A heterojunction solar cell, a preparation method thereof and the heterojunction solar cell

Abstract

A preparation method of a heterojunction solar cell and the heterojunction solar cell, comprising: cleaning a cell piece, opening a sink on the upper and lower surfaces of the cleaned cell piece, printing a metal grid on the upper and lower surfaces of the cell piece after the sink is opened, and performing solidification after printing, filling insulating glue in the sink, and then connecting a solder strip on the insulating glue and the metal grid on the upper or lower surface, and the solder strips of adjacent two cell pieces are connected to form the heterojunction solar cell. The L-shaped solder strip is adopted, and the design makes the connection of the solder strips of adjacent cell pieces more close and flat, avoids the abrupt feeling caused by the bending of the solder strip in the traditional method, and improves the overall appearance of the cell assembly. The design of the L-shaped solder strip makes the solder strip better disperse the stress when the solder strip is stressed, and reduces the occurrence of deformation. At the same time, the slope design of the solder strip makes the connection between the adjacent cell pieces more stable, and reduces the risk of solder strip fracture.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, and specifically relates to a heterojunction solar cell and its preparation method. Background Technology

[0002] Currently, competition in the global photovoltaic industry is becoming increasingly fierce, with major companies dedicating themselves to the innovation and optimization of photovoltaic products in order to stand out in the intense market competition. Against this backdrop, photovoltaic products are beginning to pursue more extreme cost reduction and efficiency improvement strategies, striving to minimize production costs while maintaining high performance. In the exploration of reducing battery costs, the rapidly developing busbar-less technology in recent years is considered a revolutionary breakthrough and is highly anticipated by the industry, hoping to lead the industry into a new stage of development through technological innovation.

[0003] However, existing photovoltaic cell manufacturing methods still face numerous challenges in practical applications. Particularly in manufacturing, transportation, and installation, traditional connection methods rely on solder ribbons forming significant bends between adjacent cells. This design not only compromises the overall aesthetics of the module but, more importantly, the excessively long solder ribbons at these bends are prone to deformation under stress. Over time, this deformation accumulates, exacerbating fatigue damage to the solder ribbons and, in extreme cases, potentially leading to ribbon breakage. This can irreversibly impact the overall performance and expected lifespan of the module. Furthermore, uneven stress on the cells during this process can also cause microcracks, further contributing to a gradual decrease in power output.

[0004] On the other hand, the connection between the solder strip and the grid is equally important. Due to the relatively limited contact area, typically limited to point or line contact, this type of contact is highly susceptible to defects such as misalignment and incomplete soldering during the welding process. These problems not only weaken the stability of the mechanical connection and reduce the reliability of the electrical contact, but may also become hidden dangers for cell performance degradation, affecting the long-term stable operation and power generation efficiency of the battery module. Therefore, exploring more advanced and reliable connection methods, as well as optimizing the contact design between the cell and the solder strip, has become one of the key technical issues that the photovoltaic industry urgently needs to address. Summary of the Invention

[0005] The purpose of this invention is to provide a heterojunction solar cell and its preparation method, and to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for fabricating a heterojunction solar cell, comprising: Clean the battery cells and create sinks on the upper and lower surfaces of the cleaned battery cells. Metal grids are printed on the upper and lower surfaces of the solar cells after the sink is opened, and then cured. The settling tank is filled with insulating adhesive, and then the welding strip is attached to the insulating adhesive and metal grid on the upper or lower surface. The solder strips of two adjacent cells are connected to form a heterojunction solar cell.

[0007] Furthermore, cleaning the battery cells includes: Use pure water or deionized water to initially rinse the surface of the battery cells. Then, select a cleaning agent according to the material of the battery cells and the type of contaminants. Under the action of the cleaning agent, remove the contaminants from the surface of the battery cells. During the use of the cleaning agent, use stirring or ultrasonic waves to accelerate the cleaning process. Finally, rinse the surface of the battery cells thoroughly with pure or deionized water to remove any residual cleaning agent and contaminants.

[0008] Furthermore, grooves are created on the upper and lower surfaces of the cleaned battery cells, including: The upper and lower surfaces of the solar cell are created using a light-cured resin drilling and casting method: Specifically, a layer of light-cured resin is coated on the entire upper and lower surfaces of the battery cell, and then ultraviolet light is irradiated to form a hard protective layer. Then, a honeycomb-shaped groove is made on the resin surface using a drilling tool, and protrusions of different sizes are carved on the bottom and sides of the groove. Furthermore, metal grids are printed on the upper and lower surfaces of the solar cell after the sink grooves have been created, and then cured after printing, including: Metal grids are printed onto the surface of the solar cell using a stencil, and then cured at high temperature to fix the metal grids onto the solar cell.

[0009] Furthermore, the metal grid is either a mesh or strips distributed at equal intervals.

[0010] Furthermore, the settling tank is filled with insulating adhesive, including: The insulating adhesive is filled into the settling tank, and then the resin layer is cured by ultraviolet light again to fix the filler.

[0011] Furthermore, the welding strip is an L-shaped welding strip, with the thickness of the short side of the L-shape being greater than the thickness of the long side. The short side of the L-shape is provided with a bevel, and the bevels of two adjacent battery cells are matched and bonded together.

[0012] Furthermore, the insulating adhesive is one of photovoltaic insulating adhesive, silicone, epoxy resin adhesive, polyurethane adhesive, or EVA film.

[0013] Furthermore, the solder strips of two adjacent solar cells are interconnected to form a heterojunction solar cell, including: When two adjacent solar cells are connected, their respective solder strips are not on the same surface, and the beveled surfaces of the two solder strips are fixedly connected by conductive adhesive.

[0014] A heterojunction solar cell is prepared by the aforementioned method for preparing a heterojunction solar cell.

[0015] Compared with the prior art, the present invention has the following technical effects: This invention employs L-shaped solder strips, and its design makes the solder strip connection between adjacent cells tighter and flatter, avoiding the abruptness caused by the bends in the solder strips in traditional methods, thereby improving the overall aesthetics of the battery assembly.

[0016] Enhanced structural stability: The L-shaped solder strip design allows for better pressure distribution under stress, reducing deformation. Simultaneously, the beveled design of the solder strip ensures a more stable connection between adjacent cells, lowering the risk of solder strip breakage.

[0017] In this technical solution, the connection between the solder strip and the metal grid is no longer limited to point contact or line contact. Instead, the L-shaped solder strip's inclined surface design increases the contact area between the solder strip and the metal grid, thereby improving the strength of the connection and the reliability of the electrical contact.

[0018] Reduce welding defects: Due to the increased contact area between the solder strip and the metal grid, the probability of defects such as weld misalignment and incomplete welding during the welding process is greatly reduced, which improves the welding quality and the performance stability of the solar cells.

[0019] By creating grooves on the upper and lower surfaces of the solar cell and filling the grooves with insulating glue, this design not only increases the mechanical strength of the solar cell but also improves its insulation performance, preventing short circuits.

[0020] Selection of insulating adhesive: The insulating adhesives mentioned in this technical solution include photovoltaic insulating adhesive, silicone, epoxy resin adhesive, polyurethane adhesive or EVA film, etc. These materials have good insulation properties and adhesion, and can effectively protect the solar cells and fix the welding ribbon.

[0021] Because this technical solution optimizes the connection between the battery cells and the solder ribbon, it reduces the unevenness of the battery cells under stress, thereby reducing the risk of microcracks and power degradation.

[0022] By improving the reliability of the connection between the solar cells and the solder ribbon and optimizing the structural design of the solar cells, this technical solution helps to improve the power generation efficiency of the solar modules, enabling the photovoltaic system to convert solar energy into electrical energy more efficiently.

[0023] In summary, this technical solution, through innovative design and optimization, addresses several challenges in existing photovoltaic cell manufacturing methods, improving the aesthetics, structural stability, connection reliability, insulation performance, long-term stable operation, and power generation efficiency of the battery modules. These technological benefits not only contribute to improving the quality and performance of photovoltaic products but also help reduce production costs and enhance market competitiveness, thus playing a significant role in promoting the sustainable development of the photovoltaic industry. Attached Figure Description

[0024] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0029] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0030] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0031] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0032] Example 1, please refer to Figure 1 This invention provides a method for fabricating a heterojunction solar cell, comprising: Clean the battery cells and create sinks on the upper and lower surfaces of the cleaned battery cells. Metal grids are printed on the upper and lower surfaces of the solar cells after the sink is opened, and then cured. The settling tank is filled with insulating adhesive, and then the welding strip is attached to the insulating adhesive and metal grid on the upper or lower surface. The solder strips of two adjacent cells are connected to form a heterojunction solar cell.

[0033] This invention increases the mechanical strength of the battery cell by creating grooves on the upper and lower surfaces and filling them with insulating glue, making it more resistant to external impacts and pressures.

[0034] The design of the settling tank also helps to disperse the pressure on the solar cells when they are under stress, reducing the risk of deformation and breakage.

[0035] After filling the settling tank with insulating adhesive, the solder ribbon is connected to the insulating adhesive and the metal grid. This connection method increases the contact area between the solder ribbon and the battery cell, improving the strength of the connection and the reliability of the electrical contact.

[0036] The L-shaped solder strip design allows the solder strips of adjacent cells to fit together more tightly, reducing stress concentration and fatigue damage caused by solder strip bends.

[0037] The L-shaped solder strip design makes the connection between adjacent cells smoother, improving the overall aesthetics of the battery module.

[0038] By optimizing the connection method between the solar cells and the solder strip and the design of the sink, the structural stability and power generation efficiency of the solar module have been improved.

[0039] The insulating adhesive filling the sump effectively isolates the circuits on the upper and lower surfaces of the solar cells, preventing short circuits and improving the safety of the solar cells.

[0040] The choice of insulating adhesive also takes into account its good adhesion and weather resistance, ensuring the stability and reliability of the battery cells during long-term use.

[0041] The preparation method provided by this invention is relatively simple, requiring no complex equipment or process steps, which helps to reduce production costs and improve production efficiency.

[0042] By optimizing the structural design and connection method of the solar cells, the use and waste of materials were reduced, further lowering costs.

[0043] In summary, the heterojunction solar cell fabrication method provided by this invention, through innovative process steps and design, improves the mechanical strength, stability, connection reliability, insulation performance, and safety of the solar cells, while simplifying the fabrication process and reducing costs. These technical effects provide the photovoltaic industry with a more efficient, reliable, and economical solar cell fabrication solution, contributing to the continued development and application of photovoltaic technology.

[0044] Example 2: This invention provides a method for fabricating a heterojunction solar cell, specifically including: Clean the battery cells: First, the surface of the battery cells is rinsed with deionized water to remove dust and impurities.

[0045] Next, a suitable cleaning agent is selected based on the material of the solar cell (e.g., monocrystalline silicon, polycrystalline silicon) and the type of contaminants (e.g., organic contaminants, metal ions). In this embodiment, a cleaning agent containing a slightly alkaline component is selected, and the cleaning is performed using an ultrasonic cleaner to accelerate the cleaning process and thoroughly remove contaminants.

[0046] After cleaning, rinse the surface of the battery cells thoroughly with deionized water again to ensure that no cleaning agent residue remains.

[0047] Constructing a settling tank: The cleaned battery cells are placed in a photocurable resin coating device, and a layer of photocurable resin is evenly coated on the entire upper and lower surfaces.

[0048] The solar cells coated with UV-curable resin are irradiated with ultraviolet light to form a hard protective layer.

[0049] Using precision drilling tools, honeycomb-shaped grooves are created in the hard protective layer. The bottom and sides of the grooves are engraved with protrusions of varying sizes to increase the adhesion between the grooves and the insulating adhesive.

[0050] Printed metal grid: Using screen printing technology, mesh-like metal grids (such as silver grids, aluminum grids, etc.) are precisely printed on the upper and lower surfaces of the solar cells after the sink grooves have been opened.

[0051] The solar cells with printed metal grids are placed in a high-temperature curing oven for high-temperature curing treatment, which firmly fixes the metal grids onto the solar cells.

[0052] Fill with insulating adhesive: Photovoltaic insulating adhesive was selected as the insulating material and was evenly filled into the grooves on the upper and lower surfaces of the solar cells.

[0053] The battery cells filled with insulating adhesive are irradiated again with ultraviolet light to make the insulating adhesive bond tightly with the light-cured resin layer and fix it.

[0054] Connecting solder strips: L-shaped welding strips are selected, with the thickness of the short side being greater than that of the long side, and the short side having a bevel.

[0055] Connect the L-shaped solder strips to the insulating adhesive and metal grid on the upper or lower surface of the solar cell, respectively, ensuring that the bevel of the solder strips is in close contact with the surface of the solar cell.

[0056] When two adjacent solar cells are connected, their solder strips are not on the same surface. Instead, the inclined surfaces of the two solder strips are fixed together by conductive adhesive to form a heterojunction solar cell.

[0057] Component assembly and testing: Multiple connected heterojunction solar cells are assembled according to a predetermined layout to form a solar cell module.

[0058] The assembled solar cell modules undergo electrical performance and mechanical strength tests to ensure that the performance and stability of the modules meet the design requirements.

[0059] By following the steps above, a heterojunction solar cell with excellent performance and stability can be fabricated. This cell not only has high photoelectric conversion efficiency but also good mechanical strength and insulation properties, making it suitable for various photovoltaic applications.

[0060] This embodiment, through the design of a heterojunction structure, enables the battery to absorb and convert solar energy more effectively, thereby improving photoelectric conversion efficiency.

[0061] Enhanced stability: The meticulous cleaning process ensures the cleanliness of the cell surface, reducing the impact of contamination on battery performance. Simultaneously, the addition of a UV-cured resin layer and insulating adhesive enhances the mechanical strength and stability of the cells, extending battery life.

[0062] Grooves are created on the upper and lower surfaces of the solar cell, which not only provides space for the filling of insulating adhesive, but also increases the adhesion area between the solar cell and the insulating adhesive, thereby improving the strength of the connection.

[0063] L-shaped solder strip: The L-shaped solder strip design ensures a tighter and smoother connection between adjacent cells, reducing stress concentration and fatigue damage caused by solder strip bends. Simultaneously, the beveled design of the solder strip facilitates the fixing of the conductive adhesive, improving connection reliability and electrical contact stability.

[0064] By selecting appropriate cleaning agents and cleaning methods, efficient cleaning of the battery cell surface was achieved, while simplifying the cleaning steps and reducing the amount of cleaning agent used.

[0065] The preparation method in this embodiment is relatively simple, requiring no complex equipment or process steps, which reduces production costs and improves production efficiency.

[0066] There is a wide variety of insulating adhesives available, and the most suitable material can be selected based on actual needs and cost considerations, further reducing costs.

[0067] The filling with insulating adhesive effectively isolates the circuitry on the upper and lower surfaces of the battery cells, preventing short circuits and improving battery safety.

[0068] The design of the L-shaped solder strip and the filling of the sink make the surface of the solar cells smoother and more aesthetically pleasing, thus improving the overall appearance quality of the solar module.

[0069] This preparation method is applicable to various types of solar cells, including monocrystalline silicon and polycrystalline silicon, and has strong adaptability.

[0070] By optimizing the battery structure and connection method, this preparation method can be easily scaled up to larger-scale battery module production to meet market demand.

[0071] In summary, this embodiment, through a series of innovative designs and optimization measures, has achieved a significant improvement in the fabrication technology of heterojunction solar cells, providing strong support for the development of the photovoltaic industry.

[0072] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for fabricating a heterojunction solar cell, characterized in that, include: Clean the battery cells and create sinks on the upper and lower surfaces of the cleaned battery cells. Metal grids are printed on the upper and lower surfaces of the solar cells after the sink is opened, and then cured. The settling tank is filled with insulating adhesive, and then the welding strip is attached to the insulating adhesive and metal grid on the upper or lower surface. The solder strips of two adjacent cells are connected to form a heterojunction solar cell.

2. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, Cleaning the battery cells includes: Use pure water or deionized water to initially rinse the surface of the battery cells. Then, select a cleaning agent according to the material of the battery cells and the type of contaminants. Under the action of the cleaning agent, remove the contaminants from the surface of the battery cells. During the use of the cleaning agent, use stirring or ultrasonic waves to accelerate the cleaning process. Finally, rinse the surface of the battery cells thoroughly with pure or deionized water to remove any residual cleaning agent and contaminants.

3. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, After cleaning, grooves are made on the upper and lower surfaces of the battery cells, including: The upper and lower surfaces of the solar cell are created using a light-cured resin drilling and casting method: Specifically, a layer of light-cured resin is coated on the entire upper and lower surfaces of the battery cell, and then ultraviolet light is irradiated to form a hard protective layer. Then, a honeycomb-shaped groove is made on the resin surface using a drilling tool, and protrusions of different sizes are carved on the bottom and sides of the groove.

4. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, Metal grids are printed on the upper and lower surfaces of the solar cells after the sink grooves have been created. After printing, the grids are cured, including: Metal grids are printed onto the surface of the solar cell using a stencil, and then cured at high temperature to fix the metal grids onto the solar cell.

5. The method for fabricating a heterojunction solar cell according to claim 4, characterized in that, Metal grids are either grid-like or equally spaced strips.

6. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, The settling tank is filled with insulating adhesive, including: The insulating adhesive is filled into the settling tank, and then the resin layer is cured by ultraviolet light again to fix the filler.

7. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, The welding strip is L-shaped, with the thickness of the short side of the L-shape being greater than that of the long side. The short side of the L-shape is beveled, and the bevels of two adjacent battery cells are matched and bonded together.

8. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, The insulating adhesive is one of the following: photovoltaic insulating adhesive, silicone, epoxy resin adhesive, polyurethane adhesive, or EVA film.

9. The method for fabricating a heterojunction solar cell according to claim 1, characterized in that, Adjacent solar cells are interconnected via solder strips to form a heterojunction solar cell, comprising: When two adjacent solar cells are connected, their respective solder strips are not on the same surface, and the beveled surfaces of the two solder strips are fixedly connected by conductive adhesive.

10. A heterojunction solar cell, characterized in that, It is prepared by the method for preparing a heterojunction solar cell as described in any one of claims 1 to 9.

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