Preparation method of solar cell, solar cell and photovoltaic module
By forming a protective layer on the side wall of the preparative oxide layer of the solar cell and forming a second doped conductive layer on the side wall by wet etching, the component heat spot problem is solved and the power generation power of the photovoltaic module is improved.
Patent Information
- Application Number
- CN202510026174.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-05-06
AI Technical Summary
In the prior art, the thermal spot problem of solar cells modules is serious, resulting in a low power generation power of photovoltaic modules.
通过提供预备电池片,包括基底、第一掺杂导电层、预备掺杂导电层和预备氧化层,形成保护层在预备氧化层的侧壁上,并通过湿法刻蚀形成第二掺杂导电层,确保其位于基底的侧壁上、第一掺杂导电层的侧壁上以及第二表面上。
By forming a second doped conductive layer on the side wall in contact with the first doped conductive layer, a PN junction is formed so that current can flow from the side wall to achieve the effect of leakage of the battery edge, thereby improving the heat spot phenomenon and increasing the power generation power of the photovoltaic module.
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Figure CN119947296A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a method for preparing a solar cell, a solar cell and a photovoltaic module. Background Art
[0002] Module hot spots refer to concentrated areas of heat energy generated by shading or cracked solar cells. With the development of photovoltaic cells, hot spot problems are becoming an increasingly important factor affecting the power generation efficiency of photovoltaic modules. At the same time, hot spots not only affect the power generation efficiency of modules, but also seriously lead to permanent failure of modules, and may even cause safety accidents such as fires, causing devastating blows to photovoltaic power stations. Therefore, solving the hot spot problem has become a necessary research direction. Modules based on N-type TOPCon high-efficiency cells are the mainstream products in the industry. Therefore, it is necessary to solve the hot spot problem on the module end based on N-type TOPCon high-efficiency cell module products. Summary of the invention
[0003] The main purpose of the present application is to provide a method for preparing a solar cell, a solar cell and a photovoltaic module, so as to solve the problem in the prior art that the hot spot problem of the solar cell module is serious, resulting in low power generation of the photovoltaic module.
[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a method for preparing a solar cell is provided, comprising: providing a prepared cell, the prepared cell comprising a substrate, a first doped conductive layer, a prepared doped conductive layer and a prepared oxide layer, wherein the substrate comprises a first surface and a second surface opposite to each other, the first doped conductive layer is located on the first surface, the prepared doped conductive layer covers the first doped conductive layer and the substrate, the prepared oxide layer covers the prepared doped conductive layer, the doping type of the first doped conductive layer is different from the doping type of the prepared doped conductive layer, and the etching rate of the prepared doped conductive layer in an acidic solution is less than the etching rate of the prepared oxide layer in the acidic solution The etching rate of the preliminary oxide layer in the alkaline solution is less than the etching rate of the preliminary doped conductive layer in the alkaline solution; a protective layer is formed on the side wall of the preliminary oxide layer to obtain a first cell, the etching rate of the protective layer in the acidic solution is less than the etching rate of the preliminary oxide layer in the acidic solution, and the etching rate of the preliminary oxide layer in the alkaline solution is less than the etching rate of the protective layer in the alkaline solution; the first cell is wet-etched, and the remaining preliminary doped conductive layer forms a second doped conductive layer to obtain a target cell, wherein the second doped conductive layer is located on the side wall of the substrate, on the side wall of the first doped conductive layer and on the second surface.
[0005] Optionally, the first cell is wet-etched to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain the target cell, wherein the sub-oxide layer is the pre-doped conductive layer located on a side of the first doped conductive layer away from the substrate, the sub-doped conductive layer is the pre-doped conductive layer in contact with the sub-oxide layer, and the oxide layer is the pre-doped conductive layer remaining except the sub-oxide layer.
[0006] Optionally, the first cell is wet-etched to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain the target cell, including: using the acidic solution to clean the first cell to remove the sub-oxide layer, and the remaining pre-doped conductive layer forms the oxide layer to obtain the second cell; using the alkaline solution to clean the second cell to remove the protective layer and the sub-doped conductive layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain a third cell; using the acidic solution to clean the third cell to remove the oxide layer to obtain the target cell.
[0007] Optionally, the material of the protective layer includes ink, and after providing the preliminary battery cell and before forming the protective layer on the sidewall of the preliminary oxide layer, the method further includes: performing laser processing on the edge of the preliminary battery cell.
[0008] Optionally, the ink includes resin, and the edge of the prepared battery sheet is subjected to laser processing, including: performing laser processing on the edge of the prepared battery sheet for 40s to 50s.
[0009] Optionally, a preliminary battery cell is provided, comprising: providing the substrate; forming the first doped conductive layer on the first surface, the doping type of the first doped conductive layer being different from the doping type of the substrate; forming a tunneling layer on the second surface and on the sidewalls of the substrate; covering the preliminary doped conductive layer on the tunneling layer and the first doped conductive layer, the material of the preliminary doped conductive layer comprising polycrystalline silicon; and covering the preliminary doped conductive layer with the preliminary oxide layer.
[0010] Optionally, providing the substrate includes: providing a silicon substrate; performing a texturing treatment on the silicon substrate; performing an alkali polishing treatment on the texturing-treated silicon substrate to obtain the substrate, and forming the first doped conductive layer on the first surface, including: performing a boron diffusion treatment on the substrate to form the first doped conductive layer on the first surface to obtain an initial prepared battery cell.
[0011] Optionally, the preliminary doped conductive layer is covered on the tunneling layer and the first doped conductive layer, and the preliminary oxide layer is covered on the preliminary doped conductive layer, comprising: performing phosphorus diffusion treatment on the initial preliminary battery cell for forming the tunneling layer to form the preliminary doped conductive layer on the tunneling layer and the first doped conductive layer, and forming the preliminary oxide layer on the preliminary doped conductive layer.
[0012] According to another aspect of the present application, a solar cell is provided, the solar cell being prepared by any one of the methods for preparing a solar cell, the solar cell comprising: a substrate comprising a first surface and a second surface opposite to each other; a first doped conductive layer located on the first surface; a second doped conductive layer located on a side wall of the substrate, on the second surface, and on a side wall of the first doped conductive layer, the doping type of the first doped conductive layer being different from the doping type of the second doped conductive layer.
[0013] According to another aspect of the present application, a photovoltaic assembly is provided, comprising: a solar cell prepared by any of the methods for preparing a solar cell sheet, or the solar cell.
[0014] According to the technical solution of the present application, a preliminary cell sheet including a substrate, a first doped conductive layer, a preliminary doped conductive layer and a preliminary oxide layer is first provided, a protective layer is then formed on the side wall of the preliminary oxide layer to obtain a first cell sheet, and finally the first cell sheet is wet-etched, and the remaining preliminary doped conductive layer forms a second doped conductive layer to obtain a target cell sheet, wherein the second doped conductive layer is located on the side wall of the substrate, on the side wall of the first doped conductive layer and on the second surface, the doping type of the first doped conductive layer is different from the doping type of the preliminary doped conductive layer, the etching rate of the preliminary doped conductive layer in an acidic solution is lower than the etching rate of the preliminary oxide layer in an acidic solution, the etching rate of the preliminary oxide layer in an alkaline solution is lower than the etching rate of the preliminary doped conductive layer in an alkaline solution, the etching rate of the protective layer in an acidic solution is lower than the etching rate of the preliminary oxide layer in an acidic solution, and the etching rate of the preliminary oxide layer in an alkaline solution is lower than the etching rate of the protective layer in an alkaline solution. Compared with the problem of serious hot spot problem of solar cell components in the prior art, which leads to low power generation of photovoltaic components, the present application forms a protective layer on the side wall of the preliminary oxide layer, and utilizes the relationship between the etching rates of the protective layer, the preliminary oxide layer and the preliminary doped conductive layer in the acidic solution and the alkaline solution respectively to wet-etch the first cell to obtain a second doped conductive layer located on the side wall of the substrate, the side wall of the first doped conductive layer and the second surface (i.e., the preliminary doped conductive layer retains the side of the first cell). Since the second doped conductive layer is in contact with the first doped conductive layer and the doping types of the two are different, the front and back emitters of the target cell are connected from the side wall (i.e., the first doped conductive layer and the second doped conductive layer form a PN junction), so that when the target cell is abnormal, the current can flow from the side wall to achieve the effect of leakage at the edge of the cell, thereby improving the hot spot phenomenon and ensuring a higher power generation of the photovoltaic component. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0016] Figure 1 A schematic flow chart of a method for preparing a solar cell provided in accordance with an embodiment of the present application is shown;
[0017] Figure 2 A schematic cross-sectional structure diagram of a prepared battery cell provided according to an embodiment of the present application is shown;
[0018] Figure 3 A schematic cross-sectional structure diagram of a first battery cell provided according to an embodiment of the present application is shown;
[0019] Figure 4A schematic cross-sectional structure diagram of a target battery cell provided according to an embodiment of the present application is shown;
[0020] Figure 5 A schematic cross-sectional structure diagram of a second battery cell provided according to an embodiment of the present application is shown;
[0021] Figure 6 A schematic cross-sectional structure diagram of a third battery cell provided according to an embodiment of the present application is shown;
[0022] Figure 7 A schematic cross-sectional structure diagram of a complete battery cell provided according to an embodiment of the present application is shown.
[0023] The above drawings include the following reference numerals:
[0024] 10. Prepared battery cell; 11. Substrate; 12. First doped conductive layer; 13. Prepared doped conductive layer; 14. Prepared oxide layer; 111. First surface; 112. Second surface; 141. First side wall; 15. Protective layer; 16. First battery cell; 17. Second doped conductive layer; 18. Target battery cell; 19. Sub-oxide layer; 20. Second battery cell; 21. Third battery cell; 22. Oxide layer; 23. Passivation layer; 24. Front anti-reflection film; 25. Back anti-reflection film; 26. First metal electrode; 27. Second metal electrode; 28. Complete battery cell; 29. Tunneling layer. DETAILED DESCRIPTION
[0025] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.
[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.
[0027] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.
[0028] As introduced in the background technology, the hot spot problem of solar cell components in the prior art is serious, resulting in low power generation of photovoltaic components. To solve the above problem, the embodiments of the present application provide a method for preparing a solar cell, a solar cell and a photovoltaic component.
[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0030] Figure 1 FIG. 1 is a flow chart of a method for preparing a solar cell according to an embodiment of the present application. Figure 1 As shown, the method comprises the following steps:
[0031] Step S101, as Figure 2 As shown, a preliminary battery cell 10 is provided, the preliminary battery cell 10 includes a substrate 11, a first doped conductive layer 12, a preliminary doped conductive layer 13 and a preliminary oxide layer 14, wherein the substrate 11 includes a first surface 111 and a second surface 112 opposite to each other, the first doped conductive layer 12 is located on the first surface 111, the preliminary doped conductive layer 13 covers the first doped conductive layer 12 and the substrate 11, the preliminary oxide layer 14 covers the preliminary doped conductive layer 13, the doping type of the first doped conductive layer 12 is different from the doping type of the preliminary doped conductive layer 13, the etching rate of the preliminary doped conductive layer 13 in an acidic solution is lower than the etching rate of the preliminary oxide layer 14 in the acidic solution, and the etching rate of the preliminary oxide layer 14 in an alkaline solution is lower than the etching rate of the preliminary doped conductive layer 13 in the alkaline solution;
[0032] Step S102, as Figure 3 As shown, a protective layer 15 is formed on the side wall (i.e., the first side wall 141) of the preliminary oxide layer 14 to obtain a first battery cell 16, and the etching rate of the protective layer 15 in the acidic solution is lower than the etching rate of the preliminary oxide layer 14 in the acidic solution, and the etching rate of the preliminary oxide layer 14 in the alkaline solution is lower than the etching rate of the protective layer 15 in the alkaline solution;
[0033] Step S103, as Figure 3 and Figure 4 As shown, the first cell 16 is wet-etched, and the remaining pre-doped conductive layer 13 forms a second doped conductive layer 17 to obtain a target cell 18, wherein the second doped conductive layer 17 is located on the side wall of the substrate 11, on the side wall of the first doped conductive layer 12 and on the second surface 112.
[0034] According to the present embodiment, a preliminary cell including a substrate, a first doped conductive layer, a preliminary doped conductive layer and a preliminary oxide layer is first provided, a protective layer is then formed on the side wall of the preliminary oxide layer to obtain a first cell, and finally the first cell is wet-etched, and the remaining preliminary doped conductive layer forms a second doped conductive layer to obtain a target cell, wherein the second doped conductive layer is located on the side wall of the substrate, on the side wall of the first doped conductive layer and on the second surface, the doping type of the first doped conductive layer is different from the doping type of the preliminary doped conductive layer, the etching rate of the preliminary doped conductive layer in an acidic solution is less than the etching rate of the preliminary oxide layer in an acidic solution, the etching rate of the preliminary oxide layer in an alkaline solution is less than the etching rate of the preliminary doped conductive layer in an alkaline solution, the etching rate of the protective layer in an acidic solution is less than the etching rate of the preliminary oxide layer in an acidic solution, and the etching rate of the preliminary oxide layer in an alkaline solution is less than the etching rate of the protective layer in an alkaline solution. Compared with the problem of serious hot spot problem of solar cell components in the prior art, which leads to low power generation of photovoltaic components, the present application forms a protective layer on the side wall of the preliminary oxide layer, and utilizes the relationship between the etching rates of the protective layer, the preliminary oxide layer and the preliminary doped conductive layer in the acidic solution and the alkaline solution respectively to wet-etch the first cell to obtain a second doped conductive layer located on the side wall of the substrate, the side wall of the first doped conductive layer and the second surface (i.e., the preliminary doped conductive layer retains the side of the first cell). Since the second doped conductive layer is in contact with the first doped conductive layer and the doping types of the two are different, the front and back emitters of the target cell are connected from the side wall (i.e., the first doped conductive layer and the second doped conductive layer form a PN junction), so that when the target cell is abnormal, the current can flow from the side wall to achieve the effect of leakage at the edge of the cell, thereby improving the hot spot phenomenon and ensuring a higher power generation of the photovoltaic component.
[0035] Specifically, the protective layer is acid-resistant but not alkali-resistant, the preliminary oxide layer is alkali-resistant but not acid-resistant, and the preliminary doped conductive layer is acid-resistant but not alkali-resistant. The ratio of the etching rate of the preliminary oxide layer in the acidic solution to the etching rate of the preliminary doped conductive layer in the acidic solution is not less than 100, the ratio of the etching rate of the preliminary doped conductive layer in the alkaline solution to the etching rate of the preliminary oxide layer in the alkaline solution is not less than 100, the ratio of the etching rate of the preliminary oxide layer in the acidic solution to the etching rate of the protective layer in the acidic solution is not less than 100, and the ratio of the etching rate of the protective layer in the alkaline solution to the etching rate of the preliminary oxide layer in the alkaline solution is not less than 100.
[0036] In an embodiment of the present application, the doping type of the above-mentioned first doped conductive layer is P-type, the doping type of the above-mentioned preliminary doped conductive layer is N-type, the doping type of the above-mentioned substrate is N-type, the material of the above-mentioned substrate includes silicon, the material of the above-mentioned second doped conductive layer includes polysilicon (that is, the above-mentioned second doped conductive layer is N-type doped polysilicon), and the material of the above-mentioned preliminary oxide layer includes phosphosilicate glass (that is, phosphorus-doped silicon dioxide).
[0037] In an optional solution, the first cell is wet-etched, and the remaining pre-doped conductive layer forms a second doped conductive layer to obtain a target cell, including: Figures 3 to 6 As shown, the first cell 16 is wet-etched to sequentially remove the sub-oxide layer 19, the protective layer 15, the sub-doped conductive layer (not shown) and the oxide layer 22, and the remaining pre-doped conductive layer 13 forms the second doped conductive layer 17, to obtain the target cell 18, wherein the sub-oxide layer 19 is the pre-doped conductive layer 14 located on the side of the first doped conductive layer 12 away from the substrate 11, the sub-doped conductive layer is the pre-doped conductive layer 13 in contact with the sub-oxide layer 19, and the oxide layer 22 is the pre-doped conductive layer 14 remaining except the sub-oxide layer 19. In this embodiment, by precisely controlling the sequential removal of each layer, it is further ensured that the obtained second doped conductive layer is more accurate, thereby further ensuring that the edge leakage effect of the target cell is better.
[0038] According to some exemplary embodiments of the present application, the first cell is wet-etched to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain the target cell, including: Figure 3 and Figure 5 As shown, the acid solution is used to clean the first battery cell 16 to remove the sub-oxide layer 19, and the remaining preliminary oxide layer 14 forms the oxide layer 22 to obtain the second battery cell 20; Figure 5 and Figure 6 As shown, the second battery cell 20 is cleaned with the alkaline solution to remove the protective layer 15 and the sub-doped conductive layer, and the remaining pre-doped conductive layer 13 forms the second doped conductive layer 17 to obtain a third battery cell 21; Figure 4 and Figure 6 As shown, the third cell 21 is cleaned with the acidic solution to remove the oxide layer 22, thereby obtaining the target cell 18. In this embodiment, by adjusting the use of the acidic solution and the alkaline solution, the etching process can be further accurately controlled, thereby further ensuring that the second doped conductive layer is obtained more accurately and further ensuring a better edge leakage effect.
[0039] In the actual application process, those skilled in the art can flexibly select the appropriate acidic solution and alkaline solution according to actual needs, and this application does not impose specific restrictions on this. In the embodiment of this application, the acidic solution includes a hydrofluoric acid solution, and the alkaline solution includes a potassium hydroxide solution.
[0040] In other embodiments, the material of the protective layer includes ink, and after providing the prepared battery cell and before forming the protective layer on the side wall of the prepared oxide layer, the method further includes: laser processing the edge of the prepared battery cell. In this embodiment, the laser processing can reduce cracks and defects at the edge of the battery cell, and the edge processed by the laser will have better compatibility and adhesion in the subsequent step of forming the protective layer, which can enhance the bonding force between the protective layer and the edge of the battery cell, thereby improving the overall structural stability of the battery cell.
[0041] Specifically, when the edge of the prepared cell is laser processed, the edge laser width is about 400 μm.
[0042] Specifically, the prepared cell sheet after laser processing is subjected to an ink edge sealing process (ie, a protective layer is formed on the side wall of the prepared oxide layer).
[0043] According to some other exemplary embodiments of the present application, the ink includes a resin, and the edge of the prepared cell is laser treated, including: performing laser treatment on the edge of the prepared cell for 40s to 50s. In this embodiment, by performing laser treatment on the edge of the prepared cell for 40s to 50s, the surface roughness of the prepared oxide layer can be further increased, thereby further improving the adhesion of the subsequent ink protective layer, and further ensuring that the protective layer is tightly bonded to the cell.
[0044] Specifically, the main component of the ink includes the resin, and the resin is a high-viscosity resin.
[0045] In some other optional schemes of the present application, a preliminary battery cell is provided, including: providing the above-mentioned substrate; forming the above-mentioned first doped conductive layer on the above-mentioned first surface, the doping type of the above-mentioned first doped conductive layer is different from the doping type of the above-mentioned substrate; forming a tunneling layer on the above-mentioned second surface and on the sidewall of the above-mentioned substrate; covering the above-mentioned preliminary doped conductive layer on the above-mentioned tunneling layer and the above-mentioned first doped conductive layer, the material of the above-mentioned preliminary doped conductive layer includes polysilicon; covering the above-mentioned preliminary doped conductive layer with the above-mentioned preliminary oxide layer. In this embodiment, the first doped conductive layer, the tunneling layer, the preliminary doped conductive layer and the preliminary oxide layer are formed to prepare for the subsequent preparation of the second doped conductive layer.
[0046] Specifically, the material of the tunneling layer includes at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide or magnesium fluoride.
[0047] In some further optional schemes of the present application, the above-mentioned substrate is provided, including: providing a silicon substrate; performing a texturing treatment on the above-mentioned silicon substrate; performing an alkali polishing treatment on the above-mentioned silicon substrate after the texturing treatment to obtain the above-mentioned substrate, and forming the above-mentioned first doped conductive layer on the above-mentioned first surface, including: performing a boron diffusion treatment on the above-mentioned substrate to form the above-mentioned first doped conductive layer on the above-mentioned first surface to obtain an initial prepared cell. In this embodiment, the texturing treatment can increase the surface roughness of the silicon substrate, which helps to improve the scattering and absorption of light, thereby improving the photoelectric conversion efficiency of the solar cell; the alkali polishing treatment can remove impurities and damaged layers on the surface of the silicon substrate, making the surface cleaner and providing a good foundation for the formation of subsequent layers; the first doped conductive layer is formed on the front side of the silicon substrate by boron diffusion (i.e., diffusion process) to create a front emitter.
[0048] In other embodiments, the preliminary doped conductive layer is covered on the tunneling layer and the first doped conductive layer, and the preliminary oxide layer is covered on the preliminary doped conductive layer, including: performing phosphorus diffusion treatment on the initial preliminary battery cell forming the tunneling layer to form the preliminary doped conductive layer on the tunneling layer and the first doped conductive layer, and forming the preliminary oxide layer on the preliminary doped conductive layer. In this embodiment, the preliminary doped conductive layer and the preliminary oxide layer are formed by phosphorus diffusion treatment, further preparing for the subsequent formation of the second doped conductive layer.
[0049] Specifically, when the substrate is subjected to boron diffusion treatment, a first doped conductive layer is first formed on the first surface, and then a BSG (Borosilicate Glass) layer is formed on the surface of the first doped conductive layer away from the substrate; therefore, after the above-mentioned substrate is subjected to boron diffusion treatment and before the above-mentioned preliminary doped conductive layer is formed, the above-mentioned method further includes: performing BSG removal treatment on the above-mentioned substrate after the boron diffusion treatment (i.e., removing the borosilicate glass generated during the boron diffusion process), and performing LP (Laser Processing) process on the above-mentioned substrate after the BSG removal treatment.
[0050] Specifically, using the acidic solution to clean the third cell to remove the oxide layer includes: using the acidic solution to clean the third cell to remove the oxide layer and the BSG layer. The BSG layer is alkali-resistant but not acid-resistant (i.e., the etching rate of the BSG layer in an alkaline solution is lower than the etching rate of the pre-doped conductive layer in an alkaline solution, and the etching rate of the pre-doped conductive layer in an alkaline solution is lower than the etching rate of the BSG layer in an alkaline solution).
[0051] In summary, the present application adds laser and ink edge sealing processes after phosphorus diffusion to retain the N-type doped conductive layer structure at the edge of the battery, thereby achieving battery edge leakage.
[0052] Specifically, after obtaining the target battery cell, the above method further includes: firstly performing an ALD (Atomic Layer Deposition) process on the target battery cell, and then performing a PE (Plasma Enhanced Chemical Vapor Deposition) process on the target battery cell.
[0053] Specifically, Figure 7 As shown, after forming the second doped conductive layer 17, the method further includes: covering the first doped conductive layer 12 and the second doped conductive layer 17 with a passivation layer 23, covering the front anti-reflection film 24 on the passivation layer 23 located near the first doped conductive layer 12, covering the back anti-reflection film 25 on the passivation layer 23 located away from the first doped conductive layer 12, forming a plurality of first metal electrodes 26 arranged at intervals on the surface of the front anti-reflection film 24 away from the substrate 11, and forming a plurality of second metal electrodes 27 arranged at intervals on the surface of the back anti-reflection film 25 away from the substrate 11, to obtain a complete cell 28. Specifically, the first metal electrode is electrically connected to the first doped conductive layer, and the second metal electrode is electrically connected to the second doped conductive layer. The material of the passivation layer includes aluminum oxide, and the materials of the front anti-reflection film and the back anti-reflection film each include one of silicon oxide, silicon nitride or silicon oxynitride. The passivation layer and the anti-reflection film may be a single-layer structure or a multi-layer structure. For a multi-layer structure, the materials of different layers may be different from each other, or the materials of a portion of the layers may be the same and different from the materials of other layers.
[0054] Specifically, the complete cell 28 further includes a tunneling layer 29 , and the tunneling layer 29 is located between the substrate 11 and the second doped conductive layer 17 .
[0055] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the method for preparing a solar cell of the present application will be described in detail below in conjunction with specific embodiments.
[0056] This embodiment relates to a specific method for preparing a solar cell, comprising the following steps:
[0057] Step S1: providing a prepared battery cell, the prepared battery cell comprising a substrate, a first doped conductive layer, a prepared doped conductive layer and a prepared oxide layer, wherein the substrate comprises a first surface and a second surface opposite to each other, the first doped conductive layer is located on the first surface, the prepared doped conductive layer covers the first doped conductive layer and the substrate, the prepared oxide layer covers the prepared doped conductive layer, the doping type of the first doped conductive layer is different from the doping type of the prepared doped conductive layer, the etching rate of the prepared doped conductive layer in an acidic solution is less than the etching rate of the prepared oxide layer in an acidic solution, and the etching rate of the prepared oxide layer in an alkaline solution is less than the etching rate of the prepared doped conductive layer in an alkaline solution;
[0058] Step S2: laser processing the edge of the prepared battery cell;
[0059] Step S3: After laser treatment, a protective layer is formed on the side wall of the preliminary oxide layer to obtain a first cell, wherein the etching rate of the protective layer in an acidic solution is lower than the etching rate of the preliminary oxide layer in an acidic solution, and the etching rate of the preliminary oxide layer in an alkaline solution is lower than the etching rate of the protective layer in an alkaline solution, and the material of the protective layer includes ink;
[0060] Step S4: wet-etching the first cell to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms a second doped conductive layer to obtain a target cell, wherein the sub-oxide layer is a pre-doped conductive layer located on a side of the first doped conductive layer away from the substrate, the sub-doped conductive layer is a pre-doped conductive layer in contact with the sub-oxide layer, and the oxide layer is the pre-doped conductive layer remaining except the sub-oxide layer.
[0061] An embodiment of the present application also provides a solar cell, which is prepared by any of the above-mentioned methods for preparing solar cells, and the above-mentioned solar cell includes: a substrate, including a first surface and a second surface opposite to each other; a first doped conductive layer, located on the above-mentioned first surface; a second doped conductive layer, located on the side wall of the above-mentioned substrate, on the above-mentioned second surface and on the side wall of the above-mentioned first doped conductive layer, and the doping type of the above-mentioned first doped conductive layer is different from the doping type of the above-mentioned second doped conductive layer.
[0062] In the above embodiment, the solar cell comprises a substrate, a first doped conductive layer and a second doped conductive layer, the doping type of the first doped conductive layer is different from the doping type of the second doped conductive layer, the substrate comprises a first surface and a second surface, the second doped conductive layer is located on the side wall of the substrate, on the second surface and on the side wall of the first doped conductive layer, and the first doped conductive layer is located on the first surface. Compared with the problem of the solar cell component hot spot problem in the prior art that leads to the low power generation of the photovoltaic component, the second doped conductive layer of the present application is located on the side wall of the substrate, on the second surface and on the side wall of the first doped conductive layer (i.e., the second doped conductive layer on the side of the battery is retained), and since the second doped conductive layer is in contact with the first doped conductive layer and the doping types of the two are different, the front and back emitters of the battery are connected from the side wall (i.e., the first doped conductive layer and the second doped conductive layer form a PN junction), so that when the battery is abnormal, the current can flow from the side wall to achieve the effect of leakage at the edge of the battery, thereby improving the hot spot phenomenon, and further ensuring the high power generation of the photovoltaic component.
[0063] The embodiment of the present application further provides a photovoltaic assembly, comprising: a solar cell prepared by any of the above-mentioned methods for preparing a solar cell sheet, or the above-mentioned solar cell.
[0064] In the above embodiment, the photovoltaic module includes a solar cell, and the solar cell prepared by the preparation method of the solar cell sheet, compared with the problem of the solar cell module hot spot problem in the prior art that leads to low power generation of the photovoltaic module, the present application forms a protective layer on the side wall of the preliminary oxide layer, and uses the relationship between the etching rates of the protective layer, the preliminary oxide layer and the preliminary doped conductive layer in the acidic solution and the alkaline solution respectively to wet-etch the first cell sheet to obtain a second doped conductive layer located on the side wall of the substrate, on the side wall of the first doped conductive layer and on the second surface (that is, the preliminary doped conductive layer on the side of the first cell sheet is retained). Since the second doped conductive layer is in contact with the first doped conductive layer and the doping types of the two are different, the front and back emitters of the target cell sheet are connected from the side wall (that is, the first doped conductive layer and the second doped conductive layer form a PN junction), so that when the target cell sheet is abnormal, the current can flow from the side wall to achieve the effect of leakage at the edge of the cell, thereby improving the hot spot phenomenon and ensuring that the power generation of the photovoltaic module is high.
[0065] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:
[0066] In the preparation method of the solar cell of the present application, a preliminary cell cell including a substrate, a first doped conductive layer, a preliminary doped conductive layer and a preliminary oxide layer is first provided, then a protective layer is formed on the side wall of the preliminary oxide layer to obtain a first cell cell, and finally the first cell cell is wet-etched, and the remaining preliminary doped conductive layer forms a second doped conductive layer to obtain a target cell cell, wherein the second doped conductive layer is located on the side wall of the substrate, on the side wall of the first doped conductive layer and on the second surface, the doping type of the first doped conductive layer is different from the doping type of the preliminary doped conductive layer, the etching rate of the preliminary doped conductive layer in an acidic solution is less than the etching rate of the preliminary oxide layer in an acidic solution, the etching rate of the preliminary oxide layer in an alkaline solution is less than the etching rate of the preliminary doped conductive layer in an alkaline solution, the etching rate of the protective layer in an acidic solution is less than the etching rate of the preliminary oxide layer in an acidic solution, and the etching rate of the preliminary oxide layer in an alkaline solution is less than the etching rate of the protective layer in an alkaline solution. Compared with the problem of serious hot spot problem of solar cell components in the prior art, which leads to low power generation of photovoltaic components, the present application forms a protective layer on the side wall of the preliminary oxide layer, and utilizes the relationship between the etching rates of the protective layer, the preliminary oxide layer and the preliminary doped conductive layer in the acidic solution and the alkaline solution respectively to wet-etch the first cell to obtain a second doped conductive layer located on the side wall of the substrate, the side wall of the first doped conductive layer and the second surface (i.e., the preliminary doped conductive layer retains the side of the first cell). Since the second doped conductive layer is in contact with the first doped conductive layer and the doping types of the two are different, the front and back emitters of the target cell are connected from the side wall (i.e., the first doped conductive layer and the second doped conductive layer form a PN junction), so that when the target cell is abnormal, the current can flow from the side wall to achieve the effect of leakage at the edge of the cell, thereby improving the hot spot phenomenon and ensuring a higher power generation of the photovoltaic component.
[0067] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a solar cell, characterized in that: include: A prepared battery cell is provided, the prepared battery cell comprising a substrate, a first doped conductive layer, a prepared doped conductive layer and a prepared oxide layer, wherein the substrate comprises a first surface and a second surface opposite to each other, the first doped conductive layer is located on the first surface, the prepared doped conductive layer covers the first doped conductive layer and the substrate, the prepared oxide layer covers the prepared doped conductive layer, the doping type of the first doped conductive layer is different from the doping type of the prepared doped conductive layer, the etching rate of the prepared doped conductive layer in an acidic solution is lower than the etching rate of the prepared oxide layer in the acidic solution, and the etching rate of the prepared oxide layer in an alkaline solution is lower than the etching rate of the prepared doped conductive layer in the alkaline solution; Forming a protective layer on the sidewall of the preliminary oxide layer to obtain a first cell, wherein the etching rate of the protective layer in the acidic solution is lower than the etching rate of the preliminary oxide layer in the acidic solution, and the etching rate of the preliminary oxide layer in the alkaline solution is lower than the etching rate of the protective layer in the alkaline solution; The first cell is wet-etched, and the remaining pre-doped conductive layer forms a second doped conductive layer to obtain a target cell, wherein the second doped conductive layer is located on the sidewall of the substrate, on the sidewall of the first doped conductive layer, and on the second surface.
2. The method for preparing a solar cell according to claim 1, characterized in that: The first cell is wet-etched, and the remaining pre-doped conductive layer is formed into a second doped conductive layer to obtain a target cell, including: The first cell is wet-etched to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain the target cell, wherein the sub-oxide layer is the pre-doped conductive layer located on a side of the first doped conductive layer away from the substrate, the sub-doped conductive layer is the pre-doped conductive layer in contact with the sub-oxide layer, and the oxide layer is the pre-doped conductive layer remaining except the sub-oxide layer.
3. The method for preparing a solar cell according to claim 2, characterized in that: The first cell is wet-etched to sequentially remove the sub-oxide layer, the protective layer, the sub-doped conductive layer and the oxide layer, and the remaining pre-doped conductive layer forms the second doped conductive layer to obtain the target cell, including: Using the acid solution to clean the first cell to remove the sub-oxide layer, the remaining preliminary oxide layer forms the oxide layer, and obtains a second cell; Using the alkaline solution to clean the second cell to remove the protective layer and the sub-doped conductive layer, the remaining pre-doped conductive layer forms the second doped conductive layer, and obtains a third cell; The third cell is cleaned using the acid solution to remove the oxide layer, thereby obtaining the target cell.
4. The method for preparing a solar cell according to claim 1, characterized in that: The material of the protective layer includes ink, After providing the prepared cell piece and before forming a protective layer on the sidewall of the prepared oxide layer, the method further includes: performing laser processing on the edge of the prepared cell piece.
5. The method for preparing a solar cell according to claim 4, characterized in that: The ink includes a resin, and laser processing is performed on the edge of the prepared cell sheet, including: The edge of the prepared battery cell is laser processed for 40s to 50s.
6. The method for preparing a solar cell according to claim 1, characterized in that: Provides prepared battery cells, including: providing the substrate; forming a first doped conductive layer on the first surface, wherein a doping type of the first doped conductive layer is different from a doping type of the substrate; forming a tunneling layer on the second surface and on the sidewalls of the substrate; Covering the preliminary doped conductive layer on the tunneling layer and the first doped conductive layer, wherein the material of the preliminary doped conductive layer comprises polysilicon; The preliminary doped conductive layer is covered with the preliminary oxide layer.
7. The method for preparing a solar cell according to claim 6, characterized in that: Providing the substrate includes: providing a silicon substrate; performing a texturing treatment on the silicon substrate; performing an alkali polishing treatment on the silicon substrate after the texturing treatment to obtain the substrate. The first doped conductive layer is formed on the first surface, comprising: performing a boron diffusion process on the substrate to form the first doped conductive layer on the first surface to obtain an initial prepared cell sheet.
8. The method for preparing a solar cell according to claim 7, characterized in that: The preliminary doped conductive layer is covered on the tunneling layer and the first doped conductive layer, and the preliminary oxide layer is covered on the preliminary doped conductive layer, comprising: performing phosphorus diffusion treatment on the initial preliminary battery cell forming the tunneling layer to form the preliminary doped conductive layer on the tunneling layer and the first doped conductive layer, and forming the preliminary oxide layer on the preliminary doped conductive layer.
9. A solar cell, characterized in that: The solar cell is prepared by the method for preparing a solar cell according to any one of claims 1 to 8, and the solar cell comprises: a substrate comprising opposing first and second surfaces; a first doped conductive layer, located on the first surface; The second doped conductive layer is located on the sidewall of the substrate, on the second surface and on the sidewall of the first doped conductive layer. The doping type of the first doped conductive layer is different from the doping type of the second doped conductive layer.
10. A photovoltaic module, characterized in that: include: A solar cell prepared by the method for preparing a solar cell according to any one of claims 1 to 8, or a solar cell according to claim 9.