Solar cell and method for manufacturing solar cell

Abstract

The application relates to a solar cell and a preparation method thereof, which comprises a substrate, a tunneling oxide passivation structure, an intrinsic amorphous silicon layer, a first passivation layer, a first transparent conductive structure and a first electrode. The substrate comprises a first surface and a second surface arranged oppositely, and the first surface comprises first areas and second areas arranged alternately; the first areas comprise electrode areas and non-electrode areas; the tunneling oxide passivation structure is arranged in the first areas; the intrinsic amorphous silicon layer is arranged in the non-electrode areas; the first passivation layer is arranged in the non-electrode areas on the side of the intrinsic amorphous silicon layer away from the tunneling oxide passivation structure; the first transparent conductive structure covers the first passivation layer and the tunneling oxide passivation structure in the electrode areas, and the thickness of the first transparent conductive structure in the electrode areas is smaller than that of the first transparent conductive structure in the non-electrode areas; and the first electrode is arranged in the electrode areas. The application can protect the intrinsic amorphous silicon layer and the first passivation layer through the first transparent conductive structure, so that the first passivation layer is not easy to be damaged.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to solar cells and methods for preparing solar cells. Background Technology

[0002] With the development of photovoltaic technology, solar cells are becoming increasingly widely used. During photoelectric conversion, the passivation layer is used to reduce carrier recombination at the semiconductor surface and interface. Damage to the passivation layer will affect the cell's anti-reflection effect, thus impacting the photoelectric conversion efficiency. Therefore, it is necessary to protect the passivation layer of solar cells to prevent a significant decrease in their photoelectric conversion efficiency. Summary of the Invention

[0003] Therefore, it is necessary to provide a solar cell that addresses the issue of how to protect the passivation layer of a solar cell.

[0004] A solar cell comprising:

[0005] The substrate includes a first surface and a second surface disposed opposite to each other, the first surface including an alternating first region and a second region; the first region includes an electrode region and a non-electrode region.

[0006] A tunneling oxide passivation structure is disposed in the first region;

[0007] An intrinsic amorphous silicon layer is disposed in the non-electrode region on the side of the tunneling oxide passivation structure opposite to the substrate;

[0008] The first passivation layer is disposed in the non-electrode region on the side of the intrinsic amorphous silicon layer opposite to the tunneling oxide passivation structure;

[0009] A first transparent conductive structure covers the first passivation layer and the tunneling oxidation passivation structure located in the electrode region, and the thickness of the first transparent conductive structure located in the electrode region is less than the thickness of the first transparent conductive structure located in the non-electrode region.

[0010] The first electrode is disposed in the electrode region.

[0011] In the aforementioned solar cell, since the thickness of the first transparent conductive structure located in the electrode region is less than the thickness of the first transparent conductive structure located in the non-electrode region, the thicker first transparent conductive structure can protect the intrinsic amorphous silicon layer and the first passivation layer below it. This makes the first passivation layer below it less susceptible to damage from the outside, thereby reducing the possibility of the passivation layer being damaged. This results in better anti-reflection effect of the solar cell and effectively ensures the stability of the photoelectric conversion efficiency of the solar cell.

[0012] In some embodiments, the thickness d1 of the first transparent conductive structure located in the electrode region and the thickness d2 of the first transparent conductive structure located in the non-electrode region satisfy the following condition:

[0013] 1.2d1≤d2≤1.5d1.

[0014] In some embodiments, the first transparent conductive structure is a continuous structure on the first surface.

[0015] In some embodiments, the intrinsic amorphous silicon layer is deposited on the side of the substrate and the second surface.

[0016] In some embodiments, the tunneling oxide passivation structure includes a second passivation layer and a first doped semiconductor layer stacked along a direction away from the substrate.

[0017] In some embodiments, the solar cell further includes a second doped semiconductor layer;

[0018] The second doped semiconductor layer is disposed on the side of the intrinsic amorphous silicon layer on the second surface that is away from the substrate; and the doping type of the second doped semiconductor layer is different from the doping type of the first doped semiconductor layer.

[0019] In some embodiments, the second doped semiconductor layer is disposed on the side of the substrate.

[0020] In some embodiments, the first passivation layer is disposed on the side of the substrate, and the first passivation layer is located on the side of the second doped semiconductor layer opposite to the substrate.

[0021] In some embodiments, the solar cell further includes a second transparent conductive structure;

[0022] The second transparent conductive structure is disposed on the side of the second doped semiconductor layer away from the substrate.

[0023] In some embodiments, the second transparent conductive structure has the same thickness as the first transparent conductive structure located in the electrode region; and / or

[0024] The second transparent conductive structure is made of the same material as the first transparent conductive structure.

[0025] This application also provides a method for preparing a solar cell, comprising:

[0026] A substrate is provided; the substrate includes a first surface and a second surface disposed opposite to each other, the first surface including an alternating first region and a second region; the first region includes an electrode region and a non-electrode region;

[0027] A tunneling oxidation passivation structure is formed in the first region of the substrate;

[0028] An intrinsic amorphous silicon layer and a first passivation layer are formed on the side of the tunneling oxide passivation structure opposite to the substrate;

[0029] A first transparent conductive layer of a first predetermined thickness is formed on the first surface;

[0030] The first transparent conductive layer is patterned to expose the tunneling oxide passivation structure in the electrode region.

[0031] A second transparent conductive layer of a second preset thickness is formed on the first surface of the substrate; wherein the first preset thickness is less than the second preset thickness;

[0032] A first electrode is formed in the electrode region.

[0033] In some embodiments, the first transparent conductive layer and the second transparent conductive layer are deposited, and the sputtering power during the deposition of the first transparent conductive layer is less than the sputtering power during the deposition of the second transparent conductive layer; and / or

[0034] The deposition flow rate when the first transparent conductive layer is formed is less than the deposition flow rate when the second transparent conductive layer is formed.

[0035] In some embodiments, the step of patterning the first transparent conductive layer specifically includes:

[0036] The first transparent conductive layer is patterned using a laser process, and an oxide film is formed in the electrode region.

[0037] In some embodiments, after the step of forming an oxide film in the electrode region, the method for fabricating the solar cell further includes:

[0038] Remove the oxide film. Attached Figure Description

[0039] Figure 1 A schematic diagram of a solar cell provided for some embodiments of this application.

[0040] Figure 2 For preparation Figure 1 The diagram shows the first state of the solar cell.

[0041] Figure 3 For preparation Figure 1 The diagram shows the second state of the solar cell.

[0042] Figure 4 For preparation Figure 1The diagram shows the third state of the solar cell.

[0043] Figure 5 For preparation Figure 1 The diagram shows the fourth state of the solar cell.

[0044] Figure 6 For preparation Figure 1 The diagram shows the fifth state of the solar cell.

[0045] Figure 7 For preparation Figure 1 The diagram shows the sixth state of the solar cell.

[0046] Figure 8 For preparation Figure 1 The diagram shows the seventh state of the solar cell.

[0047] Figure 9 For preparation Figure 1 The diagram shows the eighth state of the solar cell.

[0048] Figure 10 For preparation Figure 1 The diagram shows the ninth state of the solar cell.

[0049] Figure 11 This is a flowchart illustrating a method for fabricating a solar cell according to some embodiments of this application.

[0050] Figure label:

[0051] 110 - Substrate; 111 - First surface; 111a - First region; 111a1 - Electrode region; 111a2 - Non-electrode region; 111b - Second region; 112 - Second surface; 120 - Tunneling oxide passivation structure; 121 - Second passivation layer; 122 - First doped semiconductor layer; 130 - Intrinsic amorphous silicon layer; 140 - First passivation layer; 150 - Phosphosilicate glass; 160 - Second doped semiconductor layer; 200 - First transparent conductive structure; 210 - First transparent conductive layer; 220 - Second transparent conductive layer; 300 - First electrode; 400 - Second transparent conductive structure; 500 - Second electrode. Detailed Implementation

[0052] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0053] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0054] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0057] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, 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 possible implementation.

[0058] See Figure 1 , Figure 1 The diagram illustrates a solar cell provided in some embodiments of this application. One embodiment of the solar cell provided in this application includes a substrate 110, a tunneling oxide passivation structure 120, an intrinsic amorphous silicon layer 130, a first passivation layer 140, a first transparent conductive structure 200, and a first electrode 300. The substrate 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 includes alternating first regions 111a and second regions 111b. The first region 111a includes an electrode region 111a1 and a non-electrode region 111a2. A tunneling oxide passivation structure 120 is disposed in the first region 111a. An intrinsic amorphous silicon layer 130 is disposed in the non-electrode region 111a2 on the side of the tunneling oxide passivation structure 120 away from the substrate 110. A first passivation layer 140 is disposed in the non-electrode region 111a2 on the side of the intrinsic amorphous silicon layer 130 away from the tunneling oxide passivation structure 120. A first transparent conductive structure 200 covers the first passivation layer 140 and the tunneling oxide passivation structure 120 located in the electrode region 111a1, and the thickness of the first transparent conductive structure 200 located in the electrode region 111a1 is less than the thickness of the first transparent conductive structure 200 located in the non-electrode region 111a2. A first electrode 300 is disposed in the electrode region 111a1.

[0059] In the aforementioned solar cell, since the thickness of the first transparent conductive structure 200 located in the electrode region 111a1 is less than the thickness of the first transparent conductive structure 200 located in the non-electrode region 111a2, the thicker first transparent conductive structure 200 can protect the intrinsic amorphous silicon layer 130 and the first passivation layer 140 below it. This makes the first passivation layer 140 less susceptible to damage from the outside, thereby reducing the possibility of damage to the first passivation layer 140. This results in better anti-reflection effect of the solar cell and effectively ensures the stability of the photoelectric conversion efficiency of the solar cell.

[0060] Please see Figure 1In some embodiments, the thickness d1 of the first transparent conductive structure 200 located in electrode region 111a1 and the thickness d2 of the first transparent conductive structure 200 located in non-electrode region 111a2 satisfy the condition: 1.2d1≤d2≤1.5d1. By setting the thickness d2 of the first transparent conductive structure 200 located in non-electrode region 111a2 to be greater than or equal to 1.2 times the thickness of the first transparent conductive structure 200 in electrode region 111a1 and less than or equal to 1.5 times the thickness of the first transparent conductive structure 200 in electrode region 111a1, the thickness of the first transparent conductive structure 200 in non-electrode region 111a2 is more reasonable compared to the thickness of the first transparent conductive structure 200 in electrode region 111a1. This allows for the deposition of a thinner transparent conductive layer during fabrication, followed by the addition of... When processing electrode region 111a1, the thin transparent conductive layer of electrode region 111a1 is removed, and a thicker transparent conductive layer is deposited. This makes the thin transparent conductive layer easy to process and remove during the processing. It also allows the thin transparent conductive layer to act as a mask layer to protect the intrinsic amorphous silicon layer 130 and the first passivation layer 140 below it, thereby reducing the possibility of sputtering damage to the first passivation layer 140 and the intrinsic amorphous silicon layer 130, and thus reducing the possibility of a deterioration in the passivation effect of the solar cell.

[0061] In some embodiments, d2 is equal to 1.2 times d1. In some embodiments, d2 is equal to 1.5 times d1. In some embodiments, d2 is equal to 1.3 times d1.

[0062] In some embodiments, the first transparent conductive structure 200 is a continuous structure on the first surface 111. By making the first transparent conductive structure 200 a continuous structure on the first surface 111, the fabrication of the first transparent conductive structure 200 is more convenient, as it can be deposited on the entire first surface 111.

[0063] Please see Figure 1 In some embodiments, an intrinsic amorphous silicon layer 130 is deposited on the sides and second surface 112 of the substrate 110. By depositing the intrinsic amorphous silicon layer 130 on the sides and second surface 112 of the substrate 110, the intrinsic amorphous silicon layer 130 can also perform efficient surface passivation and selective carrier transport on the sides and second surface 112 of the substrate 110, thereby achieving more comprehensive surface defect suppression and significantly improving the performance of the solar cell. In some embodiments, the intrinsic amorphous silicon layer 130 can be (i)a-Si:H.

[0064] Please see Figure 1In some embodiments, the tunneling oxide passivation structure 120 includes a second passivation layer 121 and a first doped semiconductor layer 122 stacked along a direction away from the substrate 110. By configuring the tunneling oxide passivation structure 120 as a second passivation layer 121 and a first doped semiconductor layer 122, efficient carrier selective collection and excellent surface passivation effects can be achieved. In some embodiments, the second passivation layer 121 may be silicon oxide, and the first doped semiconductor layer 122 may be n+ poly-Si formed by phosphorus diffusion on intrinsic amorphous silicon.

[0065] Please see Figure 1 In some embodiments, the solar cell further includes a second doped semiconductor layer 160; the second doped semiconductor layer 160 is disposed on the side of the intrinsic amorphous silicon layer 130 of the second surface 112 facing away from the substrate 110; and the doping type of the second doped semiconductor layer 160 is different from the doping type of the first doped semiconductor layer 122. By disposing the second doped semiconductor layer 160 on the side of the intrinsic amorphous silicon layer 130 of the second surface 112 facing away from the substrate 110, and by having a different doping type than the first doped semiconductor layer 122, highly efficient carrier-selective contacts can be formed, greatly improving the photoelectric conversion efficiency of the cell. In some embodiments, the second doped semiconductor layer 160 can be (p)a-Si:H formed by boron diffusion.

[0066] Please see Figure 1 In some embodiments, the second doped semiconductor layer 160 is deposited on the side of the substrate 110. By depositing the second doped semiconductor layer 160 on the side of the substrate 110, the side of the substrate 110 can be passivated, thereby suppressing carrier recombination and leakage current in the edge region, thus improving the overall performance and reliability of the battery. Furthermore, when forming the second doped semiconductor layer 160 on the first surface 111 and the second surface 112, the processing of the second doped semiconductor layer 160 on the first surface 111, the second surface 112, and the side surface can be achieved in the same process, making the fabrication process relatively simple.

[0067] Please see Figure 1 In some embodiments, a first passivation layer 140 is disposed on the side of the substrate 110, and the first passivation layer 140 is located on the side of the second doped semiconductor layer 160 opposite to the substrate 110. By disposing the first passivation layer 140 on the side of the substrate 110 and being located on the side of the second doped semiconductor layer 160 opposite to the substrate 110, the side of the substrate 110 is further passivated, suppressing carrier recombination and leakage current in the edge region, thereby improving the overall performance and reliability of the battery.

[0068] Please see Figure 1In some embodiments, the solar cell further includes a second transparent conductive structure 400; the second transparent conductive structure 400 is disposed on the side of the second doped semiconductor layer 160 facing away from the substrate 110. By disposing the second transparent conductive layer 220 on the side of the second doped semiconductor layer 160 facing away from the substrate 110, the second surface 112 of the substrate 110 can be protected, while also enabling the second surface 112 of the solar cell to perform photoelectric conversion, thereby improving the photoelectric conversion efficiency of the solar cell.

[0069] In some embodiments, the second transparent conductive structure 400 has the same thickness as the first transparent conductive structure 200 located in the electrode region 111a1. By setting the thickness of the second transparent conductive structure 400 to be the same as that of the first transparent conductive structure 200 located in the electrode region 111a1, it is possible to first deposit a thinner first transparent conductive layer 210 when fabricating the solar cell provided in this application, and then remove the thinner first transparent conductive layer 210 of the electrode region 111a1 when processing the electrode region 111a1, and then deposit a thicker second transparent conductive layer 220 on the first surface 111 and the second surface 112 of the cell. The thickness of the second transparent conductive layer 220 is the same as the thickness of the second transparent conductive structure 400 and the thickness of the first transparent conductive structure 200 located in the electrode region 111a1. This makes the thinner first transparent conductive layer 210 easier to process and remove during the manufacturing process. It also allows the thinner first transparent conductive layer 210 to act as a mask layer to protect the intrinsic amorphous silicon layer 130 and the first passivation layer 140 below the first transparent conductive layer 210 on the first surface 111. This reduces the possibility of sputtering damage to the first passivation layer 140 and the intrinsic amorphous silicon layer 130, thereby reducing the possibility of a deterioration in the passivation effect of the solar cell.

[0070] In some embodiments, the second transparent conductive structure 400 is made of the same material as the first transparent conductive structure 200. By making the second transparent conductive structure 400 and the first transparent conductive structure 200 the same material, their fabrication is more convenient. In some embodiments, both the second transparent conductive structure 400 and the first transparent conductive structure 200 are made of TCO (Transparent Conductive Oxide). In some embodiments, the second transparent conductive structure 400 and the first transparent conductive structure 200 may also be made of ITO or other non-indium-based TCO materials, such as tin oxide-based TCO. In some embodiments, the second transparent conductive structure 400 and the first transparent conductive structure 200 may also be made of one or more of the following thin film stacks: IWO, ICO, IMO, SCOT, AZO, GZO, GAZO, and SnO2.

[0071] This application also provides a method for preparing a solar cell; please refer to [link to relevant documentation]. Figure 11 and combined Figures 2-10 , Figure 11 A flowchart illustrating a method for fabricating a solar cell according to some embodiments of this application is shown. Figure 2 The preparation is shown Figure 1 The diagram shows the first state of the solar cell. Figure 3 The preparation is shown Figure 1 The diagram shows the second state of the solar cell. Figure 4 The preparation is shown Figure 1 The diagram shows the third state of the solar cell. Figure 5 The preparation is shown Figure 1 The diagram shows the fourth state of the solar cell. Figure 6 The preparation is shown Figure 1 The diagram shows the fifth state of the solar cell. Figure 7 The preparation is shown Figure 1 The diagram shows the sixth state of the solar cell. Figure 8 The preparation is shown Figure 1 The diagram shows the seventh state of the solar cell. Figure 9 The preparation is shown Figure 1 The diagram shows the eighth state of the solar cell. Figure 10 The preparation is shown Figure 1 The diagram shows the ninth state of the solar cell.

[0072] The methods for fabricating solar cells provided in some embodiments of this application include:

[0073] S10: Provides substrate 110; such as Figure 2 and Figure 3 As shown, the substrate 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 includes alternating first regions 111a and second regions 111b. The first region 111a includes an electrode region 111a1 and a non-electrode region 111a2. The morphology of the substrate 110 is as follows: Figure 3 As shown.

[0074] S20: A tunneling oxidation passivation structure 120 is formed in the first region 111a of the substrate 110; the final morphology is as follows. Figure 4 As shown.

[0075] S30: An intrinsic amorphous silicon layer 130 and a first passivation layer 140 are formed on the side of the tunneling oxide passivation structure 120 facing away from the substrate 110; the final morphology is as follows. Figure 7 As shown.

[0076] S40: A first transparent conductive layer 210 of a first predetermined thickness is formed on the first surface 111; the final morphology is as follows. Figure 8 As shown.

[0077] S50: The first transparent conductive layer 210 is patterned to expose the tunneling oxide passivation structure 120 of the electrode region 111a1; the final morphology is as follows. Figure 9 As shown.

[0078] S60: A second transparent conductive layer 220 of a second preset thickness is formed on the first surface 111 of the substrate 110; wherein the first preset thickness is less than the second preset thickness; the final morphology is as follows. Figure 10 As shown.

[0079] S70: A first electrode 300 is formed in electrode region 111a1, and the final morphology is as follows. Figure 11 As shown.

[0080] When a solar cell is fabricated using the solar cell fabrication method provided in this application embodiment, a first transparent conductive layer 210 can be first formed on the first surface 111. Then, the first transparent conductive layer 210 is patterned to expose the tunneling oxide passivation structure 120 of the electrode region 111a1. Next, a second transparent conductive layer 220 of a second preset thickness is formed on the first surface 111 of the substrate 110, with the first preset thickness set to be less than the second preset thickness. Finally, a first electrode 300 is formed in the electrode region 111a1, thereby enabling the solar cell to be more transparent and passivated during processing. The thin first transparent conductive layer 210 is easy to process and remove. It can also serve as a mask layer to protect the intrinsic amorphous silicon layer 130 and the first passivation layer 140 below the first transparent conductive layer 210 on the first surface 111. This reduces the possibility of sputtering damage to the first passivation layer 140 and the intrinsic amorphous silicon layer 130, thereby reducing the possibility of a deterioration in the passivation effect of the solar cell. This results in a better anti-reflection effect of the solar cell and effectively ensures the stability of the photoelectric conversion efficiency of the solar cell.

[0081] In some embodiments, metal grid lines are printed to form the first electrode 300.

[0082] In some embodiments, the solar energy preparation method further includes: forming a third transparent conductive layer of a second preset thickness on the second surface 112 of the substrate 110, wherein the thickness of the third transparent conductive layer may be the same as the second preset thickness, and the material of the third transparent conductive layer may be the same as the material of the second transparent conductive layer 220.

[0083] In some embodiments, the formation of the third transparent conductive layer can be performed simultaneously with the formation of the second transparent conductive layer 220 in step S60, or it can be formed after or before the formation of the second transparent conductive layer 220, without any particular limitation.

[0084] In some embodiments, after forming a third transparent conductive layer of a second predetermined thickness on the second surface 112 of the substrate 110, the method for fabricating the solar cell further includes forming a second electrode 500 in a predetermined region of the second surface 112. The second electrode 500 can be formed simultaneously with, before, or after the formation of the first electrode 300; there is no particular limitation in this regard. The second electrode 500 can be formed by printing metal grid lines.

[0085] In some embodiments, a first transparent conductive layer 210 and a second transparent conductive layer 220 are deposited, and the sputtering power during the deposition of the first transparent conductive layer 210 is less than the sputtering power during the deposition of the second transparent conductive layer 220. By controlling the sputtering power during the deposition of the first transparent conductive layer 210 to be less than the sputtering power during the deposition of the second transparent conductive layer 220, it is convenient to achieve a first preset thickness that is less than a second preset thickness through the difference in sputtering power.

[0086] In some embodiments, the deposition flow rate during the deposition of the first transparent conductive layer 210 is less than the deposition flow rate during the deposition of the second transparent conductive layer 220. By controlling the deposition flow rate during the deposition of the first transparent conductive layer 210 to be less than the deposition flow rate during the deposition of the second transparent conductive layer 220, it is convenient to achieve a first preset thickness that is less than a second preset thickness by means of the difference in deposition flow rate.

[0087] In some embodiments, the step of patterning the first transparent conductive layer 210 specifically includes: patterning the first transparent conductive layer 210 using a laser process, and forming an oxide film in the electrode region 111a1.

[0088] Laser processing is used to open the electrode region 111a1 on the first transparent conductive layer 210, thereby exposing the tunneling oxide passivation structure 120 of the electrode region 111a1 to facilitate subsequent processing of the first electrode 300. After the patterning process of the first transparent conductive layer 210 is completed by laser processing, an oxide film is simultaneously formed on the electrode region 111a1. This oxide film is a naturally formed oxide thin film.

[0089] In some embodiments, after the step of forming an oxide film in electrode region 111a1, the method for fabricating a solar cell further includes: removing the oxide film.

[0090] After the electrode region 111a1 on the first transparent conductive layer 210 is processed by laser technology to perform a film-opening process, an oxide film is formed on the electrode region 111a1. Therefore, this oxide film needs to be removed to facilitate the subsequent fabrication of the first electrode 300 on the electrode region 111a1. In some embodiments, the oxide film is removed by chain HF removal.

[0091] In some embodiments, step S20: forming a tunneling oxide passivation structure 120 in the first region 111a of the substrate 110 specifically includes:

[0092] First, a substrate 110 is provided, and a tunneling oxide passivation structure 120 is formed on the outer periphery of the substrate 110. Simultaneously, during the fabrication of the tunneling oxide passivation structure 120, a layer of phosphosilicate glass 150 is formed on the side of the tunneling oxide passivation structure 120 facing away from the substrate 110, resulting in the following final morphology. Figure 2 As shown. Then, the tunneling oxide passivation structure 120 is patterned to expose the tunneling oxide passivation structure 120 in the second region 111b, and the phosphosilicate glass 150 in the second region 111b is removed, resulting in the final morphology as shown. Figure 3 As shown. Then, the second region 111b is texturized, and the tunneling oxide passivation structure 120 of the second region 111b is removed, resulting in the final morphology as shown. Figure 4 As shown.

[0093] In some embodiments, after step S20 and before step S30, the method for fabricating a solar cell further includes:

[0094] A mask structure is formed on the first surface 111 of the substrate 110. Then, the phosphosilicate glass 150 (PSG) on the back and sides, as well as the mask structure deposited around the back and sides, are removed in a chain-like manner. In some embodiments, the mask structure can be silicon oxide. The second surface 112 and sides are then polished, and the mask structure on the front surface is removed by RCA cleaning. Finally, an intrinsic amorphous silicon layer 130 is formed on the first surface 111, the second surface 112, and the sides of the substrate 110, resulting in the final morphology as shown. Figure 5 As shown. Then, a second doped semiconductor layer 160 is formed on the second surface 112 and the sides of the substrate 110, resulting in a final morphology as shown. Figure 6 As shown. A first passivation layer 140 is then formed on the first surface 111 and sides of the substrate 110, resulting in the final morphology as shown. Figure 7 As shown.

[0095] It should be understood that, in the embodiments of this application, at least some steps in the preparation method may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0097] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, The solar cell includes: The substrate (110) includes a first surface (111) and a second surface (112) disposed opposite to each other. The first surface (111) includes an alternately arranged first region (111a) and a second region (111b). The first region (111a) includes an electrode region (111a1) and a non-electrode region (111a2). A tunneling oxidation passivation structure (120) is disposed in the first region (111a). An intrinsic amorphous silicon layer (130) is disposed in the non-electrode region (111a2) of the tunneling oxide passivation structure (120) on the side opposite to the substrate (110). The first passivation layer (140) is disposed in the non-electrode region (111a2) of the intrinsic amorphous silicon layer (130) on the side opposite to the tunneling oxide passivation structure (120). A first transparent conductive structure (200) covers the first passivation layer (140) and a tunneling oxide passivation structure (120) located in the electrode region (111a1), and the thickness of the first transparent conductive structure (200) located in the electrode region (111a1) is less than the thickness of the first transparent conductive structure (200) located in the non-electrode region (111a2). The first electrode (300) is disposed in the electrode region (111a1).

2. The solar cell according to claim 1, characterized in that, The thickness d1 of the first transparent conductive structure (200) located in the electrode region (111a1) and the thickness d2 of the first transparent conductive structure (200) located in the non-electrode region (111a2) satisfy the following condition: 1.2d1≤d2≤1.5d1.

3. The solar cell according to claim 1, characterized in that, The first transparent conductive structure (200) is a continuous structure on the first surface (111).

4. The solar cell according to any one of claims 1-3, characterized in that, The intrinsic amorphous silicon layer (130) is disposed on the side of the substrate (110) and the second surface (112).

5. The solar cell according to claim 4, characterized in that, The tunneling oxide passivation structure (120) includes a second passivation layer (121) and a first doped semiconductor layer (122) stacked along a direction away from the substrate (110).

6. The solar cell according to claim 5, characterized in that, The solar cell also includes a second doped semiconductor layer (160). The second doped semiconductor layer (160) is disposed on the side of the intrinsic amorphous silicon layer (130) of the second surface (112) away from the substrate (110); and the doping type of the second doped semiconductor layer (160) is different from the doping type of the first doped semiconductor layer (122).

7. The solar cell according to claim 6, characterized in that, The second doped semiconductor layer (160) is disposed on the side of the substrate (110); and / or The first passivation layer (140) is disposed on the side of the substrate (110), and the first passivation layer (140) is located on the side of the second doped semiconductor layer (160) away from the substrate (110).

8. The solar cell according to claim 6, characterized in that, The solar cell also includes a second transparent conductive structure (400). The second transparent conductive structure (400) is disposed on the side of the second doped semiconductor layer (160) away from the substrate (110).

9. The solar cell according to claim 8, characterized in that, The second transparent conductive structure (400) has the same thickness as the first transparent conductive structure (200) located in the electrode region (111a1); and / or The second transparent conductive structure (400) is made of the same material as the first transparent conductive structure (200).

10. A method for preparing a solar cell, characterized in that, The method for preparing the solar cell includes: A substrate (110) is provided; the substrate (110) includes a first surface (111) and a second surface (112) disposed opposite to each other, the first surface (111) including an alternating first region (111a) and a second region (111b); the first region (111a) includes an electrode region (111a1) and a non-electrode region (111a2); A tunneling oxidation passivation structure (120) is formed in the first region (111a) of the substrate (110). An intrinsic amorphous silicon layer (130) and a first passivation layer (140) are formed on the side of the tunneling oxide passivation structure (120) opposite to the substrate (110). A first transparent conductive layer (210) of a first preset thickness is formed on the first surface (111). The first transparent conductive layer (210) is patterned to expose the tunneling oxide passivation structure (120) of the electrode region (111a1); A second transparent conductive layer (220) of a second preset thickness is formed on the first surface (111) of the substrate (110); wherein the first preset thickness is less than the second preset thickness; A first electrode (300) is formed in the electrode region (111a1).

11. The method for preparing a solar cell according to claim 10, characterized in that, The first transparent conductive layer (210) and the second transparent conductive layer (220) are deposited and formed, and the sputtering power when depositing and forming the first transparent conductive layer (210) is less than the sputtering power when depositing and forming the second transparent conductive layer (220); and / or The deposition flow rate when the first transparent conductive layer (210) is deposited is less than the deposition flow rate when the second transparent conductive layer (220) is deposited.

12. The method for preparing a solar cell according to claim 10 or 11, characterized in that, The step of patterning the first transparent conductive layer (210) specifically includes: The first transparent conductive layer (210) is patterned using a laser process, and an oxide film is formed in the electrode region (111a1).

13. The method for preparing a solar cell according to claim 12, characterized in that, Following the step of forming an oxide film in the electrode region (111a1), the method for fabricating the solar cell further includes: Remove the oxide film.

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