Solar cell and photovoltaic module

Abstract

The invention relates to a solar cell piece and a photovoltaic module, the solar cell piece comprises a substrate, the substrate is provided with mark points, fine grids arranged along a first direction and a harpoon structure arranged along a second direction, the harpoon structure is located at the edge of the substrate, and the harpoon structure comprises a first connecting line and a second connecting line which are electrically connected with each other. The first connecting line and the second connecting line are electrically connected with the fine grid, a first area is arranged between the first connecting line and the second connecting line, at least part of the structure of the mark point is located in the first area, and the mark point is used for positioning the solar cell. By means of the design, the mark points are not prone to position deviation, deformation or breakage, the reliability of the mark points is improved, accurate positioning of the solar cell is achieved, meanwhile, shading loss caused by the mark points is reduced, and the photoelectric conversion efficiency of the solar cell is improved. And the mark points can realize a visual hiding effect by virtue of a harpoon structure, so that the consistency of the appearance of the photovoltaic module is improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and particularly to a solar cell and a photovoltaic module. Background Art

[0002] A photovoltaic module includes solar cells, which are used to convert solar energy into electrical energy. Marking points for positioning are provided on the substrate of the solar cells. Currently, the reliability of the marking points is relatively low, which affects the production and performance of the solar cells. Summary of the Invention

[0003] In view of this, this application provides a solar cell and a photovoltaic module to facilitate solving the problem of relatively low reliability of the marking points on the solar cells in the prior art.

[0004] In a first aspect, an embodiment of this application provides a solar cell, which includes a substrate. The substrate is provided with marking points, fine grids arranged along a first direction, and harpoon structures arranged along a second direction. Among them, the harpoon structures are located at the edge of the substrate. The harpoon structure includes a first connecting line and a second connecting line that are electrically connected to each other. Both the first connecting line and the second connecting line are electrically connected to the fine grids. And there is a first area between the first connecting line and the second connecting line. At least part of the structure of the marking point is located in the first area. The marking point is used to position the solar cell.

[0005] In a possible implementation manner, the substrate has solder joints. The first connecting line and the second connecting line are connected to two ends of the solder joint along the second direction. The solder joint is electrically connected to the fine grid. The marking point is located in the first area, and the marking point is spaced apart from the first connecting line, the first connecting line, and the solder joint.

[0006] In a possible implementation manner, along the first direction, the distance D1 between the marking point and the solder joint satisfies: 0.1 mm ≤ D1 ≤ 0.3 mm, and / or, along the second direction, the distance D2 between the marking point and the first connecting line satisfies: 0.1 mm ≤ D2 ≤ 0.3 mm, and / or, along the second direction, the distance D3 between the marking point and the second connecting line satisfies: 0.1 mm ≤ D2 ≤ 0.3 mm.

[0007] In a possible implementation manner, along the first direction, the size L1 of the marking point satisfies: 0.3 mm ≤ L1 ≤ 1 mm, and / or, along the second direction, the size L2 of the marking point satisfies: 0.3 mm ≤ L2 ≤ 1 mm.

[0008] In a possible implementation, a partial structure of the fine grid is located in the first region, the marking point is located on the fine grid, or the marking point is located between two adjacent fine grids.

[0009] In a possible implementation, the marking point includes a first marking portion, a second marking portion, and a third marking portion. The first connection line and the second connection line are connected to two ends of the first marking portion along the second direction. The first marking portion is electrically connected to the fine grid. The second marking portion and the third marking portion are connected to two ends of the first marking portion along the first direction. The second marking portion is located in the first region, the third marking portion is located outside the first region, and both the second marking portion and the third marking portion extend away from the first marking portion.

[0010] In a possible implementation, along the first direction, the dimension L3 of the second marking portion satisfies: 0.3 mm ≤ L3 ≤ 0.5 mm, the dimension L4 of the third marking portion satisfies: 0.3 mm ≤ L4 ≤ 0.5 mm, and / or, along the second direction, the dimension L5 of the second marking portion satisfies: 0.3 mm ≤ L5 ≤ 0.5 mm; the dimension L6 of the third marking portion satisfies: 0.3 mm ≤ L6 ≤ 0.5 mm.

[0011] In a possible implementation, the substrate has a first side edge and a second side edge along the second direction. The harpoon structures closest to the first side edge are a first edge harpoon structure and a second edge harpoon structure respectively, and the harpoon structures closest to the second side edge are a third edge harpoon structure and a fourth edge harpoon structure respectively. The number of the marking points is four, and the four marking points are arranged in one-to-one correspondence with the first edge harpoon structure, the second edge harpoon structure, the third edge harpoon structure, and the fourth edge harpoon structure.

[0012] In a second aspect, an embodiment of the present application provides a photovoltaic module, which includes a cover plate, an encapsulation layer, and a battery string. The cover plate is connected to the battery string through the encapsulation layer. The battery string includes a plurality of the above-mentioned solar cells, and adjacent solar cells are connected by welding tapes.

[0013] In a possible implementation, along the thickness direction of the solar cell, the projection of the marking point is located within the projection of the welding tape, and the marking point is connected to the welding tape.

[0014] The beneficial effects of the present application are as follows: At least part of the structure of the marking point is located within the first region of the harpoon structure, that is, the marking point is located at the edge of the solar cell. Since the harpoon structure can disperse the stress at the edge of the solar cell, reducing the possibility of stress concentration at the edge of the solar cell leading to hidden cracks, and the deformation degree of the edge region of the solar cell is smaller under the action of high temperature or pressure, and the structural stability is higher, so that the marking point is not likely to shift, deform or break, improving the reliability of the marking point, increasing the accuracy of marking point recognition, so as to achieve the precise positioning of the solar cell, thereby improving the production efficiency of the solar cell. At the same time, it avoids the possibility of the marking point causing light shielding loss to the central region of the solar cell, that is, reduces the light shielding of the marking point, so that more light can irradiate the main power generation functional area of the solar cell, to improve the photoelectric conversion efficiency of the solar cell. On the other hand, the shape of the marking point can be combined with the shape of the harpoon structure, so that the marking point can achieve the effect of visual hiding by means of the harpoon structure, reducing the impact of the marking point on the appearance of the photovoltaic module, improving the consistency and aesthetics of the appearance of the photovoltaic module, which is beneficial to the use of the photovoltaic module.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a partial schematic diagram of a solar cell in an embodiment of the present application; Figure 2 It is a partial schematic diagram of a solar cell in another embodiment of the present application; Figure 3 It is a schematic diagram of the marking point located in the first region in an embodiment of the present application; Figure 4 It is a schematic diagram of the marking point located in the first region in another embodiment of the present application; Figure 5 It is a partial schematic diagram of a solar cell in yet another embodiment of the present application; Figure 6 For Figure 5 the schematic diagram of the marking point; Figure 7 It is a schematic diagram of a solar cell in yet another embodiment of the present application; Figure 8Schematic diagram of a photovoltaic module in an embodiment of the present application; Figure 9 Schematic diagram of adjacent solar cells connected by solder ribbons in an embodiment of the present application; Figure 10 Partial schematic diagram of the connection between a solder ribbon and a solar cell in an embodiment of the present application; Figure 11 Partial schematic diagram of the connection between a solder ribbon and a solar cell in another embodiment of the present application; Figure 12 Partial schematic diagram of the connection between a solder ribbon and a solar cell in yet another embodiment of the present application; Figure 13 Partial schematic diagram of the connection between a solder ribbon and a solar cell in yet another embodiment of the present application; Figure 14 Partial schematic diagram of the connection between a solder ribbon and a solar cell in yet another embodiment of the present application.

[0018] Reference numerals: 1000 - Photovoltaic module; 100 - Solar cell; 10 - Substrate; 10a - First side; 10b - Second side; 11 - Marking point; 111 - First marking part; 112 - Second marking part; 113 - Third marking part; 11a - First marking point; 11b - Second marking point; 12 - Fine grid; 13 - Harpoon structure; 131 - First connecting line; 132 - Second connecting line; 133 - First region; 13a - First edge harpoon structure; 13b - Second edge harpoon structure; 13c - Third edge harpoon structure; 13d - Fourth edge harpoon structure; 13e - First harpoon structure; 13f - Second harpoon structure; 14 - Solder joint; 15 - Reinforcing structure; 200 - First cover plate; 300 - First encapsulation layer; 400 - Battery string; 500 - Second encapsulation layer; 600 - Second cover plate; 700 - Solder ribbon. Detailed implementation manners

[0019] For a better understanding of the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0020] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0021] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0022] It should be understood that the term "and / or" used herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0023] Marking points (mark points) are usually provided on a solar cell. The marking points can be recognized and captured by devices such as cameras to position the solar cell, facilitating the production and assembly of the solar cell. Currently, the reliability of the marking points on the solar cell is relatively low, which affects the production and preparation of the solar cell and the photoelectric conversion efficiency of the solar cell. At the same time, after the solar cell is encapsulated into a photovoltaic module, the marking points will also affect the consistency and aesthetics of the appearance of the photovoltaic module, resulting in a poor visual effect of the photovoltaic module and affecting the use of the photovoltaic module.

[0024] Based on this, as Figure 1 shown, an embodiment of the present application provides a solar cell 100. The solar cell 100 includes a substrate 10. The substrate 10 is provided with a marking point 11, a fine grid 12 arranged along a first direction X, and a harpoon structure 13 arranged along a second direction Y. Among them, the harpoon structure 13 is located at the edge of the substrate 10. The harpoon structure 13 includes a first connecting line 131 and a second connecting line 132 that are electrically connected to each other. Both the first connecting line 131 and the second connecting line 132 are electrically connected to the fine grid 12, and there is a first region 133 between the first connecting line 131 and the second connecting line 132. At least part of the structure of the marking point 11 is located in the first region 133. The marking point 11 is used to position the solar cell 100.

[0025] The first direction X intersects with the second direction Y. The first direction X may be the width direction of the solar cell 100, and the second direction Y may be the length direction of the solar cell 100. A plurality of fine grids 12 are arranged at intervals along the first direction X, and a plurality of harpoon structures 13 are arranged at intervals along the second direction Y. Please refer to Figure 2, the harpoon structure 13 can be located at the edges of the substrate 10 along both sides of the first direction X. The harpoon structure 13 can be regarded as a grid line on the substrate 10, which is used to collect the current at the edge of the solar cell 100 and is electrically connected to the fine grid 12 at the edge of the substrate 10. The setting directions of the first connecting line 131 and the second connecting line 132 can be parallel to each other so that the two can be connected into a structure similar to a "U" shape. Alternatively, the setting direction of the first connecting line 131 can also intersect with the setting direction of the second connecting line 132 so that the two can be connected into a structure similar to a "V" shape. Along the second direction Y, the first connecting line 131 and the second connecting line 132 are arranged at intervals, and the first region 133 is located between the first connecting line 131 and the second connecting line 132.

[0026] The marking point 11 can be formed on the substrate 10 by means of paste printing. It can be understood that at least part of the structure of the marking point 11 is located in the first region 133, that is, a part of the structure of the marking point 11 is located in the first region 133, or all of the structure of the marking point 11 is located in the first region 133.

[0027] In the embodiment of the present application, by setting the harpoon structure 13, the contact area between the fine grid 12 and the substrate 10 is increased, so that the fine grid 12 can more effectively collect the current at the edge of the cell, which is beneficial to improving the current transmission efficiency. At the same time, the harpoon structure 13 can shorten the current transmission path, thereby reducing the resistance loss of the solar cell 100. In addition, the harpoon structure 13 can also disperse the stress at the edge of the solar cell 100 and reduce the possibility of hidden cracks caused by stress concentration during the welding or use of the solar cell 100.

[0028] At least a part of the structure of the marking point 11 is located within the first region 133 of the harpoon structure 13, that is, the marking point 11 is located at the edge of the solar cell 100. Compared with the central region of the solar cell 100, during the production and preparation of the solar cell 100, the deformation degree of the edge region of the solar cell 100 under the action of high temperature or pressure is smaller, its structural stability is higher, and since the harpoon structure 13 can disperse the stress at the edge of the solar cell 100, reducing the possibility of stress concentration at the edge of the solar cell 100 resulting in hidden cracks, thus making the marking point 11 not prone to position deviation, deformation or fragmentation, improving the reliability of the marking point 11, increasing the accuracy of identifying the marking point 11, so as to achieve the precise positioning of the solar cell 100, and further improving the production efficiency of the solar cell 100. The main power generation functional area of the solar cell 100 is usually set in its central region. Setting the marking point 11 in the edge region of the solar cell 100 avoids the possibility of the marking point 11 causing light shielding loss to the central region, that is, reducing the light shielding of the marking point 11, so that more light irradiates the main power generation functional area of the solar cell 100, and further improving the photoelectric conversion efficiency of the solar cell 100. On the other hand, the shape of the marking point 11 can be combined with the shape of the harpoon structure 13, so that the marking point 11 can achieve the effect of visual hiding by means of the harpoon structure 13, reducing the influence of the marking point 11 on the appearance of the photovoltaic module, improving the consistency and aesthetics of the appearance of the photovoltaic module, which is beneficial to the use of the photovoltaic module. In addition, when preparing the photovoltaic module, the marking point 11 located at the edge of the solar cell 100 is more convenient for the positioning of the solder ribbon, which is beneficial to reducing the risk of welding deviation and improving the welding quality.

[0029] In some embodiments, the solar cell is a main-gridless (0BB, 0 - Busbar) solar cell. The solar cell can use a solder ribbon to replace the original main grid, that is, the solder ribbon can be directly connected to the fine grid. Since there is no need to set the main grid anymore, the consumption of metal paste is reduced, thereby reducing the production cost of the photovoltaic module. As Figure 2 shown, Figure 2 the solar cell 100 in is a main-gridless solar cell. The fine grid 12 can be provided with a strengthening structure 15, and the strengthening structure 15 is used to position the solder ribbon (not shown in the figure) and connect with the solder ribbon. Setting the strengthening structure 15 can increase the connection area between the solder ribbon and the fine grid 12, thereby improving the stability and reliability of the connection between the solder ribbon and the fine grid 12.

[0030] In some other embodiments, the solar cell is a multi-busbar (MBB) cell, i.e., multiple main grids are printed on the substrate of the solar cell. The above-mentioned harpoon structure can be located at the end of the main grid. The multi-busbar technology can reduce the number of fine grids accordingly by increasing the number of main grids, reducing costs. At the same time, it can also shorten the current conduction path between the fine grid and the main grid to reduce power loss and thus improve the power of the cell.

[0031] The types of the above-mentioned solar cells include but are not limited to Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Interdigitated Back Contact (IBC), perovskite cells, etc.

[0032] For a PERC cell, along its thickness direction, the PERC cell sequentially includes a front surface metal silver electrode, a front surface silicon nitride passivation layer, a phosphorus layer emitter, a P-type substrate 10 silicon layer, a local aluminum back surface field, a metal aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). The PERC cell uses a passivation film to passivate the back surface, replacing the full aluminum back surface field, enhancing the internal back reflection of light in the silicon substrate, reducing the back surface recombination rate, and increasing the efficiency of the cell by 0.5% - 1%.

[0033] For a TOPCon cell, along its thickness direction, the TOPCon cell sequentially includes a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate 10 silicon layer, a diffusion doping layer, an ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metal silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide (1nm - 2nm) and a phosphorus-doped microcrystalline amorphous hybrid Si film, and the two together form a passivated contact structure. This structure can block the recombination of minority carrier holes, improving the open circuit voltage and short circuit current of the cell. The ultra-thin oxide layer allows majority carrier electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon film causes the energy band on the silicon wafer surface to bend, thus forming a field passivation effect, greatly increasing the probability of electron tunneling, reducing the contact resistance, improving the open circuit voltage and short circuit current of the cell, and thus improving the cell conversion efficiency.

[0034] For an HJT cell, along its thickness direction, the HJT cell sequentially includes a front low-temperature silver electrode, a front conductive thin film, an N-type amorphous silicon thin film, an intrinsic amorphous silicon thin film, an N-type substrate 10 silicon layer, an intrinsic amorphous silicon thin film, a P-type amorphous silicon thin film, a back conductive thin film, and a back low-temperature silver electrode.

[0035] For an IBC cell, along its thickness direction, the IBC cell sequentially includes a silicon nitride anti-reflection layer, an N+ front surface field, an N-type substrate 10 silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a metal silver electrode. The IBC cell uses ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth. There are no grid lines blocking on the front side of the cell, which can eliminate the shading current loss of the metal electrodes and maximize the utilization of incident photons. The short-circuit current of the IBC cell can be increased by about 7% compared with conventional solar cells. Due to the back contact structure, there is no need to consider the problem of grid line occlusion, and the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor. The surface passivation and surface light trapping structure can be optimized to obtain a lower front surface recombination rate and surface reflection.

[0036] For a perovskite cell, along its thickness direction, the perovskite cell sequentially includes a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite materials are converted into electrons, they are easily collected by the electrodes with less loss. Therefore, perovskite can generate a high photo-generated voltage and current, making perovskite exhibit a high photoelectric conversion efficiency.

[0037] As Figure 3 shown, in a possible implementation, the substrate 10 has a solder joint 14. The first connection line 131 and the second connection line 132 are connected to both ends of the solder joint 14 along the second direction Y. The solder joint 14 is electrically connected to the fine grid 12. The marking point 11 is located in the first region 133, and the marking point 11 is spaced from the first connection line 131, the first connection line 131, and the solder joint 14.

[0038] The solder joint 14 can effectively collect the current collected by the fine grid 12, the first connection line 131, and the second connection line 132 together, and the solder joint 14 is connected to the solder tape so that the current can be transmitted through the solder tape. By setting the solder joint 14, the stability and reliability of the connection between the solder tape and the solar cell 100 are improved, and at the same time, the risk of displacement or detachment of the solder tape during use is reduced, thereby improving the reliability of the photovoltaic module.

[0039] The first connection line 131 and the second connection line 132 are electrically connected through the solder joint 14. The marking point 11 is spaced from the first connection line 131, the first connection line 131, and the solder joint 14, so that the marking point 11 is easier to identify, thereby improving the positioning accuracy of the solar cell 100, which is beneficial to the production and preparation of the solar cell 100. At the same time, it also reduces the possibility that the marking point 11 affects the current transmission of the harpoon structure 13 and the solder joint 14, and improves the reliability of the harpoon structure 13 and the solder joint 14.

[0040] Continue as Figure 3 shown. In a possible implementation manner, along the first direction X, the distance D1 between the marking point 11 and the solder joint 14 satisfies: 0.1 mm ≤ D1 ≤ 0.3 mm, and / or, along the second direction Y, the distance D2 between the marking point 11 and the first connection line 131 satisfies: 0.1 mm ≤ D2 ≤ 0.3 mm, and / or, along the second direction Y, the distance D3 between the marking point 11 and the second connection line 132 satisfies: 0.1 mm ≤ D2 ≤ 0.3 mm.

[0041] Among them, the distance D1 between the marking point 11 and the solder joint 14 can be 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm or 0.3 mm. Of course, it can also be other values within the above range.

[0042] The distance D2 between the marking point 11 and the first connection line 131 can be 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm or 0.3 mm. Of course, it can also be other values within the above range.

[0043] The distance D3 between the marking point 11 and the second connection line 132 can be 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm or 0.3 mm. Of course, it can also be other values within the above range.

[0044] By restricting the distance D1 between the marking point 11 and the solder joint 14, the distance D2 between the marking point 11 and the solder joint 14, and the distance D3 between the marking point 11 and the second connecting line 132, the recognition accuracy of the marking point 11 is improved, thereby improving the positioning accuracy of the solar cell 100. Furthermore, it is beneficial to improve the production efficiency of the solar cell 100. At the same time, the possibility of the marking point 11 affecting the first connecting line 131, the second connecting line 132, and the solder joint 14 is reduced, ensuring stable current transmission of the first connecting line 131, the second connecting line 132, and the solder joint 14, thereby improving the stability and reliability of the solar cell 100 and the entire photovoltaic module.

[0045] In a specific embodiment, the distance D1 between the marking point 11 and the solder joint 14, the distance D2 between the marking point 11 and the first connecting line 131, and the distance D3 between the marking point 11 and the second connecting line 132 are of the same size, such that the marking point 11 is in a relatively centered position within the first region 133, facilitating the preparation of the marking point 11, being beneficial to improving the recognition accuracy of the marking point 11, and at the same time ensuring the reliability of the harpoon structure 13 and the solder joint 14.

[0046] Continue as Figure 3 shown, in a possible implementation manner, along the first direction X, the size L1 of the marking point 11 satisfies: 0.3 mm ≤ L1 ≤ 1 mm, and / or, along the second direction Y, the size L2 of the marking point 11 satisfies: 0.3 mm ≤ L2 ≤ 1 mm.

[0047] Among them, the size L1 of the marking point 11 in the first direction X can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm or 1 mm. Of course, it can also be other values within the above range.

[0048] The size L2 of the marking point 11 in the second direction Y can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm or 1 mm. Of course, it can also be other values within the above range.

[0049] If the size of the marking point 11 is too large, it will cause waste of the paste for printing the marking point 11, increase the production cost of the solar cell 100, and at the same time increase the light-shielding area of the marking point 11, affecting the photoelectric conversion efficiency of the solar cell 100. If the size of the marking point 11 is too small, it will make the marking point 11 difficult to be recognized, affecting the positioning accuracy of the solar cell 100, and thus affecting the production efficiency of the solar cell 100. Therefore, by restricting the size of the marking point 11, while ensuring that the marking point 11 can be accurately recognized, the light-shielding area of the marking point 11 is reduced, and the waste of paste is reduced, thereby improving the photoelectric conversion efficiency and production efficiency of the solar cell 100 and reducing the production cost of the solar cell 100.

[0050] The shape of the above-mentioned marking point can be rectangular, circular, triangular, rhombic, polygonal, "cross" shaped, "rice" shaped or other shapes, as long as it is ensured that the marking point can be recognized and captured by a recognition device such as a camera to achieve the positioning of the solar cell.

[0051] Such as Figure 3 and Figure 4 As shown, in a possible implementation manner, a part of the structure of the fine grid 12 is located in the first region 133, the marking point 11 is located on the fine grid 12, or the marking point 11 is located between two adjacent fine grids 12.

[0052] The fine grid 12 can pass through the first region 133 and be electrically connected to the first connection line 131 and the second connection line 132. Such as Figure 3 As shown, in some embodiments, the marking point 11 can be located between any two adjacent fine grids 12 in the first region 133 and be arranged at an interval from the fine grid 12. The marking point 11 can be flexibly arranged according to actual use needs to facilitate the production and preparation of the solar cell 100 and the photovoltaic module. Such as Figure 4 As shown, in other embodiments, the marking point 11 can be located above or below a certain fine grid 12 in the first region 133, so that the shape of the marking point 11 is combined with the shape of the fine grid 12, improving the consistency and aesthetics of the appearance of the photovoltaic module, which is beneficial to the use of the photovoltaic module. When the solar cell 100 is subsequently string-soldered, the marking point 11 can be used as a point for welding with a solder strip (not shown in the figure), thereby improving the stability and reliability of the connection between the solder strip and the solar cell 100 and realizing the normal and stable operation of the photovoltaic module.

[0053] Such as Figure 5 and Figure 6As shown, in a possible implementation, the marking point 11 includes a first marking portion 111, a second marking portion 112, and a third marking portion 113. The first connection line 131 and the second connection line 132 are connected to both ends of the first marking portion 111 along the second direction Y. The first marking portion 111 is electrically connected to the fine grid 12. The second marking portion 112 and the third marking portion 113 are connected to both ends of the first marking portion 111 along the first direction X. The second marking portion 112 is located within the first region 133, and the third marking portion 113 is located outside the first region 133. Both the second marking portion 112 and the third marking portion 113 extend in a direction away from the first marking portion 111.

[0054] The first marking portion 111 may be located on the fine grid 12, and the first connection line 131 and the second connection line 132 are electrically connected through the first marking portion 111. The second marking portion 112 is within the first region 133 and extends in the first direction X away from the first marking portion 111. The third marking portion 113 is located outside the first region 133 and extends in the first direction X away from the first marking portion 111. The first marking portion 111, the second marking portion 112, and the third marking portion 113 may be connected into a structure approximately in the shape of a "plus" sign, that is, the shape of the marking point 11 may be a "plus" sign.

[0055] The first marking portion 111 can collect the current collected by the first connection line 131, the second connection line 132, and the fine grid 12. When the subsequent solar cell 100 is string-soldered, the solder strip can be welded to the marking point 11 to transmit the current collected by the marking point 11 through the solder strip. That is, the marking point 11 can be used as a solder joint for welding with the solder strip, thereby improving the utilization rate of the marking point 11. The second marking portion 112 and the third marking portion 113 protrude outward from the first marking portion 111, increasing the contact area between the marking point 11 and the substrate 10, which is beneficial to improving the welding strength between the solder strip and the solar cell 100, reducing the problem of welding failure at the edge of the solar cell 100, and further improving the reliability of the photovoltaic module. The marking point 11 serves both a positioning function and a welding function, enabling the marking point 11 to better combine with other structures on the substrate 10 to achieve a visual hiding effect, thereby improving the consistency and aesthetics of the appearance of the photovoltaic module.

[0056] It should be noted that the marking points are only set at certain points on the substrate. That is to say, not all the harpoon structures on the substrate are combined with the marking points. Specifically, as Figure 5As shown, the connection between the first connection line 131 and the second connection line 132 of the harpoon structure 13 not combined with the marking point 11 is realized through a soldering point 14. The settings of the second marking portion 112 and the third marking portion 113 enable the harpoon structure 13 provided with the marking point 11 to be distinguished from other harpoon structures 13 on the substrate 10. That is to say, due to the "cross" structure of the marking point 11, the marking point 11 can be distinguished from the soldering points 14 of other harpoon structures 13 to improve the recognition accuracy, and thus facilitate the precise positioning of the solar cell 100.

[0057] As Figure 6 shown, in a possible implementation manner, along the first direction X, the dimension L3 (i.e., the length of the second marking portion 112) of the second marking portion 112 satisfies: 0.3 mm ≤ L3 ≤ 0.5 mm, and the dimension L4 (i.e., the length of the third marking portion 113) of the third marking portion 113 satisfies: 0.3 mm ≤ L4 ≤ 0.5 mm, and / or, along the second direction Y, the dimension L5 (i.e., the width of the second marking portion 112) of the second marking portion 112 satisfies: 0.3 mm ≤ L5 ≤ 0.5 mm, and the dimension L6 (i.e., the width of the third marking portion 113) of the third marking portion 113 satisfies: 0.3 mm ≤ L6 ≤ 0.5 mm.

[0058] Among them, the dimension L3 of the second marking portion 112 can be 0.3 mm, 0.32 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.44 mm, 0.45 mm, 0.46 mm, 0.48 mm or 0.5 mm. Of course, it can also be other values within the above range. The dimension L5 of the second marking portion 112 can be 0.3 mm, 0.31 mm, 0.33 mm, 0.35 mm, 0.37 mm, 0.39 mm, 0.4 mm, 0.41 mm, 0.43 mm, 0.45 mm, 0.47 mm, 0.49 mm or 0.5 mm. Of course, it can also be other values within the above range.

[0059] The dimension L4 of the third marking portion 113 can be 0.3 mm, 0.32 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.38 mm, 0.4 mm, 0.42 mm, 0.44 mm, 0.45 mm, 0.46 mm, 0.48 mm or 0.5 mm. Of course, it can also be other values within the above range. The dimension L6 of the third marking portion 113 can be 0.3 mm, 0.31 mm, 0.33 mm, 0.35 mm, 0.37 mm, 0.39 mm, 0.4 mm, 0.41 mm, 0.43 mm, 0.45 mm, 0.47 mm, 0.49 mm or 0.5 mm. Of course, it can also be other values within the above range.

[0060] If the sizes of the second marking part 112 and the third marking part 113 are too large, it will lead to waste of the paste of the printed marking point 11, increase the production cost of the solar cell 100, and at the same time increase the light-shielding area of the whole marking point 11, affecting the photoelectric conversion efficiency of the solar cell 100. If the sizes of the second marking part 112 and the third marking part 113 are too small, it will be difficult to distinguish the marking point 11 from other solder joints 14, resulting in the marking point 11 being difficult to be recognized, affecting the positioning accuracy of the solar cell 100, and thus affecting the production efficiency of the solar cell 100. Therefore, by restricting the sizes of the second marking part 112 and the third marking part 113, while ensuring that the marking point 11 can be accurately recognized, the light-shielding area of the marking point 11 is reduced, and the waste of paste is reduced, so as to improve the photoelectric conversion efficiency and production efficiency of the solar cell 100 and reduce the production cost of the solar cell 100.

[0061] As Figure 7 shown, in a possible implementation manner, the substrate 10 has a first side edge 10a and a second side edge 10b along the second direction Y. The harpoon structures 13 closest to the first side edge 10a are respectively a first edge harpoon structure 13a and a second edge harpoon structure 13b, and the harpoon structures 13 closest to the second side edge 10b are respectively a third edge harpoon structure 13c and a fourth edge harpoon structure 13d. The number of the marking points 11 is four, and the four marking points 11 are arranged in one-to-one correspondence with the first edge harpoon structure 13a, the second edge harpoon structure 13b, the third edge harpoon structure 13c, and the fourth edge harpoon structure 13d.

[0062] There are four symmetrically arranged marking points 11 on the substrate 10, and the four marking points 11 are respectively arranged on the first edge harpoon structure 13a, the second edge harpoon structure 13b, the third edge harpoon structure 13c, and the fourth edge harpoon structure 13d. Setting multiple marking points 11 can more accurately position the solar cell 100, reduce the positioning error, and improve the positioning accuracy. The marking points 11 are respectively combined with the corresponding edge harpoon structures 13, so as to achieve a visual hiding effect while increasing the accuracy of recognizing the marking points 11 to realize the precise positioning of the solar cell 100.

[0063] Specifically, the above four marking points 11 can all have a "cross" structure, and the four marking points 11 can all be used as solder joints connected to the solder tape. Such a design is beneficial to improving the welding strength between the solder tape and the solar cell 100, reducing the risk of welding failure at the edge of the solar cell 100, and further improving the reliability of the photovoltaic module.

[0064] In some other embodiments, the marking points can be arranged on the harpoon structures located at the middle positions, and the marking points can be flexibly arranged according to actual usage requirements.

[0065] As Figure 8 and Figure 9 shown, an embodiment of the present application provides a photovoltaic module 1000. The photovoltaic module 1000 includes a cover plate, an encapsulation layer, and a battery string 400. The cover plate is connected to the battery string 400 through the encapsulation layer. The battery string 400 includes a plurality of the above-mentioned solar cells 100, and adjacent solar cells 100 are connected by a solder ribbon 700.

[0066] Among them, the cover plate located on the upper layer of the photovoltaic module 1000 is the first cover plate 200, and the cover plate located on the lower layer of the photovoltaic module 1000 is the second cover plate 600. The encapsulation layer located between the first cover plate 200 and the battery string 400 is the first encapsulation layer 300, and the encapsulation layer located between the second cover plate 600 and the battery string 400 is the second encapsulation layer 500. The first cover plate 200, the first encapsulation layer 300, the battery string 400, the second encapsulation layer 500, and the second cover plate 600 can be arranged along the thickness direction of the photovoltaic module 1000 and are laminated together. Among them, the first cover plate 200 can be a glass cover plate, and the first cover plate 200 has a high light transmittance. The first encapsulation layer 300 bonds the first cover plate 200 and the battery string 400 together to play a role in encapsulating and protecting the battery string 400. The material of the first encapsulation layer 300 can be one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB). The second encapsulation layer 500 connects the battery layer and the second cover plate 600, and it also plays a role in encapsulating and protecting the battery string 400. The material of the second encapsulation layer 500 can be one or more of the above-mentioned EVA, POE, and PVB. The material of the second cover plate 600 can be glass, or the second cover plate 600 can also be composed of multiple polymer film layers.

[0067] In a possible implementation manner, along the thickness direction of the solar cell, the projection of the marking point is located within the projection of the solder ribbon, and the marking point is connected to the solder ribbon.

[0068] The following takes two marking points on the substrate and the harpoon structures corresponding to the two marking points as an example for specific description. The two marking points are the first marking point and the second marking point respectively, and the two harpoon structures are the first harpoon structure and the second harpoon structure respectively. At least part of the structure of the first marking point is located within the first area of the first harpoon structure, and at least part of the structure of the second marking point is located within the first area of the second harpoon structure. The first harpoon structure and the second harpoon structure are arranged along the first direction and are connected to the same solder ribbon.

[0069] As Figure 10As shown, in some embodiments, both the first marking point 11a and the second marking point 11b can be used as solder joints for connecting with the solder strip 700. The first marking point 11a and the second marking point 11b are both in a "cross" shape structure formed by connecting the above-mentioned first marking part, second marking part and third marking part. When the solder strip 700 is connected to the solar cell 100, both the first marking point 11a and the second marking point 11b are connected to the solder strip 700, and both the first marking point 11a and the second marking point 11b are covered by the solder strip 700. That is, along the thickness direction Z of the solar cell 100, the projections of the first marking point 11a and the second marking point 11b are located within the projection of the solder strip 700, so that the first marking point 11a and the second marking point 11b are hidden by the solder strip 700, thereby improving the appearance consistency and aesthetics of the photovoltaic module 1000. At the same time, because the marking point 11 has a "cross" shape structure, the contact area between the marking point 11 and the substrate 10 is increased, which is beneficial to improving the welding strength between the solder strip 700 and the solar cell 100, reducing the problem of welding failure at the edge of the solar cell 100, and further improving the reliability of the photovoltaic module 1000.

[0070] As Figure 11 shown, in some other embodiments, the first marking point 11a can be located in the first region 133 of the first harpoon structure 13e, and the second marking point 11b can be located in the first region 133 of the second harpoon structure 13f. When the solder strip 700 is connected to the solar cell 100, the second marking point 11b can be covered by the solder strip 700 and can be connected to the solder strip 700, while the first marking point 11a can be exposed outside the solder strip 700. Since the first marking point 11a is not covered by the solder strip 700, the first marking point 11a is still in a usable state, that is, the solar cell 100 can be positioned through the first marking point 11a in subsequent production processes, so that the marking point can meet the needs of various production scenarios.

[0071] As Figure 12 shown, the first marking point 11a and the second marking point 11b can also be simultaneously covered by the solder strip 700 and connected to the solder strip 700 to improve the appearance consistency and aesthetics of the photovoltaic module 1000, and at the same time improve the connection stability between the solder strip 700 and the solar cell 100, thereby improving the reliability of the photovoltaic module 1000.

[0072] As Figure 13As shown, in some embodiments, the marking point 11 may be located outside the harpoon structure 13. That is to say, the marking point 11 is not arranged in the above-mentioned first region. The marking point 11 may be located between two adjacent fine grids 12. The marking point 11 is covered by the welding tape 700 and connected to the welding tape 700, so that the marking point 11 is hidden by the welding tape 700, improving the consistency and aesthetics of the appearance of the photovoltaic module 1000.

[0073] As Figure 14 shown, in some other embodiments, the marking point 11 may be outside the harpoon structure 13. The marking point 11 is located on the fine grid 12, and it can be used as a strengthening structure on the fine grid 12 to position the welding tape 700, increasing the connection area between the welding tape 700 and the fine grid 12, thereby improving the stability and reliability of the connection between the welding tape 700 and the fine grid 12. The marking point 11 is covered by the welding tape 700 and connected to the welding tape 700, so that the marking point 11 is hidden by the welding tape, thereby improving the consistency and aesthetics of the appearance of the photovoltaic module 1000.

[0074] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solar cell, characterized in that: The solar cell sheet comprises a substrate, the substrate being provided with marking points, fine grids arranged along a first direction, and harpoon structures arranged along a second direction; Wherein, the harpoon structure is located at the edge of the substrate, and the harpoon structure includes a first connecting line and a second connecting line electrically connected to each other, the first connecting line and the second connecting line are both electrically connected to the fine grid, and there is a first area between the first connecting line and the second connecting line, at least part of the structure of the marking point is located in the first area, and the marking point is used to locate the solar cell.

2. The solar cell according to claim 1, characterized in that: The substrate has a welding point, the first connecting line and the second connecting line are connected to two ends of the welding point along the second direction, and the welding point is electrically connected to the fine grid; The marking point is located in the first area, and the marking point is spaced apart from the first connecting line, the first connecting line and the welding point.

3. The solar cell according to claim 2, characterized in that: Along the first direction, the distance D1 between the marking point and the welding point satisfies: 0.1 mm ≤ D1 ≤ 0.3 mm; and / or Along the second direction, the distance D2 between the marking point and the first connecting line satisfies: 0.1 mm ≤ D2 ≤ 0.3 mm; and / or Along the second direction, a distance D3 between the marking point and the second connecting line satisfies: 0.1 mm≤D2≤0.3 mm.

4. The solar cell according to claim 2, characterized in that: Along the first direction, the size L1 of the marking point satisfies: 0.3 mm ≤ L1 ≤ 1 mm; and / or Along the second direction, the size L2 of the marking point satisfies: 0.3 mm ≤ L2 ≤ 1 mm.

5. The solar cell according to claim 2, characterized in that: Part of the structure of the fine grid is located in the first area; The marking point is located on the fine grid, or the marking point is located between two adjacent fine grids.

6. The solar cell according to claim 1, characterized in that: The marking point includes a first marking portion, a second marking portion and a third marking portion, the first connecting line and the second connecting line are connected to two ends of the first marking portion along the second direction, and the first marking portion is electrically connected to the fine grid; The second marking portion and the third marking portion are connected to two ends of the first marking portion along the first direction, the second marking portion is located in the first area, the third marking portion is located outside the first area, and the second marking portion and the third marking portion both extend in a direction away from the first marking portion.

7. The solar cell according to claim 6, characterized in that: Along the first direction, the dimension L3 of the second marking portion satisfies: 0.3 mm ≤ L3 ≤ 0.5 mm, and the dimension L4 of the third marking portion satisfies: 0.3 mm ≤ L4 ≤ 0.5 mm; and / or Along the second direction, a size L5 of the second marking portion satisfies: 0.3 mm ≤ L5 ≤ 0.5 mm; a size L6 of the third marking portion satisfies: 0.3 mm ≤ L6 ≤ 0.5 mm.

8. The solar cell according to any one of claims 1 to 7, characterized in that: The base has a first side and a second side along the second direction, the harpoon structures closest to the first side are respectively a first edge harpoon structure and a second edge harpoon structure, and the harpoon structures closest to the second side are respectively a third edge harpoon structure and a fourth edge harpoon structure; The number of the marking points is four, and the four marking points are arranged in one-to-one correspondence with the first edge harpoon structure, the second edge harpoon structure, the third edge harpoon structure, and the fourth edge harpoon structure.

9. A photovoltaic module, characterized in that: The photovoltaic module comprises a cover plate, an encapsulation layer and a battery string, wherein the cover plate is connected to the battery string through the encapsulation layer; The battery string comprises a plurality of solar cells according to any one of claims 1 to 8, and adjacent solar cells are connected by welding ribbons.

10. The photovoltaic module according to claim 9, characterized in that: Along the thickness direction of the solar cell sheet, the projection of the marking point is located within the projection of the welding strip, and the marking point is connected to the welding strip.

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