Solar cell and photovoltaic module

Abstract

The utility model provides a solar cell and a photovoltaic module. The solar cell comprises a slice cell which is obtained by cutting a whole cell piece; the conducting medium layer is positioned on the cutting surface of the slice battery; and the passivation layer is positioned on the surface of one side, far away from the slice battery, of the conductive medium layer. According to the solar cell, half-piece passivation is combined, and the conducting medium layer and the passivation layer are introduced into the cross section of the cell, so that the problem of low electric efficiency caused by overhigh leakage current in the prior art is solved, and the performance of the solar cell is further improved.

Description

Technical Field

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

[0002] Crystalline silicon cells are the most mainstream photovoltaic technology in the market, widely used due to their high conversion efficiency and mature production process. With technological advancements and large-scale production, the production cost of crystalline silicon cells has dropped significantly in the past few years. The global market for crystalline silicon photovoltaic cells has gradually expanded, further promoting their application.

[0003] The hot spot effect is a common problem in photovoltaic solar cell (PV) systems. It may be caused by obstruction of the components, dirt, uneven lighting, shadows or other component defects. When a part of the solar panel is blocked, the unblocked part still receives sunlight, resulting in an increase in current, while the blocked part cannot generate current, so the voltage drops. This will cause an imbalance between current and voltage, resulting in local hot spots in the blocked area. The hot spot temperature may be much higher than the normal operating temperature of the component, and long-term existence may cause the performance of the component to degrade or even damage it. In the prior art, the conventional solution is to introduce leakage on the four sides of the battery through insufficient etching during the battery manufacturing process, but excessive leakage current will cause the parallel resistance of the battery to decrease, and then the fill factor of the battery to decrease, resulting in a decrease in battery efficiency. Utility Model Content

[0004] The main purpose of the present application is to provide a solar cell and a photovoltaic module to solve the problem of reduced battery efficiency caused by excessive leakage current during battery preparation in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a solar cell is provided, which includes: a sliced ​​cell, which is obtained by cutting a whole cell; a conductive dielectric layer, which is located on the cut surface of the sliced ​​cell; and a passivation layer, which is located on the surface of the conductive dielectric layer on the side away from the sliced ​​cell.

[0006] Furthermore, the thickness of the conductive medium layer is 1 to 8 nm.

[0007] Furthermore, the thickness of the passivation layer is 5 to 25 nm.

[0008] Furthermore, the conductive medium layer is made of metal oxide.

[0009] Furthermore, the metal oxide is one of tin dioxide, copper oxide, silver oxide, zinc oxide, tungsten trioxide and cobalt trioxide.

[0010] Furthermore, the material of the passivation layer is oxide.

[0011] Furthermore, the oxide is one of aluminum oxide and silicon oxide.

[0012] Furthermore, the leakage current of the solar cell has a current value of 5 to 10A.

[0013] According to another aspect of the present application, a photovoltaic assembly is provided, comprising: a cell string formed by connecting any type of solar cells; an encapsulation layer for covering the surface of the cell string; and a cover plate for covering the surface of the encapsulation layer away from the cell string.

[0014] Furthermore, the hot spot temperature of the photovoltaic module is 145-165°C.

[0015] Applying the technical solution of this application, a solar cell includes: a sliced ​​cell, which is obtained by cutting a whole cell; a conductive dielectric layer, which is located on the cut surface of the sliced ​​cell; and a passivation layer, which is located on the surface of the conductive dielectric layer on the side away from the sliced ​​cell. Forming a conductive dielectric layer on the cut cross section can achieve conduction between the upper and lower PN junctions of the cross-section cell; and the passivation layer reduces edge recombination of the cell through the field passivation effect. Compared with the four-sided leakage of conventional cells, the back three sides of the half-cell module leak; reducing leakage current, increasing parallel resistance, and improving the cell fill factor, thereby improving cell efficiency. This alleviates the problem of reduced electrical efficiency caused by excessive leakage current in the prior art, thereby improving solar cell performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0017] Figure 1 A schematic diagram showing the structure of a solar cell according to the present application is shown;

[0018] Figure 2 A schematic diagram showing the structure of a photovoltaic module according to the present application is shown.

[0019] The above drawings include the following reference numerals:

[0020] 10. Sliced ​​battery; 20. Conductive dielectric layer; 30. Passivation layer; 40. Encapsulation layer; 50. Cover plate. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element or intervening elements may be present. Moreover, in the specification and claims, when it is described that an element is "connected to" another element, the element may be "directly connected to" the other element or "connected to" the other element through a third element.

[0024] As described in the background technology, the conventional solution is to introduce leakage current on the four sides of the battery due to insufficient etching during the battery manufacturing process. However, excessive leakage current will cause the battery parallel resistance to decrease, thereby reducing the battery fill factor and causing the battery efficiency to decrease. In order to solve the above technical problems, this application proposes a solar cell and a photovoltaic module. Figure 1 Schematic diagram of the structure of a solar cell according to an embodiment of the present application. Figure 1 As shown, the structure includes:

[0025] Sliced ​​battery 10 is obtained by cutting a whole battery cell;

[0026] Solar cell wafers, also known as solar wafer cells, are devices that use solar energy to convert light into electricity. They are the core component of solar panels, generating energy by converting sunlight into electricity. Materials used for solar cell wafers include silicon-based materials, thin-film materials, organic materials, and perovskite materials. Silicon is the most commonly used solar cell material due to its high photoelectric conversion efficiency and low production cost. Silicon-based solar cells come in two types: single-crystalline silicon and multicrystalline silicon. Thin-film solar cells are made from very thin semiconductor materials, such as copper indium gallium selenide and cadmium telluride. These materials offer low production costs and high production flexibility, but their photoelectric conversion efficiency is relatively low. Organic solar cells use organic semiconductor materials, such as polymers and molecular materials. These materials offer the advantages of flexibility, lightness, and low cost, but their photoelectric conversion efficiency and stability are relatively low. Perovskite solar cells offer the advantages of high photoelectric conversion efficiency and low cost. Perovskite materials are compounds with a crystalline structure, such as methylammonium lead iodide.

[0027] A conductive dielectric layer 20 is located on the cut surface of the sliced ​​battery 10;

[0028] The conductive dielectric layer collects and transports electrons generated by solar cells, thereby improving their efficiency. Made of a highly conductive material, the conductive dielectric layer quickly transfers electrons generated by the solar cell's absorption of light energy to the cell's external circuit. In solar cells, recombination of electrons and holes reduces their efficiency. The conductive dielectric layer helps mitigate this recombination by providing an efficient electron transport path, reducing the probability of electron and hole recombination within the cell. Furthermore, the conductive dielectric layer acts as a protective barrier, protecting the solar cell from environmental damage such as moisture, oxygen, and other contaminants. Furthermore, the conductive dielectric layer can sometimes be designed with anti-reflective properties to reduce light energy loss and increase the solar cell's light absorption rate. In certain types of solar cells, the conductive dielectric layer can be tailored to enhance absorption of specific wavelengths of light by adjusting its thickness and material properties. The conductive dielectric layer also aids in thermal management, dissipating heat to lower the cell's operating temperature and improve its stability and lifespan.

[0029] A passivation layer 30 is located on a surface of the conductive medium layer 20 away from the sliced ​​battery 10 ;

[0030] The passivation layer can reduce dangling bonds on the silicon wafer surface, which could otherwise serve as centers for electron-hole recombination, hindering the flow of current. By reducing recombination, the open-circuit voltage of the solar cell can be increased, thereby improving solar cell efficiency. Furthermore, the passivation layer can also reduce the recombination of electrons and holes generated by light excitation on the surface, allowing more carriers to be collected and increasing the short-circuit current of the solar cell. Ultimately, by reducing recombination and increasing carrier collection, the passivation layer helps improve the overall photoelectric conversion efficiency of the solar cell. Materials for the passivation layer can include silicon dioxide, silicon nitride, and aluminum oxide, among others.

[0031] Applying the technical solution of the present application, the above-mentioned solar cell includes: a sliced ​​cell, which is obtained by cutting a whole cell; a conductive dielectric layer, which is located on the cut surface of the sliced ​​cell; and a passivation layer, which is located on the surface of the conductive dielectric layer on the side away from the sliced ​​cell. The conductive dielectric layer is formed on the cut cross section to achieve conduction of the upper and lower PN junctions of the cross-section cell; and the passivation layer reduces the edge recombination of the cell through the field passivation effect. Compared with the four-sided leakage of conventional cells, the back three sides of the half-cell module leak; reducing the leakage current, increasing the parallel resistance, and improving the fill factor of the cell, thereby improving the cell efficiency. This alleviates the problem of reduced electrical efficiency caused by excessive leakage current in the existing technology, thereby improving the performance of solar cells.

[0032] In another embodiment of the present application, the thickness of the conductive dielectric layer is 1 to 8 nm. The conductive dielectric layer can form an effective barrier to prevent current leakage, reduce the leakage current, and further improve the electrical efficiency and battery performance of the solar cell.

[0033] In practical applications, the thickness of the conductive dielectric layer is determined by factors such as light absorption, carrier collection, material and processing costs, temperature stability, mechanical stability, and cross-sectional characteristics. The thicker the conductive dielectric layer, the more light energy the cell can absorb. If the conductive dielectric layer is too thin, the cell may not absorb light energy effectively, resulting in reduced energy conversion efficiency. However, if the conductive dielectric layer is too thick, light may be scattered or reflected during its passage through the layer, also affecting cell performance. Furthermore, the thickness of the conductive dielectric layer also affects its conductivity, so a balance must be found to ensure sufficient carrier collection without energy loss due to excessive resistance. Furthermore, while ensuring cell performance, the layer thickness should be minimized to reduce material and processing costs. The conductive dielectric layer is affected by temperature during solar cell operation, and its thickness must be considered for stability under varying temperature conditions to ensure that the cell maintains good performance even in high-temperature environments. The thickness of the conductive dielectric layer affects its mechanical stability, so it is important to ensure that the layer is thick enough to withstand external pressure while maintaining cell performance. The interface characteristics between the conductive dielectric layer and other layers of the battery have a great influence on the battery performance. The thickness of the conductive dielectric layer needs to ensure good interface characteristics to improve the overall performance of the battery.

[0034] In another embodiment of the present application, the thickness of the passivation layer is 5 to 25 nm. The thickness of the passivation layer is set to reduce the oxidation of the metal surface, prevent the release of metal ions, further prevent the leakage of current, reduce the leakage current, and further improve the insulation performance of the solar cell.

[0035] Specifically, the thickness of the passivation layer is influenced by several factors, including material properties, surface defects, process conditions, cell structure, performance indicators, cost factors, and environmental stability. The physical and chemical properties of the passivation layer material significantly influence the passivation effect. For example, the band gap width and refractive index of the passivation layer material can affect the passivation effect. Therefore, when selecting the passivation layer material, these factors must be comprehensively considered to achieve the optimal passivation effect. Surface defects on the solar cell can affect the quality and effectiveness of the passivation layer. For example, defects such as surface oxidation and impurities can increase the defect density of the passivation layer, thereby reducing the passivation effect. Therefore, when setting the passivation layer thickness, the impact of surface defects must be considered to ensure that the passivation layer adequately covers surface defects and enhances the passivation effect. The passivation layer preparation process conditions, such as deposition temperature, pressure, and gas flow rate, can also affect the quality and performance of the passivation layer. When setting the passivation layer thickness, it must be optimized based on the actual process conditions to achieve the optimal passivation effect. Different solar cell structures may require different passivation layer thickness requirements. For example, n-type and p-type cells may require different passivation layer thicknesses. Therefore, when setting the passivation layer thickness, it is necessary to adjust it according to the battery structure to meet the needs of different battery structures. The passivation layer thickness has a significant impact on the performance indicators of solar cells, such as open-circuit voltage, short-circuit current, fill factor, etc. When setting the passivation layer thickness, it is necessary to optimize it according to the performance requirements of the battery to achieve optimal battery performance. The thickness setting of the passivation layer also needs to consider cost factors. A passivation layer that is too thick will increase the preparation cost, while a passivation layer that is too thin may not achieve the ideal passivation effect. Therefore, when setting the passivation layer thickness, it is necessary to find a balance between passivation effect and cost. The passivation layer needs to maintain stable performance during long-term use. Therefore, when setting the passivation layer thickness, it is necessary to consider its stability under different environmental conditions to ensure that the passivation layer can maintain an efficient passivation effect during long-term use.

[0036] In order to further reduce the undesired flow of electrons between materials and lower the leakage current, the material of the conductive dielectric layer is metal oxide.

[0037] Specifically, metal oxides as conductive dielectric layers have excellent electrical insulation properties, good thermal stability, and mechanical strength. Commonly used materials include indium tin oxide, zinc oxide, and aluminum oxide, which can provide the required conductive and insulating properties in different applications.

[0038] In some further embodiments, the metal oxide is one of tin dioxide, copper oxide, silver oxide, zinc oxide, tungsten trioxide and cobalt tetroxide, which optimizes the electronic structure, reduces the interface state density, effectively suppresses leakage current, and further improves device stability.

[0039] Specifically, tin dioxide is an n-type semiconductor material with high transparency, good electrical conductivity, and high electron mobility, which helps improve the selective transport and collection efficiency of electrons. Furthermore, its good chemical stability helps improve the stability and lifespan of solar cells. Copper oxide is a p-type semiconductor material that can be used as a hole transport layer in solar cells. Furthermore, copper oxide has a high light absorption coefficient, which helps improve the light absorption efficiency of solar cells. Silver oxide has high electrical conductivity and chemical stability and can be used as a highly conductive dielectric layer in solar cells. Zinc oxide is an n-type semiconductor material with high transparency, good electrical conductivity, and high electron mobility, which helps improve electron transport efficiency. Tungsten trioxide is an n-type semiconductor material with a high light absorption coefficient and good electrochemical stability, making it suitable as a counter electrode in photovoltaic devices. Cobalt trioxide is a p-type semiconductor material with high light absorption performance and good electrical conductivity, which can be used as a light absorption layer or hole transport layer in solar cells. It also has good thermal stability, which helps improve the long-term stability of solar cells.

[0040] In order to further increase the interface barrier, reduce carrier injection, and lower leakage current, the material of the passivation layer is oxide.

[0041] Specifically, oxides, as passivation layers, offer excellent chemical stability and corrosion resistance, effectively protecting metal surfaces. Common oxide passivation layer materials include aluminum oxide, zirconium oxide, and titanium oxide. These are typically applied chemically or electrochemically to metal surfaces, forming a dense, continuous protective film.

[0042] In order to further increase the interface barrier, reduce carrier injection, and lower leakage current, the oxides are aluminum oxide and silicon oxide.

[0043] Specifically, using aluminum oxide or silicon oxide as the passivation layer of solar cells can significantly reduce the recombination of electrons on the cell surface, thereby improving the efficiency of solar cells. Aluminum oxide or silicon oxide as passivation layer materials provide electron and hole blocking functions, respectively, which can significantly reduce the chance of recombination.

[0044] In order to reduce internal loss, improve electrical efficiency and increase solar cell performance, the leakage current of the solar cell has a current value of 5 to 10A.

[0045] Specifically, low solar leakage current means reduced energy loss in solar panels, thereby improving energy conversion efficiency. Lower leakage current reduces unnecessary electrical energy consumption, allowing more solar energy to be converted into electricity, which directly improves the overall performance of solar systems. Furthermore, lower leakage current helps extend the service life of solar panels, as less current flow reduces wear and degradation of panel materials.

[0046] In another typical embodiment of the present application, a photovoltaic assembly is provided, such as Figure 2 Shown, including:

[0047] A battery string is formed by connecting any of the above solar cells;

[0048] Specifically, the solar cell includes: a sliced ​​cell 10, which is obtained by cutting a whole cell; a conductive dielectric layer 20, which is located on the cut surface of the sliced ​​cell 10; and a passivation layer 30, which is located on the surface of the conductive dielectric layer 20 away from the sliced ​​cell 10.

[0049] An encapsulation layer 40 is used to cover the surface of the battery string;

[0050] The encapsulation layer is a crucial structure for protecting semiconductor devices from environmental influences. Common materials include epoxy resin, silicone rubber, metal alloys, and ceramics. Epoxy resin is widely used due to its excellent mechanical strength and electrical insulation properties. The encapsulation layer not only protects semiconductor devices from physical impact and chemical corrosion but also provides electrical connectivity and thermal management. Through the encapsulation structure, it connects the device to external circuits while isolating it from environmental factors such as moisture and dust, preventing device performance degradation or failure.

[0051] A cover plate 50, used to cover the surface of the packaging layer away from the battery string;

[0052] In photovoltaic modules, the cover provides a physical protective layer for the cells, preventing damage from external environmental factors (such as wind, sand, hail, and birds). Furthermore, photovoltaic modules need to operate in a variety of climates, so the cover material must have excellent weather resistance and be able to withstand the long-term effects of environmental factors such as ultraviolet rays, humidity, and temperature fluctuations.

[0053] Comparative Example

[0054] This comparative example provides a solar cell, comprising:

[0055] The whole solar cell, the material of the solar cell is tin oxide.

[0056] Example 1

[0057] This embodiment provides a solar cell, including:

[0058] Sliced ​​batteries, the above-mentioned sliced ​​batteries are obtained by cutting the whole battery cell;

[0059] A conductive dielectric layer is located on the cut surface of the sliced ​​battery, the conductive dielectric layer is made of tin oxide, and has a thickness of 8 nm;

[0060] The passivation layer is located on the surface of the conductive medium layer on the side away from the sliced ​​battery. The material of the passivation layer is silicon oxide, and the thickness of the passivation layer is 7 nm.

[0061] Example 2

[0062] This embodiment provides a solar cell, including:

[0063] Sliced ​​batteries, the above-mentioned sliced ​​batteries are obtained by cutting the whole battery cell;

[0064] A conductive dielectric layer is located on the cut surface of the sliced ​​battery, wherein the conductive dielectric layer is made of silver oxide and has a thickness of 5 nm;

[0065] The passivation layer is located on the surface of the conductive medium layer on the side away from the sliced ​​battery. The material of the passivation layer is aluminum oxide, and the thickness of the passivation layer is 7 nm.

[0066] Example 3

[0067] This embodiment provides a solar cell, including:

[0068] Sliced ​​batteries, the above-mentioned sliced ​​batteries are obtained by cutting the whole battery cell;

[0069] A conductive dielectric layer is located on the cut surface of the sliced ​​battery, wherein the conductive dielectric layer is made of silver oxide and has a thickness of 3 nm;

[0070] The passivation layer is located on the surface of the conductive medium layer on the side away from the sliced ​​battery. The material of the passivation layer is aluminum oxide, and the thickness of the passivation layer is 15 nm.

[0071] Table 1 shows the IV test results for the solar cells in the comparative example and Examples 1-3. The leakage current is the leakage current of the half-cell obtained in the comparative example and Examples 1-3 under negative bias (typically -10V to -12V). A higher leakage current corresponds to a lower parallel resistance of the cell, which reduces the cell's fill factor (FF), leading to a decrease in cell conversion efficiency.

[0072] Table 1

[0073] Leakage current A Component hot spot temperature Example 1 12A 145℃ Example 2 8A 155℃ Example 3 5A 165℃ Comparative Example Less than 1A 175℃

[0074] It can be seen from Table 1 above that the performance of the solar cells of the present application is effectively improved compared with the conventional solar cells formed in the comparative examples according to the solar cells formed according to the above embodiments 1 to 3; the component temperature of embodiment 1 is lower than that of embodiment 2 and embodiment 3, and the performance of the solar cell of embodiment 1 is effectively improved compared with those of embodiments 2 and 3.

[0075] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0076] 1) The aforementioned solar cell comprises: a sliced ​​cell, which is obtained by cutting a whole cell; a conductive dielectric layer, which is located on the cut surface of the sliced ​​cell; and a passivation layer, which is located on the surface of the conductive dielectric layer away from the sliced ​​cell. Forming a conductive dielectric layer on the cut cross-section enables conduction of the upper and lower PN junctions of the cross-sectioned cell; and the passivation layer reduces edge recombination of the cell through a field passivation effect. Compared to the four-sided leakage of conventional cells, the back three sides of a half-cell module leak; reducing leakage current, increasing parallel resistance, and improving the cell fill factor, thereby improving cell efficiency. This alleviates the problem of reduced electrical efficiency caused by excessive leakage current in the prior art, thereby improving solar cell performance.

[0077] 2) The photovoltaic module includes: a cell string formed by connecting any type of solar cells; an encapsulation layer for covering the surface of the cell string; and a cover plate for covering the surface of the encapsulation layer away from the cell string. A conductive dielectric layer is formed on the cut section to achieve conduction of the upper and lower PN junctions of the cross-sectioned cells; and the passivation layer reduces the edge recombination of the cells through the field passivation effect. Compared with the four-sided leakage of conventional cells, the back three sides of the half-cell module leak; reducing leakage current, increasing parallel resistance, and improving the fill factor of the cell, thereby improving cell efficiency. This alleviates the problem of reduced electrical efficiency caused by excessive leakage current in the existing technology, thereby improving the performance of solar cells.

[0078] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A solar cell, characterized in that: include: Sliced ​​batteries, which are obtained by cutting a whole battery cell; a conductive medium layer, located on the cut surface of the sliced ​​battery; A passivation layer is located on a surface of the conductive medium layer that is away from the sliced ​​battery.

2. The solar cell according to claim 1, wherein The thickness of the conductive medium layer is 1-8 nm.

3. The solar cell according to claim 1, wherein The thickness of the passivation layer is 5 to 25 nm.

4. The solar cell according to claim 1, wherein The material of the conductive medium layer is metal oxide.

5. The solar cell according to claim 4, wherein The metal oxide is one of tin dioxide, copper oxide, silver oxide, zinc oxide, tungsten trioxide and cobalt trioxide.

6. The solar cell according to claim 1, wherein The material of the passivation layer is oxide.

7. The solar cell according to claim 6, characterized in that The oxide is one of aluminum oxide and silicon oxide.

8. The solar cell according to claim 1, wherein The leakage current of the solar cell has a current value of 5 to 10A.

9. A photovoltaic module, characterized in that: include: A battery string formed by connecting the solar cells according to any one of claims 1 to 8; an encapsulation layer, used to cover the surface of the battery string; A cover plate is used to cover a surface of the packaging layer away from the battery string.

10. The photovoltaic module according to claim 9, characterized in that: The hot spot temperature of the photovoltaic module is 145-165°C.

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