Grid line structure and solar cell
The grid structure formed by laser transfer technology solves the wear resistance and stability problems of triangular conductive wire stacked grid technology, improves the current utilization rate and current CTM of solar cells, and reduces process complexity and cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2026-03-06
AI Technical Summary
Existing triangular conductive wire stacked grid technology has poor wear resistance and low stability in solar cells, resulting in low current utilization.
The grid structure formed by laser transfer technology is designed to have an upper and lower end in the height direction, with the upper end protruding. The projection of the top surface in the direction perpendicular to the bottom surface is located within the bottom surface range. The side is designed with a gradual or abrupt zigzag connection. It has ultra-high reflectivity and aspect ratio. The bottom surface width is 10μm-25μm, the top surface width is 0μm-24μm, and the height is 5μm-25μm.
It improves the current utilization rate of solar cells, reduces the equivalent shading area of the cell surface, replaces the triangular conductive wire grid assembly, and enhances stability and wear resistance.
Smart Images
Figure CN223979001U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of solar cell technology, specifically relating to a grid structure and a solar cell. Background Technology
[0002] Metallization is a crucial process in solar energy technology, involving the printing of silver paste onto solar cells to collect current. In the exploration of metallization, increasing current flow while maintaining low resistance has been a key research direction. To this end, a method utilizing grid stacking technology has been proposed to increase the surface current utilization rate of the cell.
[0003] The core structure of traditional stacked grids involves fabricating a conductive seed layer on the cell surface to collect surface current. Above this seed layer, extremely fine triangular conductive filaments with ultra-high surface reflectivity are placed. These ultra-fine triangular conductive filaments with ultra-high surface reflectivity can reduce the effective light-shielding area of the cell surface to below 1%.
[0004] Although stacked grid technology can significantly improve the utilization rate of battery surface current, the extremely fine triangular conductive wires in it have poor wear resistance and relatively low stability.
[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content
[0006] The purpose of this invention is to provide a grid structure and a solar cell. The grid structure also has ultra-high reflectivity, which can reduce the equivalent shading area of the cell surface. It can replace the triangular conductive wire stacked grid assembly currently used in the industry, and at the same time, it has higher stability and better wear resistance than the triangular conductive wire.
[0007] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:
[0008] A grid structure for use in a solar cell, the grid structure having an upper end and a lower end in the height direction, the upper end being configured to protrude in the width direction of the grid structure away from the lower end, and the projection of the upper end in the height direction being located within the area of the lower end.
[0009] In one or more embodiments of the present invention, the grid structure has a bottom surface, two oppositely arranged side surfaces and a top surface; the upper end includes the top surface and the lower end includes the bottom surface; the top surface is configured as a curved surface that curves away from the bottom surface in the width direction of the grid structure, and the projection of the top surface in the direction perpendicular to the bottom surface is located within the area of the bottom surface.
[0010] In one or more embodiments of this utility model, in the width direction of the grid structure, the vertical distance between the top surface and the bottom surface first gradually increases and then gradually decreases.
[0011] In one or more embodiments of the present invention, the side surface includes a plurality of segments distributed sequentially along a direction away from the bottom surface, and some or all of the segments are configured as planes or as curved surfaces that are bent in the width direction of the grid structure.
[0012] In one or more embodiments of the present invention, a first segment surface is included among the plurality of said segments, which is connected to the bottom surface. The first segment surface is configured as a curved surface that bends toward the bottom surface in the width direction of the grid structure.
[0013] In one or more embodiments of this utility model, the angle between the first segment and the bottom surface is smaller than the angle between any of the other segments and the bottom surface.
[0014] In one or more embodiments of this utility model, the included angle between any of the segment surfaces and the bottom surface is greater than or equal to 30° and less than or equal to 90°.
[0015] In one or more embodiments of this utility model, on any cross-section perpendicular to the length direction of the grid structure, the width W of the top surface is... t The width W of the bottom surface is smaller than b ; and / or,
[0016] On any cross-section perpendicular to the length of the grid structure, the included angle γ between the lines connecting the two sides of the top surface to the midpoint of the bottom surface is greater than 0° and less than or equal to 90°; and / or,
[0017] The width W of the bottom surface b Satisfying: 10μm≤W b ≤25μm; and / or,
[0018] The width W of the top surface t The range is: 0μm < W t ≤24μm; and / or,
[0019] The height H of the grid structure satisfies: 5μm≤H≤25μm.
[0020] In one or more embodiments of this invention, the grid structure is formed by laser transfer paste having high reflectivity.
[0021] A solar cell includes a solar cell and grid line electrodes disposed on the surface of the solar cell, the grid line electrodes comprising a plurality of the above-described grid line structures.
[0022] In one or more embodiments of this utility model, the bottom surface of the grid structure is in contact with the surface of the solar cell; or,
[0023] The surface of the solar cell is provided with a metal seed layer, and the bottom surface of the grid structure is in contact with the metal seed layer.
[0024] In one or more embodiments of this utility model, the distance between adjacent gate line structures is 500μm-2700μm; and / or,
[0025] The grid line electrodes are located on the light-receiving surface and / or the backlight surface of the solar cell.
[0026] Compared with the prior art, the grid structure and solar cell of this utility model have ultra-high reflectivity, which can reduce the equivalent shading area of the cell surface and replace the triangular conductive wire stacked grid components currently used in the industry. At the same time, it has higher stability and better wear resistance than triangular conductive wire. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a cross-sectional schematic diagram of the grid structure in Embodiment 1 of this utility model;
[0029] Figure 2 This is a cross-sectional schematic diagram of the grid structure in Embodiment 2 of this utility model;
[0030] Figure 3 and Figure 4 This is a schematic diagram of the upper and lower ends of the grid structure defined in Embodiment 1 of this utility model;
[0031] Figure 5 and Figure 6 This is a schematic diagram of the upper and lower ends of the grid structure defined in Embodiment 2 of this utility model;
[0032] Figure 7 This is a cross-sectional schematic diagram of the grid structure in Embodiment 3 of this utility model;
[0033] Figure 8This is a partial cross-sectional schematic diagram of a solar cell (with a metal seed layer) in one embodiment of the present invention;
[0034] Figure 9 This is a partial cross-sectional schematic diagram of a solar cell (without a metal seed layer) in one embodiment of the present invention. Detailed Implementation
[0035] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.
[0036] As mentioned in the background section, the existing traditional screen-printed grid structure has low surface reflectivity, resulting in low surface current utilization of the battery. To improve current, stacked grid technology was developed. The ultra-fine triangular conductive wires in stacked grid technology have extremely high surface reflectivity, reducing the equivalent light-shielding area of the battery surface to less than 1%, greatly improving the surface current utilization of the battery and increasing the current. However, the ultra-fine triangular conductive wires in stacked grid technology have drawbacks such as poor wear resistance and relatively low stability.
[0037] Based on this, the present invention proposes a grid structure and a solar cell with the grid structure. The grid structure also has ultra-high reflectivity, which can reduce the equivalent shading area of the cell surface. It can replace the triangular conductive wire stacked grid assembly currently used in the industry, and at the same time, it has higher stability and better wear resistance than triangular conductive wire.
[0038] The grid structure in one embodiment of this utility model can be applied to solar cells. The grid structure is formed by directly transferring paste using laser transfer technology. Structurally, the grid structure has an upper end and a lower end in the height direction. The upper end is configured to protrude in the width direction of the grid structure away from the lower end, and the projection of the upper end in the height direction is located within the area of the lower end.
[0039] For example, such as Figure 1 As shown, the grid structure has a bottom surface 10, two oppositely arranged side surfaces 20, and a top surface 30. One side of the side surface 20 of the grid structure is connected to the bottom surface 10 in the height direction, and the other side is connected to the top surface 30.
[0040] Since the grid structure of this application is an integral structure formed by laser transfer paste, the side surface 20 of the grid structure can be connected to the top surface 30 in a slow, curved manner. That is, on any cross-section perpendicular to the length direction of the grid structure, there is a small angle change between the extension line A of the top surface 30 and the side surface 20 starting from the connection point, for example, the angle change is less than 15°. Figure 1 As shown; it can also be a sudden, broken-line connection, that is, on any cross-section perpendicular to the length direction of the grid structure, there is a significant angle change between the extension lines A of the top surface 30 and the side surface 20 starting from the connection point, for example, the angle change is greater than or equal to 15°, such as... Figure 2 As shown.
[0041] When the side surface 20 of the grid structure connects abruptly with the top surface 30 in a zigzag manner, the side surface and top surface of the grid structure can be relatively clearly distinguished. Therefore, the upper end of the grid structure in this application may only include the top surface 10; the lower end of the grid structure may include the bottom surface 30 and the portion of the side surface 20 that contacts the bottom surface 30, as shown in the attached figure. Figure 5 As shown. (Attached) Figure 5 The shaded area in the upper middle part is defined as the upper end of the grid structure, and the shaded area in the lower part is defined as the lower end of the grid structure.
[0042] Alternatively, the upper end of the gate structure in this application may only include the top surface 10; the lower end of the gate structure may include the bottom surface 30 and all the side surfaces 20, as shown in the attached figure. Figure 6 As shown. (Attached) Figure 6 The shaded area in the upper middle part is defined as the upper end of the grid structure, and the shaded area in the lower part is defined as the lower end of the grid structure.
[0043] It is understandable that although this technical solution can relatively clearly distinguish the side and top surfaces of the grid structure, the upper end of the grid structure in this technical solution can still include the top surface 10 and the part of the side surface 20 that contacts the top surface 10.
[0044] In this technical solution, the bottom surface is constructed as a planar structure. The top surface 30 is constructed as a curved surface that curves away from the bottom surface 10 in the width direction of the grid structure, such that the upper end protrudes in the width direction of the grid structure away from the lower end; the projection of the top surface 30 in the direction perpendicular to the bottom surface 10 is located within the area of the bottom surface 10. Preferably, the width W of the top surface 30 of the grid structure is... t Width W less than 10 of the base b .
[0045] When the side surface 20 of the grid structure gradually curves into the top surface 30, it is not possible to clearly distinguish between the side surface and the top surface of the grid structure. Therefore, the upper end of the grid structure in this application may also include the top surface 10 and the part of the side surface 20 that contacts the top surface 10; the lower end of the grid structure may also include the bottom surface 30 and the part of the side surface 20 that contacts the bottom surface 30; wherein, the part of the side surface 20 that contacts the top surface 10 and the part of the side surface 20 that contacts the bottom surface 30 may together constitute all the side surfaces 20 of the grid structure, or they may only be part of the side surfaces 20 of the grid structure, such as... Figure 3 and Figure 4 As shown.
[0046] In this technical solution, the bottom surface is still constructed as a planar structure. The top surface 30 is still constructed as a curved surface that curves away from the bottom surface 10 in the width direction of the grid structure, so that the upper end is convex in the direction away from the lower end in the width direction of the grid structure; the projection of the top surface 30 in the direction perpendicular to the bottom surface 10 is still within the range of the bottom surface 10, and the projection of the part of the side surface 20 in contact with the top surface 10 in the direction perpendicular to the bottom surface 10 is also within the range of the bottom surface 10. Preferably, the width W of the top surface 30 of the grid structure is... t Width W less than 10 of the base b The width W of the side surface 20 where the grid structure contacts the top surface 10 m Width W less than 10 of the base b。
[0047] It is understood that the upper and lower ends in this application document should also cover the corresponding portions of the two end faces on both sides of the grid line structure along its length.
[0048] In the above embodiments, in the width direction of the grid structure, the vertical distance between the top surface 30 and the bottom surface 10 of the grid structure shows a trend of first gradually increasing and then gradually decreasing.
[0049] like Figure 1 As shown, the side surface 20 of the grid structure may include a plurality of segments (21 / 22 / 23 / 24) distributed sequentially in a direction away from the bottom surface 10, and some or all of the segments are constructed as planes or as curved surfaces that are curved in the width direction of the grid structure.
[0050] It is important to note that Figure 1 In the illustrated embodiment, the side surface 20 is divided into four segments. In other embodiments, it may also be divided into two, three, five or more segments.
[0051] When all segments are constructed as planes, side 20 becomes a planar structure, such as... Figure 7As shown. The included angles between the two sides 20 and the bottom surface 10 can be the same or different, but the included angles between the two sides 20 and the bottom surface 10 are both greater than or equal to 30° and less than or equal to 90°.
[0052] When some facets are constructed as planes, some facets are constructed as curved surfaces curving in the width direction of the grid structure, or all facets are constructed as curved surfaces, the curved surfaces are all set as concave surfaces, that is, the curved surfaces bend towards the bottom surface 10 or the other side surface in the width direction of the grid structure, such as... Figure 1 and Figure 2 As shown. The angle between any facet 20 and the bottom surface 10 is greater than or equal to 30° and less than or equal to 90°. The angles between the two side faces 20 and the bottom surface 10 can be the same or different.
[0053] In a preferred embodiment, such as Figure 1 As shown, among the multiple segments, there is a first segment 21 that is in contact with the bottom surface 10. The first segment 21 is configured as a concave surface that curves toward the bottom surface 10 in the width direction of the grid structure. The angle α between the first segment 21 and the bottom surface 10 is smaller than the angle between any of the other segments and the bottom surface 10.
[0054] In a preferred embodiment, such as Figure 1 As shown, on any cross section perpendicular to the length direction of the grid structure, the included angle γ between the two sides of the top surface 30 and the midpoint of the bottom surface 10 is greater than 0° and less than or equal to 90°.
[0055] The grid structure of this utility model has a bottom surface 10 with a width W. b Satisfying: 10μm≤W b ≤25μm. Width W of the top surface is 30. t The range is: 0μm < W t ≤24μm. The height H of the gate structure satisfies: 5μm≤H≤25μm.
[0056] Compared with existing technologies, the grid structure of this invention has ultra-high reflectivity, which can reduce the equivalent light-shielding area of the battery surface, and can replace the triangular conductive wire stacked grid assembly currently used in the industry. At the same time, it has higher stability and better wear resistance than triangular conductive wire.
[0057] refer to Figure 8 and Figure 9 As shown, this utility model also provides a solar cell, including a solar cell 100 and grid line electrodes 200 disposed on the surface of the solar cell 100. The grid line electrodes 200 are located on the light-receiving surface and / or the back-lighting surface of the solar cell 100. The grid line electrodes 200 include a plurality of the above-described grid line structures. The distance B between adjacent grid line structures is 500 μm-2700 μm.
[0058] The bottom surface 10 of the grid structure is in direct contact with the surface of the solar cell 100, such as... Figure 9 As shown. Alternatively, a metal seed layer 300 is disposed on the surface of the solar cell 100, and the bottom surface 10 of the grid structure is in contact with the metal seed layer 300, as shown. Figure 8 As shown.
[0059] Comparative Example 1
[0060] Solar cells with grid structure formed using traditional screen printing methods.
[0061] The performance parameters of the solar cells of Comparative Example 1 and those using the grid structure of this invention, after testing, are shown in the table below:
[0062]
[0063] As can be seen, compared with Comparative Example 1, the solar cell with the grid structure of this utility model has an increased cell current of 190mA, an increased power of 2.8W, and an increased current CTM of 0.38%.
[0064] The grid structure of this invention has a unique line shape and aspect ratio. The grid morphology is very similar to that of a triangular conductive wire. It also has the same high reflectivity as the triangular conductive wire, but has higher stability and better wear resistance.
[0065] The solar cell using this invention exhibits higher current and current conversion time (CTM) compared to traditional screen-printed solar cells. Furthermore, the grid structure of this invention can directly contact the solar cell, eliminating the need for the seed layer growth step in existing stacked grid modules, thus reducing costs and manufacturing complexity.
[0066] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0067] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A grid line structure applied to a solar cell, characterized by, The gate line structure is a unitary structure, the gate line structure has an upper end and a lower end in the height direction, the upper end is configured to be convexly arranged in a direction away from the lower end in the width direction of the gate line structure, and a projection of the upper end in the height direction is located in a range where the lower end is located; The gate line structure has a bottom surface, two oppositely arranged side surfaces, and a top surface; The upper end includes the top surface, and the lower end includes the bottom surface; The top surface is configured to be a curved surface that curves away from the bottom surface in the width direction of the gate line structure; The side surface includes a plurality of segment surfaces that are sequentially arranged in a direction away from the bottom surface, and the plurality of segment surfaces include a first segment surface that is in contact with the bottom surface, and the first segment surface is configured to be a curved surface that curves toward the bottom surface in the width direction of the gate line structure.
2. The gate line structure of claim 1, wherein, A projection of the top surface in a direction perpendicular to the bottom surface is located in a range where the bottom surface is located.
3. The gate line structure of claim 1, wherein, In the width direction of the gate line structure, the vertical distance between the top surface and the bottom surface gradually increases and then gradually decreases.
4. The gate line structure of claim 1, wherein, Part of the segment surfaces are configured to be planar or configured to be curved surfaces that curve in the width direction of the gate line structure.
5. The gate line structure of claim 1, wherein, An included angle between the first segment surface and the bottom surface is smaller than an included angle between any other segment surface and the bottom surface.
6. The gate line structure of claim 1, wherein, An included angle between any segment surface and the bottom surface is greater than or equal to 30° and less than or equal to 90°.
7. The gate line structure of claim 1, wherein, In any cross section perpendicular to the length direction of the gate line structure, the width W of the top surface t is less than the width W of the bottom surface b ; and / or, In any cross section perpendicular to the length direction of the gate line structure, an included angle γ between a line connecting two sides of the top surface to a midpoint of the bottom surface is greater than 0° and less than or equal to 90°; and / or, the width W of the bottom surface b satisfies: 10 pm ≤ W b ≤ 25 pm; and / or, a width W of the top surface t in the range: 0 μm < W t ≤ 24 μm; and / or, A height H of the gate line structure satisfies: 5 μm≤H≤25 μm.
8. A solar cell, characterized by The solar cell includes a solar cell sheet and a gate line electrode arranged on a surface of the solar cell sheet, and the gate line electrode includes a plurality of gate line structures according to any one of claims 1-7.
9. The solar cell of claim 8, wherein, The bottom surface of the gate line structure is in contact with the surface of the solar cell sheet; or The surface of the solar cell sheet is provided with a metal seed layer, and the bottom surface of the gate line structure is in contact with the metal seed layer.
10. The solar cell of claim 8, wherein, A distance between adjacent gate line structures is 500 μm-2700 μm; and / or The gate line electrode is located on a light-receiving surface and / or a back surface of the solar cell sheet.