Solar cell, photovoltaic module and photovoltaic system
By setting an insulating layer on the front side of the solar cell, including a sparse middle layer and a dense edge layer, the problem of damage to the front film layer of the cell during transportation is solved, achieving both protection and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG AIKO SOLAR ENERGY TECH CO LTD
- Filing Date
- 2025-06-09
- Publication Date
- 2026-04-21
AI Technical Summary
The front film layer of BC solar cells is easily damaged during the process of being sent to the module after the metal grid lines are printed on the cells.
An isolation layer is set on the front side of the solar cell. The isolation layer includes a sparse middle layer and a dense edge layer. The dense edge layer is closer to the edge of the cell and has a hollowed-out isolation pattern to avoid damage to the front side.
It protects the front side of the solar cell, improves production efficiency, reduces the amount of insulating layer used and manufacturing costs, and avoids contamination of other solar cells.
Smart Images
Figure CN224154577U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of solar energy technology, and in particular to a solar cell, photovoltaic module and photovoltaic system. Background Technology
[0002] A back contact solar cell (BC) is a type of solar cell in which both the emitter and base contact electrodes are placed on the back of the cell (the non-light-receiving side, i.e., the back side). The light-receiving side (i.e., the front side) of the cell is not blocked by any metal electrodes, thereby effectively increasing the effective light-receiving area of the cell.
[0003] However, during the process of printing metal grid lines on BC solar cells and sending them to the module, the front film layer of BC solar cells is easily damaged. Utility Model Content
[0004] This invention provides a solar cell, a photovoltaic module, and a photovoltaic system, which avoids damage to the front side of the solar cell by setting an isolation layer.
[0005] According to one aspect of the present invention, a solar cell is provided, comprising:
[0006] Silicon substrate, insulating layer, first electrode and second electrode;
[0007] The isolation layer is disposed on the front side of the silicon substrate away from the back side of the silicon substrate; the first electrode and the second electrode are disposed on the back side of the silicon substrate, and the first electrode and the second electrode have opposite polarities and are insulated from each other; wherein the front side and the back side of the silicon substrate are disposed opposite to each other;
[0008] The isolation layer is provided with an isolation pattern including a hollowed-out graphic;
[0009] The isolation layer further includes an intermediate sparse layer and an edge dense layer. The edge dense layer is closer to the edge of the solar cell than the intermediate sparse layer, and there is a predetermined distance between the edge dense layer and the edge of the solar cell.
[0010] The density of the edge dense layer is greater than the density of the middle sparse layer;
[0011] The ratio of the dimension of the edge dense layer located on one side of the intermediate sparse layer along a predetermined direction to the dimension of the front surface along the predetermined direction is greater than or equal to 20% and less than or equal to 45%, where the predetermined direction is the direction from which the intermediate sparse layer points perpendicularly to the edge dense layer.
[0012] Optionally, the isolation pattern is asymmetrically arranged about the center of the solar cell.
[0013] Optionally, the widths of the edge dense layers located on either side of the intermediate sparse layer are different;
[0014] Alternatively, the intermediate sparse layer includes multiple first isolation lines and multiple second isolation lines, wherein the extension directions of the first isolation lines and the extension directions of the second isolation lines are perpendicular to each other, the number of first isolation lines is greater than the number of second isolation lines, and the multiple second isolation lines are asymmetrically arranged about the center of the solar cell.
[0015] Alternatively, the intermediate sparse layer includes multiple third isolation lines, multiple fourth isolation lines, and multiple fifth isolation lines. The extension directions of the third isolation lines are perpendicular to and intersect with the extension directions of the fourth isolation lines to form multiple grid patterns. The extension directions of the fifth isolation lines intersect with the extension directions of the third isolation lines and the extension directions of the fourth isolation lines. The number of third isolation lines is greater than the number of fifth isolation lines, and the number of fourth isolation lines is greater than the number of fifth isolation lines. The multiple fifth isolation lines are asymmetrically arranged about the center of the solar cell.
[0016] Optionally, the edge dense layer is located on the first and second sides of the intermediate sparse layer;
[0017] The first side and the second side are arranged opposite to each other.
[0018] Optionally, the edge dense layer is located on the third and fourth sides of the intermediate sparse layer, and the third and fourth sides are arranged opposite to each other.
[0019] Optionally, when the edge dense layer is located on the first side and the second side of the intermediate sparse layer, the ratio of the dimension of the edge dense layer on one side of the intermediate sparse layer along the first direction to the dimension of the front side along the first direction is greater than or equal to 20% and less than or equal to 30%, the first direction is the direction from which the intermediate sparse layer points perpendicularly to the edge dense layer, and the first direction is parallel to the direction of the long side of the solar cell, the first direction being the preset direction.
[0020] Optionally, when the edge dense layer is located on the third and fourth sides of the intermediate sparse layer, the ratio of the dimension of the edge dense layer on one side of the intermediate sparse layer along the second direction to the dimension of the front side along the second direction is greater than or equal to 20% and less than or equal to 45%, the second direction is the direction from which the intermediate sparse layer points perpendicularly to the edge dense layer, and the second direction is parallel to the direction of the short side of the solar cell, the second direction being the preset direction.
[0021] Optionally, the vertical distance between the edge-dense layer and the edge location of the solar cell is greater than or equal to 50 micrometers and less than or equal to 500 micrometers.
[0022] Optionally, the thickness of the isolation layer is greater than or equal to 4 micrometers and less than or equal to 15 micrometers.
[0023] Optionally, the edge dense layer includes multiple sub-dense layers with different densities.
[0024] Optionally, the edge dense layer includes at least two first sub-dense layers and at least one second sub-dense layer; the second sub-dense layer is located between the two first sub-dense layers;
[0025] The density of the first sub-dense layer is greater than that of the second sub-dense layer.
[0026] Optionally, the thickness of the first sub-dense layer is greater than the thickness of the second sub-dense layer.
[0027] Optionally, the edge dense layer includes two first sub-dense layers and one second sub-dense layer;
[0028] The two first sub-dense layers include a central first sub-dense layer and an edge first sub-dense layer, and the second sub-dense layer is located between the central first sub-dense layer and the edge first sub-dense layer, with the edge first sub-dense layer located on the side of the second sub-dense layer away from the central sparse layer.
[0029] The second sub-dense layer includes a first boundary, which is the boundary of the second sub-dense layer near the middle first sub-dense layer;
[0030] The distance from the first boundary to the side of the first sub-dense layer near the edge of the solar cell is greater than or equal to 10 mm.
[0031] Optionally, the first sub-dense layer near the center includes a second boundary, which is the boundary of the first sub-dense layer near the center close to the middle sparse layer.
[0032] The distance between the second boundary and the side of the first sub-dense layer near the edge of the solar cell is greater than or equal to 40 mm.
[0033] Optionally, the first sub-dense layer near the edge includes a third boundary, which is the boundary of the first sub-dense layer near the edge close to the intermediate sparse layer; the distance between the third boundary and the side of the first sub-dense layer near the edge of the solar cell is greater than 4.25 mm.
[0034] Optionally, the isolation layer includes multiple isolation sections, each of which includes isolation lines and / or isolation points.
[0035] Optionally, in the edge dense layer, a plurality of the isolation portions form a cross-shaped pattern;
[0036] In the intermediate sparse layer, multiple isolation sections form a linear pattern.
[0037] Optionally, in the edge dense layer, a plurality of the isolation portions form a grid pattern;
[0038] In the intermediate sparse layer, multiple isolation portions form a grid pattern, and the area of a single grid in the edge dense layer is smaller than the area of a single grid in the intermediate sparse layer.
[0039] Optionally, in the intermediate sparse layer, the grid pattern includes a plurality of square grids, wherein the side length of the square grids is greater than or equal to 4 mm and less than or equal to 4.5 mm.
[0040] Optionally, the edge compacted layer includes at least two first sub-compacted layers and at least one second sub-compacted layer; the second sub-compacted layer is located between the two first sub-compacted layers; the compactness of the first sub-compacted layer is greater than the compactness of the second sub-compacted layer;
[0041] In the first sub-dense layer, the grid pattern includes a plurality of square grids, the side length of which is greater than or equal to 1 mm and less than or equal to 1.5 mm; and / or, in the second sub-dense layer, the grid pattern includes a plurality of square grids, the side length of which is greater than or equal to 2 mm and less than or equal to 2.5 mm.
[0042] Optionally, the isolation portion is thicker in the middle and thinner at the edges, and the surface of the isolation portion away from the silicon substrate is arc-shaped.
[0043] On the cross-section of the isolation portion, the line connecting the point closest to the edge of the isolation portion and the point furthest from the silicon substrate in vertical distance is a preset line. The angle between the preset line and the plane perpendicular to the thickness direction of the solar cell is greater than or equal to 4° and less than or equal to 30°.
[0044] Optionally, when the isolation portion includes the isolation line, the length of the short side of the isolation line is greater than or equal to 50 micrometers and less than or equal to 120 micrometers.
[0045] According to another aspect of the present invention, a photovoltaic module is provided, comprising at least one solar cell as described in any embodiment of the present invention.
[0046] Optionally, a pre-adhesive film is disposed on the surface of the isolation layer away from the silicon substrate;
[0047] The surface of the front adhesive film away from the isolation layer is planar;
[0048] And / or, the coefficient of thermal expansion of the insulating layer is greater than the coefficient of thermal expansion of the pre-adhesive film.
[0049] Optionally, a back coating film is disposed on the side of the first electrode and the second electrode away from the silicon substrate;
[0050] The coefficient of thermal expansion of the front adhesive film is greater than that of the rear adhesive film.
[0051] According to another aspect of the present invention, a photovoltaic system is provided, characterized in that it includes the photovoltaic module described in any of the embodiments of the present invention.
[0052] The solar cell, photovoltaic module, and photovoltaic system provided in this embodiment of the invention have an insulating layer disposed on the front side of the silicon substrate away from the back side. This insulating layer protects the solar cell during fabrication and transportation, preventing scratches on the front side. Furthermore, by disposing the insulating layer on the front side of the silicon substrate away from the back side, the need for repeated placement and removal of the insulating layer during transportation is eliminated, improving the production efficiency of the solar cell. The insulating layer also features an insulating pattern including perforated designs, which, while protecting the solar cell, reduces the area of the solid portion of the insulating layer, thereby reducing the amount of insulating layer used and lowering manufacturing costs. The insulating layer includes a sparse middle layer and a dense edge layer. The dense edge layer is closer to the edge of the solar cell than the sparse middle layer. By increasing the amount of material used in the insulating layer near the edge of the solar cell, the dense edge layer is used for the parts of the solar cell with a large contact area with the conveying equipment or the stacked solar cells, where the probability of being grasped is high. The sparse middle layer is used for the parts of the solar cell with a small contact area with the conveying equipment or the stacked solar cells, where the probability of being grasped is low. This further reduces the area of the solid part in the insulating layer while ensuring the protective effect, thereby reducing the amount of insulating layer used and the manufacturing cost. Furthermore, the edge dense layer is spaced at a predetermined distance from the edge of the solar cell to prevent the material of the edge dense layer from extending into the conveying equipment after the insulating layer is manufactured, thus avoiding contamination of other solar cells.
[0053] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description
[0054] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0055] Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of the present invention;
[0056] Figure 2 yes Figure 1 Enlarged view of the area within the red dashed box;
[0057] Figure 3 yes Figure 1 A top view of one type of isolation layer;
[0058] Figure 4 yes Figure 1 A top view of another type of isolation layer;
[0059] Figure 5 This is a scanning electron microscope image of an isolation section provided in an embodiment of this utility model;
[0060] Figure 6 yes Figure 5 A schematic diagram of the cross-sectional structure of the two isolation sections in the A1-A2 direction;
[0061] Figure 7 This is a schematic diagram of a photovoltaic module provided in an embodiment of the present invention. Detailed Implementation
[0062] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0063] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0064] To prevent damage to the front side of the solar cell during transportation, the present invention provides the following technical solution:
[0065] like Figures 1-4 As shown, Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of the present invention. Figure 2 yes Figure 1 Enlarged view of the area within the red dashed box. Figure 3 yes Figure 1 A top view of an isolation layer. Figure 4 yes Figure 1 A top view of another type of insulating layer in the solar cell, the solar cell including: a silicon substrate 100, an insulating layer 200, a first electrode 300, and a second electrode 400; the insulating layer 200 is disposed on the front side of the silicon substrate 100 away from the back side of the silicon substrate 100; the first electrode 300 and the second electrode 400 are disposed on the back side of the silicon substrate 100, and the first electrode 300 and the second electrode 400 have opposite polarities and are insulated from each other; wherein, the front and back sides of the silicon substrate 100 are arranged opposite to each other; the insulating layer 200 is provided with an insulating pattern including a hollow pattern; the insulating layer 200 also includes an intermediate sparse layer. The solar cells 210 and 220 are located closer to the edge of the solar cell than the intermediate sparse layer 210. A predetermined distance separates the edge dense layer 220 from the edge of the solar cell. The density of the edge dense layer 220 is greater than that of the intermediate sparse layer 210. The dimension of the edge dense layer 220 located on one side of the intermediate sparse layer 210 along a predetermined direction is greater than or equal to 20% and less than or equal to 45% of the dimension of the front side along the predetermined direction. The predetermined direction is the direction from which the intermediate sparse layer 210 is perpendicular to the edge dense layer 220. Figure 3 The X direction in the equation.
[0066] The silicon substrate 100 has a textured surface on its front side, which can increase the light trapping effect of the solar cell.
[0067] like Figure 2 As shown, the isolation layer 200 includes a solid portion 201 and a cutout portion 202. The gap between the solid portions 201 and 202 is the cutout portion 202. The arrangement of the solid portions 201 and the cutout portion 202 causes the isolation layer 200 to include an isolation pattern with a cutout design. The isolation layer 200 may be composed of isolation lines and / or isolation points, which constitute the isolation pattern with the cutout design. For example, Figure 3 and Figure 4 The isolation layer 200 includes isolation lines. That is, the solid part is the isolation line.
[0068] The fact that the density of the edge dense layer 220 is greater than that of the middle sparse layer 210 means that, within the same area size, the projected area of the solid portion 201 of the edge dense layer 220 on the front is greater than that of the solid portion 201 of the middle sparse layer 210 on the front. In other words, the edge dense layer 220 uses more material.
[0069] like Figure 3 As shown, with the preset direction being the X direction, the ratio of the dimension L1 of the edge dense layer 220 located on one side of the intermediate sparse layer 210 along the X direction to the dimension L01 of the front side along the X direction is greater than or equal to 20% and less than or equal to 30%.
[0070] like Figure 4 As shown, when the preset direction is the X direction, the ratio of the dimension L1 of the edge dense layer 220 located on one side of the intermediate sparse layer 210 along the X direction to the dimension L01 of the front surface along the X direction is greater than or equal to 20% and less than or equal to 30%. When the preset direction is the Y direction, the ratio of the dimension L2 of the edge dense layer 220 located on one side of the intermediate sparse layer 210 along the Y direction to the dimension L02 of the front surface along the Y direction is greater than or equal to 20% and less than or equal to 45%.
[0071] It should be noted that the isolation layer 200 can be disposed on the front side of the solar cell after the front structure of the solar cell (the film layer between the isolation layer 200 and the silicon substrate 100) is fabricated, but before the fabrication of the first electrode 300 and the second electrode 400. Of course, the fabrication steps of the isolation layer 200 are not limited to this; for example, it can be disposed on the front side of the solar cell after the fabrication of the first electrode 300 and the second electrode 400, without specific limitation. For example, if the front side of the solar cell includes an anti-reflection layer and a passivation layer disposed on the front side of the silicon substrate, then after the fabrication of the anti-reflection layer and the passivation layer, the isolation layer 200 is fabricated on the side of the passivation layer and the anti-reflection layer away from the silicon substrate 100. In this way, the isolation layer 200 better protects the front side of the solar cell, preventing damage to the front side of the solar cell during the subsequent fabrication processes of the first electrode 300 and the second electrode 400. Furthermore, after the solar cell is fabricated, during the transportation of multiple solar cells stacked together, the isolation layer 200 can isolate adjacent solar cells, protecting the front side of the solar cell and preventing scratches. The insulating layer 200 can be, but is not limited to, inkjet printing and printing processes. Exemplarily, before the insulating layer 200 is prepared by inkjet printing, the solar cell can undergo electrical performance testing. After the insulating layer 200 is prepared by inkjet printing, the module fabrication process can proceed. Exemplarily, before the insulating layer 200 is prepared by printing, the solar cell has not yet completed electrical performance testing. After the insulating layer 200 is prepared by printing, the solar cell still needs to complete electrical performance testing before the module fabrication process can proceed. Therefore, considering the wear and tear on the insulating layer 200 during transportation, the thickness of the insulating layer 200 prepared by printing can be set to be greater than the thickness of the insulating layer 200 prepared by inkjet printing.
[0072] The edge dense layer 220 located on one side of the middle sparse layer 210 has a size along a preset direction that is greater than or equal to 20% and less than or equal to 45% of the size of the front side along the preset direction. On the one hand, this can prevent the edge dense layer 220 from being too large, which would affect the absorption of light by the solar cell. On the other hand, it can ensure that the part of the solar cell with a large contact area with the transmission equipment or the solar cells stacked above and below, and with a high probability of being grabbed, has a sufficient area of edge dense layer 220, thereby ensuring the protective effect of edge dense layer 220 on the front side of the solar cell.
[0073] The technical solution provided in this embodiment of the invention involves an isolation layer 200 disposed on the front side of the silicon substrate 100, away from the back side. The isolation layer 200 protects the solar cell during fabrication and transportation, preventing scratches on the front side. Furthermore, the isolation layer 200's placement on the front side of the silicon substrate 100 eliminates the need for repeated placement and removal during transportation, improving solar cell production efficiency. Additionally, the isolation layer 200 features an isolation pattern including perforated designs, reducing the area of the solid portion while still protecting the solar cell, thereby reducing the amount of isolation layer 200 used and lowering manufacturing costs. The isolation layer 200 includes a middle sparse layer 210 and an edge dense layer 220. The edge dense layer 220 is closer to the edge of the solar cell than the middle sparse layer 210. By increasing the amount of material used in the isolation layer 200 near the edge of the solar cell, the portion of the solar cell with a large contact area with the conveying device or the stacked solar cells, and with a high probability of being grasped, is provided with the edge dense layer 220. The portion of the solar cell with a small contact area with the conveying device or the stacked solar cells, and with a low probability of being grasped, is provided with the middle sparse layer 210. This further reduces the area of the solid portion of the isolation layer 200 while ensuring the protective effect, thereby reducing the amount of isolation layer 200 used and the manufacturing cost. Furthermore, the predetermined distance between the edge dense layer 220 and the edge of the solar cell prevents the material of the edge dense layer 220 from extending into the conveying device after the isolation layer 200 is manufactured, thus avoiding contamination of other solar cells.
[0074] Optionally, when the direction of the intermediate sparse layer 210 perpendicular to the direction of the edge dense layer 220 is perpendicular to the transmission direction of the solar cell, the edge dense layer 220 is provided on the side edge of the solar cell that contacts the transmission device (i.e., the side away from the back side) in the transmission direction. This ensures that the portion of the solar cell with the largest contact area with the transmission device or the stacked solar cells, and which has a high probability of being gripped, is provided with the edge dense layer 220, thus protecting the front side of the solar cell. Figure 3 In this example, the transmission direction of the solar cell is the Y direction. Figure 4 In this process, the transmission direction of the solar cell can be either the X direction or the Y direction.
[0075] Alternatively, based on the above technical solution, the isolation pattern is arranged asymmetrically about the center of the solar cell.
[0076] The isolation pattern is asymmetrically arranged about the center of the solar cell, including but not limited to the following three cases:
[0077] The first case is that the widths of the edge dense layers 220 located on both sides of the middle sparse layer 210 are different.
[0078] Alternatively, in the first case: the intermediate sparse layer 210 includes multiple first isolation lines and multiple second isolation lines, the extension directions of the first isolation lines and the extension directions of the second isolation lines are perpendicular to each other, the number of first isolation lines is greater than the number of second isolation lines, and the multiple second isolation lines are asymmetrically arranged about the center of the solar cell.
[0079] For example, Figure 3 In the illustrated isolation pattern, the intermediate sparse layer 210 includes isolation lines 201a extending along the X direction. These isolation lines 201a serve as second isolation lines, and their extension directions are perpendicular to those of the first isolation lines. The number of first isolation lines is greater than the number of isolation lines 201a. These multiple isolation lines 201a are asymmetrically arranged about the center of the solar cell, such that… Figure 3 The isolation pattern is asymmetrically arranged about the center of the solar cell.
[0080] Alternatively, the intermediate sparse layer includes multiple third isolation lines, multiple fourth isolation lines, and multiple fifth isolation lines. The extension directions of the third isolation lines and the fourth isolation lines are perpendicular to each other and intersect to form multiple grid patterns. The extension directions of the fifth isolation lines intersect with the extension directions of the third isolation lines and the fourth isolation lines. The number of third isolation lines is greater than the number of fifth isolation lines, the number of fourth isolation lines is greater than the number of fifth isolation lines, and the multiple fifth isolation lines are asymmetrically arranged about the center of the solar cell.
[0081] For example, Figure 4 In the illustrated isolation pattern, the intermediate sparse layer 210 includes inclined isolation lines 201b, which are the fifth isolation lines. The isolation lines excluding isolation lines 201b are the third and fourth isolation lines; the extension directions of the third and fourth isolation lines are perpendicular and intersect to form multiple grid patterns. The extension directions of isolation lines 201b intersect with both the extension directions of the third and fourth isolation lines. The number of third isolation lines is greater than the number of isolation lines 201b, and the number of fourth isolation lines is greater than the number of isolation lines 201b. These multiple isolation lines 201b are asymmetrically arranged about the center of the solar cell, making... Figure 4 The isolation pattern is asymmetrically arranged about the center of the solar cell.
[0082] It should be noted that the isolation layer 200 can be fabricated using processes including, but not limited to, inkjet printing and printing. The isolation portion in the isolation layer 200 includes isolation lines and / or isolation points. During the fabrication of the isolation layer, if the isolation pattern is symmetrically arranged about the center of the solar cell, the accuracy requirements for shape parameters such as the width, height, and length of the isolation portion are relatively high. Strict control of the fabrication process parameters of the isolation layer 200 is necessary to ensure that the shape parameters of the isolation portion achieve the preset accuracy, which increases the fabrication cost of the isolation layer 200. Therefore, the fabrication difficulty of the isolation layer 200 with an asymmetrical isolation pattern about the center of the solar cell is lower, thereby reducing the fabrication cost. Optionally, based on the above technical solution, such as... Figure 3 As shown, the edge dense layer 220 is located on the first and second sides of the middle sparse layer 210; the first and second sides are arranged opposite to each other.
[0083] For example, Figure 3 In this configuration, the extension directions of the first and second sides are parallel to the short side direction of the solar cell. It should be noted that the extension direction (Y direction) of the first and second sides is the same as the transmission direction of the solar cell on the transmission equipment. This ensures that the edge-dense layer 220 is located in the part of the solar cell with the largest contact area with the transmission equipment or the stacked solar cells, and where the probability of being gripped is high, thus providing protection for the front side of the solar cell. Optionally, Figure 3 The insulating layer 200 is fabricated using an inkjet printing process. Before fabricating the insulating layer 200 using the inkjet printing process, the electrical performance of the solar cell has already been tested. After fabricating the insulating layer 200 using the inkjet printing process, the module fabrication process can be carried out in a single transmission using a transmission device. During the aforementioned transmission process, because the number of transmissions is small and the transmission direction is relatively definite, edge-dense layers 220 can be set on the two sides (i.e., the first side and the second side) of the intermediate sparse layer 210.
[0084] Optionally, based on the above technical solutions, such as Figure 4 As shown, the edge dense layer 220 is located on the first and second sides of the intermediate sparse layer 210; the first and second sides are arranged opposite to each other. Furthermore, the edge dense layer 220 is located on the third and fourth sides of the intermediate sparse layer 110, and the third and fourth sides are arranged opposite to each other.
[0085] The first and second side extend in the Y direction, while the third and fourth side extend in the X direction.
[0086] Optionally, Figure 4The insulating layer 200 is fabricated using a printing process. After the insulating layer 200 is fabricated using the printing process, the solar cells still need to undergo electrical performance testing before the module fabrication process can begin. After the insulating layer 200 is fabricated using the printing process, the solar cells also need to be transported multiple times through a transmission device. During the above transmission process, due to the large number of transmissions, the transmission direction can be either the X-direction or the Y-direction. Therefore, a dense edge layer 220 is provided around the circumference of the intermediate sparse layer 210. Regardless of whether the solar cell is transported along the X-direction or the Y-direction, the portion of the solar cell located in the transmission direction on the transmission device, where the contact area between the solar cell and the transmission device or the solar cells stacked above and below is large and the probability of being grasped is provided with a dense edge layer 220 to achieve the protection of the front side of the solar cell.
[0087] Optionally, when the edge dense layer 220 is located on the first and second sides of the intermediate sparse layer 210, the ratio of the dimension of the edge dense layer 220 along the first direction to the dimension of the front side along the first direction is greater than or equal to 20% and less than or equal to 30%, where the first direction is the direction perpendicular to the intermediate sparse layer 210 pointing to the edge dense layer 220, and the first direction is parallel to the direction of the long side of the solar cell. Figure 3 The X direction in the equation. The first direction is the preset direction.
[0088] Optionally, when the edge dense layer 220 is located on the third and fourth sides of the intermediate sparse layer 210, the ratio of the dimension of the edge dense layer 220 along the second direction to the dimension of the front side along the second direction is greater than or equal to 20% and less than or equal to 45%, where the second direction is the direction perpendicular to the intermediate sparse layer 210 pointing towards the edge dense layer 220, and the second direction is parallel to the direction of the short side of the solar cell. The second direction is... Figure 4 The Y direction is specified in the diagram. The second direction is a preset direction. Optionally, based on the above technical solution, the vertical distance between the edge dense layer 220 and the edge position of the solar cell is greater than or equal to 50 micrometers and less than or equal to 500 micrometers.
[0089] Specifically, the vertical distance between the edge dense layer 220 and the edge of the solar cell is greater than or equal to 50 micrometers and less than or equal to 500 micrometers. On the one hand, this can prevent the material of the edge dense layer 220 from extending to the conveying device after the isolation layer 200 is prepared, thereby avoiding contamination of other solar cells. On the other hand, it allows the edge dense layer 220 to be provided as much as possible in the parts of the solar cell that have a large contact area with the conveying device or the solar cells stacked above and below, and that are more likely to be grasped, so as to achieve the protection of the front side of the solar cell.
[0090] Optionally, based on the above technical solutions, such as Figures 1-4 As shown, the thickness of the isolation layer 200 is greater than or equal to 4 micrometers and less than or equal to 15 micrometers.
[0091] Specifically, the thickness of the insulating layer 200 is greater than or equal to 4 micrometers and less than or equal to 15 micrometers. On the one hand, this can prevent the insulating layer 200 from being worn down during contact between the solar cell and the transmission equipment or the solar cells stacked above and below, so as to ensure the protective effect of the insulating layer 200 on the front side of the solar cell. On the other hand, it can prevent the insulating layer 200 from being too thick, which would affect the absorption of light by the solar cell.
[0092] Optionally, based on the above technical solutions, such as Figure 4 As shown, the edge dense layer 220 includes multiple sub-dense layers with different densities.
[0093] For example, Figure 4 Three sub-compact layers are shown, including a central first sub-compact layer 221, an edge first sub-compact layer 222, and a second sub-compact layer 223, which is located between the central first sub-compact layer 221 and the edge first sub-compact layer 222. The compactness of the second sub-compact layer 223 is less than that of the central and edge first sub-compact layers 221 and 222, but greater than that of the central sparse layer 210.
[0094] Specifically, the edge dense layer 220 includes multiple sub-dense layers with different densities, which can reduce the amount of material used in the isolation layer 200 as much as possible while ensuring that the isolation layer 200 has a certain protective effect on the front side of the solar cell, thereby reducing the manufacturing cost.
[0095] Optionally, based on the above technical solutions, such as Figure 4 As shown, the edge compact layer 220 includes at least two first sub-compact layers and at least one second sub-compact layer 223; the second sub-compact layer 223 is located between the two first sub-compact layers; the compactness of the first sub-compact layers is greater than the compactness of the second sub-compact layer 223.
[0096] Specifically, the first sub-dense layer 221 in the middle and the first sub-dense layer 222 at the edge are the first sub-dense layers. The second sub-dense layer 223 is arranged between the two first sub-dense layers, so that in the edge dense layer 220, the sub-dense layers with relatively high density and the sub-dense layers with relatively low density are arranged alternately. This can further reduce the amount of material used in the separator layer 200 while ensuring that the separator layer 200 has a certain protective effect on the front side of the solar cell, thereby reducing the manufacturing cost.
[0097] Furthermore, the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge of the solar cell are more prone to wear. Therefore, setting the density of the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge to be greater than the density of the second sub-dense layer 223 can better protect the solar cell.
[0098] Optionally, based on the above technical solutions, such as Figure 4 As shown, the thickness of the first sub-compact layer is greater than the thickness of the second sub-compact layer 223.
[0099] For example, Figure 4 In this structure, the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge are the first sub-dense layers. The thickness of the first sub-dense layer is greater than that of the second sub-dense layer 223, which increases the wear resistance of the relatively dense first sub-dense layer and can further ensure that the first sub-dense layer can achieve the protective function of the front side of the solar cell.
[0100] In other optional embodiments of this utility model, the thickness of the edge dense layer 220 can be set to be greater than the thickness of the middle sparse layer 210 to increase the wear resistance of the relatively dense edge dense layer 220, which can further ensure that the edge dense layer 220 can achieve the protective effect on the front of the solar cell.
[0101] Optionally, based on the above technical solutions, such as Figure 4 As shown, the edge dense layer 220 includes two first sub-dense layers and one second sub-dense layer; the two first sub-dense layers include a central first sub-dense layer 221 and an edge first sub-dense layer 222, and the second sub-dense layer 223 is located between the central first sub-dense layer 221 and the edge first sub-dense layer 222, with the edge first sub-dense layer 222 located on the side of the second sub-dense layer 223 away from the central sparse layer 210; the second sub-dense layer 223 includes a first boundary, which is the boundary of the second sub-dense layer 223 near the central first sub-dense layer 221; the distance L3 from the first boundary to the side of the edge first sub-dense layer 222 near the edge of the solar cell is greater than or equal to 10 mm.
[0102] Optionally, based on the above technical solutions, such as Figure 4 As shown, the first sub-dense layer 221 near the center includes a second boundary, which is the boundary of the first sub-dense layer near the center and close to the middle sparse layer 210; the distance L4 from the second boundary to the side of the first sub-dense layer 222 near the edge of the solar cell is greater than or equal to 40 mm.
[0103] Optionally, based on the above technical solutions, such as Figure 4 As shown, the first sub-dense layer 222 near the edge includes a third boundary, which is the boundary of the first sub-dense layer 222 near the edge close to the middle sparse layer 210; the distance L5 from the third boundary to the side of the first sub-dense layer 222 near the edge of the solar cell is greater than 4.25 mm.
[0104] Specifically, the distance L4 between the second boundary of the first sub-dense layer 221 in the middle and the side of the first sub-dense layer 222 near the edge of the solar cell is greater than or equal to 40 mm, thus reserving a portion of the area for the second sub-dense layer 223 and the first sub-dense layer 222 near the edge.
[0105] The distance L3 from the first boundary of the second sub-dense layer 223 to the side of the first sub-dense layer 222 near the edge of the solar cell is greater than or equal to 10 mm, thus reserving a portion of the area for the first sub-dense layer 222 near the edge.
[0106] The distance L5 between the third boundary of the first sub-dense layer 222 near the edge of the solar cell and the side of the first sub-dense layer 222 near the edge of the solar cell is greater than 4.25 mm, which ensures that the first sub-dense layer 222 near the edge provides a certain degree of protection for the front of the solar cell. If the distance L5 between the third boundary and the side of the first sub-dense layer 222 near the edge of the solar cell is too small, the protective effect of the first sub-dense layer 222 on the front of the solar cell will be weakened.
[0107] Optionally, based on the above technical solutions, such as Figures 2-4 As shown, the isolation layer 200 includes multiple isolation sections, each including isolation lines and / or isolation points. The isolation lines can be solid or dashed.
[0108] Specifically, the isolation layer 200 can be composed of isolation lines and / or isolation points, which form an isolation pattern with a hollowed-out design. For example, Figure 3 and Figure 4 The isolation layer 200 includes isolation lines.
[0109] Optionally, based on the above technical solutions, such as Figure 3 As shown, in the edge dense layer 220, multiple insulating portions form a cross-shaped pattern; and / or, in the middle sparse layer 210, multiple insulating portions form a straight line pattern. It can be understood that setting the edge dense layer 220 into a cross-shaped pattern can improve the bonding degree between the edge dense layer 220 and the solar cell and reduce the probability of the edge dense layer 220 falling off.
[0110] Specifically, in the edge dense layer 220, multiple isolation portions form a cross-shaped pattern, which increases its density compared to multiple isolation portions forming a straight line pattern. In the intermediate sparse layer 210, multiple isolation portions form a straight line pattern, which decreases its density compared to multiple isolation portions forming a cross-shaped pattern.
[0111] Optionally, based on the above technical solutions, such as Figure 4 As shown, in the edge dense layer 220, multiple isolation portions form a grid pattern; and / or, in the middle sparse layer 210, multiple isolation portions form a grid pattern, and the area of a single grid in the edge dense layer 220 is smaller than the area of a single grid in the middle sparse layer 210.
[0112] Understandably, setting the edge dense layer 220 and the middle sparse layer 210 into a grid pattern can improve the bonding between the separator and the solar cell, and reduce the probability of the separator detaching. The grid pattern can be composed of solid lines or dashed lines.
[0113] Specifically, by setting the area of a single grid in the edge dense layer 220 to be smaller than the area of a single grid in the middle sparse layer 210, the density of the edge dense layer 220 is greater than the density of the middle sparse layer 210.
[0114] Optionally, based on the above technical solutions, such as Figure 4 As shown, in the intermediate sparse layer 210, the grid pattern includes multiple square grids. The side length of the square grids is greater than or equal to 4 mm and less than or equal to 4.5 mm. The side length of the square grids in the edge dense layer 220 can be set to be smaller, so that the density of the intermediate sparse layer 210 is less than the density of the edge dense layer 220.
[0115] Optionally, based on the above technical solutions, such as Figure 4 As shown, the edge compact layer 220 includes at least two first sub-compact layers and at least one second sub-compact layer 223; the second sub-compact layer 223 is located between the two first sub-compact layers; the compactness of the first sub-compact layers is greater than the compactness of the second sub-compact layer 223; in the first sub-compact layer, the grid pattern includes a plurality of square grids, the side length of the square grids being greater than or equal to 1 mm and less than or equal to 1.5 mm; and / or, in the second sub-compact layer 223, the grid pattern includes a plurality of square grids, the side length of the square grids being greater than or equal to 2 mm and less than or equal to 2.5 mm.
[0116] For example, the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge are the first sub-dense layers. In the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge, the grid pattern includes multiple square grids, the side length of the square grids is greater than or equal to 1 mm and less than or equal to 1.5 mm. In the second sub-dense layer 223, the grid pattern includes multiple square grids, the side length of the square grids is greater than or equal to 2 mm and less than or equal to 2.5 mm. The above technical solution makes the density of the second sub-dense layer 223 less than the density of the first sub-dense layer 221 near the center and the first sub-dense layer 222 near the edge. This allows the sub-dense layers with relatively higher density and the sub-dense layers with relatively lower density to be arranged alternately. This can further reduce the amount of material used in the isolation layer 200 while ensuring that the isolation layer 200 has a certain protective effect on the front side of the solar cell, thereby reducing the manufacturing cost.
[0117] Optionally, based on the above technical solutions, such as Figure 5 and Figure 6 As shown, Figure 5 This is a scanning electron microscope image of an isolation section provided in an embodiment of this utility model. Figure 6 yes Figure 5 The schematic diagram of the cross-sectional structure of the two isolation sections in the A1-A2 direction shows that the isolation section is thick in the middle and thin at the edges, and the surface of the isolation section away from the silicon substrate 100 is an arc-shaped surface. On the cross-section of the isolation section, the line connecting the point W1, which is the closest point of vertical distance between the edge of the isolation section and the silicon substrate 100, and the point W2, which is the farthest point of vertical distance between the isolation section and the silicon substrate 100, is a preset line. The angle α between the preset line and the plane perpendicular to the thickness direction of the solar cell is greater than or equal to 4° and less than or equal to 30°.
[0118] Specifically, the insulating portion has a structure that is thicker in the middle and thinner at the edges. The thicker middle portion of the insulating portion mainly serves to protect the front side of the silicon substrate 100. The thinner edge portion of the insulating portion has higher light transmittance, which increases the light absorption of the solar cell. Furthermore, the thinner edge portion can also reflect light reflected from within the solar cell back into the solar cell. The larger the angle α between the preset connecting line and the front side of the silicon substrate 100, the greater the thickness of the thicker middle portion of the insulating portion, given a fixed size for the thinner edge portion. The angle between the preset connecting line and the front side of the silicon substrate 100 is greater than or equal to 4° and less than or equal to 30°, ensuring that the thickness of the thicker middle portion of the insulating portion is within an optimal range. On the one hand, during contact between the solar cell and the transmission equipment or stacked solar cells, even after the insulating layer 200 is partially worn, a portion of the insulating layer 200 remains, ensuring the protective effect of the insulating layer 200 on the front side of the solar cell. On the other hand, it avoids the insulating layer 200 being too thick, which would affect the light absorption of the solar cell.
[0119] Optionally, based on the above technical solutions, such as Figure 3 , Figure 4 and Figure 6 As shown, when the isolation section includes an isolation line, the length of the short side d1 of the isolation line is greater than or equal to 50 micrometers and less than or equal to 120 micrometers.
[0120] Specifically, the length of the short side d1 of the isolation line is greater than or equal to 50 micrometers and less than or equal to 120 micrometers. It can be calculated that the minimum value of the tangent of angle α is 4 / 60 and the maximum value of the tangent of angle α is 15 / 25. Therefore, the angle α between the preset connection line and the front side of the silicon substrate 100 is greater than or equal to 4° and less than or equal to 30°.
[0121] Optionally, based on the above technical solutions, such as Figure 1 As shown, the solar cell further includes: a first doped layer 500, a second doped layer 600, a first passivation layer 700, a first antireflection layer 800, a second passivation layer 900, and a second antireflection layer 1000; the first doped layer 500 and the second doped layer 600 are disposed on the back side of the silicon substrate 10, the first passivation layer 700 is disposed on the side of the first doped layer 500 and the second doped layer 600 away from the silicon substrate 10, the first antireflection layer 800 is disposed on the side of the first passivation layer 700 away from the silicon substrate 100, and the first passivation layer 700 and the first antireflection layer 800 cover the first doped layer 500 and the second doped layer 600; An electrode 300 is disposed on the side of the first antireflection layer 800 away from the silicon substrate 100, and the first electrode 300 passes through the first antireflection layer 800 and the first passivation layer 700 to contact the first doped layer 500; a second electrode 400 is disposed on the side of the first antireflection layer 800 away from the silicon substrate 100, and the second electrode 400 passes through the first antireflection layer 800 and the first passivation layer 700 to contact the second doped layer 600; a second passivation layer 900 and a second antireflection layer 1000 are disposed between the silicon substrate 100 and the isolation layer 200, and the second antireflection layer 1000 is disposed on the side of the second passivation layer 900 away from the silicon substrate 100.
[0122] Specifically, the first passivation layer 700 covers the entire back side of the silicon substrate 100. The first passivation layer 700 can be a passivating film layer such as an aluminum oxide layer, and there are no specific limitations here. The first antireflection layer 800 is used to reduce sunlight reflection, allowing more sunlight to be absorbed inside the solar cell. The first antireflection layer 800 can be a film layer such as a silicon nitride layer.
[0123] The second passivation layer 900 and the second antireflection layer 1000 cover the front side of the silicon substrate 100. The second passivation layer 900 can be a passivating film such as an aluminum oxide layer. The second antireflection layer 1000 is used to reduce sunlight reflection, allowing more sunlight to be absorbed inside the solar cell. The second antireflection layer 1000 can be a film such as a silicon nitride layer.
[0124] One of the first doped layer 500 and the second doped layer 600 is a P-type doped layer, and the other is an N-type doped layer. Both the first doped layer 500 and the second doped layer 600 can be polycrystalline silicon doped layers. For example, the silicon substrate 100 is an N-type single-crystal silicon substrate, the first doped layer 500 is a P-type polycrystalline silicon doped layer, and the second doped layer 600 is an N-type polycrystalline silicon doped layer.
[0125] It should be noted that this embodiment only exemplifies the various film layers of a solar cell, as well as their shapes and positional relationships, and is not intended to limit the scope of this invention. Solar cells may also include other film layers, such as tunneling oxide layers.
[0126] This utility model also provides a photovoltaic module, including at least one solar cell as described in any embodiment of this utility model.
[0127] Specifically, Figure 7 This is a schematic diagram of a photovoltaic module provided in an embodiment of the present invention, for reference only. Figure 7 A photovoltaic module may include multiple solar cells 002, which are connected in series and / or in parallel.
[0128] In this embodiment, the isolation layer of the solar cell 002 in the photovoltaic module is disposed on the front side of the silicon substrate. The isolation layer can protect the solar cell during the manufacturing and transportation of the solar cell, prevent the front side of the solar cell from being scratched, thereby improving the power generation efficiency of the photovoltaic module.
[0129] Based on the above embodiments, refer to Figure 1 and Figure 7 Photovoltaic modules also include:
[0130] A front encapsulant film 003 is disposed on the surface of the insulating layer 200 away from the silicon substrate 100; the coefficient of thermal expansion of the insulating layer 200 is greater than that of the front encapsulant film 003. Specifically, the front encapsulant film 003 covers the insulating layer 200 on the front side of the solar cell 002 and fills the gaps between adjacent solar cells 002.
[0131] It is understandable that the first electrode 300 and the second electrode 400 on the back of the solar cell 002 have a certain coefficient of thermal expansion. When the temperature changes, the first electrode 300 and the second electrode 400 will deform, which will bring certain stress to the cell. By setting the coefficient of thermal expansion of the insulating layer 200 to be greater than that of the front encapsulant film 003, the coefficient of thermal expansion of the insulating layer 200 is close to that of the first electrode 300 and the second electrode 400. This allows the stress brought about by the deformation of the insulating layer 200 when the temperature changes to offset part of the stress brought about by the deformation of the first electrode 300 and the second electrode 400, thereby avoiding stress concentration inside the photovoltaic module and improving the reliability of the photovoltaic module.
[0132] Based on the above embodiments, optionally, the photovoltaic module further includes:
[0133] The back film 004 is disposed on the side of the first electrode 300 and the second electrode 400 away from the silicon substrate 100; the coefficient of thermal expansion of the front film 003 is greater than that of the back film 004.
[0134] Specifically, because the coefficients of thermal expansion of the first electrode 300 and the second electrode 400 are relatively large, adjusting the coefficient of thermal expansion of the insulating layer 200 alone may not completely offset the stress on the back side of the solar cell 002. Since the coefficient of thermal expansion of the front encapsulant film 003 is greater than that of the rear encapsulant film 004, when the temperature changes, the stress caused by the deformation of the insulating layer 200 and the front encapsulant film 003 on the front side of the solar cell 002 can be better offset by the stress caused by the deformation of the first electrode 300, the second electrode 400, and the rear encapsulant film 004 on the back side of the solar cell 002. This further avoids stress concentration inside the photovoltaic module and improves the reliability of the photovoltaic module.
[0135] In addition, the photovoltaic module also includes a glass substrate 005 and a backsheet 006. The glass substrate 005 is disposed on the side of the front encapsulant film 003 away from the solar cell 002, and the backsheet 006 is disposed on the side of the rear encapsulant film 004 away from the solar cell 002. The backsheet 006 can be a glass substrate or other substrates, and this embodiment does not specifically limit it.
[0136] This utility model also provides a photovoltaic system, including the photovoltaic module described in any embodiment of this utility model. The beneficial effects of this photovoltaic system, including the photovoltaic module, are described in any of the above-described ways and will not be repeated here.
[0137] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.
[0138] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A solar cell, characterized by, include: Silicon substrate, insulating layer, first electrode and second electrode; The isolation layer is disposed on the front side of the silicon substrate away from the back side of the silicon substrate; the first electrode and the second electrode are disposed on the back side of the silicon substrate, and the first electrode and the second electrode have opposite polarities and are insulated from each other; wherein the front side and the back side of the silicon substrate are disposed opposite to each other; The isolation layer is provided with an isolation pattern including a hollowed-out graphic; The isolation layer further includes an intermediate sparse layer and an edge dense layer. The edge dense layer is closer to the edge of the solar cell than the intermediate sparse layer, and there is a predetermined distance between the edge dense layer and the edge of the solar cell. The density of the edge dense layer is greater than the density of the middle sparse layer; The ratio of the dimension of the edge dense layer located on one side of the intermediate sparse layer along a predetermined direction to the dimension of the front surface along the predetermined direction is greater than or equal to 20% and less than or equal to 45%, where the predetermined direction is the direction in which the intermediate sparse layer points perpendicularly to the edge dense layer.
2. The solar cell according to claim 1, characterized in that: The isolation pattern is asymmetrically arranged about the center of the solar cell.
3. The solar cell according to claim 2, characterized in that: The widths of the edge dense layers located on either side of the intermediate sparse layer are different; Alternatively, the intermediate sparse layer includes multiple first isolation lines and multiple second isolation lines, wherein the extension directions of the first isolation lines and the extension directions of the second isolation lines are perpendicular to each other, the number of first isolation lines is greater than the number of second isolation lines, and the multiple second isolation lines are asymmetrically arranged about the center of the solar cell. Alternatively, the intermediate sparse layer includes multiple third isolation lines, multiple fourth isolation lines, and multiple fifth isolation lines. The extension directions of the third isolation lines and the fourth isolation lines are perpendicular to each other and intersect to form multiple grid patterns. The extension directions of the fifth isolation lines intersect with the extension directions of the third isolation lines and the fourth isolation lines. The number of the third isolation lines is greater than the number of the fifth isolation lines, the number of the fourth isolation lines is greater than the number of the fifth isolation lines, and the multiple fifth isolation lines are asymmetrically arranged about the center of the solar cell.
4. The solar cell according to claim 1, characterized in that: The edge dense layer is located on the first and second sides of the intermediate sparse layer; The first side and the second side are arranged opposite to each other.
5. The solar cell according to claim 4, characterized in that: The edge dense layer is located on the third and fourth sides of the middle sparse layer, and the third and fourth sides are arranged opposite to each other.
6. The solar cell according to claim 4 or 5, characterized in that: When the edge dense layer is located on the first and second sides of the intermediate sparse layer, the ratio of the dimension of the edge dense layer on one side of the intermediate sparse layer along the first direction to the dimension of the front side along the first direction is greater than or equal to 20% and less than or equal to 30%. The first direction is the direction from which the intermediate sparse layer points perpendicularly to the edge dense layer, and the first direction is parallel to the direction of the long side of the solar cell. The first direction is the preset direction.
7. The solar cell according to claim 5, characterized in that: When the edge dense layer is located on the third and fourth sides of the intermediate sparse layer, the ratio of the dimension of the edge dense layer on one side of the intermediate sparse layer along the second direction to the dimension of the front side along the second direction is greater than or equal to 20% and less than or equal to 45%. The second direction is the direction from which the intermediate sparse layer points perpendicularly to the edge dense layer, and the second direction is parallel to the direction of the short side of the solar cell. The second direction is the preset direction.
8. The solar cell according to claim 1, characterized in that: The vertical distance between the edge-dense layer and the edge of the solar cell is greater than or equal to 50 micrometers and less than or equal to 500 micrometers.
9. The solar cell according to claim 1, characterized in that: The thickness of the isolation layer is greater than or equal to 4 micrometers and less than or equal to 15 micrometers.
10. The solar cell according to claim 1, characterized in that: The edge dense layer comprises multiple sub-dense layers with different densities.
11. The solar cell according to claim 10, characterized in that: The edge compact layer includes at least two first sub-compact layers and at least one second sub-compact layer; the second sub-compact layer is located between the two first sub-compact layers; The density of the first sub-dense layer is greater than that of the second sub-dense layer.
12. The solar cell according to claim 11, characterized in that: The thickness of the first sub-dense layer is greater than the thickness of the second sub-dense layer.
13. The solar cell according to claim 11, characterized in that: The edge dense layer comprises two first sub-dense layers and one second sub-dense layer; The two first sub-dense layers include a central first sub-dense layer and an edge first sub-dense layer, and the second sub-dense layer is located between the central first sub-dense layer and the edge first sub-dense layer, with the edge first sub-dense layer located on the side of the second sub-dense layer away from the central sparse layer. The second sub-dense layer includes a first boundary, which is the boundary of the second sub-dense layer near the middle first sub-dense layer; The distance from the first boundary to the side of the first sub-dense layer near the edge of the solar cell is greater than or equal to 10 mm.
14. The solar cell according to claim 13, characterized in that: The first sub-dense layer near the center includes a second boundary, which is the boundary of the first sub-dense layer near the center close to the middle sparse layer. The distance between the second boundary and the side of the first sub-dense layer near the edge of the solar cell is greater than or equal to 40 mm.
15. The solar cell according to claim 13, characterized in that: The first sub-dense layer near the edge includes a third boundary, which is the boundary of the first sub-dense layer near the edge close to the middle sparse layer; the distance between the third boundary and the side of the first sub-dense layer near the edge of the solar cell is greater than 4.25 mm.
16. The solar cell according to claim 1, characterized in that: The isolation layer includes multiple isolation sections, each of which includes isolation lines and / or isolation points.
17. The solar cell according to claim 16, characterized in that: In the edge-dense layer, the plurality of isolation portions form a cross-shaped pattern; In the intermediate sparse layer, multiple isolation sections form a linear pattern.
18. The solar cell according to claim 16, characterized in that: In the edge-dense layer, the plurality of isolation portions form a grid pattern; In the intermediate sparse layer, multiple isolation portions form a grid pattern, and the area of a single grid in the edge dense layer is smaller than the area of a single grid in the intermediate sparse layer.
19. The solar cell according to claim 18, characterized in that: In the intermediate sparse layer, the grid pattern includes multiple square grids, the side length of which is greater than or equal to 4 mm and less than or equal to 4.5 mm.
20. The solar cell according to claim 19, characterized in that: The edge compacted layer includes at least two first sub-compacted layers and at least one second sub-compacted layer; the second sub-compacted layer is located between the two first sub-compacted layers; the compactness of the first sub-compacted layer is greater than the compactness of the second sub-compacted layer; In the first sub-dense layer, the grid pattern includes a plurality of square grids, the side length of which is greater than or equal to 1 mm and less than or equal to 1.5 mm; and / or, in the second sub-dense layer, the grid pattern includes a plurality of square grids, the side length of which is greater than or equal to 2 mm and less than or equal to 2.5 mm.
21. The solar cell according to claim 16, characterized in that: The isolation portion is thicker in the middle and thinner at the edges, and the surface of the isolation portion away from the silicon substrate is arc-shaped. On the cross-section of the isolation portion, the line connecting the point closest to the edge of the isolation portion and the point furthest from the silicon substrate in vertical distance is a preset line. The angle between the preset line and the plane perpendicular to the thickness direction of the solar cell is greater than or equal to 4° and less than or equal to 30°.
22. The solar cell according to claim 21, characterized in that: When the isolation section includes the isolation line, the length of the short side of the isolation line is greater than or equal to 50 micrometers and less than or equal to 120 micrometers.
23. A photovoltaic module, characterized by, It includes at least one solar cell as described in any one of claims 1-22.
24. The photovoltaic module of claim 23, wherein, Also includes: A pre-adhesive film, wherein the pre-adhesive film is disposed on the surface of the isolation layer away from the silicon substrate; The surface of the front adhesive film away from the isolation layer is planar; And / or, the coefficient of thermal expansion of the insulating layer is greater than the coefficient of thermal expansion of the pre-adhesive film.
25. The photovoltaic module of claim 24, wherein, Also includes: A post-adhesive film is disposed on the side of the first electrode and the second electrode away from the silicon substrate; The coefficient of thermal expansion of the front adhesive film is greater than that of the rear adhesive film.
26. A photovoltaic system characterized by, Includes the photovoltaic module as described in any one of claims 23-25.