperature is between 80° C. and 200° C.;
[0032] And / or, the fourth preset time length is between 3 minutes and 10 minutes.
[0033] In one embodiment, the metal precursor solution further includes metal particles, and the metal particles include any one of gold, silver, nickel, tin, and platinum, and the particle size of the metal particles is 1 nm to 2 um.
[0034] In one embodiment, the step of providing a battery body includes:
[0035] providing a substrate;
[0036] Forming a doped layer and an amorphous transparent conductive layer on at least one side of the substrate;
[0037] After the step of forming a recessed structure and a conductive structure on the transparent conductive layer, the method for preparing a solar cell further includes:
[0038] The amorphous transparent conductive layer is annealed at a third preset temperature for a fifth preset time to obtain a crystallized transparent conductive layer.
[0039] In one embodiment, the third preset temperature is between 150° C. and 200° C.; the fifth preset time is between 10 min and 45 min.
[0040] In one embodiment, after the step of forming a first electrode electrically connected to the conductive structure on a side of the transparent conductive layer away from the substrate, the method further includes:
[0041] The first electrode is subjected to laser assisted sintering.
[0042] An embodiment of a second aspect of the present application provides a photovoltaic assembly, comprising the solar cell described in any one of the above embodiments.
[0043] The solar cell and the preparation method thereof provided in the embodiment of the present application are provided with a recessed structure on the surface of the transparent conductive layer away from the substrate, so that at least part of the conductive structure is arranged in the recessed structure, and the conductive structure is electrically connected to the first electrode. In other words, the first electrode is electrically connected to the transparent conductive layer through the conductive structure. Since at least part of the conductive structure is arranged in the recessed structure, the conductive structure and the transparent conductive layer can have a larger contact area, thereby indirectly increasing the contact area between the first electrode and the transparent conductive layer, thereby reducing the contact resistance between the first electrode and the transparent conductive layer, and further reducing the contact resistance between the first electrode and the substrate, reducing the series resistance of the solar cell, and improving the conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Figure 1 A schematic diagram of the structure of a solar cell provided in some embodiments of the present application.
[0045] Figure 2 Schematic diagram of the structure of solar cells provided in other embodiments of the present application.
[0046] Figure 3 Schematic diagram of the structure of solar cells provided in some other embodiments of the present application.
[0047] Figure 4 A schematic diagram of the structure of a solar cell provided in some further embodiments of the present application.
[0048] Figure 5 A flow chart of a method for preparing a solar cell provided in some embodiments of the present application.
[0049] Figure 6 A flow chart of a method for preparing a solar cell provided in some other embodiments of the present application.
[0050] Figure 7 A flow chart of a method for preparing a solar cell provided in some other embodiments of the present application.
[0051] Figure 8 A flow chart of a method for preparing a solar cell provided in some further embodiments of the present application.
[0052] Description of reference numerals:
[0053] 10. Solar cell; 11. Battery body; 111. Substrate; 112. Intrinsic amorphous silicon layer; 113. Doped layer; 114. Transparent conductive layer; 115. Recessed structure; 115a. Groove; 12. Conductive structure; 121. First filling part; 122. First connecting part; 13. First electrode; Z, first direction; Y, second direction. DETAILED DESCRIPTION
[0054] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0055] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0056] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0057] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated 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, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0058] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0059] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.
[0060] First, see Figures 1 to 4 The embodiment of the present application provides a solar cell 10, including a cell body 11, a first electrode 13 and a conductive structure 12; the cell body 11 includes a substrate 111, and a doping layer 113 and a transparent conductive layer 114 are stacked on at least one side of the substrate 111; the first electrode 13 is provided on the side of the transparent conductive layer 114 away from the substrate 111; wherein a recessed structure 115 is provided on the surface of the transparent conductive layer 114 away from the substrate 111; at least a part of the conductive structure 12 is provided in the recessed structure 115, and the conductive structure 12 and the first electrode 13 are electrically connected.
[0061] The solar cell 10 provided in the embodiment of the present application is provided with a recessed structure 115 on the surface of the transparent conductive layer 114 away from the substrate 111, so that at least a portion of the conductive structure 12 is disposed in the recessed structure 115, and the conductive structure 12 and the first electrode 13 are electrically connected. That is, the first electrode 13 is electrically connected to the transparent conductive layer 114 through the conductive structure 12. Since at least a portion of the conductive structure 12 is disposed in the recessed structure 115, the conductive structure 12 and the transparent conductive layer 114 can have a larger contact area, thereby indirectly increasing the contact area between the first electrode 13 and the transparent conductive layer 114, thereby reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114, and further reducing the contact resistance between the first electrode 13 and the substrate 111, thereby reducing the series resistance of the solar cell 10 and improving the conversion efficiency of the solar cell 10.
[0062] It should be noted that the substrate 111 may be a silicon substrate 111; the doped layer 113 may be any one of a doped amorphous silicon layer, a doped microcrystalline silicon layer, and a doped nanocrystalline silicon layer; and the transparent conductive layer 114 is disposed on the side of the doped layer 113 away from the substrate 111. The solar cell may be a heterojunction cell (HJT cell), an HBC (superimposed HJT heterojunction cell and IBC back contact cell) cell, or a hybrid cell, and the hybrid cell may include a passivation contact structure layer in a TOPCon cell and an intrinsic amorphous silicon layer in a HJT cell.
[0063] In one embodiment, see Figures 1 to 4 , the orthographic projection of the conductive structure 12 on the substrate 111 overlaps with the orthographic projection of the recessed structure 115 on the substrate 111 ; the orthographic projection of the first electrode 13 on the substrate 111 overlaps with the orthographic projection of the conductive structure 12 on the substrate 111 .
[0064] In this way, it can be ensured that at least a portion of the conductive structure 12 is disposed within the recessed structure 115, so that the contact area between the conductive structure 12 and the transparent conductive layer 114 is larger; it can be ensured that the first electrode 13 is electrically connected to the conductive structure 12, thereby increasing the contact area between the first electrode 13 and the transparent conductive layer 114, reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114, and thus improving the conversion efficiency of the solar cell 10.
[0065] In one embodiment, see Figure 2 The conductive structure 12 includes a first filling portion 121 . The first filling portion 121 is disposed in the recessed structure 115 . The first filling portion 121 is electrically connected to the first electrode 13 .
[0066] In this way, by arranging the first filling portion 121 in the recessed structure 115, the contact area between the conductive structure 12 and the transparent conductive layer 114 can be increased, thereby increasing the contact area between the first electrode 13 and the transparent conductive layer 114, and reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114, thereby improving the conversion efficiency of the solar cell 10.
[0067] In one embodiment, see Figure 1 , Figure 3 and Figure 4 The conductive structure 12 further includes a first connecting portion 122 connected to the first filling portion 121 . The first connecting portion 122 is disposed on a side of the transparent conductive layer 114 away from the substrate 111 . The first connecting portion 122 is electrically connected to the first electrode 13 .
[0068] In this way, by setting the first connecting portion 122, the electrical connection between the conductive structure 12 and the first electrode 13 can be facilitated. At the same time, the contact area between the conductive structure 12 and the transparent conductive layer 114 can be further increased, thereby further increasing the contact area between the first electrode 13 and the transparent conductive layer 114, reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114, thereby improving the conversion efficiency of the solar cell 10.
[0069] In one embodiment, see Figures 1 to 4 The recessed structure 115 includes a plurality of grooves 115a arranged at intervals.
[0070] In this way, the contact area between the conductive structure 12 and the transparent conductive layer 114 can be further increased, thereby further increasing the contact area between the first electrode 13 and the transparent conductive layer 114 and reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114 , thereby improving the conversion efficiency of the solar cell 10 .
[0071] In one embodiment, see Figures 2 to 4 The groove 115 a penetrates the transparent conductive layer 114 along a first direction Z, and the conductive structure 12 is electrically connected to the doping layer 113 and the first electrode 13 . The first direction Z is the thickness direction of the battery body 11 .
[0072] Specifically, the contact resistance between the doping layer 113 and the transparent conductive layer 114 is relatively large. If the first electrode 13 is electrically connected to the doping layer 113 through the transparent conductive layer 114, the contact resistance between the first electrode 13 and the substrate 111 will be relatively large, the series resistance of the solar cell 10 will be relatively large, and the conversion efficiency of the solar cell 10 will be relatively low. In this embodiment, by making the groove 115a penetrate the transparent conductive layer 114 along the first direction Z, the conductive structure 12 and the doping layer 113 and the first electrode 13 are electrically connected, that is, the first electrode 13 is electrically connected to the doping layer 113 through the conductive structure 12, so that the contact resistance between the first electrode 13 and the substrate 111 can be reduced, thereby reducing the series resistance of the solar cell 10 and improving the conversion efficiency of the solar cell 10.
[0073] In one embodiment, the dimension of the groove 115 a along the second direction Y is 1 nm to 500 nm, and the second direction Y is perpendicular to the first direction Z.
[0074] In this way, micrometer-scale and nanometer-scale channels can be formed on the transparent conductive layer, so that micro-nano contact is formed between the first electrode 13 and the doping layer 113, thereby reducing the contact resistance between the first electrode 13 and the doping layer 113, and further reducing the contact resistance between the first electrode 13 and the substrate 111, reducing the series resistance of the solar cell 10, and improving the conversion efficiency of the solar cell 10.
[0075] In one embodiment, see Figure 4 A doping layer 113 and a transparent conductive layer 114 are stacked on opposite sides of the substrate 111 .
[0076] In this way, the surface of each transparent conductive layer 114 away from the substrate 111 can be provided with a recessed structure 115, so that the first electrode 13 located on the side of each transparent conductive layer 114 away from the substrate 111 is electrically connected to the conductive structure 12. In this way, the contact resistance between the first electrode 13 located on the side of each transparent conductive layer 114 away from the substrate 111 and the substrate 111 can be reduced, the series resistance of solar energy is greatly reduced, and the conversion efficiency of the solar cell 10 is effectively improved.
[0077] In one embodiment, see Figures 1 to 4 The solar cell 10 further includes an intrinsic amorphous silicon layer 112 , which is disposed between the substrate 111 and the doping layer 113 .
[0078] In this way, the intrinsic amorphous silicon layer 112 can play a chemical passivation effect, passivate the dangling bonds on the surface of the substrate 111 , and reduce the surface defect density, which is beneficial to improving the conversion efficiency of the solar cell 10 .
[0079] In one embodiment, the conductive structure 12 includes any one of metal materials such as gold, silver, nickel, tin, platinum, etc.
[0080] Thus, by making the conductive structure 12 include one of the above metal materials, the conductive performance of the conductive structure 12 can be improved, thereby reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114 , thereby improving the conversion efficiency of the solar cell 10 .
[0081] Second, see Figure 5 The present invention provides a method for preparing a solar cell, comprising:
[0082] S10, providing a battery body 11, wherein the battery body 11 includes a substrate 111, and a doping layer 113 and a transparent conductive layer 114 are stacked on at least one side of the surface of the substrate 111;
[0083] S20, forming a recessed structure 115 and a conductive structure 12 on the transparent conductive layer 114; the recessed structure 115 is disposed on a surface of the transparent conductive layer 114 away from the substrate 111; and the conductive structure 12 is at least partially disposed in the recessed structure 115;
[0084] S30 , forming a first electrode 13 electrically connected to the conductive structure 12 on a side of the transparent conductive layer 114 away from the substrate 111 .
[0085] The method for preparing the solar cell 10 provided in the embodiment of the present application is as follows: a recessed structure 115 and a conductive structure 12 are formed on a transparent conductive layer 114; the recessed structure 115 is disposed on the surface of the transparent conductive layer 114 away from the substrate 111; the conductive structure 12 is at least partially disposed in the recessed structure 115, and a first electrode 13 electrically connected to the conductive structure 12 is formed on the side of the transparent conductive layer 114 away from the substrate 111, that is, the first electrode 13 is electrically connected to the transparent conductive layer 114 through the conductive structure 12. Since at least a portion of the conductive structure 12 is disposed in the recessed structure 115, the conductive structure 12 and the transparent conductive layer 114 can have a larger contact area, thereby indirectly increasing the contact area between the first electrode 13 and the transparent conductive layer 114, thereby reducing the contact resistance between the first electrode 13 and the transparent conductive layer 114, and further reducing the contact resistance between the first electrode 13 and the substrate 111, thereby reducing the series resistance of the solar cell 10 and improving the conversion efficiency of the solar cell 10.
[0086] In one embodiment, see Figure 6 In S20, a recessed structure 115 and a conductive structure 12 are formed on the transparent conductive layer 114, specifically including:
[0087] S210, etching the transparent conductive layer 114 with a first etching solution for a first preset time to form a recessed structure 115 on the transparent conductive layer 114, wherein the recessed structure 115 penetrates the transparent conductive layer 114 along a first direction Z, where the first direction Z is a thickness direction of the battery body 11;
[0088] Specifically, the first etching solution may be an acid solution, which may be an organic acid or an inorganic acid. The organic acid may be acetic acid or citric acid, etc.; the inorganic acid may be hydrochloric acid, sulfuric acid or nitric acid, etc.; the transparent conductive layer 114 may be immersed in the acid solution, or the acid solution may be sprayed on the area to be etched of the transparent conductive layer 114, so as to form a recessed structure 115 on the surface of the transparent conductive layer 114 away from the substrate 111, and the recessed structure 115 passes through the transparent conductive layer 114 along the first direction Z.
[0089] S220, filling the recessed structure 115 with a metal precursor solution, drying and thermally reducing the metal precursor solution at a first preset temperature, and continuing for a second preset time, to obtain a conductive structure 12 at least partially disposed in the recessed structure 115, and the conductive structure 12 and the doping layer 113 are electrically connected; the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
[0090] In this embodiment, by using the first etching solution to etch the transparent conductive layer 114, a recessed structure 115 can be conveniently formed on the transparent conductive layer 114, and the recessed structure 115 can penetrate the transparent conductive layer 114 along the first direction Z. By using a metal precursor solution to fill the recessed structure 115, the metal precursor solution is dried and thermally reduced at a first preset temperature for a second preset time, and the metal ions in the metal precursor solution can be reduced, so that a conductive structure 12 at least partially disposed in the recessed structure 115 can be obtained, and the conductive structure 12 is electrically connected to the doping layer 113. In this way, the first electrode 13 can be electrically connected to the doping layer 113 through the conductive structure 12, and the contact resistance between the first electrode 13 and the substrate 111 can be reduced, thereby reducing the series resistance of the solar cell 10 and improving the conversion efficiency of the solar cell 10.
[0091] In one embodiment, the first preset time is between 30s and 600s. Specifically, the first preset time may be between 30s and 100s, 100s and 200s, 200s and 300s, 300s and 400s, 400s and 500s, or 500s and 600s. The first preset time may be determined according to the etching ability of the first etching solution; when the first etching solution is an acid solution, the first preset time may be determined according to the pH value of the acid solution; when the pH value of the acid solution is less than 4, the first preset time is between 200s and 600s; when the pH value of the acid solution is greater than 4 and less than 7, the first preset time is between 30s and 300s.
[0092] In one embodiment, the first preset temperature is between 80°C and 200°C. Specifically, the first preset temperature may be between 80°C and 120°C, between 120°C and 150°C, or between 150°C and 200°C.
[0093] In one embodiment, the second preset time is between 3 minutes and 10 minutes. Specifically, the second preset time can be between 3 minutes and 5 minutes, between 5 minutes and 7 minutes, or between 7 minutes and 10 minutes.
[0094] In one embodiment, see Figure 7 In S20, a recessed structure 115 and a conductive structure 12 are formed on the transparent conductive layer 114, specifically including:
[0095] A first solution is used to cover a portion of the surface of the transparent conductive layer 114 away from the substrate 111 for a third preset time; the first solution is dried and thermally reduced at a second preset temperature for a fourth preset time to form a recessed structure 115 and a conductive structure 12 on the transparent conductive layer 114, wherein the recessed structure 115 penetrates the transparent conductive layer 114 along a first direction Z, and the first direction Z is the thickness direction of the battery body 11; the conductive structure 12 is at least partially disposed in the recessed structure 115, and the conductive structure 12 is electrically connected to the doping layer 113; the first solution includes a first etching solution and a metal precursor solution, and the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
[0096] In this embodiment, the first solution is used to cover a portion of the surface of the transparent conductive layer 114 away from the substrate 111 for a third preset time, so that the first etching solution in the first solution etches the transparent conductive layer 114 to form a recessed structure 115 on the transparent conductive layer 114, and the metal precursor solution at least fills the recessed structure 115. The first solution is dried and thermally reduced at a second preset temperature for a fourth preset time, so that the metal ions in the metal precursor solution can be reduced, thereby obtaining a conductive structure 12 at least partially disposed in the recessed structure 115. The conductive structure 12 is electrically connected to the doping layer 113. In this way, the first electrode 13 can be electrically connected to the doping layer 113 through the conductive structure 12, so that the contact resistance between the first electrode 13 and the substrate 111 can be reduced, thereby reducing the series resistance of the solar cell 10 and improving the conversion efficiency of the solar cell 10.
[0097] In one embodiment, the third preset time is between 30s and 600s. Specifically, the first preset time may be between 30s and 100s, 100s and 200s, 200s and 300s, 300s and 400s, 400s and 500s, or 500s and 600s. The first preset time may be determined according to the etching ability of the first etching solution; when the first etching solution is an acid solution, the first preset time may be determined according to the pH value of the acid solution; when the pH value of the acid solution is less than 4, the first preset time is between 200s and 600s; when the pH value of the acid solution is greater than 4 and less than 7, the first preset time is between 30s and 300s.
[0098] In one embodiment, the second preset temperature is 80° C. to 200° C. Specifically, the first preset temperature may be 80° C. to 120° C., 120° C. to 150° C., or 150° C. to 200° C.
[0099] In one embodiment, the fourth preset time is 3 minutes to 10 minutes. Specifically, the second preset time can be 3 minutes to 5 minutes, 5 minutes to 7 minutes, or 7 minutes to 10 minutes.
[0100] In one embodiment, the metal precursor solution further includes metal particles, the metal particles include any one of gold, silver, nickel, tin, and platinum, and the particle size of the metal particles is 1 nm to 2 um.
[0101] In this way, when the metal precursor solution is dried and thermally reduced, the metal particles can be a matrix group, and the reduced metal can be attached to the metal particles, so that the metal particles continue to grow, and adjacent metal particles are fused together, thereby obtaining a conductive structure 12 with a dense structure and good conductive performance. In this way, when the first electrode 13 is electrically connected to the transparent conductive layer 114 through the conductive structure 12, and the first electrode 13 is electrically connected to the doping layer 113 through the conductive structure 12, the contact resistance between the first electrode 13 and the transparent conductive layer 114 can be reduced, and the contact resistance between the first electrode 13 and the doping layer 113 can be reduced, thereby reducing the contact resistance between the first electrode 13 and the substrate 111, which is beneficial to improving the conversion efficiency of the solar cell 10.
[0102] In one embodiment, see Figure 8 In S10, a battery body 11 is provided, which specifically includes:
[0103] Providing a substrate 111;
[0104] A doping layer 113 and an amorphous transparent conductive layer 114 are stacked on at least one side of the substrate 111;
[0105] After forming the recessed structure 115 and the conductive structure 12 on the transparent conductive layer 114 in step S20, the method for preparing the solar cell 10 further includes:
[0106] S30a, performing annealing treatment on the amorphous transparent conductive layer 114 at a third preset temperature for a fifth preset time to obtain a crystallized transparent conductive layer 114.
[0107] In the present embodiment, by stacking the doping layer 113 and the amorphous transparent conductive layer 114 on the two opposite side surfaces of the substrate 111, the amorphous transparent conductive layer 114 is more easily corroded, so that the recessed structure 115 can be conveniently formed on the transparent conductive layer 114; after forming the recessed structure 115 and the conductive structure 12 on the transparent conductive layer 114, the amorphous transparent conductive layer 114 is annealed at a third preset temperature for a fifth preset time to obtain a crystallized transparent conductive layer 114, so that the conductive performance of the transparent conductive layer 114 can be improved, which is beneficial to improve the conversion efficiency of the solar cell 10.
[0108] In one embodiment, the third preset temperature is between 150° C. and 200° C.; and the fifth preset time is between 10 min and 45 min.
[0109] In one embodiment, see Figure 8 After forming a first electrode 13 electrically connected to the conductive structure 12 on a side of the transparent conductive layer 114 away from the substrate 111 at S30, the method for preparing the solar cell 10 further includes:
[0110] S40 , performing laser-assisted sintering on the first electrode 13 .
[0111] In this way, the first electrode 13 and the doping layer 113 can form better contact, reduce the contact resistance between the first electrode 13 and the doping layer 113, thereby reducing the series resistance of the solar cell 10, which is beneficial to improving the conversion efficiency of the solar cell 10.
[0112] In a third aspect, an embodiment of the present application provides a photovoltaic module, comprising the solar cell 10 in any of the above embodiments, so as to improve the efficiency of the photovoltaic module.
[0113] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0114] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A solar cell, characterized in that: comprising a battery body, a first electrode and a conductive structure; The battery body comprises a substrate, at least one side of which is provided with a doping layer and a transparent conductive layer; The first electrode is disposed on a side of the transparent conductive layer away from the substrate; A recessed structure is provided on the surface of the transparent conductive layer away from the substrate; at least a part of the conductive structure is provided in the recessed structure, and the conductive structure is electrically connected to the first electrode.
2. The solar cell according to claim 1, characterized in that The orthographic projection of the conductive structure on the substrate overlaps with the orthographic projection of the recessed structure on the substrate; the orthographic projection of the first electrode on the substrate overlaps with the orthographic projection of the conductive structure on the substrate.
3. The solar cell according to claim 1 or 2, characterized in that: The conductive structure includes a first filling portion, the first filling portion is disposed in the recessed structure, and the first filling portion is electrically connected to the first electrode.
4. The solar cell according to claim 3, characterized in that: The conductive structure further includes a first connecting portion connected to the first filling portion, wherein the first connecting portion is disposed on a side of the transparent conductive layer away from the substrate; and the first connecting portion is electrically connected to the first electrode.
5. The solar cell according to claim 1, characterized in that: The recessed structure includes a plurality of recesses arranged at intervals.
6. The solar cell according to claim 5, characterized in that: The groove penetrates the transparent conductive layer along a first direction, and the conductive structure is electrically connected to the doping layer and the first electrode; the first direction is the thickness direction of the battery body.
7. The solar cell according to claim 6, characterized in that: The size of the groove along the second direction is 1 nm to 500 nm, and the second direction is perpendicular to the first direction.
8. The solar cell according to claim 1, characterized in that The doping layer and the transparent conductive layer are stacked on both opposite sides of the substrate; and / or, The solar cell further comprises an intrinsic amorphous silicon layer, and the intrinsic amorphous silicon layer is arranged between the substrate and the doping layer.
9. The solar cell according to any one of claims 1, 2, 4 to 8, characterized in that: The conductive structure includes any one of gold, silver, nickel, tin and platinum.
10. A method for preparing a solar cell, characterized in that: include: Providing a battery body, the battery body comprising a substrate, at least one side of the substrate having a doping layer and a transparent conductive layer stacked on the surface; A recessed structure and a conductive structure are formed on the transparent conductive layer; the recessed structure is disposed on a surface of the transparent conductive layer away from the substrate; and the conductive structure is at least partially disposed in the recessed structure; A first electrode electrically connected to the conductive structure is formed on a side of the transparent conductive layer away from the substrate.
11. The method for preparing a solar cell according to claim 10, characterized in that: The step of forming a recessed structure and a conductive structure on the transparent conductive layer includes: The transparent conductive layer is etched with a first etching solution for a first preset time to form the recessed structure on the transparent conductive layer, wherein the recessed structure penetrates the transparent conductive layer along a first direction, wherein the first direction is a thickness direction of the battery body; The recessed structure is filled with a metal precursor solution, and the metal precursor solution is dried and thermally reduced at a first preset temperature for a second preset time to obtain a conductive structure at least partially disposed within the recessed structure, wherein the conductive structure is electrically connected to the doping layer; the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
12. The method for preparing a solar cell according to claim 11, characterized in that: The first preset duration is between 30s and 600s; and / or, the first preset temperature is between 80°C and 200°C; And / or, the second preset time length is between 3 minutes and 10 minutes.
13. The method for preparing a solar cell according to claim 10, characterized in that: The step of forming a recessed structure and a conductive structure on the transparent conductive layer includes: A first solution is used to cover a portion of the surface of the transparent conductive layer away from the substrate side for a third preset time; the first solution is dried and thermally reduced at a second preset temperature for a fourth preset time to form a recessed structure and a conductive structure on the transparent conductive layer, wherein the recessed structure penetrates the transparent conductive layer along a first direction, and the first direction is the thickness direction of the battery body; the conductive structure is at least partially arranged in the recessed structure, and the conductive structure is electrically connected to the doping layer; the first solution includes a first etching solution and a metal precursor solution, and the metal precursor solution includes any one of gold ions, silver ions, nickel ions, tin ions, and platinum ions.
14. The method for preparing a solar cell according to claim 13, characterized in that: The third preset time length is between 30s and 600s; and / or, the second preset temperature is between 80° C. and 200° C.; And / or, the fourth preset time length is between 3 minutes and 10 minutes.
15. The method for preparing a solar cell according to claim 11 or 13, characterized in that: The metal precursor solution also includes metal particles, and the metal particles include any one of gold, silver, nickel, tin, and platinum. The particle size of the metal particles is 1 nm to 2 um.
16. The method for preparing a solar cell according to claim 10, characterized in that: The step of providing a battery body comprises: providing a substrate; Forming a doped layer and an amorphous transparent conductive layer on at least one side of the substrate; After the step of forming a recessed structure and a conductive structure on the transparent conductive layer, the method for preparing a solar cell further includes: The amorphous transparent conductive layer is annealed at a third preset temperature for a fifth preset time to obtain a crystallized transparent conductive layer.
17. The method for preparing a solar cell according to claim 16, characterized in that: The third preset temperature is between 150° C. and 200° C.; the fifth preset time is between 10 min and 45 min.
18. The method for preparing a solar cell according to claim 10, characterized in that: After the step of forming a first electrode electrically connected to the conductive structure on a side of the transparent conductive layer away from the substrate, the method further includes: The first electrode is subjected to laser assisted sintering.
19. A photovoltaic module, characterized in that: A solar cell comprising the solar cell according to any one of claims 1 to 9.