Solar cell, cell assembly and photovoltaic system
By optimizing the electrode structure of solar cells and increasing the light reflection and refraction paths, the problem of low photoelectric conversion efficiency in existing solar cells has been solved, achieving higher photoelectric conversion efficiency and structural stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG AIKO SOLAR TECHNOLOGY CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-01
AI Technical Summary
Existing solar cells have low photoelectric conversion efficiency.
Design a solar cell electrode structure in which the width of the seed layer is smaller than that of the first metal layer, the portion of the first metal layer extending beyond the seed layer is suspended, and the second metal layer and the first metal mixture layer are also partially suspended. A bending structure is set in the edge region to increase the reflection and refraction path of light, and different surface treatment methods are combined to improve the light utilization rate.
By increasing the light reflection and refraction paths, the light incident area is increased, improving the photoelectric conversion efficiency. At the same time, the contact area between the metal layer and the silicon substrate is reduced, the risk of ion diffusion is decreased, and the stability of the battery structure is enhanced.
Smart Images
Figure CN224192361U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of solar energy technology, and in particular to a solar cell, a battery module and a photovoltaic system. Background Technology
[0002] A solar cell is a thin photovoltaic semiconductor wafer that generates electricity directly using sunlight. It is also known as a "solar chip" or "photovoltaic cell". As long as it is irradiated with light that meets certain illumination conditions, it can instantly output voltage and generate current when there is a circuit.
[0003] However, existing solar cells suffer from low photoelectric conversion efficiency. Utility Model Content
[0004] This invention provides a solar cell, a battery module, and a photovoltaic system to improve the photoelectric conversion efficiency of solar cells.
[0005] According to one aspect of the present invention, a solar cell is provided, comprising:
[0006] A silicon substrate and an electrode disposed on one side of the silicon substrate, the electrode comprising a seed layer, a first metal layer and a second metal layer sequentially stacked along a direction away from the silicon substrate;
[0007] Along the width direction of the electrode, the width of the first metal layer is greater than the width of the seed layer.
[0008] Optionally, along the width direction of the electrode, the width of the second metal layer is greater than the width of the first metal layer;
[0009] The electrode further includes a mixture layer of a first metal and a second metal disposed between the first metal layer and the second metal layer; along the width direction of the electrode, the width of the mixture layer of the first metal and the second metal is greater than the width of the first metal layer.
[0010] Optionally, the electrode includes a central region and an edge region disposed on at least one side of the central region; the central region includes the seed layer, the first metal layer, a mixture of the first metal and the second metal layer, and the second metal layer; the edge region includes the second metal layer;
[0011] The edge region bends away from the central region in a direction away from the silicon substrate.
[0012] Optionally, at least a portion of the edge region is bent first toward the silicon substrate and then away from the silicon substrate in a direction away from the central region, so that there is a cavity between the edge region, the central region, and the silicon substrate.
[0013] Optionally, the cavity has a cross-sectional shape that is Z-shaped along the extension direction perpendicular to the electrode.
[0014] Optionally, the width of the edge region along the width direction of the electrode is 0.1-10 micrometers.
[0015] Optionally, the surface of the silicon substrate adjacent to the electrode includes a first region and a second region, and the electrode includes a first electrode and a second electrode, wherein the first electrode is disposed in the first region and the second electrode is disposed in the second region;
[0016] The first region is a velvety surface region, and the second region is a polished surface region, or the first region is a polished surface region and the second region is a velvety surface region.
[0017] Optionally, the electrode has at least one of the following features:
[0018] The second metal layer of the electrode disposed in the polished surface area has particulate matter and / or pores.
[0019] The density of the second metal layer of the electrode disposed in the textured area is greater than the density of the second metal layer of the electrode disposed in the polished area;
[0020] A gap exists between at least a portion of the surface of the electrode located in the polished surface region adjacent to the silicon substrate and the film layer adjacent to the electrode;
[0021] The surface of the electrode disposed on the textured area away from the silicon substrate is wavy, and the surface of the electrode disposed on the polished area away from the silicon substrate has multiple dendritic protrusions.
[0022] Optionally, the solar cell also includes:
[0023] First doped layer, second doped layer, antireflection layer and passivation layer;
[0024] The first doped layer is disposed between the first region and the first electrode, and the second doped layer is disposed between the second region and the second electrode; the passivation layer is disposed on the side of the first doped layer and the second doped layer away from the silicon substrate, and the antireflection layer is disposed on the side of the passivation layer away from the silicon substrate;
[0025] The first electrode passes through the passivation layer and the antireflection layer to contact the first doped layer, and the second electrode passes through the passivation layer and the antireflection layer to contact the second doped layer.
[0026] Optionally, the thickness of the first metal layer is 2-15 micrometers, and the thickness of the second metal layer is 0.2-2 micrometers;
[0027] The first metal layer comprises at least one of copper, aluminum, and silver, and the second metal layer comprises at least one of tin and nickel.
[0028] According to another aspect of the present invention, a battery assembly is provided, characterized in that it includes at least one solar cell as described in any embodiment of the present invention.
[0029] According to another aspect of the present invention, a photovoltaic system is provided, characterized in that it includes the battery module described in any embodiment of the present invention.
[0030] The electrode of the solar cell in this embodiment includes a seed layer, a first metal layer, and a second metal layer stacked sequentially. By setting the width of the first metal layer to be greater than the width of the seed layer along the width direction of the electrode, the portion of the first metal layer extending beyond the seed layer is suspended, which increases the light reflection path, reduces the area of light blocked by the metal layer, increases the light incident area, increases the amount of light entering the solar cell, and improves the photoelectric conversion efficiency of the solar cell. Furthermore, the contact area between the first metal layer and the silicon substrate is smaller, reducing the ion diffusion path between the first metal layer and the silicon substrate, thereby further ensuring that the cell has a high efficiency. In addition, the seed layer, as an adhesion layer, has a width smaller than the width of the first metal layer, which can disperse stress concentration points, reduce the risk of electrode detachment due to differences in thermal expansion coefficients, and improve the structural stability of the solar cell.
[0031] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 This is a schematic diagram of a solar cell provided in this utility model.
[0034] Figure 2 This is a magnified view of a portion of a solar cell.
[0035] Figure 3 This is a magnified view of another type of solar cell.
[0036] Figure 4This is a magnified view of another type of solar cell.
[0037] Figure 5 This is a cross-sectional scanning electron microscope image of the electrode located in the polished surface area.
[0038] Figure 6 This is a top-view scanning electron microscope image of the surface of the electrode located in the textured region, away from the silicon substrate.
[0039] Figure 7 This is a top-view scanning electron microscope image of the surface of the electrode located in the polished area, away from the silicon substrate.
[0040] Figure 8 This is another scanning electron microscope image of an electrode located in the textured area.
[0041] Figure 9 This is another scanning electron microscope image of an electrode located in the textured area.
[0042] Figure 10 This is another scanning electron microscope image of an electrode located in the polished surface area. Detailed Implementation
[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0045] This utility model embodiment provides a solar cell. Figure 1 This is a schematic diagram of a solar cell provided in this utility model. Figure 2 This is a magnified view of a partial section of a solar cell. (Reference) Figure 1 and Figure 2 The solar cells include:
[0046] The silicon substrate 10 and the electrode 20 disposed on one side of the silicon substrate 10, the electrode 20 including a seed layer 21, a first metal layer 22 and a second metal layer 23 sequentially stacked in a direction away from the silicon substrate 10;
[0047] Along the width direction X of electrode 20, the width of the first metal layer 22 is greater than the width of the seed layer 21.
[0048] The silicon substrate 10 can be a monocrystalline silicon wafer or a polycrystalline silicon wafer, and can be a P-type or N-type silicon wafer; no specific limitation is made here. The electrode 20 is used to conduct the current generated by the solar cell. The seed layer 21 is used to improve the adhesion between the first metal layer 22 and the film layer below the seed layer 21; the first metal layer 21 can be made of metal elements such as Cu or Al. The second metal layer 23 can include metal elements such as Sn or Ni.
[0049] Specifically, the seed layer 21 serves as a transition layer between the first metal layer 22 and the silicon substrate 10. The width of the first metal layer 22 is greater than the width of the seed layer 21, which limits the contact area between the first metal layer 22 and the silicon substrate 10, reducing the ion diffusion path between them and thus ensuring cell efficiency. Furthermore, the portion of the first metal layer 22 extending beyond the seed layer 21 is suspended, increasing the light reflection path, reducing the area of light blocked by the metal layer, increasing the light incident area, and improving photoelectric conversion efficiency. In addition, the seed layer 21, as an adhesion layer, has a width smaller than the first metal layer 22, which disperses stress concentration points, reducing the risk of electrode 20 detachment due to differences in thermal expansion coefficients and improving the structural stability of the solar cell.
[0050] The electrode 20 of the solar cell in this embodiment includes a seed layer 21, a first metal layer 22, and a second metal layer 23 stacked sequentially. By setting the width of the first metal layer 22 to be greater than the width of the seed layer 21 along the width direction X of the electrode 20, the portion of the first metal layer 22 extending beyond the seed layer 21 is suspended, which increases the light reflection path, reduces the area of light blocked by the metal layer, increases the light incident area, increases the amount of light entering the solar cell, and improves the photoelectric conversion efficiency of the solar cell. Furthermore, the contact area between the first metal layer 22 and the silicon substrate 10 is smaller, reducing the ion diffusion path between the first metal layer 22 and the silicon substrate 10, thereby further ensuring that the cell has a high efficiency. In addition, the seed layer 21, as an adhesive layer, has a width smaller than the width of the first metal layer 22, which can disperse stress concentration points, reduce the risk of electrode 20 detachment due to differences in thermal expansion coefficients, and improve the structural stability of the solar cell.
[0051] It should be noted that the solar cell provided in this embodiment of the invention can be a bifacial solar cell or a single-sided solar cell, and can be exemplarily a back-contact solar cell. When the solar cell is a bifacial solar cell, it can be exemplarily a PERC (Passivated Emitter Rear Cell) solar cell, a TOPCon (Tunnel Oxide Passivated Contact) solar cell, or an HJT (Heterojunction with Intrinsic Thin-layer) solar cell. When the solar cell is a back-contact solar cell, it can be exemplarily an HTBC (Heterojunction Tunnel Oxide Passivated Contact Back Contact) solar cell, an HBC (Heterojunction Back Contact) solar cell, a TBC (Tunnel Oxide Passivated Contact Back Contact) solar cell, or an HPBC (Hybrid Passivated Back Contact) solar cell.
[0052] Figure 3 This is a magnified view of another type of solar cell, for reference. Figure 3 Based on the above embodiments, optionally, along the width direction X of the electrode 20, the width of the second metal layer 23 is greater than the width of the first metal layer 22.
[0053] Specifically, by setting the width of the second metal layer 23 to be greater than the width of the first metal layer 22, and suspending the portion of the second metal layer 23 that extends beyond the first metal layer 22, when sunlight enters from the side where the electrode 20 is located, the suspended second metal layer 22 can reflect or refract the light, allowing more light to enter the silicon substrate 10, thereby increasing light trapping and further improving the photoelectric conversion efficiency of the solar cell. When light from within the silicon substrate 10 is emitted outward, the refraction or reflection by the suspended second metal layer 22 allows the light to re-enter the silicon substrate 10, improving light utilization and photoelectric conversion efficiency.
[0054] Figure 4 This is a magnified view of another type of solar cell, for reference. Figure 4 The electrode 20 also includes a mixture layer 24 of a first metal and a second metal disposed between the first metal layer 22 and the second metal layer 23; along the width direction X of the electrode 20, the width of the mixture layer 24 of the first metal and the second metal is greater than the width of the first metal layer 21.
[0055] By setting the width of the first metal and second metal mixture layer 24 along the width direction X of the electrode 20 to be greater than the width of the first metal layer 22, a portion of the first metal and second metal mixture layer 24 is suspended. When sunlight is incident from the side where the electrode 20 is located, the suspended first metal and second metal mixture layer 24 can reflect or refract the light, allowing more light to enter the silicon substrate 10, thereby increasing light trapping and further improving the luminous efficiency of the solar cell. When light is emitted outward from the silicon substrate 10, the light is refracted or reflected by the suspended first metal and second metal mixture layer 24, allowing the light to re-enter the silicon substrate 10, improving light utilization and photoelectric conversion efficiency.
[0056] Based on the above embodiments, optionally, the electrode 20 includes a central region 201 and an edge region 202 disposed on at least one side of the central region 201; the central region 201 includes a seed layer 21, a first metal layer 22, a first metal and second metal mixture layer 24, and a second metal layer 23; the edge region 202 includes the second metal layer 23.
[0057] The edge region 202 bends away from the central region 201 in a direction away from the silicon substrate 10.
[0058] Specifically, the edge region 202 can be disposed on one side, both sides, or multiple sides of the central region 201. For example, the edge region 202 can be disposed on both sides of the central region 201 along the width direction X of the electrode 20. The edge region 202 may or may not include a first metal and a second metal mixture layer 24. By setting the edge region 202 to bend away from the central region 201 in a direction away from the silicon substrate 10, more light can enter the gap between the edge region 202 and the silicon substrate 10, allowing the edge region 202 to reflect or refract more light, thus allowing more light to enter the silicon substrate 10 and further improving the luminous efficiency of the solar cell.
[0059] Based on the above embodiments, optionally, at least a portion of the edge region 202 is bent first toward the direction adjacent to the silicon substrate 10 and then bent away from the silicon substrate 10 in a direction away from the central region 201, so that there is a cavity 30 between the edge region 202, the central region 201 and the silicon substrate 10.
[0060] This configuration allows more light rays at large angles to enter the cavity 30 and undergo refraction or reflection within it, enabling more light to enter the silicon substrate 10 and further improving the luminous efficiency of the solar cell.
[0061] Based on the above embodiments, optionally, the cross-sectional shape of the cavity 30 along the extension direction perpendicular to the electrode 20 is Z-shaped.
[0062] in, Figure 4 The cross-section shown is of the cavity 30 along the extension direction perpendicular to the electrode 20. The shape of the cross-section of the cavity 30 along the extension direction perpendicular to the electrode 20 is Z-shaped or Z-like. The Z-shaped cavity 30 allows more light to enter and can reflect or refract the light multiple times, allowing more light to enter the silicon substrate 10, further improving the luminous efficiency of the solar cell.
[0063] Based on the above embodiments, optionally, the width of the edge region 202 along the width direction X of the electrode 20 is 0.1-10 micrometers.
[0064] Specifically, if the width of the edge region 202 is too small, the edge region 10 can reflect or refract less light. If the width of the edge region 202 is too large, the width of the central region 201 will be reduced due to the limited width of the electrode 20, thus decreasing the adhesion stability between the electrode 20 and the film layer below it. During the application of the solar cell, the electrode 20 may peel off due to external forces or other reasons. By setting the width of the edge region 202 to 0.1-10 micrometers, more light enters between the edge region 10 and the silicon substrate 10, significantly increasing the amount of light entering the silicon substrate 10. At the same time, it ensures that the central region 201 has a large width, improving the adhesion strength between the electrode 20 and the film layer below, preventing the electrode 20 from peeling off, and ensuring the structural stability of the solar cell.
[0065] Based on the above embodiments, optionally, refer to the following: Figure 1 The surface of the silicon substrate 10 adjacent to the electrode 20 includes a first region 11 and a second region 12. The electrode 20 includes a first electrode 210 and a second electrode 220. The first electrode 210 is disposed in the first region 11 and the second electrode 220 is disposed in the second region 12.
[0066] The first area 11 is a velvet area, and the second area 12 is a polished area, or the first area 11 is a polished area and the second area 12 is a velvet area.
[0067] Specifically, the solar cell can be a back-contact solar cell, with the first electrode 210 and the second electrode 220 disposed on the same surface. When the solar cell is a back-contact solar cell, it can be a bifacial cell. The first region 11 can be texturized to make it a textured surface, and the second region 12 can be polished to make it a polished surface. Alternatively, the second region 12 can be texturized to make it a textured surface, and the first region 11 can be polished to make it a polished surface.
[0068] Figure 5 This is a cross-sectional scanning electron microscope image of the electrode located in the polished surface area. Figure 6This is a top-view scanning electron microscope image of the surface of the electrode located in the textured region, away from the silicon substrate. Figure 7 This is a top-view scanning electron microscope image of the surface of the electrode located in the polished area, away from the silicon substrate. Figure 8 This is another scanning electron microscope image of the electrode located in the textured area. Figure 9 This is another scanning electron microscope image of the electrode located in the textured area. Figure 10 This is another scanning electron microscope (SEM) image of an electrode located in the polished surface area. Based on the above embodiments, refer to... Figures 5-10 Optionally, electrode 20 has at least one of the following features:
[0069] refer to Figure 5 The second metal layer 23 of the electrode 20 disposed in the polished surface area has particulate matter 231 and / or pores 232;
[0070] refer to Figure 6 and Figure 7 The density of the second metal layer 23 of the electrode 20 disposed in the textured area is greater than that of the second metal layer 23 of the electrode 20 disposed in the polished area.
[0071] refer to Figure 5 A gap exists between at least a portion of the surface of the silicon substrate 10 adjacent to the electrode 20 located in the polished surface area and the film layer adjacent to the electrode 20.
[0072] refer to Figures 8-10 The surface of the electrode 20 disposed on the textured area away from the silicon substrate 10 is wavy, and the surface of the electrode 20 disposed on the polished area away from the silicon substrate 10 has multiple dendritic protrusions.
[0073] For details, please refer to Figure 5 The second metal layer 23 of the electrode 20 located in the polished surface area has particles 231 and / or pores 232. The particles 231 and pores 232 can reflect, refract, scatter, etc., so that more light stays in the solar cell and improves the photoelectric conversion efficiency of the cell.
[0074] refer to Figure 6 and Figure 7 , Figure 6 and Figure 7 The image is a scanning electron microscope image of the electrode 20 located in the textured area and the polished area, magnified by the same magnification. It can be seen that the second metal layer 23 in the textured area is denser, while the second metal layer 23 in the polished area is sparser. This arrangement allows the second metal layer 23 in the textured area to be better optically matched with the textured silicon substrate 10, and the second metal layer 23 in the polished area to be better optically matched with the polished silicon substrate 10, so that more light remains in the solar cell and the photoelectric conversion efficiency of the cell is improved.
[0075] refer to Figure 5 The electrode 20 disposed in the polished surface area has a gap between at least a portion of the surface of the silicon substrate 10 adjacent to the electrode 20 and the film layer adjacent to the electrode 20. Light can be reflected or refracted multiple times through the gap, allowing light to enter the silicon substrate 10, so that more light remains in the solar cell and the photoelectric conversion efficiency of the cell is improved.
[0076] Figure 9 yes Figure 8 Enlarged view of the central area, for reference. Figures 8-10 The surface of the electrode 20 in the textured area away from the silicon substrate 10 is wavy, and the surface of the electrode 20 in the polished area away from the silicon substrate 10 has multiple dendritic protrusions, which can increase the area of the electrode 20, reduce the resistance of the electrode, and improve the current transmission efficiency.
[0077] Based on the above embodiments, refer to Figure 1 Optionally, the solar cell may also include:
[0078] The first doped layer 50, the second doped layer 60, the anti-reflection layer 80, and the passivation layer 70;
[0079] The first doped layer 50 is disposed between the first region 11 and the first electrode 210, the second doped layer 60 is disposed between the second region 12 and the second electrode 220; the passivation layer 70 is disposed on the side of the first doped layer 50 and the second doped layer 60 away from the silicon substrate 10, and the antireflection layer 80 is disposed on the side of the passivation layer 70 away from the silicon substrate 10.
[0080] The first electrode 210 passes through the passivation layer 70 and the antireflection layer 80 and contacts the first doped layer 50, and the second electrode 220 passes through the passivation layer 70 and the antireflection layer 80 and contacts the second doped layer 60.
[0081] In this configuration, one of the first doped layer 50 and the second doped layer 60 is a P-type doped layer, and the other is an N-type doped layer. Both the first doped layer 50 and the second doped layer 60 can be polycrystalline silicon doped layers. For example, the silicon substrate 10 is an N-type single-crystal substrate, the first doped layer 50 is a P-type polycrystalline silicon doped layer, and the second doped layer 60 is an N-type polycrystalline silicon doped layer.
[0082] The passivation layer 70 covers the entire exposed first surface of the silicon substrate 10 and the first doped layer 50 and the second doped layer 60 disposed on the first surface. The passivation layer 70 can be a film layer with passivation function, such as an aluminum oxide layer. For example, the passivation layer 70 includes a stacked aluminum oxide layer and a silicon nitride layer. Of course, it can also include one or more combinations of silicon oxynitride layer, intrinsic silicon carbide layer, intrinsic amorphous silicon layer and silicon oxide layer, and the specifics are not limited here. The antireflection layer 80 is used to reduce sunlight reflection, so that more sunlight is absorbed inside the solar cell. The antireflection layer 80 can be a film layer such as a silicon nitride layer.
[0083] It should be noted that this embodiment only exemplifies the various film layers of the solar cell and their shapes and positional relationships, and is not intended to limit the present invention. The solar cell may also include other film layers, such as a second passivation layer 90, a second antireflection layer 100, and a tunneling oxide layer. The second passivation layer 90 and the second antireflection layer 100 cover the second surface of the silicon substrate 10. The second passivation layer 90 may be a passivating film layer such as an aluminum oxide layer. For example, the second passivation layer 90 includes stacked aluminum oxide and silicon nitride layers. It may also include one or more combinations of silicon oxynitride, intrinsic silicon carbide, intrinsic amorphous silicon, and silicon oxide layers; specific details are not limited here. The second antireflection layer 100 is used to reduce sunlight reflection, allowing more sunlight to be absorbed inside the solar cell. The second antireflection layer 100 may be a silicon nitride layer or similar film layer.
[0084] Based on the above embodiments, optionally, refer to Figure 2 The thickness of the first metal layer 22 is 2-15 micrometers, and the thickness of the second metal layer 23 is 0.2-2 micrometers;
[0085] The first metal layer 22 includes at least one of copper, aluminum and silver, and the second metal layer 22 includes at least one of tin and nickel.
[0086] For example, the thickness of the first metal layer 22 can be 3 micrometers, 5 micrometers, 7 micrometers, 9 micrometers, or 13 micrometers, etc. The thickness of the second metal layer 23 can be 0.4 micrometers, 0.6 micrometers, 0.8 micrometers, 1 micrometer, 1.2 micrometers, 1.4 micrometers, 1.6 micrometers, or 1.8 micrometers, etc.
[0087] This utility model also provides a battery assembly, including at least one solar cell as described in any embodiment of this utility model.
[0088] Solar cells in a battery module can be connected in series and / or in parallel. In some embodiments, multiple solar cells in a battery module can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between individual solar cells can be achieved by welding ribbons, or the connection between battery strings can be achieved by busbars.
[0089] This utility model embodiment also provides a photovoltaic system, including the battery module described in any embodiment of this utility model.
[0090] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, the application scenarios of photovoltaic systems are not limited to these; they can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter, converts it into AC power required by the mains grid, and then connects to the mains grid to achieve solar power supply.
[0091] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.
[0092] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A solar cell, characterized by, Comprising: A silicon substrate and an electrode disposed on one side of the silicon substrate, the electrode including a seed layer, a first metal layer, and a second metal layer sequentially stacked in a direction away from the silicon substrate; In the width direction of the electrode, the width of the first metal layer is greater than the width of the seed layer.
2. The solar cell according to claim 1, wherein: In the width direction of the electrode, the width of the second metal layer is greater than the width of the first metal layer; The electrode further includes a mixture layer of a first metal and a second metal disposed between the first metal layer and the second metal layer; in the width direction of the electrode, the width of the mixture layer of the first metal and the second metal is greater than the width of the first metal layer.
3. The solar cell according to claim 2, wherein: The electrode includes a central region and an edge region disposed on at least one side of the central region; the central region includes the seed layer, the first metal layer, the mixture layer of the first metal and the second metal, and the second metal layer; the edge region includes the second metal layer; The edge of the edge region away from the central region is bent in a direction away from the silicon substrate.
4. The solar cell according to claim 3, wherein: In a direction away from the central region, at least part of the edge region is first bent in a direction adjacent to the silicon substrate and then bent in a direction away from the silicon substrate, so that there is a cavity between the edge region, the central region, and the silicon substrate.
5. The solar cell according to claim 4, wherein: The shape of the cross-section of the cavity perpendicular to the extension direction of the electrode is a U-shape.
6. The solar cell according to claim 3, wherein: In the width direction of the electrode, the width of the edge region is 0.1 - 10 microns.
7. The solar cell according to claim 1, wherein: The surface of the silicon substrate adjacent to the electrode includes a first region and a second region, the electrode includes a first electrode and a second electrode, the first electrode is disposed in the first region, and the second electrode is disposed in the second region; The first region is a textured region, the second region is a polished region, or the first region is a polished region, and the second region is a textured region.
8. The solar cell according to claim 7, wherein: The electrode has at least one of the following characteristics: Particles and / or pores are present in the second metal layer of the electrode disposed in the polished region; The density of the second metal layer of the electrode disposed in the textured region is greater than the density of the second metal layer of the electrode disposed in the polished region; There is a gap between at least part of the surface of the electrode disposed in the polished region adjacent to the silicon substrate and the film layer adjacent to the electrode; The surface of the electrode disposed on the textured region away from the silicon substrate is wavy, and the surface of the electrode disposed on the polished region away from the silicon substrate has multiple dendritic protrusions.
9. The solar cell according to claim 7, characterized in that, It further includes: A first doping layer, a second doping layer, an antireflection layer, and a passivation layer; The first doped layer is disposed between the first region and the first electrode, and the second doped layer is disposed between the second region and the second electrode; the passivation layer is disposed on the side of the first doped layer and the second doped layer away from the silicon substrate, and the antireflection layer is disposed on the side of the passivation layer away from the silicon substrate; The first electrode passes through the passivation layer and the antireflection layer to contact the first doped layer, and the second electrode passes through the passivation layer and the antireflection layer to contact the second doped layer.
10. The solar cell according to claim 1, characterized in that: The thickness of the first metal layer is 2-15 micrometers, and the thickness of the second metal layer is 0.2-2 micrometers; The first metal layer comprises at least one of copper, aluminum, and silver, and the second metal layer comprises at least one of tin and nickel.
11. A battery assembly, characterized in that, It includes at least one solar cell as described in any one of claims 1-10.
12. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 11.