Solar cell and solar cell module

Abstract

The utility model relates to the field of photovoltaic technology, and discloses a solar cell and a solar cell module. The solar cell comprises a silicon wafer and metalized mesh grid lines, the metalized mesh grid lines are arranged on the silicon wafer, each metalized mesh grid line comprises a plurality of main grids and a plurality of auxiliary grids, all the auxiliary grids are parallel to one another and arranged at intervals, all the main grids are parallel to one another and perpendicularly intersect with the auxiliary grids, each main grid comprises a plurality of main grid units, and each main grid unit comprises a plurality of main grid units. The plurality of main grid units are arranged at intervals, each main grid unit of two adjacent main grids is connected with different auxiliary grids, so that electrons at any positions of the auxiliary grids can be transmitted to the main grids, the main grids are connected with the welding strip, and at least one auxiliary grid is connected with the welding strip, so that electrons at any positions of the auxiliary grids can be transmitted to the welding strip. By adopting the design of the scheme, the links of current transmission can be partially reduced, the use amount of slurry is reduced, the process cost is reduced, the conversion efficiency of converting light energy into electric energy is improved, and the effects of improving efficiency and reducing cost are achieved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a solar cell assembly. Background Art

[0002] In recent years, photovoltaic technology, due to its ability to directly convert sunlight into electricity, has become a research hotspot in the field of new energy. Existing solar cells typically consist of a main grid, a corresponding number of solder ribbons, and an even larger number of secondary grids. When a solar cell is operating, current first flows to the nearest secondary grid, then through the secondary grid to the nearest main grid. From there, current flows to the solder ribbons, forming a current loop to generate electricity.

[0003] In the related technology, the main grid is horizontally connected to the auxiliary grid, and a welding strip is welded on a main grid. Such solar cells require more slurry when printing, and the current transmission link is more complicated. The longer current transmission link will cause current loss, which in turn affects the photoelectric conversion efficiency of the solar cell. Utility Model Content

[0004] The embodiments of the present application disclose a solar cell and a solar cell module, which can optimize the path of current transmission, improve the conversion efficiency of light energy into electrical energy, reduce the silver content and the amount of paste used, save costs, and comprehensively achieve the goal of improving efficiency while reducing costs.

[0005] To achieve the above objectives, in a first aspect, embodiments of the present application disclose a solar cell, wherein a plurality of solar cells are connected by a welding ribbon, and the solar cell comprises:

[0006] silicon wafers;

[0007] Metallized mesh grid lines, the metallized mesh grid lines are arranged on the silicon wafer, the metallized mesh grid lines include a plurality of main grids and a plurality of auxiliary grids, all of the auxiliary grids are parallel to each other and arranged at intervals, and all of the main grids are parallel to each other and arranged at intervals, and intersect the auxiliary grids perpendicularly;

[0008] A main grid includes several main grid units, and the several main grid units are arranged at intervals. Each main grid unit of two adjacent main grids is connected to a different auxiliary grid. At least one main grid is connected to the welding strip, and at least one auxiliary grid is connected to the welding strip.

[0009] As an optional embodiment, two adjacent main grids among the plurality of main grids include a first main grid and a second main grid, the first main grid includes a plurality of first main grid units, the first main grid units are arranged at intervals, and each of the first main grid units is connected to a plurality of the auxiliary grids;

[0010] The second main gate includes a plurality of second main gate units, which are arranged at intervals. Each second main gate unit is located between two adjacent first main gate units of the first main gate along a direction perpendicular to the auxiliary gate and is connected to a plurality of the auxiliary gates.

[0011] As an optional implementation manner, every two adjacent main grid units belonging to the same main grid are connected via one welding strip.

[0012] As an optional implementation manner, all the main grid units belonging to the same main grid are connected to the same welding strip.

[0013] As an optional implementation manner, the length of the main gate unit along the extension direction perpendicular to the auxiliary gate is 10-12 mm, and the width of the main gate unit is 1-20 μm.

[0014] As an optional implementation, one of the auxiliary grids includes a plurality of auxiliary grid units, the plurality of auxiliary grid units are arranged at intervals, and every two adjacent auxiliary grid units belonging to the same auxiliary grid are connected by welding via one of the welding strips.

[0015] As an optional implementation manner, all the auxiliary grid units belonging to the same auxiliary grid are connected to the same welding strip.

[0016] As an optional implementation manner, the length of the auxiliary gate unit along the extension direction parallel to the auxiliary gate is 12-50 mm, and the height of the auxiliary gate unit along the direction perpendicular to the silicon wafer is 0.1-3 μm.

[0017] As an optional implementation, the width of the auxiliary grid is 1-20 μm, and the distance between two adjacent auxiliary grids is 5-6 mm.

[0018] As an optional embodiment, the central axis of the welding strip and the central axis of the auxiliary grid are located in the same plane perpendicular to the silicon wafer, and the central axis of the welding strip and the central axis of the main grid are located in the same plane perpendicular to the silicon wafer.

[0019] As an optional implementation, the material of the metallized mesh grid line includes metal aluminum.

[0020] In a second aspect, the present application discloses a solar cell assembly, comprising:

[0021] a number of welding ribbons; and,

[0022] In the solar cells as described in the first aspect above, two adjacent solar cells are connected via a welding ribbon.

[0023] As an optional implementation manner, the width of the welding strip is 50-70 μm.

[0024] As an optional implementation, the light-receiving surface of the soldering strip is a smooth curved surface or a convex surface that is at least partially bent.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The present invention provides a solar cell and solar cell with main grid units arranged at intervals on a metalized mesh grid line. The main grid units intersect perpendicularly with the auxiliary grids, so that all auxiliary grids are connected to the main grid units. Some welding strips are welded to the main grid, and some welding strips are welded to the auxiliary grids. In this way, the welding strips are welded horizontally and vertically, ensuring that welding strips are welded above the main grid and the auxiliary grid, so that electrons from the entire solar cell can be fully collected. At the same time, the spaced main grid units save slurry during printing, achieving efficiency and cost reduction, and partially reducing the current transmission link, thereby improving the efficiency of the solar cell's photoelectric conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a structural diagram of an existing solar cell;

[0029] Figure 2 A schematic plan view of a solar cell (with the soldering ribbon omitted) disclosed in an embodiment of the present application;

[0030] Figure 3 This is an isometric diagram of a solar cell disclosed in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of a solar cell connection (the cross-section of the welding ribbon is semicircular) disclosed in an embodiment of the present application;

[0032] Figure 5 This is a schematic diagram of the solar cell connection (the cross-section of the welding ribbon is triangular) disclosed in an embodiment of the present application.

[0033] Description of reference numerals:

[0034] 100-solar cells;

[0035] 1-Silicon wafer;

[0036] 2-metallized mesh grid line; 21-sub-grid; 211-sub-grid unit; 22-main grid; first main grid 22a; second main grid 22b; 221-main grid unit; first main grid unit 221a; second main grid unit 221b;

[0037] 300-solar cell module; 301-welding ribbon;

[0038] a-solar cell; b-main grid; c-fine grid; d-tinned solder strip. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0040] In this application, the terms "upper" and "lower" and other terms indicating positions or locations are based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe this application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0041] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0042] Furthermore, the terms "disposed" and "connected" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0043] Unless otherwise specified, "plurality" means two or more.

[0044] Photovoltaic technology is a technology that can convert light energy into electrical energy. It has become a hot topic in the field of new energy research. In photovoltaic technology, solar cells are a crucial component, which is related to the conversion efficiency of light energy into electrical energy. Figure 1As shown, solar cell a typically consists of a main grid b, a corresponding number of tinned solder strips d, and a larger number of auxiliary grids c. When solar cell a is operating, light energy is converted into electrons on the silicon wafer. These electrons are then collected by the silicon wafer and transported to the nearest auxiliary grid c. The electrons are then transferred from the auxiliary grid c to the nearest main grid a. Finally, they are transferred to the main grid a and then to the tinned solder strips d, forming a closed current loop. However, current solar cells have multiple electron transmission links, which can easily lead to current loss during the transmission process, affecting the efficiency of converting light energy into electricity. Furthermore, both the main grid and auxiliary grid require printing with silver paste, which requires a large amount of silver paste and is costly.

[0045] Based on this, the present application discloses a solar cell, which adopts a design in which the main grid is composed of main grid units arranged at intervals, and the auxiliary grids are vertically connected to the welding strips through mutually parallel auxiliary grids, so that electrons are mainly transmitted by the welding strips, and the main grid and auxiliary grid assist in collecting current. This adjusts the current transmission structure, improves the efficiency of photoelectric conversion, and can effectively reduce the use of silver paste printing, reduce costs, and achieve efficiency improvement and cost reduction.

[0046] The technical solution of the present application will be further described below with reference to the embodiments and drawings.

[0047] See also Figure 2 and Figure 3 , Figure 2 Schematic diagram of a plan view of a solar cell 100 (with the soldering ribbon 301 omitted) disclosed in an embodiment of the present application. Figure 3 This is an isometric schematic diagram of a solar cell 100 disclosed in an embodiment of the present application. In a first aspect, the present application discloses a solar cell 100, which is used in a solar cell module 300. The solar cell module 300 includes a plurality of solder ribbons 301, through which the plurality of solar cells 100 are connected. Specifically, the solar cell 100 includes a silicon wafer 1 and a metallized mesh grid line 2, which is disposed on the silicon wafer 1. The metallized mesh grid line 2 includes a plurality of auxiliary grids 21 and a plurality of main grids 22. All auxiliary grids 21 are parallel to each other and arranged at intervals. All main grids 22 are parallel to each other and arranged at intervals, and intersect perpendicularly with the auxiliary grids 21. A main grid 22 includes a plurality of main grid units 221. The plurality of main grid units 221 are arranged at intervals, and each main grid unit 221 of two adjacent main grids 22 is connected to a different auxiliary grid 21 so that electrons at any position of the auxiliary grid 21 can be transmitted to the main grid 22. At least one main grid 22 is connected to a welding strip 301 so that current at any position of the main grid 22 can be transmitted to the welding strip 301. At least one auxiliary grid 21 is connected to a welding strip 301 so that electrons at any position on the auxiliary grid 21 can be transmitted to the welding strip 301.

[0048] In this way, when the solar cell 100 receives light, the sunlight on the silicon wafer 1 generates electrons, which are collected on the auxiliary grid 21. At the part where the welding strip 301 is connected to the auxiliary grid 21, the electrons are directly transmitted to the welding strip 301 via the auxiliary grid 21. At the part where the main grid unit 221 is connected to the auxiliary grid 21, the electrons are collected from the silicon wafer 1 to the auxiliary grid 21. The auxiliary grid 21 then transmits the electrons to the nearby main grid unit 221, and then the electrons are collected by the main grid 22 and transmitted to the welding strip 301. By dividing the main grid 22 into a plurality of spaced main grid units 221, light can be more directly irradiated onto the active area of ​​the solar cell 100, reducing the obstruction of light by the front electrode and reducing the amount of silver paste required for printing the main grid 22, thereby saving costs. At the same time, the vertical intersection of the auxiliary grid 21 and the main grid 22 ensures the effective transmission of electrons within the solar cell 100, improves the collection efficiency of the photocurrent, and forms a dense electron transmission network. The electron transmission process in this mode is simple. The traditional current transmission mode of silicon wafer-auxiliary grid-main grid-welding ribbon is replaced with silicon wafer-main-auxiliary grid-welding ribbon. That is, the unitized and extremely low-height grid line can be approximated to conduct current in a direction perpendicular to the horizontal direction and directly collect it on the welding ribbon. This can reduce the loss of electrons in the transmission process and improve the efficiency of electron transmission. By optimizing the electron transmission path and reducing resistance, the solar cell 100 can further improve the photoelectric conversion efficiency of the battery.

[0049] It is understood that the silicon wafer 1 of the solar cell 100 is the foundation of the entire structure, and the material selection for the silicon wafer 1 directly impacts the performance and cost of the solar cell 100. In this embodiment, the silicon wafer 1 is made of high-purity, low-defect density single-crystal silicon or polycrystalline silicon. These materials offer excellent photoelectric conversion efficiency and stability, meeting the long-term operational requirements of photovoltaic cells.

[0050] Further, if Figure 2 As shown, two adjacent main gates 22 among the several main gates 22 include a first main gate 22a and a second main gate 22b, the first main gate 22a includes a plurality of first main gate units 221a, the plurality of first main gate units 221a are arranged at intervals, and each first main gate unit 221a is connected to a plurality of auxiliary gates 21, the second main gate 22b includes a plurality of second main gate units 221b, the second main gate units 221b are arranged at intervals, and each second main gate unit 221b is located between two adjacent first main gate units 221a of the first main gate 22a along a direction perpendicular to the auxiliary gate 21, and is connected to a plurality of auxiliary gates 21.

[0051] In this way, by alternating the first main grid 22a and the second main grid 22b, the number of paths for current to be collected from the auxiliary grid 21 to the main grid 22 is increased. Each main grid unit 221 can independently collect the current on the auxiliary grid 21 connected to it, thereby improving the overall current collection efficiency. The main grid units 221 are arranged at intervals and each main grid unit 221 is connected to the auxiliary grid 21, which helps to shorten the transmission distance of the current on the auxiliary grid 21 and reduce the energy loss caused by resistance. At the same time, the design of the main grid 22 using multiple main grid units 221 can reduce the amount of metal paste used while ensuring connection strength and current transmission, reducing costs and achieving cost reduction and efficiency improvement.

[0052] Furthermore, every two adjacent busbar units 221 belonging to the same busbar 22 are connected by a welding ribbon 301, so that the welding ribbon 301 connects the busbar units 221 of a busbar 22, facilitating current transmission on the welding ribbon 301. It is understood that the above-mentioned connection method between the busbar units 221 and the welding ribbon 301 can also be such that all busbar units 221 belonging to the same busbar 22 are connected to the same welding ribbon 301, so that the welding ribbon 301 can completely cover all busbar units 221 of a busbar 22, facilitating current collection by the busbar units 221 and then transmission to the welding ribbon 301.

[0053] In this way, connecting every two adjacent busbar units 221 via the welding ribbon 301 effectively forms a continuous current transmission path, ensuring uninterrupted current transmission between the busbar units 221 and the welding ribbon 301. Current can be transmitted more smoothly on the busbar 22, reducing energy loss caused by poor connection or excessive resistance. At the same time, connecting a welding ribbon 301 between two adjacent busbar units 221 along a busbar 22 can reduce the length of the welding ribbon 301, thereby saving costs. Furthermore, using a single welding ribbon 301 to completely cover all busbar units 221 along a busbar 22, because the welding ribbon 301 directly covers all busbar units 221 along the entire busbar 22, there is virtually no interruption or branching during current transmission. This direct connection method significantly reduces resistance and energy loss, maximizing current transmission efficiency. Compared to individually connecting each busbar unit 221 to a welding ribbon 301, this full-coverage connection method simplifies the manufacturing process, reduces the number of welding points on the welding ribbon 301, and reduces production costs and manufacturing difficulty. Furthermore, when the welding ribbon 301 completely covers the main grid 22 , it increases the strength and rigidity of the solar cell 100 in this area, helps to resist external stress and vibration, and improves the overall durability and reliability.

[0054] Optionally, the length of the main grid 22 along the direction perpendicular to the extension of the auxiliary grid 21 is 10-12 mm, and the width of the main grid 22 is 1-20 μm. Thus, on the one hand, the length of the main grid 22 between 10-12 mm can ensure more connectivity between the main grid 22 and the auxiliary grid 21 while ensuring more uniform current distribution on the solar cell 100, reducing resistance losses and thus improving overall current transmission efficiency. On the other hand, the appropriate width of the main grid 22 of 1-20 μm can reduce the shading area to a certain extent, allowing more sunlight to reach the surface of the solar cell 100, thereby achieving a good balance between current transmission and photoelectric conversion efficiency, thereby improving photoelectric conversion efficiency.

[0055] See Figure 2 and Figure 3 In some embodiments, a sub-grid 21 is divided into a plurality of sub-grid units 211, which are arranged at intervals. These sub-grid units 211 are densely distributed to form a sub-grid 21, and each two adjacent sub-grid units 211 belonging to the same sub-grid 21 are connected by a welding ribbon 301, so that the welding ribbon 301 can connect each sub-grid unit 211 to facilitate current transmission. It is worth noting that the connection method between each two adjacent sub-grid units 211 and a welding ribbon 301 is spot welding. Spot welding can better improve the reliability of multiple solder joints in this connection method and ensure a strong weld between the welding ribbon 301 and the sub-grid unit 211.

[0056] It can be understood that the connection method between the above-mentioned auxiliary grid unit 211 and the welding strip 301 can also be that all the auxiliary grid units 211 belonging to the same auxiliary grid 21 are connected to the same welding strip 301, so that the welding strip 301 can completely cover all the auxiliary grid units 211 of an auxiliary grid 21, thereby facilitating the vertical transmission of current between the auxiliary grid unit 211 and the welding strip 301.

[0057] In this way, a sub-grid 21 is divided into several sub-grid units 211, and the sub-grid units 211 are arranged at intervals, which helps when using silver paste to print the sub-grid 21, only the part with the sub-grid units 211 needs to be printed, reducing the amount of silver paste used and saving costs. At the same time, multiple sub-grid units 211 can make the current distribution on the solar cell 100 more uniform, avoiding heat loss and efficiency reduction caused by excessive local current. Connecting a welding strip 301 between two adjacent sub-grid units 211 or connecting a welding strip 301 to all sub-grid units 211 can ensure the timely transfer of electrons from the sub-grid unit 211 to the welding strip 301, further reducing the loss of electrons during the transfer process. Each two adjacent auxiliary grid units 211 belonging to the same auxiliary grid 21 are connected by a welding strip 301, so that each auxiliary grid unit 211 has an independent electron transmission path. On the one hand, since each auxiliary grid unit 211 is independently connected, this connection method is more flexible in layout, and the spacing between the auxiliary grid units 211 and the position of the welding strip 301 can be adjusted according to specific needs. On the other hand, if a welding strip 301 or auxiliary grid unit 211 fails, its impact is usually limited to the welding strip 301 and the adjacent auxiliary grid unit 211, and its impact on the entire system is relatively small, avoiding affecting the operation of the entire solar cell 100. In addition, this connection method can also save a portion of the length of the welding strip 301, thereby saving costs. Having one welding strip 301 completely cover all the auxiliary grid units 211 of an auxiliary grid 21 is conducive to forming an integrated current transmission path, and at the same time, realizing vertical current transmission between the auxiliary grid unit 211 and the welding strip 301.

[0058] Furthermore, the length of the auxiliary grid unit 211 along the direction parallel to the auxiliary grid 21 is 12-50 mm, and the height of the auxiliary grid unit 211 along the direction perpendicular to the silicon wafer 1 is 0.1-3 μm. In this way, the length of the auxiliary grid unit 211 along the extension direction parallel to the auxiliary grid 21 is within 12-50 mm, which can make the volume of the auxiliary grid unit 211 on a auxiliary grid 21 small enough and dense enough, and can improve the collection efficiency of the solar cell 100 for electrons near the auxiliary grid 21 while ensuring the cost of printing silver paste, thereby achieving the effect of improving efficiency and reducing costs. The height of the auxiliary grid unit 211 along the direction perpendicular to the silicon wafer 1 can determine the transmission distance of electrons from the auxiliary grid unit 211 to the welding ribbon 301. The greater the transmission distance, the greater the resistance during the transmission process, which will cause more current to be lost during the transmission process. Therefore, the height of the auxiliary grid unit 211 along the direction perpendicular to the silicon wafer 1 is within 0.1-3 μm, which reduces the loss of current in the process of being transmitted from the auxiliary grid unit 211 to the welding strip 301, and makes the height of the auxiliary grid lower, further reducing the amount of silver paste used during printing and saving costs.

[0059] See Figure 2 and Figure 3 In some embodiments, the width of the sub-grid 21 is 1-20 μm, and the spacing between two adjacent sub-grids 21 is 5-6 mm. Designing the width of the sub-grid 21 to be 1-20 μm can make the sub-grid 21 on the solar cell 100 more densely arranged, making it easier for all sub-grids 21 to collect current more densely. At the same time, the width of the sub-grid 21 is as small as possible, which is conducive to the transmission of current on the sub-grid 21, and can improve the efficiency of current transmission, thereby improving the photoelectric conversion efficiency of the solar cell. The spacing between adjacent sub-grids 21 within 5-6 mm ensures that the sub-grid 21 is more densely distributed on the solar cell 100, while the solar cell 100 can have more effective areas for receiving light, which can further improve the efficiency of converting light energy into electrical energy of the solar cell 100, and avoid the phenomenon of electron transmission interference between adjacent sub-grids 21 caused by the spacing between adjacent sub-grids 21 being too small.

[0060] Further, such as Figure 4 and Figure 5 As shown, the central axis of the auxiliary grid 21 and the central axis of the welding strip 301 are located in the same plane perpendicular to the silicon wafer 1, and the central axis of the main grid 22 and the central axis of the welding strip 301 are located in the same plane perpendicular to the silicon wafer 1. This ensures that the welding strip 301 is vertically connected to the surface of the auxiliary grid 21, allowing electrons to be vertically transmitted from the auxiliary grid 21 to the welding strip 301, optimizing the transmission mode of some electrons to vertical transmission. This layout shortens the transmission distance of current, allowing the current to be conducted to the welding strip 301 after traveling through fewer grid lines, significantly reducing the cost of slurry. At the same time, the welding strip 301 is vertically connected to the surface of the main grid 22, which facilitates the direct transmission of electrons collected by the main grid 22 to the welding strip 301.

[0061] It is understandable that the metalized mesh grid lines 2 are made of aluminum. The conductivity of aluminum and silver is very similar, but aluminum is cheaper than silver. Furthermore, aluminum has excellent conductivity and corrosion resistance. Using aluminum paste to print the metalized mesh grid lines 2 instead of silver paste can significantly reduce process costs.

[0062] It is worth noting that the metallized mesh grid lines 2 can be processed using micro-nano processing technologies such as photolithography and etching, or screen printing technology can be used to process the metallized mesh grid lines 2, which is not specifically limited in this embodiment. Photolithography technology can achieve pattern transfer at the micron or even submicron level, ensuring the precise size and position of the auxiliary grid 21. In addition, photolithography technology can achieve high resolution, meeting the requirements for the fineness of the auxiliary grid 21. Etching technology can make the auxiliary grid 21 have smooth edges and accurate dimensions. The smooth, defect-free surface processed using etching technology can improve the optical and electrical properties of the auxiliary grid 21. Moreover, by precisely controlling the etching process, the stability and reliability of the auxiliary grid 21 structure can be ensured, extending the service life of the solar cell 100. Screen printing technology is a low-cost and relatively simple technology. Choosing screen printing technology to process the metallized mesh grid lines 2 can achieve high-precision pattern printing and can be printed on substrates of different shapes, different areas, and different materials. At the same time, screen printing can adjust the thickness of the printed layer to adapt to different conductive properties.

[0063] Optionally, the metalized mesh grid lines 2 are formed on the silicon wafer 1 using techniques such as photolithography, evaporation, or printing. The specific steps include: coating a layer of photoresist on the silicon wafer 1 and forming a pattern of the secondary grid 21 through a photolithography process; then depositing a metal aluminum paste or a metal silver paste on the photoresist pattern using evaporation or printing techniques; and finally removing the photoresist to form the metalized mesh grid lines 2 composed of the metal aluminum paste or the metal silver paste. It is understood that the deposition of the metal aluminum paste or the metal silver paste can also be performed by depositing a metal layer on the silicon wafer 1 through techniques such as physical vapor deposition (PVD) and chemical vapor deposition (CVD) to form the metalized mesh grid lines 2.

[0064] In a second aspect, the present application discloses a solar cell module 300 comprising a plurality of soldering ribbons 301 and a plurality of solar cells 100 as described in the aforementioned embodiments, with adjacent solar cells 100 connected by the soldering ribbons 301. The solar cell module 300 employing the solar cells 100 can improve the efficiency of converting light energy into electrical energy, thereby enhancing cell performance while reducing process costs.

[0065] It is worth noting that there are many ways to connect the soldering ribbon 301 to the solar cell 100, such as welding dispensing, dispensing or coating, which are not specifically limited in this embodiment. The soldering dispensing process welds the soldering ribbon 301 to the surface of the solar cell 100, so that alloying is formed between the soldering ribbon 301 and the auxiliary grid 21, and then the soldering ribbon 301 is further fixed to the solar cell 100 with glue or tape. This double fixing method significantly enhances the bonding strength between the soldering ribbon 301 and the solar cell 100 and improves the hot spot resistance of the component. The dispensing process first applies glue (such as UV glue, hot melt glue and other adhesives) on the solar cell 100, and then solidifies the entire soldering ribbon 301 on the solar cell 100, and then realizes the alloying of the soldering ribbon 301 and the solar cell 100 through lamination. The dispensing process eliminates the welding step and simplifies the process flow. The laminating process directly presses the solar cells 100 and the soldering ribbons 301 together at one time to connect them in series, thereby forming a cell string. This ensures that the soldering ribbons 301 are highly adhered to the solar cells 100 and are not easily detached.

[0066] The soldering ribbon 301 is used to connect two adjacent solar cells 100. Its material must possess excellent electrical conductivity and welding properties. In this embodiment, the soldering ribbon 301 is made of highly conductive copper or a copper alloy to ensure efficient current transmission and reliable connection. Alternatively, the soldering ribbon 301 can be made of a copper-tin alloy. The substrate of the soldering ribbon 301 is a copper material with precise dimensions, good electrical conductivity, and a certain strength. The copper substrate is coated with a tin alloy or other coating material using a special coating process such as electroplating, vacuum deposition, spraying, or hot-dip coating. The coating material, such as a tin alloy, is uniformly applied to the copper substrate surface in a specific composition ratio and thickness. The copper substrate itself lacks good welding properties. The primary purpose of spraying the tin alloy layer on its surface is to ensure solderability of the soldering ribbon 301 and to securely solder the soldering ribbon 301 to the metallized mesh grid lines 2 of the solar cell 100, thereby providing effective current conduction.

[0067] Furthermore, the width of the soldering ribbon 301 in a direction perpendicular to the auxiliary grid 21 within the plane of the silicon wafer 1 is 50-70 μm. The width of the soldering ribbon 301 affects the ability to conduct current and also affects whether the light-receiving area of ​​the solar cell module 300 is shielded. Keeping the soldering ribbon 301 within the 50-70 μm width ensures that the soldering ribbon 301 has good current transmission capability while minimizing the area of ​​the solar cell module 300's effective light-receiving area shielded by the soldering ribbon 301, thereby improving the photovoltaic conversion efficiency of the solar cell module 300 to a certain extent.

[0068] In some embodiments, the light-receiving surface of the soldering ribbon 301 is a smooth curved surface or a convex surface that is at least partially bent. It should be noted that the light-receiving surface of the soldering ribbon 301 is a surface that has no contact with the solar cell 100, and sunlight is irradiated on the light-receiving surface. Such a design reduces the shielding and reflection of sunlight by the soldering ribbon 301, increases the chances of light scattering and multiple reflections on the surface of the solar cell 100, and thus improves the light absorption efficiency of the solar cell module 300. For example, Figure 4 and Figure 5 As shown, the shape formed by the light-receiving surface of the welding ribbon 301 and the solar cell 100 can be circular, semicircular or triangular. According to optical principles, the light-receiving surface of the circular or semicircular welding ribbon 301 can more effectively reflect light back to the solar cell when irradiated by light, reducing the scattering and loss of light. At the same time, this shape also helps to reduce the impact of the reflected light from the light-receiving surface of the welding ribbon 301 on the adjacent solar cells 100, thereby improving the photoelectric conversion efficiency of the overall solar cell module 300. Moreover, compared with rectangular or flat welding ribbons, the triangular or semicircular welding ribbon 301 produces less shadow obstruction when light is incident at an angle, which reduces the loss of light energy caused by the obstruction of the welding ribbon 301 and improves the optical utilization rate of the solar cell module 300.

[0069] The following is a brief description of the solar cell and the process flow of the solar cell of the present application:

[0070] First, a silicon wafer 1 is prepared. High-quality silicon material is selected as the silicon wafer 1. The silicon wafer 1 is then thoroughly cleaned to remove surface dirt and impurities. The surface of the silicon wafer is treated by chemical or physical methods to form a microstructure that is conducive to the attachment of the auxiliary gate 21 and current transmission.

[0071] Next, a material with good electrical conductivity, such as aluminum, is selected and a metal mesh grid line 2 is formed on the silicon wafer 1 by photolithography, printing, or laser etching. The width of the secondary grid 21, the spacing between adjacent secondary grids 21, and the length and width of the main grid 22 are controlled according to the aforementioned embodiment.

[0072] Furthermore, the welding ribbon 301 is connected to the auxiliary grid 21 of the metallized mesh grid line 2 to ensure smooth electron transmission from the auxiliary grid 21 to the welding ribbon 301. The connection method can be to connect a welding ribbon 301 between each two auxiliary grid units 211, or to connect all the auxiliary grid units 211 of a auxiliary grid 21 with a common welding ribbon 301. The quality and strength of the welding points are tested to ensure that the connection between the welding ribbon 301 and the auxiliary grid 21 is firm and reliable.

[0073] Finally, multiple solar cells 100 are connected by welding ribbons 301, and two adjacent solar cells 100 are connected by multiple welding ribbons 301 to form a complete solar cell module 300. The solar cell module 300 is encapsulated using tempered glass to protect the internal circuits and components from the influence of the external environment.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A solar cell, characterized in that: The plurality of solar cells are connected by welding ribbons, and the solar cells include: silicon wafers; Metallized mesh grid lines, the metallized mesh grid lines are arranged on the silicon wafer, the metallized mesh grid lines include a plurality of main grids and a plurality of auxiliary grids, all of the auxiliary grids are parallel to each other and arranged at intervals, and all of the main grids are parallel to each other and arranged at intervals, and intersect the auxiliary grids perpendicularly; A main grid includes several main grid units, and the several main grid units are arranged at intervals. Each main grid unit of two adjacent main grids is connected to a different auxiliary grid. At least one main grid is connected to the welding strip, and at least one auxiliary grid is connected to the welding strip.

2. The solar cell according to claim 1, characterized in that Two adjacent main grids among the plurality of main grids include a first main grid and a second main grid, the first main grid includes a plurality of first main grid units, the plurality of first main grid units are arranged at intervals, and each of the first main grid units is connected to a plurality of the auxiliary grids; The second main gate includes a plurality of second main gate units, which are arranged at intervals, and each second main gate unit is located between two adjacent first main gate units of the first main gate along a direction perpendicular to the auxiliary gate, and is connected to a plurality of the auxiliary gates.

3. The solar cell according to claim 2, characterized in that Each two adjacent main grid units belonging to the same main grid are connected by a welding strip, or All the main grid units belonging to the same main grid are connected to the same welding strip.

4. The solar cell according to claim 3, characterized in that The length of the main gate unit along the extending direction perpendicular to the auxiliary gate is 10-12 mm, and the width of the main gate unit is 1-20 μm.

5. The solar cell according to claim 1, wherein One of the auxiliary grids includes a plurality of auxiliary grid units, and the plurality of auxiliary grid units are arranged at intervals, and each two adjacent auxiliary grid units belonging to the same auxiliary grid are connected by one of the welding strips, or, All the auxiliary grid units belonging to the same auxiliary grid are connected to the same welding strip.

6. The solar cell according to claim 5, characterized in that The width of the auxiliary grid is 1-20 μm, and the distance between two adjacent auxiliary grids is 5-6 mm; and / or, The length of the auxiliary gate unit along the extension direction parallel to the auxiliary gate is 12-50 mm, and the height of the auxiliary gate unit along the direction perpendicular to the silicon wafer is 0.1-3 μm.

7. The solar cell according to claim 1, wherein The central axis of the welding strip and the central axis of the auxiliary grid are located in the same plane perpendicular to the silicon wafer, and the central axis of the welding strip and the central axis of the main grid are located in the same plane perpendicular to the silicon wafer.

8. The solar cell according to any one of claims 1 to 7, characterized in that: The material of the metal mesh grid line includes metal aluminum.

9. A solar cell module, characterized in that: The solar cell assembly comprises: a number of welding ribbons; and, According to any one of claims 1 to 8, two adjacent solar cells are connected via a welding ribbon.

10. The solar cell assembly according to claim 9, characterized in that: The width of the welding strip is 50-70 μm; and / or, The light-receiving surface of the soldering strip is a smooth curved surface or a convex surface that is at least partially bent.

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