Solar cell and photovoltaic module

Abstract

The utility model relates to a solar cell and a photovoltaic assembly. The solar cell comprises a silicon substrate, at least one groove extending in the circumferential direction of the silicon substrate is formed in the side face of the silicon substrate, and the side face of the silicon substrate is divided into at least two areas through the groove; the outer surface of the silicon substrate is sequentially coated with an intrinsic amorphous silicon layer and a doped layer from inside to outside, the doped layer is covered with a transparent conductive thin film layer except the groove, and an electrode is arranged on the transparent conductive thin film layer. According to the solar cell provided by the utility model, the side surface structure of the silicon substrate is designed, so that the transparent conductive film layers on the front surface and the back surface can realize zero contact without a mask, the problem of short circuit of the cell is solved, and the photoelectric conversion efficiency of the cell is improved.

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, by designing the side structure of the silicon substrate, enables the transparent conductive film layers on the front and back sides to achieve zero contact without 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 at least one groove extending circumferentially along the side of the silicon substrate is provided, the groove dividing the side of the silicon substrate into at least two regions.

[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, except for the groove, is covered with a transparent conductive thin film layer, and electrodes are provided on the transparent conductive thin film layer.

[0006] In one embodiment, the width ratio of any two regions is 1:1 to 1:3.

[0007] In one embodiment, the width of any of the grooves on the side of the silicon substrate is 0.5%-50% of the thickness of the silicon substrate.

[0008] In one embodiment, the width of any of the grooves is 0.1 μm to 20 μm.

[0009] In one embodiment, in the longitudinal section of the silicon substrate, the depth of any of the grooves is 2.38 × 10⁻⁶ times the length of the silicon substrate. -6 -0.0476%.

[0010] In one embodiment, the depth of any of the grooves is 0.5 μm-100 μm.

[0011] In one embodiment, the total volume of the groove accounts for 0.07%-1.4% of the volume of the silicon substrate.

[0012] In one embodiment, the number of grooves is 1 to 3.

[0013] In one embodiment, the longitudinal section of the groove is rectangular or semi-circular.

[0014] A photovoltaic module, comprising a solar cell as described above.

[0015] The solar cell described in this invention achieves effective isolation between the front and back transparent conductive film layers by designing grooves with specific positions on the side of the silicon substrate, using the grooves as a boundary. This breaks the limitation of photoelectric conversion efficiency imposed by masks in traditional solar cell structures, allowing the front and back transparent conductive film layers to achieve zero contact without masks. As a result, the solar cell described in this invention overcomes the short-circuit problem while improving the photoelectric conversion efficiency of the cell. 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 top view of a silicon substrate with grooves according to one embodiment of the present invention.

[0018] Wherein, 10 is a silicon substrate; 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 width of the groove; b is the depth of the groove. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model 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 utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0020] 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.

[0021] 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.

[0022] In this utility model, unless otherwise explicitly 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through 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. "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.

[0024] 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.

[0025] 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 and Figure 2 The diagram 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. The side of the silicon substrate 10 is provided with at least one groove extending circumferentially along the silicon substrate 10, and the groove divides the side of the silicon substrate 10 into at least two regions.

[0026] 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 is covered with a transparent conductive thin film layer 40 in the area other than the groove. An electrode 50 is provided on the transparent conductive thin film layer 40.

[0027] It is understood that the groove is an annular groove, and the annulus is a closed loop. From another perspective, the groove 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 in the area other than the groove, it can be understood that the transparent conductive film layer 40 is divided by the groove, forming a first transparent conductive film layer 401 located in the upper part of the groove and a second transparent conductive film layer 402 located in the lower part of the groove.

[0028] The solar cell of this invention, by designing grooves with specific positions 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, using the grooves as a boundary. This breaks the limitation of photoelectric conversion efficiency imposed by the mask in the traditional solar cell structure, and enables the transparent conductive film layers on the front and back sides to achieve zero contact without a mask. Thus, the solar cell of this invention overcomes the short-circuit problem while improving the photoelectric conversion efficiency of the cell.

[0029] It should be noted that the first surface and the second surface of the silicon substrate 10 are disposed opposite to each other and connected to the side surface of the silicon substrate 10. 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 provided with P-type doping, the second surface is N-type doping; when the first surface is provided with N-type doping, the second surface is P-type doping. The P-type doping 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.

[0030] In one embodiment of this utility model, the width ratio of the two regions includes, but is not limited to, any one of the values ​​of 1:1, 1:2, 1:3, 1:4, 1:5 or any range between two of them, preferably 1:1-1:3.

[0031] By adjusting the size of the groove in the silicon substrate 10, it is beneficial to further improve efficiency while ensuring that the silicon substrate 10 does not break.

[0032] In one embodiment of the present invention, on the side of the silicon substrate 10, the width 'a' of any of the grooves accounts for 0.5%-50% of the thickness of the silicon substrate 10, including but not limited to any one of 0.5%, 1%, 10%, 15%, 20%, 30%, 40%, 50% or any range between two.

[0033] In one embodiment of this utility model, the width 'a' of any of the grooves is 0.1μm-20μm, including but not limited to any one of 0.1μm, 0.5μm, 1μm, 2μm, 5μm, 10μm, 15μm, 20μm or any range between two of them.

[0034] In one embodiment of this invention, in the longitudinal section of the silicon substrate 10, the depth b of any of the grooves is 2.38 × 10⁻⁶ times the length of the silicon substrate 10. -6 % -0.0476%, including but not limited to 2.38 × 10 -6 %, 9×10 -6 %, 2×10 -5 %, 5×10 -4 %, 5×10 -3 %, 2×10 -3 %, 1×10 -2 %, 3×10 -2 Any single value in % or a range of values ​​between both.

[0035] In one embodiment of this utility model, the depth b of any of the grooves is 0.5μm-100μm, including but not limited to any point value or any range between 0.5μm, 1μm, 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, and 100μm.

[0036] It should be noted that this utility model does not limit the ratio of the width to the depth of the groove. The width a of the groove can be greater than the depth b of the groove, the width a of the groove can be less than the depth b of the groove, and the width a of the groove can also be equal to the depth b of the groove.

[0037] In one embodiment of the present invention, the total volume of the groove accounts for 0.07%-1.4% of the volume of the silicon substrate 10, including but not limited to any one of 0.07%, 0.12%, 0.25%, 0.4%, 0.6%, 0.8%, 1.0%, 1.4% or any range between two of them.

[0038] In one embodiment of this utility model, the number of grooves is 1 to 3. It can be understood that when there is 1 groove, the groove divides the side surface of the silicon substrate 10 into two regions; when there are 2 grooves, the groove divides the side surface of the silicon substrate 10 into three regions; and when there are 3 grooves, the groove divides the side surface of the silicon substrate 10 into four regions.

[0039] It should be noted that the width ratio of any two regions in this invention can be the same or different. When the width ratio of any two regions is the same, it indicates that the groove uniformly divides the side surface of the silicon substrate 10.

[0040] This invention does not limit the specific shape of the groove, including but not limited to rectangular, semi-circular, trapezoidal or other irregular shapes, as long as the groove ensures that the side of the silicon substrate 10 is separated.

[0041] In one embodiment of the present invention, the longitudinal section of the groove is rectangular. Further, it is preferred that there is one groove located in the middle of the side of the silicon substrate 10, so that the side of the silicon substrate 10 is divided into two regions, and the width ratio of the two regions is 1:1.

[0042] In one embodiment of the present invention, the longitudinal section of the groove is semi-circular, and the width-to-depth ratio of the groove is 2:1. Further, it is preferable that there is one groove located in the middle of the side of the silicon substrate 10, so that the side of the silicon substrate 10 is divided into two regions, and the width ratio of the two regions is 1:1.

[0043] 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 inner wall of the groove can also be textured. When the inner wall of the groove is textured, a small amount of transparent conductive thin film layer 40 is attached to the edge of the groove.

[0044] This invention does not limit the preparation method of the groove, the intrinsic amorphous silicon layer 20, the doped layer 30, and the transparent conductive thin film layer 40; conventional preparation processes can be used. For example, the groove can be prepared using laser technology; the intrinsic amorphous silicon layer 20 and the doped layer 30 can be prepared using chemical vapor deposition to ensure passivation inside the groove; and the transparent conductive thin film layer 40 can be prepared using physical vapor deposition or electron beam evaporation. In this case, the transparent conductive thin film layer 40 adheres to the edge of the groove to form a micro-surface-mounted structure, i.e., as shown in the figure. Figure 1 As shown, the transparent conductive film layer 40 forms a slope that is inclined toward the inside of the groove at the edge of the groove opening.

[0045] 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.

[0046] 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.

[0047] 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 at least one groove extending along the circumference of the silicon substrate, the groove dividing the side surface of the silicon substrate into at least two regions; The outer surface of the silicon substrate is successively coated with an intrinsic amorphous silicon layer and a doped layer from inside to outside, the doped layer being covered with a transparent conductive film layer except in the region of the groove, and the transparent conductive film layer being provided with an electrode.

2. The solar cell according to claim 1, characterized in that, The width ratio of any two regions is 1:1-1:

3.

3. The solar cell according to claim 1, characterized in that, The width of any groove on the side surface of the silicon substrate is 0.5%-50% of the thickness of the silicon substrate.

4. The solar cell according to claim 1 or 3, characterized in that, The width of any groove is 0.1 μm-20 μm.

5. The solar cell of claim 1, wherein In a longitudinal section of the silicon substrate, the depth of any of the grooves represents 2.38 x 10 -6 - 0.0476 %.

6. The solar cell according to claim 1 or 5, characterized in that, The depth of any groove is 0.5 μm-100 μm.

7. The solar cell of claim 1, wherein The total volume of the grooves is 0.07%-1.4% of the volume of the silicon substrate.

8. The solar cell of claim 1, wherein, The number of grooves is 1-3.

9. The solar cell of claim 1, wherein, The longitudinal section of the groove is rectangular or semicircular.

10. A photovoltaic module, characterized by, A solar cell comprising the solar cell as claimed in any one of claims 1-9.

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