Solar cell and method of manufacturing the same, stacked cell, and photovoltaic module

Abstract

This application relates to the field of solar cell technology, providing a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module, which at least improves the benefit of laser-assisted sintering of sectional cells in terms of contact resistance. The manufacturing method includes: providing a solar cell, the solar cell including opposing first and second surfaces; forming a first grid on the first surface and a second grid on the second surface; irradiating the first surface of the solar cell with a first laser and applying a first voltage to the first and second grids; cutting the solar cell to divide it into at least two sectional cells, and passivating the cut surfaces of the sectional cells; irradiating at least a portion of the first surface of the sectional cells with a second laser and applying a second voltage to the first and second grids; wherein the energy density of the second laser is less than the energy density of the first laser, and / or the second voltage is less than the first voltage.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module. Background Technology

[0002] The electrode contact resistance on the surface of crystalline silicon solar cells has a significant impact on the fill factor and conversion efficiency. The lower the contact resistance, the higher the fill factor and conversion efficiency. Therefore, reducing contact resistance has become an urgent need for major cell manufacturers.

[0003] To reduce contact resistance, conventional techniques employ laser-assisted sintering. This involves using a laser to excite charge carriers in the solar cell, which then flow in a directed manner under the reverse bias of an external electric field to form a circuit. When the circuit current flows through the metal-semiconductor interface, a significant thermal effect is generated due to the relatively high contact resistance between the metal and semiconductor. This further promotes the mutual diffusion between the metal and semiconductor, resulting in excellent contact characteristics after sintering.

[0004] However, the improvement in contact resistance achieved by using laser-assisted sintering for segmented cells remains relatively low. Summary of the Invention

[0005] This application provides a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module, which at least helps to improve the contact resistance of slab cells by using laser-assisted sintering.

[0006] According to some embodiments of this application, one aspect of this application provides a method for manufacturing a solar cell, comprising: providing a solar cell, the solar cell including opposing first and second surfaces; forming a first grid on the first surface and a second grid on the second surface; irradiating the first surface of the solar cell with a first laser and applying a first voltage to the first and second grids; cutting the solar cell to divide it into at least two sub-cells and passivating the cut surfaces of the sub-cells; irradiating at least a portion of the first surface of the sub-cells with a second laser and applying a second voltage to the first and second grids; wherein the energy density of the second laser is less than the energy density of the first laser, and / or the second voltage is less than the first voltage.

[0007] In some embodiments, after passivation treatment, before irradiating at least a portion of the first surface of the cell with a second laser and applying a second voltage to the first and second grids, the method includes: obtaining the actual contact resistance value of the cell; if the actual contact resistance value is greater than a preset resistance value, irradiating the first surface of the cell with a second laser and applying a second voltage to the first and second grids; if the actual contact resistance value is less than or equal to the preset resistance value, not processing the cell.

[0008] In some embodiments, after irradiating the first surface of the battery cell with a first laser and applying a first voltage to the first and second grids, and before performing a cutting process, the method includes: performing a first test on the battery cell to obtain a first contact resistance; after passivation, and before irradiating at least a portion of the first surface of the segmented battery cell with a second laser and applying a second voltage to the first and second grids, the method includes: performing a second test on the segmented battery cell to obtain a second contact resistance; obtaining a deviation value of the second contact resistance relative to the first contact resistance; if the deviation value is greater than a target value, irradiating the first surface of the segmented battery cell with a second laser and applying a second voltage to the first and second grids; if the deviation value is less than or equal to the target value, not processing the segmented battery cell.

[0009] In some embodiments, in the first test, the cell is divided into at least two sub-regions, each sub-region corresponding to a cell segment, and the first contact resistance is characterized as the contact resistance of the sub-region; in the second test, the second contact resistance is characterized as the contact resistance of the cell segment.

[0010] In some embodiments, in the steps of irradiating the first surface of the slab battery with a second laser and applying a second voltage to the first and second grids, different energy densities of the second laser and the second voltage are selected according to the magnitude of the deviation value.

[0011] In some embodiments, in the first test, the cell is divided into at least two sub-regions, each sub-region corresponding to a cell segment, and the first contact resistance is characterized as the contact resistance between each of the first grids in a portion of the sub-region and the cell; in the second test, the second contact resistance is characterized as the contact resistance between each of the first grids selected in the first test and the cell segment.

[0012] In some embodiments, in the steps of irradiating the first surface of the cell with a second laser and passing a second voltage to the first and second grids, the energy density of the second laser corresponding to different first grids is selected according to the magnitude of the deviation value, and the magnitude of the second voltage used for different first grids on the same cell is the same.

[0013] In some embodiments, in a sub-region, the total number of first fine gates is a first number, and a second number of first contact resistances corresponding to the first fine gates are selected in the sub-region, with the ratio of the second number to the first number being 0.5 to 1.

[0014] In some embodiments, a second laser is used to irradiate the first surface of all the cell segments, and a second voltage is applied to the first and second grids.

[0015] In some embodiments, the steps of irradiating at least a portion of the first surface of the cell with a second laser and applying a second voltage to the first and second grids further include: irradiating at least a portion of the second surface of the cell with a third laser; wherein the energy density of the third laser is less than the energy density of the second laser.

[0016] In some embodiments, the spot size of the first laser is larger than the spot size of the second laser.

[0017] In some embodiments, after irradiating at least a portion of the first surface of the cell with a second laser and applying a second voltage to the first and second grids, the method further includes: irradiating at least a portion of the second surface of the cell with a second laser and applying a second voltage to the first and second grids.

[0018] According to some embodiments of this application, another aspect of this application provides a solar cell prepared using the solar cell manufacturing method described in the above embodiments.

[0019] According to some embodiments of this application, another aspect of this application provides a tandem solar cell, including: a perovskite top cell; a crystalline silicon bottom cell, the crystalline silicon bottom cell being the solar cell in the above embodiments; and a composite layer located between the perovskite top cell and the crystalline silicon bottom cell.

[0020] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: at least two battery components, the battery components being solar cells as described in the above embodiments, or tandem cells as described in the above embodiments; a connecting component for connecting adjacent battery components; an encapsulating film covering the surface of the battery components; and a cover plate located on the side of the encapsulating film away from the battery components.

[0021] The technical solution provided in this application has at least the following advantages:

[0022] In the solar cell manufacturing method provided in this application embodiment, after forming a first fine grid and a second fine grid on the first and second surfaces of the cell, respectively, a first laser and a first voltage are used to perform laser-assisted sintering on the first fine grid to form a good ohmic contact between the first fine grid and the cell. During the laser-assisted sintering process, the first laser excites the cell to generate charge carriers, which flow in a directional manner using a second voltage to form a loop. When the loop current flows through the interface between the first fine grid and the semiconductor in the cell, a significant thermal effect is generated due to the relatively high contact resistance between the metal and the semiconductor, thereby promoting the mutual diffusion between the metal and the semiconductor to obtain a first fine grid with excellent contact characteristics after sintering. Subsequently, the cell is cut and passivated to form multiple cell segments. Since the cutting and passivation processes cause a decrease in the contact resistance between the first fine grid and the cell, a second laser and a second voltage are further used to optimize the contact resistance of at least some of the cell segments. Using a second laser with a lower energy density and / or a smaller second voltage can accurately and gently repair the contact resistance. The second voltage creates an electric field within the cell slabs, driving glass ions in the silver paste to migrate towards the interface. Combined with the localized thermal effect of the second laser, this locally anneales the stress-damaged interface areas, repairing microcracks and lattice distortions caused by the cutting process, and restoring tight contact between the metal and semiconductor. Because it uses lower energy and / or voltage, the contact resistance optimization process is gentler, repairing only those contact points whose performance has degraded due to cutting and passivation, without over-sintering those that remain in good condition. Compared to first performing cutting and passivation, and then using laser-assisted sintering to form fine grids on the cell slabs, significant costs can be saved. Attached Figure Description

[0023] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A flowchart corresponding to a method for manufacturing a solar cell provided in an embodiment of this application;

[0025] Figure 2 A schematic diagram of the structure corresponding to each step of a method for manufacturing a solar cell provided in this application embodiment;

[0026] Figure 3 A top view of a battery cell provided in an embodiment of this application;

[0027] Figure 4 A top view of the battery cell provided in the embodiments of this application after it has been cut into multiple battery cells;

[0028] Figure 5 This is a schematic diagram of a stacked battery provided in an embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100. Solar cell; 101. First surface; 102. Second surface; 111. First grid; 112. Second grid; 1001. Segmented solar cell; 1002. Cut surface; 10. Sub-region; 201. Perovskite top solar cell; 202. Crystalline silicon bottom solar cell; 203. Composite layer; 211. Electron transport layer; 221. Perovskite absorber layer; 231. Hole transport layer; 301. Solar cell component; 302. Connecting component; 303. Encapsulant film; 304. Cover plate. Detailed Implementation

[0032] As can be seen from the background technology, the improvement in contact resistance achieved by using laser-assisted sintering for segmented cells is still relatively low.

[0033] Photovoltaic modules typically consist of multiple identical solar cells connected in series and / or parallel. The high current flowing through the interconnecting elements between these solar cells can lead to significant resistance losses. To address this issue, laser cutting technology is used to slice the entire solar cell into one or more smaller cells. These smaller cells are then connected in series using conductive solder strips. The series current is lower than the overall current, and this reduced current in the smaller cells helps improve the power loss of the photovoltaic module.

[0034] However, during laser slicing, the laser locally melts the entire solar cell along a predetermined path, and then mechanical force is used to break the cell along the same path to achieve slicing. This leaves cutting edges on the slicing cells, forming laser-damaged and mechanically fractured zones. As a result, silicon atoms at these cutting edges cannot maintain their original ordered arrangement, and the surface contains numerous dangling bonds and defect states, which become effective recombination centers for charge carriers. A large number of charge carriers recombine at these centers, severely impacting the photoelectric conversion efficiency of the slicing cells. To address this issue, a passivation layer is typically formed on the cut surfaces of the slicing cells to prevent the reduction in photoelectric conversion efficiency caused by slicing.

[0035] Typically, after the entire solar cell is formed, it is cut. At this point, the fine grid on the entire solar cell has been prepared. The fine grid formed by laser-assisted sintering technology has a low contact resistance with the cell. However, after cutting and passivation, the contact resistance between the fine grid and the cell increases. This reduces the benefit of improving the contact resistance of the segmented cells and also reduces the benefit of improving the efficiency of the segmented cells. Furthermore, the increased contact resistance can easily lead to damage and overheating of the photovoltaic module, and the hot spot problem will also be aggravated.

[0036] This is because laser cutting or mechanical cutting generates enormous thermal and mechanical stresses, which are transmitted through the solar cell to the already sintered grid-cell contact interface. This leads to microcracks, lattice distortion, or loosening of the originally dense contact at the interface. Microscopically, this is equivalent to destroying some of the already formed good ohmic contact points, increasing the barrier for charge carriers to cross the interface, thus increasing the contact resistance (Rc). Passivation treatment often requires a certain heat treatment process. The temperature profile of this heat treatment process may not match the characteristics of the silver paste, leading to further oxidation of the silver particles at the interface, changes in the state of the glass powder, or secondary recrystallization of the metal. These can all alter the ideal interface morphology formed during the initial sintering, degrading the performance of some good contact points and increasing the non-uniformity and average value of the contact resistance.

[0037] However, if the entire solar cell without a fine grid is first cut and passivated, and then the fine grid is formed on the individual cells using laser-assisted sintering, the manufacturing cost of the fine grid will increase exponentially.

[0038] This application provides a solar cell and its manufacturing method, a tandem cell, and a photovoltaic module, which at least helps to improve the contact resistance of slab cells by using laser-assisted sintering.

[0039] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0040] In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0043] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0044] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included.

[0045] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0046] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0047] Figure 1 A flowchart corresponding to a method for manufacturing a solar cell provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure corresponding to each step of a method for manufacturing a solar cell provided in an embodiment of this application.

[0048] refer to Figure 1 and Figure 2 The method for manufacturing a solar cell provided in this application includes:

[0049] S101, Provide a battery cell 100, the battery cell 100 including a first surface 101 and a second surface 102 opposite to each other;

[0050] S102, A first fine gate 111 is formed on the first surface 101, and a second fine gate 112 is formed on the second surface 102;

[0051] S103. The first surface 101 of the battery cell 100 is irradiated with the first laser L1, and the first voltage V1 is applied to the first fine grid 111 and the second fine grid 112 to perform laser-assisted sintering on at least the first fine grid 111.

[0052] S104. The battery cell 100 is cut to divide the battery cell 100 into at least two sub-cells 1001, and the cut surface 1002 of the sub-cell 1001 is passivated.

[0053] S105. At least a portion of the first surface 101 of the segmented cell 1001 is irradiated with a second laser L2, and a second voltage V2 is applied to the first fine grid 111 and the second fine grid 112 to optimize the contact resistance of at least a portion of the segmented cell 1001; wherein the energy density of the second laser L2 is less than the energy density of the first laser L1, and / or the second voltage V2 is less than the first voltage V1.

[0054] For example, in the following situations: (1) the energy density of the second laser L2 is less than the energy density of the first laser L1, and the second voltage V2 is less than the first voltage V1; (2) the energy density of the second laser L2 is less than the energy density of the first laser L1, and the second voltage V2 is greater than or equal to the first voltage V1; (3) the second voltage V2 is less than the first voltage V1, and the energy density of the second laser L2 is greater than or equal to the energy density of the first laser L1. In other words, in the process of optimizing contact resistance, at least one of the laser energy or voltage used needs to be lower than the laser energy or voltage used in the laser-assisted sintering process in order to achieve the purpose of gentle repair.

[0055] In the solar cell manufacturing method provided in this application embodiment, after forming a first fine grid and a second fine grid on the first and second surfaces of the cell, respectively, a first laser and a first voltage are used to perform laser-assisted sintering on the first fine grid to form a good ohmic contact between the first fine grid and the cell. During the laser-assisted sintering process, the first laser excites the cell to generate charge carriers, which flow in a directional manner using a second voltage to form a loop. When the loop current flows through the interface between the first fine grid and the semiconductor in the cell, a significant thermal effect is generated due to the relatively high contact resistance between the metal and the semiconductor, thereby promoting the mutual diffusion between the metal and the semiconductor to obtain a first fine grid with excellent contact characteristics after sintering. Subsequently, the cell is cut and passivated to form multiple cell segments. Since the cutting and passivation processes cause a decrease in the contact resistance between the first fine grid and the cell, a second laser and a second voltage are further used to optimize the contact resistance of at least some of the cell segments. Using a second laser with a lower energy density and / or a smaller second voltage can accurately and gently repair the contact resistance. The second voltage creates an electric field within the cell slabs, driving glass ions in the silver paste to migrate towards the interface. Combined with the localized thermal effect of the second laser, this locally anneales the stress-damaged interface areas, repairing microcracks and lattice distortions caused by the cutting process, and restoring tight contact between the metal and semiconductor. Because it uses lower energy and / or voltage, the contact resistance optimization process is gentler, repairing only those contact points whose performance has degraded due to cutting and passivation, without over-sintering those that remain in good condition. Compared to first performing cutting and passivation, and then using laser-assisted sintering to form fine grids on the cell slabs, significant costs can be saved.

[0056] In S101, the solar cell can be any of the following: PERC cell (Passivated Emitter and Rear Cell), PERT cell (Passivated Emitter and Rear Totally-diffused cell), TOPCon cell (Tunnel Oxide Passivated Contact), or HJT cell (Heterojunction Technology).

[0057] In some embodiments, the solar cell can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0058] In some embodiments, one of the first surface or the second surface can be used as a light-receiving surface, and the other of the first surface or the second surface can be used as a backlighting surface to form a single-sided battery; in other embodiments, both the first surface and the second surface can be used as light-receiving surfaces to form a double-sided battery.

[0059] In some embodiments, the first or second surface may have a textured structure, such as a pyramidal textured surface. This textured structure can enhance the absorption and utilization rate of incident light by the solar cell, thereby improving the light conversion efficiency of the solar cell. If the solar cell is a single-sided cell, the texture can be formed only on one of the first or second surfaces, and the other surface can be a polished surface, which is flatter than the textured surface. It should be noted that for a single-sided cell, texture can also be formed on both the first and second surfaces. If the solar cell is a double-sided cell, texture can be formed on both the first and second surfaces.

[0060] In step S102, the first grid has not yet formed an ohmic contact with the solar cell, while the second grid may or may not have formed an ohmic contact, meaning the second grid is in an under-sintered state. When the second grid may not have formed an ohmic contact with the solar cell, the combined effect of the first laser and the first voltage during subsequent laser-assisted sintering can promote the sintering of the second grid, thereby enabling the second grid to form an ohmic contact with the solar cell. The first grid is either a positive or negative grid, and the second grid is either a positive or negative grid.

[0061] In S103, an ohmic contact is formed between the first fine grid and the second fine grid by applying a first voltage between the first fine grid and the second fine grid and by irradiating the first surface with a first laser.

[0062] exist Figure 2 In this example, taking the first fine grid as the negative grid and the second fine grid as the positive grid, the positive terminal of the first voltage is connected to the first fine grid, and the negative terminal of the first voltage is connected to the second fine grid. In this way, the first voltage forms a reverse bias voltage on the solar cell.

[0063] In other embodiments, the first fine grid can be a positive fine grid, the second fine grid can be a negative fine grid, the positive terminal of the first voltage is connected to the second fine grid, and the negative terminal of the first voltage is connected to the first fine grid, so that the first voltage forms a reverse bias voltage on the battery cell.

[0064] The beam width of the first laser is 100μm to 1500μm, for example, it can be 100μm, 300μm, 500μm, 800μm, 1000μm, 1130μm, 1250μm, 1360μm, 1480μm or 1500μm. The beam width of the first laser refers to the maximum distance between any two points on the edge of the beam of the first laser.

[0065] The first laser can sequentially perform laser-assisted sintering on different first fine grids using a scanning method, and the area irradiated by the first laser spot covers part of the first fine grid and the nearby first surface.

[0066] exist Figure 2 In this example, a first voltage is applied between all the first fine grids and all the second fine grids. In other embodiments, the first voltage can be applied sequentially between the first fine grids and the second fine grids in the corresponding regions according to the area scanned by the first laser, that is, the first voltage is applied between the first fine grids and the second fine grids corresponding to the local area of ​​laser-assisted sintering. It should be noted that for a solar cell with a main grid, the first surface may also have a first main grid, which is electrically connected to multiple first fine grids, and the second surface may also have a second main grid, which is electrically connected to multiple second fine grids. The first voltage can be applied to the first fine grids and the second fine grids by applying the first main grid and the second main grid. If the main grid does not need to be in direct electrical contact with the solar cell, the first main grid and the second main grid only play the role of electrical transmission. Even if the first laser irradiates the area near the main grid during laser-assisted sintering, it will not cause the first main grid (or the first main grid and the second main grid) to be electrically connected to the solar cell. If the main busbar needs to be in direct electrical contact with the solar cell, the first laser irradiates the area near the main busbar during the laser-assisted sintering process, which will also promote the electrical connection between the first main busbar (or the first main busbar and the second main busbar) and the solar cell. Furthermore, during the subsequent contact resistance optimization process, the contact resistance of the first main busbar (or the first main busbar and the second main busbar) will also be optimized.

[0067] For solar cells without a main grid, different first grids are not electrically connected to each other due to the presence of a main grid. Similarly, different second grids are not electrically connected to each other due to the presence of a main grid. Therefore, when applying a first voltage between the first and second grids, it is possible to apply the first voltage only between a portion of the first and second grids, or to apply the first voltage between all the first and second grids.

[0068] Whether voltage is applied to the main grid or the fine grid, it can be achieved by using a pin or by connecting metal wires.

[0069] The shape of the first laser spot can be circular, elliptical, or other shapes.

[0070] The pulse width of the first laser can be from 0.1ns to 500ns, specifically 0.1ns, 0.5ns, 1ns, 5ns, 10ns, 60ns, 100ns, 150ns, 240ns, 350ns, 460ns, or 500ns.

[0071] The wavelength of the first laser can be 300nm~1200nm, for example, it can be 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm or 1200nm.

[0072] The energy density of the first laser can be 20 J / cm². 2 ~60J / cm 2 For example, it can be 20J / cm 2 25J / cm 2 30J / cm 2 35J / cm 2 40J / cm 2 45J / cm 2 50J / cm 2 55J / cm 2 Or 60J / cm 2 .

[0073] The first voltage can be 10V~30V, for example, it can be 10V, 15V, 20V, 25V or 30V.

[0074] In S104, the cutting process divides the solar cell into at least two sub-cells, specifically 2, 3, 4, 6, or 8 sub-cells. The areas of the different sub-cells can be the same or different.

[0075] Cutting processes can employ laser cutting, non-destructive laser scribing, thermal vaporization and melting, and laser-induced scoring separation. Laser cutting utilizes a high-power laser beam to irradiate the solar cell, rapidly heating it to a high temperature, causing the material to melt or vaporize, thus creating a cut. Non-destructive laser scribing uses a laser to rapidly heat the solar cell locally, generating a non-uniform temperature field that induces thermal stress, causing the material to fracture. Thermal vaporization and melting involves directly irradiating the solar cell with a laser beam during the cutting process, causing the material on the cell to rapidly vaporize and melt, forming a cut. Laser-induced scoring separation creates fine scoring on the solar cell, then injects liquid to separate the cell along these scoring lines.

[0076] Passivation treatment involves forming a passivation layer on the cut surface. The material of the passivation layer includes silicon oxide, aluminum oxide, silicon nitride, or amorphous silicon.

[0077] The processes for forming a passivation layer include atomic layer deposition, chemical vapor deposition, physical vapor deposition, or plasma-enhanced chemical vapor deposition.

[0078] After the passivation process forms a passivation layer on the cut surface, it also includes annealing and cooling. The annealing temperature can be between 220℃ and 240℃, such as 220℃, 225℃, 230℃, 235℃, or 240℃; the annealing time can be between 10 minutes and 15 minutes, such as 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or 15 minutes. Cooling can be achieved by air cooling or natural cooling to bring the sectional cells down to room temperature (around 25℃), and the cooling time is usually between 15 minutes and 20 minutes, such as 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, or 20 minutes.

[0079] In S105, a second laser and a second voltage are used to repair the increased contact resistance caused by the cutting and passivation processes, thereby reducing the contact resistance between the first grid and the solar cell again. The energy density of the second laser is less than or equal to the energy density of the first laser, and / or the second voltage is less than the first voltage. This allows for precise and gentle repair of contact points whose performance has degraded due to the cutting and passivation processes, avoiding over-sintering of those contact points that still maintain good contact performance.

[0080] In some embodiments, the spot size of the first laser is larger than that of the second laser. Since all the first grids on the entire solar cell need to be sintered during laser-assisted sintering, a larger spot size of the first laser is beneficial to improving the efficiency of laser-assisted sintering. In the process of contact resistance optimization, it is necessary to accurately optimize the contact points with degraded performance, and the area to be irradiated is relatively small. Therefore, the second laser can use a smaller spot size.

[0081] The beam width of the second laser is 10μm to 500μm, for example, it can be 10μm, 30μm, 50μm, 80μm, 100μm, 148μm, 200μm, 260μm, 300μm, 340μm, 400μm, 450μm or 500μm. The beam width of the second laser refers to the maximum distance between any two points on the edge of the beam of the second laser.

[0082] The second laser can sequentially optimize the contact resistance of different first fine grids by scanning, and the area irradiated by the second laser spot covers part of the first fine grid and the nearby first surface.

[0083] The shape of the second laser spot can be circular, elliptical, or other shapes.

[0084] The pulse width of the second laser can be from 0.1ns to 500ns, specifically 0.1ns, 0.5ns, 1ns, 5ns, 10ns, 60ns, 100ns, 150ns, 240ns, 350ns, 460ns, or 500ns.

[0085] The wavelength of the second laser can be 300nm~1200nm, for example, it can be 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm or 1200nm.

[0086] The energy density of the second laser can be 1 J / cm². 2 ~30J / cm 2 For example, it could be 1 J / cm 2 3J / cm 2 5J / cm 2 10J / cm 2 15J / cm 2 20J / cm 2 25J / cm 2 Or 30J / cm 2 .

[0087] In some embodiments, the wavelength of the first laser is the same as the wavelength of the second laser. This improves process repeatability and reliability, avoiding absorption uncertainties caused by using different wavelengths for the first and second lasers. The same wavelength ensures that laser energy is preferentially absorbed by the same material, allowing contact resistance optimization to be precisely applied to the interface region formed by laser-assisted sintering, rather than other areas. Furthermore, since the first and second lasers have the same wavelength, laser-assisted sintering and contact resistance optimization can be performed on the same equipment, eliminating the need for physical switching or optical path calibration between the two lasers. This saves conversion time between processes, increases production cycle time, and improves overall capacity. In addition, it significantly reduces experimental variables and complexity, accelerating the process maturation cycle.

[0088] The second voltage can be 5V~20V, for example, it can be 5V, 8V, 10V, 13V, 15V, 17V or 20V.

[0089] In some embodiments, after irradiating at least a portion of the first surface of the cell with a second laser and applying a second voltage to the first and second grids, the method further includes: irradiating at least a portion of the second surface of the cell with the second laser and applying a second voltage to the first and second grids. This can also optimize the contact resistance of the second grids on the second surface to correct defects caused by increased contact resistance between the second grids and the cell due to cutting and passivation processes.

[0090] For example, the first surface is first irradiated with a second laser while a second voltage is applied to the first and second fine grids; then the cell is flipped over and the second surface is irradiated with a second laser while a second voltage is applied to the first and second fine grids, so that the contact resistance of the first and second fine grids can be optimized in sequence, thus eliminating the need for additional laser equipment.

[0091] During the process of using the second laser to irradiate the second surface, the second laser can sequentially optimize the contact resistance of different second fine grids by scanning. The area irradiated by the second laser spot covers the second fine grid and a part of the second surface nearby.

[0092] In other embodiments, the steps of irradiating at least a portion of the first surface of the segmented cell with a second laser and applying a second voltage to the first and second grids further include: irradiating the second surface with a third laser; wherein the energy density of the third laser is lower than the energy density of the second laser. The simultaneous action of the third laser and the second voltage can repair defects caused by increased contact resistance between the second grid and the cell due to cutting and passivation processes.

[0093] For example, a second laser is used to irradiate the first surface, while a third laser is used to irradiate the second surface. A second voltage is applied to both the first and second fine gates to simultaneously optimize their contact resistance, thus improving the efficiency of contact resistance optimization. Since the first and second surfaces are irradiated by the second and third lasers respectively, the energy density of the third laser needs to be lower (compared to the energy density of the second laser) under the combined effect of the two lasers to avoid over-sintering of the second fine gate.

[0094] During the process of using a third laser to irradiate the second surface, the third laser can sequentially optimize the contact resistance of different second fine grids by scanning. The area irradiated by the spot of the third laser covers the second fine grid and a part of the second surface nearby.

[0095] In some embodiments, the orthographic projection of the second laser on the first surface and the orthographic projection of the third laser on the first surface can overlap, so that the contact resistance of the first and second fine grids in the same area of ​​the slab battery can be optimized simultaneously.

[0096] exist Figure 2 In this example, a second voltage is applied between all the first and second fine gates. In other embodiments, the second voltage can be applied sequentially between the first and second fine gates in the corresponding regions scanned by the second or third laser; or the second voltage can be applied between the first and / or second fine gates where contact resistance optimization is required.

[0097] The specific method of applying the second voltage to the first and second fine gates can refer to the method of applying the first voltage to the first and second fine gates described above, and will not be repeated here.

[0098] In some embodiments, a second laser is used to irradiate at least a portion of the first surface of the cell slabs, and a second voltage is applied to the first and second grids, thereby selecting a portion of the cell slabs for contact resistance optimization. In other embodiments, a second laser is used to irradiate the first surface of all cell slabs, and a second voltage is applied to the first and second grids, thereby directly optimizing the contact resistance of all cell slabs.

[0099] The following explanation will focus on optimizing the contact resistance of selected battery cells.

[0100] As an example of screening cell segments prior to S105, the specific steps may include: obtaining the actual contact resistance value of the cell segments; if the actual contact resistance value is greater than a preset resistance value, then optimizing the contact resistance of the cell segments; if the actual contact resistance value is less than or equal to the preset resistance value, then not optimizing the contact resistance of the cell segments. Screening out cell segments requiring contact resistance optimization based on preset resistance values ​​and then optimizing them can save the contact resistance optimization steps, improving production cycle time and capacity.

[0101] In some embodiments, the preset resistance value can be the contact resistance value of the solar cell after laser-assisted sintering. If the contact resistance of the segmented solar cells does not increase, contact resistance optimization is not required for the segmented solar cells; optimization is only needed for the segmented solar cells whose contact resistance increases due to cutting and passivation processes.

[0102] In other embodiments, the preset resistance value can also be the contact resistance value of the segmented battery while meeting the preset conversion efficiency. If the contact resistance of the segmented battery can still meet a high conversion efficiency even if it is increased, then contact resistance optimization is not required for the segmented batteries; optimization can be performed only for the segmented batteries with lower conversion efficiency gains.

[0103] As another example of screening cell slabs before S105, the specific steps can be as follows: after laser-assisted sintering and before cutting, a first test is performed on the cell slabs to obtain a first contact resistance; after passivation and before contact resistance optimization, a second test is performed on the cell slabs to obtain a second contact resistance; contact resistance optimization is performed on at least some of the cell slabs, which can specifically include: obtaining the deviation value of the second contact resistance from the first contact resistance; if the deviation value is greater than a target value, contact resistance optimization is performed; if the deviation value is less than or equal to the target value, contact resistance optimization is not performed.

[0104] In other words, based on the deviation values ​​of the first contact resistance of the solar cell after laser-assisted sintering and the second contact resistance of the segmented solar cell after cutting and passivation, it is determined whether the contact resistance of the segmented solar cell has increased due to the cutting and passivation processes. If it has not increased or the increase is within a reasonable range, contact resistance optimization is not necessary. Only the segmented solar cells with significantly increased contact resistance need to be optimized.

[0105] The target value can be calculated based on the allowable increase in contact resistance. For example, if the contact resistance of the segmented battery is allowed to rise to 1.2 times the first contact resistance, then the target value can be set as the first contact resistance multiplied by 0.2.

[0106] Figure 3 A top view of a battery cell provided in an embodiment of this application; Figure 4 A top view of the battery cell provided in the embodiments of this application after it has been cut into multiple battery segments.

[0107] Reference Figure 3 and Figure 4 In some embodiments, in the first test (before the cutting and passivation processes), the battery cell 100 is divided into at least two sub-regions 10 according to the cutting line S. Each sub-region 10 corresponds to a segment of the battery cell 1001 after the cutting and passivation processes. The first contact resistance is characterized by the contact resistance of the sub-region 10. In the second test (after the cutting and passivation processes), the second contact resistance is characterized by the contact resistance of the segment of the battery cell 1001. That is, the first and second tests use the segment of the battery cell as a test unit to determine whether the contact resistance of a single segment of the battery cell increases due to the cutting and passivation processes.

[0108] It is understandable that cutting and passivation processes have different effects on different areas of the solar cell, and consequently, the contact resistance of different cell segments is affected to varying degrees. By using a single cell segment as a test unit, contact resistance optimization can be carried out in a targeted manner based on the changes in contact resistance of each cell segment.

[0109] Furthermore, in the contact resistance optimization step, different energy densities and voltages of the second laser are selected based on the magnitude of the deviation value. This allows for the selection of appropriate second laser energy densities and voltages for each cell segment with varying degrees of contact resistance increase. A larger deviation value indicates that the individual cell segment is more significantly affected by the cutting and passivation processes, requiring a relatively higher second laser energy density and voltage for contact resistance optimization compared to other cell segments to improve the repair outcome. Conversely, a smaller deviation value indicates that the individual cell segment is less affected by the cutting and passivation processes, requiring a relatively lower second laser energy density and voltage for contact resistance optimization compared to other cell segments.

[0110] For example, the energy density range of the second laser is divided into a first energy range and a second energy range, where the maximum value of the first energy range equals the minimum value of the second energy range; similarly, the range of the second voltage is divided into a first voltage range and a second voltage range, where the maximum value of the first voltage range equals the minimum value of the second voltage range. If the difference between the second contact resistance and the first contact resistance is within the first range, then a value within the first energy range is selected as the energy density of the second laser, and a value within the first voltage range is selected as the magnitude of the second voltage for contact resistance optimization. If the difference between the second contact resistance and the first contact resistance is within the second range, then a value within the second energy range is selected as the energy density of the second laser, and a value within the second voltage range is selected as the magnitude of the second voltage. Here, the minimum value of the first range equals the maximum value of the second range.

[0111] Reference Figure 3 and Figure 4 In some embodiments, in the first test (before the cutting and passivation processes), the cell 100 is divided into at least two sub-regions 10 according to the cutting line S. Each sub-region 10 corresponds to a cell 1001 after the cutting and passivation processes. The first contact resistance is characterized by the contact resistance between a portion of the first grids 111 in the sub-region 10 and the cell. In the second test, the second contact resistance is characterized by the contact resistance between the selected first grids 111 in the first test and the cell 1001. That is, the first and second tests use a single first grid as a test unit. Based on whether the contact resistance of a single first grid increases due to the cutting and passivation processes, it is determined whether contact resistance optimization of the cell 1001 is necessary.

[0112] It is understandable that cutting and passivation processes have different effects on different areas of the solar cell, and consequently, the contact resistance of different first grids is affected to varying degrees. By using a single first grid as a test unit, the contact resistance of individual solar cells can be optimized in a targeted manner based on the changes in the contact resistance of each single first grid.

[0113] For example, refer to Figure 3 In the first test, the first fine grids selected were 111a, 111b, 111c, 111d, 111e, and 111f, and the first contact resistance was the contact resistance value corresponding to the length of 111a, 111b, 111c, 111d, 111e, and 111f in each sub-region 10. Because... Figure 3 The two sub-regions 10, one above the other, are of the same size. Therefore, when testing the first contact resistance of 111a, 111b, and 111c in the upper left sub-region 10, the length of the first fine grid is measured using the cutting line S as the boundary. Only the contact resistance values ​​of 111a, 111b, and 111c located above the cutting line S are measured as the first contact resistance values. The testing method for the first contact resistance of the selected first fine grid in other sub-regions 10 is similar. (Reference) Figure 4 In the second test, the second contact resistances corresponding to 111a, 111b, 111c, 111d, 111e, and 111f were obtained on each of the cell segments 1001.

[0114] Furthermore, in the contact resistance optimization step, the energy density of the second laser corresponding to different first fine grids is selected according to the magnitude of the deviation value. On the same cell segment, the second voltage used for different first fine grids is the same. During the contact resistance optimization process for the cell segment, each single first fine grid is treated as a unit, and contact resistance optimization is performed only on the first fine grid that needs repair; it is not necessary to optimize the contact resistance of all first fine grids in the entire cell segment. The applied second voltage is applied to the entire cell segment as a unit, and the second voltage applied between different first and second fine grids is the same. Only the energy density of the corresponding second laser needs to be selected for different first fine grids, thus improving the efficiency of contact resistance optimization. Specifically, if the deviation value is large, it indicates that the single first fine grid is more affected by the cutting and passivation processes, requiring a relatively larger second laser energy density for contact resistance optimization compared to other first fine grids to improve the repair degree; if the deviation value is small, it indicates that the single first fine grid is less affected by the cutting and passivation processes, requiring a relatively smaller second laser energy density for contact resistance optimization compared to other first fine grids.

[0115] In the above embodiments, for ease of explanation, it is taken as an example that the number of first fine grids selected in each sub-region is 3.

[0116] In some embodiments, within a sub-region, the total number of first fine grids is a first number, and a second number of first fine grids corresponding to a first contact resistance are selected within the sub-region. The ratio of the second number to the first number is 0.5 to 1. That is, at least half of the first fine grids on the cell are selected for corresponding first and second tests, while the remaining first fine grids are not tested or have their contact resistance optimized. Since there are a large number of fine grids on the cell, selecting at least half of the first fine grids for the first and second tests, and optimizing the contact resistance, can improve production cycle time and capacity, while ensuring that the overall contact resistance of the cell can be effectively repaired.

[0117] Contact resistance can be tested using the TLM (Transmission Line Method), a method for measuring the contact resistance of electronic devices. Its basic principle is to use transmission line theory to calculate the contact resistance by measuring the voltage and current on the device pins.

[0118] exist Figure 3 and Figure 4 In this example, the battery cell 100 is cut into four identical battery segments 1001. In other embodiments, the number of battery segments into which the battery cell is cut can be 2, 3, 5, 8, or 10, and the sizes of the different battery segments can also be different. The division methods for the first test and the second test can be adjusted accordingly in conjunction with the above embodiments.

[0119] exist Figure 3 and Figure 4 In this example, two perpendicular cutting lines are used for illustration, which does not constitute a limitation on the direction and number of cutting lines. In other embodiments, continuing with the example of four-cell cells, the number of cutting lines can be three, and the three cutting lines can be parallel to each other to divide the cell into four cells of the same length.

[0120] In the solar cell manufacturing method provided in this application embodiment, after forming a first fine grid and a second fine grid on the first and second surfaces of the cell, respectively, a first laser and a first voltage are used to perform laser-assisted sintering on the first fine grid to form a good ohmic contact between the first fine grid and the cell. During the laser-assisted sintering process, the first laser excites the cell to generate charge carriers, which flow in a directional manner using a second voltage to form a loop. When the loop current flows through the interface between the first fine grid and the semiconductor in the cell, a significant thermal effect is generated due to the relatively high contact resistance between the metal and the semiconductor, thereby promoting the mutual diffusion between the metal and the semiconductor to obtain a first fine grid with excellent contact characteristics after sintering. Subsequently, the cell is cut and passivated to form multiple cell segments. Since the cutting and passivation processes cause a decrease in the contact resistance between the first fine grid and the cell, a second laser and a second voltage are further used to optimize the contact resistance of at least some of the cell segments. Using a second laser with a lower energy density and / or a smaller second voltage can accurately and gently repair the contact resistance. The second voltage creates an electric field within the cell slabs, driving glass ions in the silver paste to migrate towards the interface. Combined with the localized thermal effect of the second laser, this locally anneales the stress-damaged interface areas, repairing microcracks and lattice distortions caused by the cutting process, and restoring tight contact between the metal and semiconductor. Because it uses lower energy and / or voltage, the contact resistance optimization process is gentler, repairing only those contact points whose performance has degraded due to cutting and passivation, without over-sintering those that remain in good condition. Compared to first performing cutting and passivation, and then using laser-assisted sintering to form fine grids on the cell slabs, significant costs can be saved.

[0121] According to a specific embodiment of this application: after forming a first fine grid with a linewidth of 8.86 μm and a line height of 18.7 μm on the battery cell, a first laser and a first voltage are used to perform laser-assisted sintering on all the first fine grids on the entire battery cell, and the average contact resistance of the first fine grids after sintering is 2.4 mΩ; then the battery cell is cut and passivated, and the average contact resistance of the first fine grids on the segmented battery is 3.0 mΩ; after optimizing the contact resistance of the segmented battery by using a second laser with the same first laser and first current and a second voltage, the average contact resistance of the first fine grids on the segmented battery can be reduced to 2.5 mΩ.

[0122] According to another specific embodiment of this application, after forming a first fine grid with a linewidth of 8.62 μm and a line height of 12.51 μm on the battery cell, a first laser and a first voltage are used to perform laser-assisted sintering on all the first fine grids on the entire battery cell. The average contact resistance of the first fine grids after sintering is 2.2 mΩ. Then, the battery cell is cut and passivated, and the average contact resistance of the first fine grids on the segmented battery is 3.3 mΩ. After optimizing the contact resistance of the segmented battery by using a second laser and a second voltage, which are the same as the first laser and the first voltage, the average contact resistance of the first fine grids on the segmented battery can be reduced to 2.3 mΩ.

[0123] For finer grids with narrower linewidths, the effects of cutting and passivation processes on the contact resistance of the grids are more pronounced. Using the solar cell manufacturing method provided in this embodiment, a first fine grid with excellent contact performance is first formed on the cell using laser-assisted sintering, followed by cutting and passivation processes. This optimizes the contact resistance of the cell segments and can repair the contact points of the cell segments whose performance has degraded due to cutting and passivation processes, thereby reducing the contact resistance again.

[0124] Accordingly, another embodiment of this application also provides a solar cell, which is prepared using the solar cell manufacturing method described in the above embodiments. For parts that are the same as or corresponding to the previous embodiment, please refer to the corresponding descriptions of the foregoing embodiments; detailed descriptions will not be repeated below.

[0125] The solar cell is manufactured using the method described in the above embodiments. The first grid on the solar cell is sintered using laser-assisted sintering to form a good ohmic contact between the first grid and the cell. After cutting and passivation, although the contact resistance between the first grid and the cell segments decreases, the contact resistance is optimized using a second laser and a second voltage. Using a second laser with lower energy density and / or a lower second voltage allows for precise and gentle repair of the contact resistance, enabling the metal and semiconductor to re-establish a tight contact. The good ohmic contact between the grid and the cell segments in the solar cell helps reduce power loss and improve the efficiency of the solar cell.

[0126] Solar cells can be any type of PERC cell, PERT cell, TOPCon cell, or HJT cell.

[0127] Solar cells can be monocrystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, or multi-component compound solar cells. Specifically, multi-component compound solar cells can be cadmium sulfide solar cells, gallium arsenide solar cells, copper indium selenide solar cells, or perovskite solar cells.

[0128] Figure 5 This is a schematic diagram of a stacked battery provided in an embodiment of this application.

[0129] refer to Figure 5 According to some embodiments of this application, another aspect of this application provides a tandem battery, including: at least two perovskite top cells 201; a crystalline silicon bottom cell 202, the crystalline silicon bottom cell 202 being the solar cell in the above embodiments; and a composite layer 203 located between the perovskite top cell 201 and the crystalline silicon bottom cell 202.

[0130] The perovskite top solar cell 201 may include an electron transport layer 211, a perovskite absorber layer 221 and a hole transport layer 231, with the perovskite absorber layer 221 located between the electron transport layer 211 and the hole transport layer 231.

[0131] The chemical formula of the perovskite absorber layer 221 is ABX3, where A can be CH3NH3. + NH(CH3)2 + Cs + Or Rb + B can be Pb 2+ Sn 2+ Or Sr 2+ X can be I - ,Br - Cl - .

[0132] The materials of electron transport layer 211 include tin oxide, titanium dioxide, and C. 60 Materials such as fullerenes and their derivatives.

[0133] The hole transport layer 231 is made of molybdenum oxide, cuprous thiocyanate, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], and poly(3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS).

[0134] exist Figure 5 In one embodiment, the hole transport layer 231 is located between the composite layer 203 and the perovskite absorber layer 221, and the electron transport layer 211 is located on the side of the perovskite absorber layer 221 away from the composite layer 203. In other embodiments, the electron transport layer is located between the composite layer and the perovskite absorber layer, and the hole transport layer is located on the side of the perovskite absorber layer away from the composite layer.

[0135] The composite layer 203 is made of transparent conductive oxide (TCO), metal oxide, or ultrathin metal.

[0136] Transparent conductive oxides include indium tin oxide (ITO) or zinc oxide; metal oxides include MoO. x WOx Or V2O5, etc.; ultrathin metals (1nm~2nm) include gold (Au) or silver (Ag).

[0137] It should be noted that, in Figure 5 In this illustration, the hole transport layer 231 is in direct contact with the composite layer 203, the perovskite absorber layer 221, and the electron transport layer 211, respectively. This does not imply that the perovskite top solar cell 201 only includes the aforementioned film layers. In other embodiments, other film layers may also be included between the hole transport layer 231 and the composite layer 203, between the hole transport layer 231 and the perovskite absorber layer 221, and between the perovskite absorber layer 221 and the electron transport layer 211.

[0138] Figure 6 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0139] refer to Figure 6 According to some embodiments of this application, another aspect of this application also provides a photovoltaic module, including: a battery component 301, which is a solar cell in the above embodiments or a tandem battery in the above embodiments; a connecting component 302, which is used to connect adjacent battery components 301; an encapsulating film 303, which covers the surface of the battery component 301; and a cover plate 304, which is located on the side of the encapsulating film away from the battery component 301.

[0140] The connecting component 302 includes a busbar and a solder strip. The solder strip is used to connect adjacent solar cells or tandem cells to form a cell string. The solder strip is responsible for transmitting the current generated by the cell string to the busbar. The busbar is used to collect the current from multiple cell strings and transmit it to the junction box to ensure effective current conduction.

[0141] The materials for the 303 film can be organic encapsulation films such as ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0142] The cover plate 304 can be a glass cover plate, a plastic cover plate, or other cover plates with light transmission function.

[0143] In some embodiments, the surface of the cover plate 304 facing the adhesive film 303 can be an uneven surface, thereby increasing the utilization rate of incident light.

[0144] exist Figure 6 The positive and negative electrodes of the battery component 301 are located on the two side surfaces of the battery component 301, respectively, and the two ends of the corresponding connecting component 302 are located on the opposite side surfaces of two adjacent battery components 301.

[0145] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for manufacturing a solar cell, characterized in that, include: A battery cell is provided, the battery cell including opposing first and second surfaces; A first fine gate is formed on the first surface, and a second fine gate is formed on the second surface; The first surface of the battery cell is irradiated with a first laser, and a first voltage is applied to the first and second fine grids; The battery cell is cut to divide it into at least two battery segments, and the cut surfaces of the battery segments are passivated. The first surface of at least a portion of the segmented cell is irradiated with a second laser, and a second voltage is applied to the first and second fine grids; The second surface of at least a portion of the segmented battery is irradiated with a third laser; wherein the energy density of the third laser is less than or equal to the energy density of the second laser. Wherein, the energy density of the second laser is less than the energy density of the first laser, and / or, the second voltage is less than the first voltage.

2. The method for manufacturing a solar cell according to claim 1, characterized in that, After the passivation treatment is performed, before irradiating at least a portion of the first surface of the sectional cell with the second laser and before applying the second voltage to the first and second grids, the process includes: Obtain the actual contact resistance value of the segmented battery; If the actual contact resistance value is greater than the preset resistance value, the second laser is used to irradiate the first surface of the segmented battery, and the second voltage is applied to the first fine grid and the second fine grid. If the actual contact resistance value is less than or equal to the preset resistance value, then the segmented battery will not be processed.

3. The method for manufacturing a solar cell according to claim 1, characterized in that, After irradiating the first surface of the solar cell with the first laser and applying the first voltage to the first and second grids, and before performing the cutting process, the process includes: performing a first test on the solar cell to obtain a first contact resistance; After the passivation treatment is performed, before irradiating at least a portion of the first surface of the sectional cell with the second laser and before applying the second voltage to the first and second grids, the process includes: A second test is performed on the segmented battery to obtain the second contact resistance; Obtain the deviation value of the second contact resistance compared to the first contact resistance; If the deviation value is greater than the target value, the second laser is used to irradiate the first surface of the segmented battery, and the second voltage is applied to the first and second fine grids; If the deviation value is less than or equal to the target value, then the segmented battery will not be processed.

4. The method for manufacturing a solar cell according to claim 3, characterized in that, In the first test, the battery cell is divided into at least two sub-regions, each sub-region corresponding to one of the battery cells, and the first contact resistance is characterized as the contact resistance of the sub-region; In the second test, the second contact resistance is characterized as the contact resistance of the segmented battery.

5. The method for manufacturing a solar cell according to claim 4, characterized in that, In the step of irradiating the first surface of the segmented cell with the second laser and passing the second voltage to the first and second fine grids, different energy densities of the second laser and the second voltage are selected according to the magnitude of the deviation value.

6. The method for manufacturing a solar cell according to claim 3, characterized in that, In the first test, the battery cell is divided into at least two sub-regions, each sub-region corresponding to one of the battery cells, and the first contact resistance is characterized as the contact resistance between each of the first grids in a certain number of the sub-regions and the battery cell. In the second test, the second contact resistance is characterized as the contact resistance between each of the first fine grids selected in the first test and the segmented cell.

7. The method for manufacturing a solar cell according to claim 6, characterized in that, In the step of irradiating the first surface of the cell with the second laser and passing the second voltage to the first and second fine grids, the energy density of the second laser corresponding to different first fine grids is selected according to the magnitude of the deviation value. On the same cell, the magnitude of the second voltage used for different first fine grids is the same.

8. The method for manufacturing a solar cell according to claim 6, characterized in that, In the sub-region, the total number of the first fine gates is a first number, and a second number of the first contact resistances corresponding to the first fine gates are selected in the sub-region. The ratio of the second number to the first number is 0.5 to 1.

9. The method for manufacturing a solar cell according to claim 1, characterized in that, The second laser is used to irradiate the first surface of all the segmented cells, and the second voltage is applied to the first and second grids.

10. The method for manufacturing a solar cell according to claim 1, characterized in that, The spot size of the first laser is larger than the spot size of the second laser.

11. A solar cell, characterized in that, It is prepared by the manufacturing method of any one of claims 1 to 10.

12. A stacked battery, characterized in that, include: Perovskite top solar cell; A crystalline silicon bottom cell, wherein the crystalline silicon bottom cell is the solar cell described in claim 11; A composite layer is located between the perovskite top cell and the crystalline silicon bottom cell.

13. A photovoltaic module, characterized in that, include: At least two battery components, wherein the battery components are solar cells as described in claim 11, or tandem cells as described in claim 12; A connecting component for connecting adjacent battery components; An adhesive film covering the surface of the battery component; A cover plate located on the side of the adhesive film away from the battery component.

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