Solar cell and photovoltaic module
By designing a first groove with a specific structure on the side of the silicon substrate, the transparent conductive thin film layer is effectively blocked, solving the short-circuit problem in traditional solar cells and improving the photoelectric conversion efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2026-03-13
AI Technical Summary
In traditional solar cells, direct contact between the transparent conductive film layers on the front and back sides leads to short circuits, affecting photoelectric conversion efficiency. Furthermore, existing mask designs limit carrier collection.
A first groove with a specific structure is designed on the side of the silicon substrate, so that the transparent conductive film layers on the front and back sides do not need to be separated by a mask. Effective isolation of the transparent conductive film layers is achieved by designing a first groove with a specific position and structure on the side of the silicon substrate.
It overcomes the battery short-circuit problem and improves photoelectric conversion efficiency, breaking the limitation of photoelectric conversion efficiency imposed by the mask.
Smart Images
Figure CN223993857U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic manufacturing technology, and in particular to a solar cell and a photovoltaic module. Background Technology
[0002] In traditional solar cells, the coating process involves wrapping around the front and back surfaces, causing direct contact between the transparent conductive film layers on the front and back sides, leading to short circuits. To overcome this problem, a mask is typically used on the coating area on the back side of the cell to pattern the transparent conductive film layer and prevent it from contacting the front side. However, the mask on the back side restricts the complete collection of charge carriers, thus affecting the cell's photoelectric conversion efficiency. Utility Model Content
[0003] Based on this, it is necessary to provide a solar cell and photovoltaic module to address the above problems. The solar cell described in this utility model, through structural design of the side of the silicon substrate, enables the transparent conductive film layers on the front and back sides to achieve zero contact without the need for a mask, which not only overcomes the short circuit problem of the battery, but also improves the photoelectric conversion efficiency of the battery.
[0004] A solar cell includes a silicon substrate, wherein a first groove extending circumferentially along the side of the silicon substrate is provided, the top edge of the first groove coincides with the top edge of the side of the silicon substrate, and the first groove includes a first inner wall that gradually slopes inward from top to bottom, the top edge of the first inner wall being the top edge of the first groove.
[0005] The outer surface of the silicon substrate is sequentially covered with an intrinsic amorphous silicon layer and a doped layer from the inside out. The doped layer includes a first region, which includes at least a portion of the first inner wall. A transparent conductive thin film layer is covered on the area of the doped layer other than the portion of the first region, and an electrode is provided on the transparent conductive thin film layer.
[0006] In one embodiment, the maximum width of the first groove accounts for 5%-80% of the thickness of the silicon substrate.
[0007] In one embodiment, the maximum width of the first groove is 10μm-70μm.
[0008] In one embodiment, the maximum depth of the first groove is 12μm-100μm.
[0009] In one embodiment, the longitudinal section of the first groove is triangular, and the first groove further includes a second inner wall connected to the first inner wall.
[0010] In one embodiment, the angle between the first inner wall and the second inner wall is 40°-70°.
[0011] In one embodiment, the second inner wall is perpendicular to the side of the silicon substrate.
[0012] In one embodiment, the longitudinal section of the first groove is trapezoidal.
[0013] In one embodiment, the side of the silicon substrate is further provided with a second groove extending circumferentially along the silicon substrate, the top edge of the second groove coinciding with the bottom edge of the side of the silicon substrate.
[0014] A photovoltaic module, comprising a solar cell as described above.
[0015] The solar cell of this invention, by designing a first groove with a specific position and structure on the side of the silicon substrate, effectively isolates the transparent conductive film layer on the front side from the transparent conductive film layer on the back side by using a portion of the area corresponding to the first inner wall of the first groove as the boundary. This breaks the limitation of photoelectric conversion efficiency imposed by the mask in the traditional solar cell structure, thereby improving the photoelectric conversion efficiency of the solar cell of this invention while overcoming the short-circuit problem. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of a solar cell in one embodiment of the present invention;
[0017] Figure 2 This is a partial structural diagram of the longitudinal section of a silicon substrate in one embodiment of the present invention;
[0018] Figure 3 This is a schematic diagram of the longitudinal cross-sectional structure of a solar cell in another embodiment of the present invention;
[0019] Figure 4 This is a schematic diagram of the longitudinal cross-sectional structure of a solar cell in another embodiment of the present invention;
[0020] Figure 5 This is a schematic diagram of the longitudinal cross-sectional structure of a solar cell in another embodiment of the present invention.
[0021] Wherein, 10 is a silicon substrate; 101 is a first groove; 1011 is the top edge of the first groove; 1012 is a first inner wall; 1013 is a second inner wall; 102 is a second groove; 20 is an intrinsic amorphous silicon layer; 30 is a doped layer; 40 is a transparent conductive thin film layer; 401 is a first transparent conductive thin film layer; 402 is a second transparent conductive thin film layer; 50 is an electrode; a is the maximum width of the first groove; b is the maximum depth of the first groove. Detailed Implementation
[0022] To facilitate understanding of this utility model, it will be described in more detail below. However, it should be understood that this utility model can be implemented in many different forms and is not limited to the embodiments or examples described herein. Rather, these embodiments or examples are provided to make the disclosure of this utility model more thorough and complete.
[0023] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 utility model.
[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments or examples only and is not intended to be limiting of the invention.
[0026] This utility model provides a solar cell, including but not limited to heterojunction cells, TOPCon cells, PERC cells, etc., specifically, in combination with... Figure 1 The figure shown is a schematic diagram of the longitudinal cross-sectional structure of a solar cell in one embodiment of the present invention, including a silicon substrate 10, wherein a first groove 101 extending circumferentially along the side of the silicon substrate 10 is provided.
[0027] Combination Figure 2 As shown, the top edge 1011 of the first groove coincides with the top edge of the side of the silicon substrate 10. The first groove 101 includes a first inner wall 1012 that gradually slopes inward from top to bottom, and the top edge of the first inner wall 1012 is the top edge 1011 of the first groove.
[0028] The outer surface of the silicon substrate 10 is sequentially covered with an intrinsic amorphous silicon layer 20 and a doped layer 30 from the inside out. The doped layer 30 includes a first region, which includes at least a portion of the first inner wall 1012. The area of the doped layer 30 other than the portion of the first region is covered with a transparent conductive thin film layer 40, and an electrode 50 is provided on the transparent conductive thin film layer 40.
[0029] It is understood that the first groove 101 is an annular groove, and the annulus is a closed loop. From another perspective, the first groove 101 divides the entire surface of the silicon substrate 10 into upper and lower parts, and the upper and lower parts are not connected to each other. Furthermore, based on the fact that the doped layer 30 is covered with a transparent conductive film layer 40 except for a portion of the first region, it can be understood that the transparent conductive film layer 40 is divided by a portion of the first region, forming a first transparent conductive film layer 401 located at the upper part of the first region and a second transparent conductive film layer 402 located at the lower part of the first region. In this utility model, "from top to bottom" means the direction from the top edge of the side surface of the silicon substrate 10 to the bottom edge of the side surface of the silicon substrate 10, and "inward" means towards the interior of the silicon substrate 10.
[0030] The solar cell of this invention, by designing a first groove 101 with a specific position and structure on the side of the silicon substrate 10, effectively isolates the transparent conductive film layer on the front side from the transparent conductive film layer on the back side, with the portion corresponding to the first inner wall 1012 in the first groove 101 as the boundary. This breaks the limitation of photoelectric conversion efficiency imposed by the mask in the traditional solar cell structure, thereby improving the photoelectric conversion efficiency of the solar cell while overcoming the short circuit problem.
[0031] It should be noted that the first surface of the silicon substrate 10 is connected to the top edge of its side surface, and the second surface of the silicon substrate 10 is disposed opposite to the first surface. The first surface can be a light-receiving surface, in which case the second surface is a backlighting surface; alternatively, the first surface can also be a backlighting surface, in which case the second surface is a light-receiving surface. This invention does not limit the specific application of this method. The doped layer 30 includes P-type doping and N-type doping. It is understood that when the first surface is doped with P-type, the second surface is doped with N-type; when the first surface is doped with N-type, the second surface is doped with P-type. The P-type and N-type doping form a stacked structure on the side surface of the silicon substrate 10. This can be either P-type doping stacked on the N-type doped surface or N-type doping stacked on the P-type doped surface. This invention does not limit the specific application of this method.
[0032] By adjusting the size of the first groove 101 in the silicon substrate 10, it is beneficial to further improve efficiency while ensuring that the silicon substrate 10 does not break.
[0033] In one embodiment of the present invention, the maximum width a of the first groove 101 accounts for 5%-80% of the thickness of the silicon substrate 10, including but not limited to any one of 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or any range between two of them.
[0034] In one embodiment of this utility model, the maximum width a of the first groove 101 is 10μm-70μm, including but not limited to any one value among 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, and 70μm, or any range between two of them.
[0035] In one embodiment of this utility model, the maximum depth b of the first groove 101 is 12μm-100μm, including but not limited to any one of 12μm, 25μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, and 100μm or any range between two of them.
[0036] It should be noted that the present invention does not limit the ratio of the maximum width a and the maximum depth b of the first groove 101. The maximum width a of the first groove 101 can be greater than the maximum depth b of the first groove 101, the maximum width a of the first groove 101 can be less than the maximum depth b of the first groove 101, and the maximum width a of the first groove 101 can also be equal to the maximum depth b of the first groove 101.
[0037] The present invention does not limit the specific shape of the first groove 101, including but not limited to triangle, trapezoid or other irregular shape, as long as the first inner wall 1012 in the first groove 101 gradually slopes inward from top to bottom.
[0038] In one embodiment of this utility model, combined with Figure 1 and Figure 2 As shown, the longitudinal section of the first groove 101 is preferably triangular. In this case, the first groove 101 has two inner walls, namely the first inner wall 1012 and the second inner wall 1013, and the second inner wall 1013 is connected to the first inner wall 1012.
[0039] It should be noted that this utility model does not limit the specific shape of the triangle. The triangle can be an acute triangle, an obtuse triangle, or a right triangle.
[0040] When the triangle is a right triangle, in one embodiment of this utility model, combined with Figure 1As shown, the second inner wall 1013 is perpendicular to the side surface of the silicon substrate 10. It can be understood that the angle between the first inner wall 1012 and the second inner wall 1013 is an acute angle at this time.
[0041] More preferably, the angle between the first inner wall 1012 and the second inner wall 1013 is 40°-70°.
[0042] When the triangle is a right triangle, in another embodiment of this utility model, combined with Figure 3 As shown, the angle between the first inner wall 1012 and the second inner wall 1013 is a right angle.
[0043] In other embodiments of this utility model, the included angle between the first inner wall 1012 and the second inner wall 1013 may also be an obtuse angle.
[0044] In one embodiment of this utility model, combined with Figure 4 As shown, the longitudinal section of the first groove 101 is trapezoidal. At this time, the first groove 101 has three inner walls. This utility model does not limit the other two inner walls in the trapezoid besides the first inner wall 1012. Preferably, the included angle of the other two inner walls is a right angle, and either of the other two inner walls is perpendicular to the side of the silicon substrate 10.
[0045] In one embodiment of this utility model, combined with Figure 5 As shown, the side of the silicon substrate 10 is also provided with a second groove 102 extending circumferentially along the silicon substrate 10, and the top edge of the second groove 102 coincides with the bottom edge of the side of the silicon substrate.
[0046] It is understood that when the second groove 102 is present, the maximum width 'a' of the first groove 101 and the maximum width of the second groove 102 are both less than 50% of the thickness of the silicon substrate 10. The second groove 102 can have the same shape and size as the first groove 101, so that the longitudinal section of the solar cell can have a symmetrical structure in the horizontal direction; the second groove 102 can also have a different shape and size than the first groove 101, and this utility model does not limit this.
[0047] It should be noted that the surface of the silicon substrate 10 can be flat or textured. When the surface of the silicon substrate 10 is textured, the first inner wall 1012 can also be textured. When the first inner wall 1012 is textured, a small amount of transparent conductive film layer 40 is attached to the edge of the first region to form a micro-plating structure, and the textured side facing away from the first region is less likely to have transparent conductive film layer 40 attached, which helps to further avoid plating contact.
[0048] This invention does not limit the dimensions of the intrinsic amorphous silicon layer 20, the transparent conductive thin film layer 40, and the electrode 50; conventional parameters can be used for design. For example, the thickness of the intrinsic amorphous silicon layer 20 is preferably 2nm-8nm; the thickness of the transparent conductive thin film layer 40 is preferably 60nm-90nm; and the height of the electrode 50 is preferably 6μm-20μm, and the width is preferably 10μm-40μm.
[0049] This invention also provides a photovoltaic module, including the solar cell described above, which can be widely used in power generation, outdoor lighting, mobile power supplies, and aerospace, among other fields. It should be noted that this invention does not limit the structure of the photovoltaic module.
[0050] 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.
[0051] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A solar cell comprising a silicon substrate, characterized in that, The side surface of the silicon substrate is provided with a first groove extending along the circumference of the silicon substrate, a top edge of the first groove coincides with a top edge of the side surface of the silicon substrate, the first groove comprises a first inner wall gradually inclined inward from top to bottom, and a top edge of the first inner wall is the top edge of the first groove; An intrinsic amorphous silicon layer and a doped layer are sequentially coated on the outer surface of the silicon substrate from inside to outside, the doped layer comprises a first region, the first region comprises at least part of the first inner wall, a transparent conductive film layer is coated on the region of the doped layer except the part of the first region, and an electrode is arranged on the transparent conductive film layer.
2. The solar cell according to claim 1, characterized in that, The maximum width of the first groove accounts for 5%-80% of the thickness of the silicon substrate.
3. The solar cell according to claim 1 or 2, characterized in that, The maximum width of the first groove is 10 μm-70 μm.
4. The solar cell of claim 1, wherein The maximum depth of the first groove is 12 μm-100 μm.
5. The solar cell of claim 1, wherein The longitudinal section of the first groove is triangular, and the first groove further comprises a second inner wall connected with the first inner wall.
6. The solar cell according to claim 5, characterized in that, The included angle between the first inner wall and the second inner wall is 40°-70°.
7. The solar cell according to claim 5 or 6, characterized in that, The second inner wall is perpendicular to the side surface of the silicon substrate.
8. The solar cell of claim 1, wherein, The longitudinal section of the first groove is trapezoidal.
9. The solar cell of claim 1, wherein, The side surface of the silicon substrate is further provided with a second groove extending along the circumference of the silicon substrate, and a top edge of the second groove coincides with a bottom edge of the side surface of the silicon substrate.
10. A photovoltaic module, characterized by, The solar cell comprises the solar cell as claimed in any one of claims 1-9.