Photovoltaic cell and photovoltaic module

Abstract

The application relates to a photovoltaic cell and a photovoltaic module. The photovoltaic cell comprises a semiconductor substrate, a passivation layer arranged on the surface of the semiconductor substrate, a main grid line arranged on the passivation layer, and a soldering point. The soldering point is used for electrical connection with a solder strip. In the thickness direction of the photovoltaic cell, the soldering point is arranged on the side of the main grid line away from the passivation layer, or the soldering point is arranged on the passivation layer. The main grid line comprises connection lines arranged at intervals in a first direction, and the adjacent connection lines are electrically connected through the soldering point. In the thickness direction of the photovoltaic cell, the vertical distance between the highest point of the soldering point and the surface of the passivation layer is L1, the vertical distance between the main grid line and the surface of the passivation layer is L2, and L1>=L2. When the solder strip is placed on the soldering point, a gap exists between the solder strip and the main grid line, the deformation allowance of the solder strip is increased, the risk of deformation of the solder strip and the semiconductor substrate caused by the shrinkage of the solder strip is reduced, and the risk of damage to the photovoltaic cell caused by the deformation of the solder strip under the condition of temperature reduction is reduced.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic cell and a photovoltaic module. Background Technology

[0002] A photovoltaic module comprises multiple photovoltaic cells and multiple solder ribbons. Adjacent photovoltaic cells are electrically connected via solder ribbons to achieve series and parallel connections between multiple photovoltaic cells. A photovoltaic cell includes a semiconductor substrate, a passivation layer, a main grid line coated on the surface of the passivation layer, and solder joints. Multiple solder joints are spaced apart along the extension direction of the main grid line, dividing the main grid line into multiple connecting lines. Solder ribbons are fixedly connected to the solder joints and cover the main grid line to collect current from the photovoltaic cells.

[0003] In existing technologies, the welding ribbon is directly attached to the surface of the photovoltaic cell. After the welding ribbon and the welding point are welded and fixed at a certain welding temperature, when the welding ribbon and the photovoltaic cell cool to room temperature, the welding ribbon shrinks due to the difference in thermal expansion coefficients between the welding ribbon and the photovoltaic cell, causing the photovoltaic cell to warp and deform, which increases the risk of damage to the photovoltaic cell. Summary of the Invention

[0004] This application provides a photovoltaic cell and a photovoltaic module that reduces the risk of deformation and damage to the photovoltaic cell after welding and cooling.

[0005] The first aspect of this application provides a photovoltaic cell, comprising:

[0006] Semiconductor substrate;

[0007] A passivation layer is disposed on the surface of a semiconductor substrate;

[0008] Multiple main grid lines are disposed on the passivation layer. The main grid lines extend along a first direction and are spaced apart along a second direction. The first direction and the second direction are respectively the length direction of the photovoltaic cell and the width direction of the photovoltaic cell.

[0009] Multiple solder joints are provided for electrical connection with the welding strip. Along the thickness direction of the photovoltaic cell, the solder joints are located on the side of the main grid line away from the passivation layer, or the solder joints are located on the passivation layer. The main grid line includes connecting lines spaced apart along a first direction, and adjacent connecting lines are electrically connected by solder joints.

[0010] Along the thickness direction of the photovoltaic cell, the vertical distance between the highest point of the solder joint and the surface of the passivation layer is L1, and the vertical distance between the main grid line and the surface of the passivation layer is L2. L1 and L2 satisfy: L1≥L2.

[0011] In this application, L1≥L2. When the solder ribbon is placed on the solder joint, there is a gap between the solder ribbon and the main grid line in the thickness direction of the photovoltaic cell, and / or in the first direction, and / or in the second direction. After the solder ribbon is welded and fixed to the solder joint and cooled to room temperature, the naturally curved part on the solder ribbon is straightened under the characteristics of thermal expansion and contraction, thereby reducing the risk of the solder ribbon shrinking and pulling the solder joint to deform, and the semiconductor substrate warping and deforming, and thus reducing the risk of deformation and damage after the photovoltaic cell is welded and cooled.

[0012] In some embodiments, L1 and L2 satisfy: 0 ≤ L1 - L2 ≤ 0.5 mm.

[0013] In some embodiments, when L1 > L2 along the thickness direction of the photovoltaic cell, the main grid line is a cuboid structure extending along the first direction.

[0014] In some embodiments, along the thickness direction of the photovoltaic cell, a portion of the main grid line is bent toward the semiconductor substrate to form a first bend.

[0015] The projection shape of the first bend in the second direction is U-shaped, V-shaped, or S-shaped.

[0016] In some embodiments, the semiconductor substrate is provided with a groove, and at least a portion of the first bend is located within the groove.

[0017] In some embodiments, along the second direction, a portion of the main grid line is bent away from the solder joint to form a second bend;

[0018] The projection shape of the second bend in the thickness direction of the photovoltaic cell is U-shaped, V-shaped, or S-shaped.

[0019] In some embodiments, the projection shape of the main grid line in the second direction is rectangular.

[0020] In some embodiments, along the thickness direction of the photovoltaic cell, a portion of the main grid line is recessed towards the semiconductor substrate to form a recessed portion;

[0021] The profile of the recessed portion in the thickness direction of the photovoltaic cell is arc-shaped, U-shaped, or V-shaped.

[0022] A second aspect of this application provides a photovoltaic module, comprising:

[0023] Multiple photovoltaic cells are connected by welding strips. Each photovoltaic cell includes a first surface and a second surface that are arranged opposite each other along its own thickness direction. The first surface is located on the side facing the sunlight.

[0024] A first photovoltaic glass is disposed on a first surface, and a first adhesive film is disposed between the first photovoltaic glass and the first surface;

[0025] A back support structure is disposed on the second surface, and a second adhesive film is disposed between the back support structure and the second surface.

[0026] The back support structure is a back panel or a second photovoltaic glass;

[0027] The photovoltaic cell includes a semiconductor substrate, a passivation layer, multiple main grid lines, and multiple solder joints, with the solder strips electrically connected to the solder joints;

[0028] A passivation layer is disposed on the surface of a semiconductor substrate;

[0029] The main grid line is disposed on the passivation layer and extends along the first direction. Multiple main grid lines are distributed at intervals along the second direction. The first direction and the second direction are respectively the length direction of the photovoltaic cell and the width direction of the photovoltaic cell.

[0030] Along the thickness direction of the photovoltaic cell, the solder joint is located on the side of the main grid line away from the passivation layer, or the solder joint is located on the passivation layer. The main grid line includes connecting lines spaced apart along a first direction, and adjacent connecting lines are electrically connected by solder joints.

[0031] Along the thickness direction of the photovoltaic cell, the vertical distance between the highest point of the solder joint and the surface of the passivation layer is L1, and the vertical distance between the main grid line and the surface of the passivation layer is L2. L1 and L2 satisfy: L1≥L2.

[0032] In this application, there is a gap between the solder ribbon and the main grid line, which increases the deformation allowance of the solder ribbon and reduces the risk of solder joint deformation caused by solder ribbon shrinkage and semiconductor substrate warping deformation. During the processing, installation and use of photovoltaic modules, the risk of solder ribbon shrinkage damage and photovoltaic cell deformation caused by changes in ambient temperature and the temperature of the photovoltaic module itself is reduced, thereby improving the working stability of the photovoltaic module and extending the service life of the photovoltaic module.

[0033] In some embodiments, the diameter d of the solder strip satisfies: 0.1mm ≤ d ≤ 0.5mm.

[0034] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0035] Figure 1 This is a cross-sectional view of the photovoltaic module provided in this application in one embodiment;

[0036] Figure 2 A cross-sectional view of the photovoltaic module provided in this application in another embodiment;

[0037] Figure 3 A schematic diagram of the surface structure of the photovoltaic cell provided in this application in one embodiment;

[0038] Figure 4 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in one embodiment, wherein the solder strip is in a contracted state;

[0039] Figure 5 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in another embodiment, wherein the solder strip is in an unshrunken state;

[0040] Figure 6 for Figure 5 A schematic diagram of the structure after the solder strip shrinks;

[0041] Figure 7 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in another embodiment, wherein the solder strip is in a contracted state;

[0042] Figure 8 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in another embodiment, wherein the solder strip is in a contracted state;

[0043] Figure 9 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in another embodiment, wherein the solder strip is in a contracted state;

[0044] Figure 10 for Figure 3 A partial structural diagram of a photovoltaic cell connected to a solder strip in another embodiment, wherein the solder strip is in a contracted state;

[0045] Figure 11 This is a schematic diagram of the photovoltaic cell provided in this application connected to the solder strip in another embodiment.

[0046] Figure 12 for Figure 11 A schematic diagram of the surface structure of a photovoltaic cell.

[0047] Figure label:

[0048] 1- Photovoltaic cells;

[0049] 11-Main busbar;

[0050] 111 - Connecting cable;

[0051] 112 - First bend;

[0052] 113 - Second bend;

[0053] 114 - Depression;

[0054] 12- Solder joint;

[0055] 13-Semiconductor substrate;

[0056] 131 - Groove;

[0057] 14-Passivation layer;

[0058] 2-Welding strip;

[0059] 21-Connection area;

[0060] 22-Suspended area;

[0061] 10- Photovoltaic cell string;

[0062] 20 - First Photovoltaic Glass;

[0063] 30 - First film;

[0064] 40 - Second film;

[0065] 50- Back support structure.

[0066] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Detailed Implementation

[0067] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0068] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0069] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0070] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0071] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0072] This application provides a photovoltaic module, such as... Figure 1 and Figure 2 As shown, the photovoltaic module includes a first photovoltaic glass 20, a first encapsulating film 30, a photovoltaic cell string 10, a second encapsulating film 40, and a back support structure 50. Along the thickness direction of the photovoltaic module, the first encapsulating film 30 and the second encapsulating film 40 are positioned opposite each other on both sides of the photovoltaic cell string 10. The first encapsulating film 30 is located on the side of the photovoltaic cell string 10 facing sunlight, the first photovoltaic glass 20 is located on the side of the first encapsulating film 30 away from the photovoltaic cell string 10, and the back support structure 50 is located on the side of the second encapsulating film 40 away from the photovoltaic cell string 10. The photovoltaic cell string 10 includes multiple photovoltaic cells 1, and adjacent photovoltaic cells 1 are electrically connected by solder strips 2 to improve the working efficiency and performance of the photovoltaic module.

[0073] In one embodiment, the back support structure 50 can be a back sheet, that is, the back support structure 50 is made of an opaque material to improve the structural strength of the photovoltaic module on the side facing away from the sunlight, facilitate the installation of the photovoltaic module, thereby simplifying the installation structure of the photovoltaic module and shortening the installation cycle of the photovoltaic module. In this case, the photovoltaic module is a single-glass module.

[0074] In another embodiment, the back support structure 50 is a second photovoltaic glass, that is, the back support structure 50 is made of a light-transmitting material, so that the side of the photovoltaic module facing away from sunlight can absorb some light, thereby improving the utilization rate of sunlight by the photovoltaic module and thus improving the photoelectric conversion efficiency of the photovoltaic module. In this case, the photovoltaic module is a double-glass module. This application does not impose any special limitations on the specific material or type of the back support structure 50 or the type of photovoltaic module.

[0075] The diameter d of the solder strip 2 satisfies: 0.1mm≤d≤0.5mm. Specifically, the diameter of the solder strip 2 can be 0.1mm, 0.2mm, 0.35mm, 0.46mm, 0.5mm, etc., to facilitate the processing of the solder strip 2 and reduce the material and processing costs of the solder strip 2. At the same time, 0.1mm≤d≤0.5mm increases the dimensional flexibility of the solder strip 2, thereby improving the replaceability of the solder strip 2, which facilitates the subsequent maintenance and replacement of the solder strip 2, and thus reduces the maintenance cost of the photovoltaic module.

[0076] The thickness of photovoltaic cell 1 is less than or equal to 140μm. Specifically, the thickness of photovoltaic cell 1 can be 100μm, 115μm, 126μm, 132μm, 140μm, etc., to facilitate the processing of photovoltaic cell 1 and reduce the material cost and processing cost of photovoltaic cell 1.

[0077] The side of photovoltaic cell 1 facing the sunlight is the front side of photovoltaic cell 1, and the side of photovoltaic cell 1 facing away from the sunlight is the back side of photovoltaic cell 1.

[0078] In one embodiment, such as Figure 1 As shown, one end of the solder ribbon 2 is located on the back of the photovoltaic cell 1, and the other end is bent and extended along the thickness direction of the photovoltaic cell 1 and connected to the front of the adjacent photovoltaic cell 1 to increase the connection stability between the solder ribbon and the adjacent photovoltaic cell 1.

[0079] In another embodiment, such as Figure 2 As shown, the solder ribbon 2 is located on the back of the photovoltaic cell 1. At this time, the photovoltaic cell 1 is a back contact cell. The solder ribbon 2 is located on the back of the photovoltaic cell 1, which reduces the shading of the front of the photovoltaic cell 1 by the solder ribbon 2, thereby increasing the area of ​​the front of the photovoltaic cell 1 that receives sunlight, and thus improving the photoelectric conversion efficiency of the photovoltaic cell 1.

[0080] When the photovoltaic cell string is 10, as shown Figure 1 In the structure shown, when one end of the welding ribbon 2 is welded and fixed to the back of the photovoltaic cell 1 and the other end is fixed to the front of the adjacent photovoltaic cell 1, after the photovoltaic cell string 10 is welded and cooled to room temperature, the welding ribbon 2 shrinks due to the thermal expansion and contraction characteristics. Since the welding ribbon 2 is fixedly connected to both the front and back of the photovoltaic cell 1, the shrinkage of the welding ribbon 2 has little effect on the warping deformation of the photovoltaic cell 1.

[0081] When photovoltaic cell 1 is a back-contact cell, that is, photovoltaic cell 1 is only fixedly connected to the back side of the welding strip 2, after the photovoltaic cell string 10 is welded and cooled to room temperature, the welding strip 2 will shrink due to the thermal expansion and contraction characteristics. Under the pull of the welding strip 2, photovoltaic cell 1 will warp and deform in the direction of the welding strip 2, which may result in damage to photovoltaic cell 1.

[0082] To address the warping and deformation problem of the back contact battery, a second aspect of this application provides a photovoltaic cell 1, such as... Figures 3 to 12As shown, the photovoltaic cell 1 includes a semiconductor substrate 13, a passivation layer 14, a plurality of main grid lines 11, and a plurality of solder joints 12. The solder ribbon 2 is electrically connected to the solder joints 12. The passivation layer 14 is disposed on the surface of the semiconductor substrate 13. The main grid lines 11 are disposed on the surface of the passivation layer 14. The main grid lines 11 extend along a first direction X, and the plurality of main grid lines 11 are distributed at intervals along a second direction Y. Of the first direction X and the second direction Y, one is the length direction of the photovoltaic cell 1, and the other is the width direction of the photovoltaic cell 1.

[0083] In one embodiment, such as Figure 3 and Figure 4 As shown, along the thickness direction Z of the photovoltaic cell 1, the solder joint 12 is located on the side of the main grid line 11 away from the passivation layer 14. That is, during the fabrication process of the photovoltaic cell 1, the main grid line 11 is first fabricated on the passivation layer 14, and then the solder joint 12 is fabricated on the main grid line 11. The vertical distance between the highest point of the solder joint 12 and the surface of the passivation layer 14 is L1, and the vertical distance between the main grid line 11 and the surface of the passivation layer 14 is L2, so L1 > L2.

[0084] When the solder ribbon 2 is placed on the solder joint 12, there is a gap between the solder ribbon 2 and the main grid line 11 in the thickness direction Z of the photovoltaic cell 1. This results in the formation of a connection area 21 for connecting with the solder joint 12 and a suspended area 22 above the gap. When the solder ribbon 2 is placed on the solder joint 12 and the solder ribbon 2 is not welded to the photovoltaic cell 1, at least a portion of the suspended area 22 can bend into the gap, thereby increasing the deformation allowance of the solder ribbon 2. After the solder ribbon 2 is welded to the solder joint 12 and cooled to room temperature, the naturally bent portion of the suspended area 22 on the solder ribbon 2 is straightened under the characteristics of thermal expansion and contraction, thereby reducing the risk of the solder ribbon 2 shrinking and pulling the solder joint 12 to deform and the semiconductor substrate 13 warping and deforming. This reduces the risk of the photovoltaic cell 1 deforming and being damaged after welding and cooling. At the same time, during the processing, installation and use of the photovoltaic module, the risk of the solder ribbon 2 shrinking and being damaged and the photovoltaic cell 1 deforming due to changes in ambient temperature and the photovoltaic module's own temperature is reduced, thereby improving the working stability of the photovoltaic module and extending the service life of the photovoltaic module.

[0085] In another embodiment, such as Figure 3 , Figure 5 and Figure 6As shown, solder joints 12 are disposed on the passivation layer 14. The main grid line 11 includes connecting lines 111 spaced apart along the first direction X. Adjacent connecting lines 111 are electrically connected through solder joints 12. That is, during the fabrication of the photovoltaic cell 1, solder joints 12 and main grid lines 11 are fabricated simultaneously. Wherein, L1≥L2, when the solder ribbon 2 is placed on the solder joint 12, there is a gap between the solder ribbon 2 and the main grid line 11 in the thickness direction Z of the photovoltaic cell 1, and / or in the first direction X, and / or in the second direction Y. This reduces the risk of the solder ribbon 2 shrinking and pulling the solder joint 12 to deform, and the semiconductor substrate 13 warping and deforming. This reduces the risk of deformation and damage to the photovoltaic cell 1 after welding and cooling. At the same time, it reduces the risk of the solder ribbon 2 shrinking and being damaged, and the photovoltaic cell 1 deforming due to changes in ambient temperature and the temperature of the photovoltaic module itself. This improves the working stability of the photovoltaic module and extends its service life.

[0086] The specific structure of the main gate line 11 is as follows: Figures 5 to 12 As shown, in one embodiment, along the thickness direction Z of the photovoltaic cell 1, when L1 > L2, as... Figure 5 and Figure 6 As shown, the main grid line 11 is a cuboid structure extending along the first direction X, meaning that the thickness of the main grid line 11 is consistent along the first direction X, in order to simplify the structure of the main grid line 11 and reduce the manufacturing cost of the main grid line 11. In this embodiment, when the solder ribbon 2 is placed on the solder joint 12, there is a gap between the solder ribbon 2 and the main grid line 11 in the thickness direction Z of the photovoltaic cell 1.

[0087] In another embodiment, the structure of the main gate line 11 is as follows: Figure 7 and Figure 9 As shown, along the thickness direction Z of the photovoltaic cell 1, a portion of the main grid line 11 is bent toward the semiconductor substrate 13 to form a first bend 112, so that there is a gap between the solder ribbon 2 and the main grid line 11 in the thickness direction Z of the photovoltaic cell 1.

[0088] In this embodiment, when L1 = L2, as follows Figure 7 As shown, a portion of the main grid line 11 can support the solder ribbon 2, increasing the expansion and contraction allowance of the solder ribbon 2 while increasing the stability of the connection structure between the solder ribbon 2 and the photovoltaic cell 1, and reducing the risk of damage due to the small contact area between the solder ribbon 2 and the solder joint 12; when L1 > L2, as Figure 9 As shown, a first bend 112 is provided on the main grid line 11, which can increase the thickness of the main grid line 11 and the solder strip 2, while increasing the distance between the solder strip 2 and the main grid line 11. This reduces the risk of short service life and poor working efficiency of photovoltaic cell 1 due to the thinness of the main grid line 11, thereby improving the working stability of photovoltaic cell 1.

[0089] The projection shape of the first bent portion 112 in the second direction Y is U-shaped, V-shaped, S-shaped or other deformed structure. This application does not make any special limitation on the specific shape of the first bent portion 112.

[0090] Specifically, such as Figure 7 and Figure 9 As shown, the semiconductor substrate 13 is provided with a groove 131, and at least a portion of the first bent portion 112 is located within the groove 131.

[0091] In this embodiment, a portion of the passivation layer 14 is located within the groove 131, resulting in a recess in the passivation layer 14 that is recessed along the thickness direction Z of the photovoltaic cell 1. At least a portion of the first bend 112 is located within the recess, reducing the risk of interference between the first bend 112 and the passivation layer 14 causing the main grid line 11 to bulge locally and abut against the solder strip 2. This improves the flatness of the main grid line 11 on the surface of the passivation layer 14 and enhances the accuracy and stability of the distance between the first bend 112 and the solder strip 2.

[0092] In another embodiment, the structure of the main gate line 11 is as follows: Figure 8 and Figure 10 As shown, along the thickness direction Z of the photovoltaic cell 1, a portion of the main grid line 11 is recessed towards the semiconductor substrate 13 to form a recess 114. That is, along the first direction X, the thickness of the main grid line 11 is inconsistent, and the thickness of the main grid line 11 decreases at the recess 114, so that there is a gap between the solder ribbon 2 and the main grid line 11 in the thickness direction Z of the photovoltaic cell 1.

[0093] In this embodiment, the main gate line 11 is provided with a recessed portion 114. While meeting the requirement of a gap between the solder ribbon 2 and the main gate line 11, this simplifies the structure of the main gate line 11 and the semiconductor substrate 13, thereby simplifying the fabrication process of the semiconductor substrate 13, the passivation layer 14, and the main gate line 11. This reduces the fabrication cost of the semiconductor substrate 13, the passivation layer 14, and the main gate line 11, and shortens the fabrication cycle. Simultaneously, the recessed portion 114 on the main gate line 11 reduces the height of the solder joint 12, thereby reducing the processing difficulty and cost (i.e., material cost) of the solder joint 12. It also increases the structural stability of the solder joint 12, reducing the risk of damage to the solder joint 12 due to external forces during processing, installation, transportation, and use. This extends the service life of the solder joint 12, and consequently extends the service life of the photovoltaic cell 1 and the photovoltaic module, and improves the operational stability of the photovoltaic cell 1 and the photovoltaic module.

[0094] The profile shape of the recess 114 in the thickness direction Z of the photovoltaic cell 1 is an arc, U, V or other deformed structure. This application does not make any special limitation on the specific shape of the recess 114.

[0095] In another embodiment, the structure of the main gate line 11 is as follows: Figure 11 and Figure 12 As shown, along the second direction Y, a portion of the main grid line 11 bends away from the solder joint 12 to form a second bend 113. That is, within the plane enclosed by the first direction X and the second direction Y, a portion of the main grid line 11 bends and deforms towards both sides of the solder strip 2 to form the second bend 113, so that there is a gap between the solder strip 2 and the main grid line 11 in the first direction X and / or the second direction Y. At this time, in the second direction Y, the second bend 113 is located on one or both sides of the suspended area 22.

[0096] In this embodiment, the main grid line 11 is provided with a second bend portion 113 that bends in the plane formed by the first direction X and the second direction Y, so that L1 can be equal to L2, thereby simplifying the processing steps of the solder joint 12 and the main grid line 11, and thus reducing the processing difficulty and processing cost of the main grid line 11.

[0097] The number of second bending portions 113 can be one or more, and the multiple second bending portions 113 are distributed along the first direction X, with adjacent second bending portions 113 having opposite bending directions. The projection shape of the second bending portion 113 on the thickness direction Z of the photovoltaic cell 1 is U-shaped, V-shaped, S-shaped or other deformed structure. In this application embodiment, the specific number and shape of the second bending portions 113 are not specifically limited.

[0098] In addition, the thickness of the main gate line 11 is consistent along the first direction X, that is, the projection shape of the main gate line 11 in the second direction Y is rectangular, so as to simplify the structure of the main gate line 11 and further reduce the processing cost of the main gate line 11.

[0099] During the fabrication of the main gate line 11, the structure of the main gate line 11 can be one of the above embodiments, or a combination of two or more of the above embodiments can be used to increase the diversity and flexibility of the structure of the main gate line 11.

[0100] In any of the above embodiments, L1 and L2 satisfy: 0≤L1-L2≤0.5mm. Specifically, the difference between L1 and L2 can be 0mm, 0.1mm, 0.2mm, 0.35mm, 0.4mm, 0.5mm, etc.

[0101] In this embodiment, if L1-L2 > 0.5mm, the height of solder joint 12 is relatively large, which increases the processing difficulty and material requirements of solder joint 12, thereby increasing the processing cost and material cost of solder joint 12. Therefore, 0 ≤ L1-L2 ≤ 0.5mm, while ensuring that there is a gap between the solder strip 2 and the main grid line 11, reduces the processing difficulty and cost of solder joint 12.

[0102] In summary, as Figure 4 As shown, when solder joint 12 is located on main grid line 11, L1 > L2. In this case, main grid line 11 can also have the following characteristics: Figure 7 The first bend 112 shown increases the distance between the main grid line 11 and the solder strip 2, while reducing the height of the solder joint 12; and / or, the main grid line 11 may also have, as shown in the figure Figure 8 The recessed portion 114 shown increases the distance between the main grid line 11 and the solder strip 2, while reducing the height of the solder joint 12; and / or, the main grid line 11 may also have, as shown in the figure Figure 12 The second bend 113 shown creates a gap between the main grid line 11 and the solder strip in the first direction X and / or the second direction Y, thereby further increasing the size of the suspended area 22 of the solder strip 2.

[0103] When solder joint 12 is disposed on passivation layer 14, and solder joint 12 divides main gate line 11 into as follows: Figure 6 When multiple connecting lines 111 are shown, and when L1 = L2, the main grid line 11 has the following characteristics: Figure 7 The first bend 112 shown creates a gap between the main busbar 11 and the solder strip 2 in the thickness direction Z of the photovoltaic cell 1; and / or, the main busbar 11 has the following characteristics: Figure 8 The recessed portion 114 shown creates a gap between the main grid line 11 and the solder strip 2 in the thickness direction Z of the photovoltaic cell 1; and / or, the grid line 11 has as shown in the figure. Figure 12 The second bend 113 shown creates a gap between the main grid line 11 and the solder strip 2 in the first direction X and / or the second direction Y.

[0104] like Figure 6 As shown, when the solder joint 12 is disposed on the passivation layer 14, and the solder joint 12 divides the main grid line 11 into multiple connecting lines 111, when L1 > L2, the main grid line 11 has a uniform thickness in the thickness direction Z of the photovoltaic cell 1 along the first direction X; or, the main grid line has the following characteristics: Figure 7 The first bend 112 shown is as follows: Figure 8 The recessed portion 114 shown is as follows: Figure 12 One or more of the second bends 113 shown.

[0105] Furthermore, in one embodiment, the multiple main gate lines 11 and solder joints 12 distributed along the second direction Y have the same structure, so as to facilitate the processing of the main gate lines 11 and solder joints 12, thereby shortening the processing cycle of the main gate lines 11 and solder joints 12 and reducing the processing cost of the main gate lines 11 and solder joints 12.

[0106] In another embodiment, the structures of the multiple main grid lines 11 and solder joints 12 distributed along the second direction Y are different. That is, in the actual processing and production process, some of the main grid lines 11 and solder joints 12 adopt the processing method of the prior art, that is, the main grid lines 11 and solder joints 12 are prepared at the same time, and after the solder strip 2 and the solder joint 12 are fixedly connected, there is no gap between the solder strip 2 and some of the main grid lines 11. Meanwhile, the structure of another part of the main grid lines 11 and solder joints 12 is a combination of one or more of the above embodiments, so that there is a gap between the solder strip 2 and some of the main grid lines 11.

[0107] In this embodiment, there is a gap between the solder ribbon 2 and part of the main busbar 11, which reduces the total processing cost of the main busbar 11 and reduces the impact of the shrinkage of the solder ribbon 2 on the warping deformation of the photovoltaic cell 1, thereby improving the service life and working stability of the photovoltaic cell.

[0108] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photovoltaic cell, characterized in that, The photovoltaic cell includes: Semiconductor substrate; A passivation layer is disposed on the surface of the semiconductor substrate; Multiple main grid lines are disposed on the passivation layer. The main grid lines extend along a first direction, and the multiple main grid lines are spaced apart along a second direction. One of the first direction and the second direction is the length direction of the photovoltaic cell, and the other is the width direction of the photovoltaic cell. Multiple solder joints are provided for electrical connection with the solder strip. Along the thickness direction of the photovoltaic cell, the solder joints are located on the side of the main grid line away from the passivation layer, or the solder joints are located on the passivation layer. The main grid line includes connecting lines spaced apart along the first direction, and adjacent connecting lines are electrically connected through the solder joints. Along the thickness direction of the photovoltaic cell, the vertical distance between the highest point of the solder joint and the surface of the passivation layer is L1, and the vertical distance between the main grid line and the surface of the passivation layer is L2. L1 and L2 satisfy: L1≥L2; Along the thickness direction of the photovoltaic cell, a portion of the main grid line is bent toward the semiconductor substrate to form a first bend, so that there is a gap between the main grid line and the solder strip. The semiconductor substrate is provided with a groove, and at least a portion of the first bend is located in the groove.

2. The photovoltaic cell according to claim 1, characterized in that, L1 and L2 satisfy: 0≤L1-L2≤0.5mm.

3. The photovoltaic cell according to claim 1, characterized in that, The projection shape of the first bent portion in the second direction is U-shaped, V-shaped, or S-shaped.

4. The photovoltaic cell according to claim 1, characterized in that, Along the second direction, a portion of the main grid line bends away from the solder joint to form a second bend. The projection shape of the second bending portion in the thickness direction of the photovoltaic cell is U-shaped, V-shaped, or S-shaped.

5. The photovoltaic cell according to claim 4, characterized in that, The projection shape of the main grid line in the second direction is rectangular.

6. The photovoltaic cell according to claim 1 or 4, characterized in that, Along the thickness direction of the photovoltaic cell, a portion of the main grid line is recessed towards the semiconductor substrate to form a recessed portion; The profile of the recessed portion in the thickness direction of the photovoltaic cell is an arc shape, a U shape, or a V shape.

7. A photovoltaic module, characterized in that, The photovoltaic module includes: Multiple photovoltaic cells are connected to each other by welding strips. Each photovoltaic cell includes a first surface and a second surface that are disposed opposite to each other along its own thickness direction. The first surface is located on the side facing the sunlight. A first photovoltaic glass, wherein the first photovoltaic glass is disposed on the first surface, and a first adhesive film is disposed between the first photovoltaic glass and the first surface; A back support structure is disposed on the second surface, and a second adhesive film is disposed between the back support structure and the second surface; The back support structure is made of an opaque material, or the back support structure is a second photovoltaic glass; The photovoltaic cell includes a semiconductor substrate, a passivation layer, multiple main grid lines, and multiple solder joints, wherein the solder strip is electrically connected to the solder joints; The passivation layer is disposed on the surface of the semiconductor substrate; The main grid line is disposed on the passivation layer, the main grid line extends along a first direction, and a plurality of the main grid lines are distributed at intervals along a second direction. In the first direction and the second direction, one is the length direction of the photovoltaic cell and the other is the width direction of the photovoltaic cell. Along the thickness direction of the photovoltaic cell, the solder joint is located on the side of the main grid line away from the passivation layer, or the solder joint is located on the passivation layer. The main grid line includes connecting lines spaced apart along the first direction, and adjacent connecting lines are electrically connected through the solder joint. Along the thickness direction of the photovoltaic cell, the vertical distance between the highest point of the solder joint and the surface of the passivation layer is L1, and the vertical distance between the main grid line and the surface of the passivation layer is L2. L1 and L2 satisfy: L1≥L2; Along the thickness direction of the photovoltaic cell, a portion of the main grid line is bent toward the semiconductor substrate to form a first bend, so that there is a gap between the solder ribbon and the main grid line. The semiconductor substrate is provided with a groove, and at least a portion of the first bend is located in the groove.

8. The photovoltaic module according to claim 7, characterized in that, The diameter d of the welding strip satisfies: 0.1mm≤d≤0.5mm.

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