Solar cell and method of manufacturing the same, photovoltaic module

Abstract

The application relates to the photovoltaic technical field and discloses a solar cell, a preparation method thereof and a photovoltaic module. The preparation method of the solar cell comprises the following steps: providing a cell piece, the cell piece being provided with a demarcation area on the surface and printing areas located on the two sides of the demarcation area, and the printing areas being printed with metal grid lines; adopting a first laser to sinter the metal grid lines; adopting a second laser to cut the demarcation area within a preset time, so that the printing areas on the two sides of the demarcation area are separated; wherein the first laser and the second laser are emitted by the same laser head, or the laser head for emitting the first laser and the laser head for emitting the second laser are connected to the same laser via a light splitting device. The solar cell, the preparation method thereof and the photovoltaic module provided by the application can be beneficial to improving the production efficiency and processing precision of the solar cell.

Description

Technical Field

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

[0002] With the continuous development of new energy technologies, the installed power generation capacity of photovoltaic modules is also constantly increasing. Photovoltaic modules can be installed in various environments such as factory rooftops, deserts, and water surfaces, making them applicable to a wide range of scenarios. Photovoltaic modules are formed by encapsulating solar cells, which possess the photovoltaic effect, enabling them to absorb solar energy and output electrical energy.

[0003] The manufacturing process of solar cells involves multiple steps, and the successful execution of each step directly impacts the production efficiency and processing precision of the solar cells. Therefore, improving the production efficiency and processing precision of solar cells is a crucial issue. Summary of the Invention

[0004] The purpose of this application is to provide a solar cell and its preparation method, as well as a photovoltaic module, which can help improve the production efficiency and processing accuracy of solar cells.

[0005] To address the aforementioned technical problems, embodiments of this application provide a method for fabricating a solar cell. The method for fabricating a solar cell includes:

[0006] A battery cell is provided, the surface of which has a dividing area and a printing area on both sides of the dividing area, the printing area having metal grid lines printed on it;

[0007] The metal grid lines are sintered using a first laser.

[0008] Within a preset time, a second laser is used to cut the dividing area, separating the printing areas on both sides of the dividing area.

[0009] In this configuration, the first laser and the second laser are emitted from the same laser head, or the laser head emitting the first laser and the laser head emitting the second laser are connected to the same laser via a beam splitter.

[0010] The embodiments of this application also provide a solar cell, which is manufactured using the above-described solar cell fabrication method. The solar cell includes a cell with metal grid lines on its surface, the metal grid lines being subjected to a first laser sintering treatment, and the cell having a cut edge formed by a second laser scribing process.

[0011] This application also provides a photovoltaic module. The photovoltaic module includes a battery string, an encapsulating film, and a cover plate. The battery string includes multiple solar cells as described above, or solar cells manufactured using the aforementioned solar cell fabrication method. The encapsulating film covers the surface of the battery string. The cover plate covers the surface of the encapsulating film away from the battery string.

[0012] The solar cells and their fabrication methods, as well as the photovoltaic modules provided in this application, undergo laser scribing within a preset time after the solar cells have undergone laser sintering. The first laser during sintering and the second laser during scribing can be emitted from the same laser head or from laser heads located on different optical paths of the laser, thus integrating the sintering laser and the scribing laser to perform the laser sintering and scribing processes of the solar cells in a coordinated manner. This improves the processing efficiency of the solar cells, reduces positioning errors, and increases processing accuracy.

[0013] In some implementations, the preset time is greater than or equal to 5ms and less than or equal to 10ms.

[0014] In some embodiments, before cutting the boundary area with a second laser, the method further includes scanning the cutting position of the boundary area with a first laser.

[0015] In some embodiments, sintering the metal grid lines with a first laser includes: sintering the metal grid lines on one side of the boundary region with a first laser; sintering the metal grid lines on the other side of the boundary region with a first laser; and scanning the cutting position of the boundary region with a first laser after sintering the metal grid lines on one side of the boundary region with a first laser and before sintering the metal grid lines on the other side of the boundary region with a first laser.

[0016] In some implementations, the spot width of the first laser when scanning the boundary region is 300 μm to 600 μm.

[0017] In some implementations, the diameter of the laser spot used to cut the boundary region by the second laser is 600 μm to 1300 μm.

[0018] In some embodiments, the metal grid line includes multiple fine grids, and sintering the metal grid line with a first laser includes: scanning sequentially along the extension path of the multiple fine grids with the first laser, and the areas traversed by the first laser when scanning two adjacent fine grids are adjacent to each other.

[0019] In some embodiments, after cutting the boundary area with a second laser, the method further includes: using a second laser to perform a secondary cut on the cut battery cell, wherein the diameter of the laser spot during the secondary cut is less than or equal to 100 μm. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This is a flowchart of a method for fabricating a solar cell provided in some embodiments of this application;

[0022] Figure 2 This is a schematic diagram of the structure of the solar cell provided in the method for preparing a solar cell according to some embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in some embodiments of this application.

[0024] Reference numerals: 10, solar cell; 101, dividing area; 102, printing area; 11, metal grid line; 111, fine grid; 112, main grid; 12, irradiation area; 20, solder ribbon; 100, solar cell string; 200, encapsulation film; 300, cover plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0028] After the grid electrodes of a solar cell are printed using a screen printing process, it undergoes a sintering process to solidify the electrode paste on the surface. Following this, the solar cell is diced, dividing the entire cell into individual cells. With the application of laser processing technology, both the sintering and dicing of solar cells can be performed using lasers. Lasers can generate significant radiation energy in a short time, thereby heating the electrode paste on the surface of the solar cell and heating the diced areas.

[0029] Currently, laser-assisted sintering and laser scribing of solar cells are performed at different stations. After laser sintering, the solar cells undergo testing. Following testing, they are transferred to the scribing station for laser scribing. This results in the solar cells undergoing multiple positioning processes during manufacturing, affecting their processing accuracy. Furthermore, performing laser scribing after directional and positional adjustments negatively impacts processing efficiency.

[0030] In order to improve the processing efficiency and accuracy of solar cells, some embodiments of this application provide a method for preparing solar cells by integrating sintering laser and scribing laser to achieve seamless connection between the two processes, thereby improving processing accuracy and processing efficiency simultaneously.

[0031] The following is combined Figure 1 This application describes methods for fabricating solar cells according to some embodiments. Among them, Figure 2 The structure of the battery cell is shown.

[0032] like Figure 1 As shown, some embodiments of this application provide a method for fabricating a solar cell that includes the following steps:

[0033] Step S110: Provide a battery cell with a dividing area on its surface and printing areas on both sides of the dividing area, the printing areas being printed with metal grid lines.

[0034] The solar cell 10, as a crucial component of the photovoltaic module, plays a vital role in converting solar energy into electrical energy. The PN junction formed in the solar cell 10 exhibits the photovoltaic effect, generating current under sunlight and discharging it externally via solder ribbons connected to the solar cell 10. The solar cell 10 typically includes a substrate, a PN junction and passivation structure formed on the substrate, and grid electrodes, i.e., metal grid lines 11, located on the surface of the solar cell 10. The substrate is typically silicon, and the grid electrodes include fine grids 111, which are used to conduct the current generated by the PN junction. The materials of the grid electrodes can include one or more of aluminum, silver, gold, nickel, molybdenum, and copper. The grid electrodes may also include a main grid 112, which collects the current conducted by the fine grids 111 and connects to the solder ribbons, allowing the current to be discharged to the outside.

[0035] The solar cell 10 can be a PERC cell (Passivated Emitter and Rear Cell), a PERT cell (Passivated Emitter and Rear Totally diffused cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Heterojunction Technology), or a BC cell (BackContact). In some embodiments, the solar cell 10 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.

[0036] The battery cell 10 has a large front and back surface. The front surface can serve as a light-receiving surface to receive incident light, while the back surface can serve as a backlighting surface; that is, the battery cell 10 is a single-sided battery. In some embodiments, both the front and back surfaces can serve as light-receiving surfaces, meaning the battery cell 10 is a double-sided battery. It is understood that the backlighting surface referred to in the embodiments of this application can also receive incident light, but the degree of reception of incident light is weaker than that of the light-receiving surface, and therefore it is defined as a backlighting surface.

[0037] The surface of the solar cell 10 has a dividing area 101, which is the area on the surface of the solar cell 10 where the metal grid lines 11 are not printed, while the printed area 102 is the area on the surface of the solar cell 10 where the metal grid lines 11 are printed. The dividing area 101 is located in the area where the center dividing line AA' of the solar cell 10 is located, corresponding to the position of the laser scribing. The metal grid lines 11 can be printed on one or both sides of the solar cell 10 to form a single-sided cell or a double-sided cell. It should be noted that the dividing area 101 and the printed area 102 are artificially defined areas for ease of explanation and are not actually clearly defined areas on the surface of the solar cell 10.

[0038] Step S120: The metal grid lines are sintered using a first laser.

[0039] The first laser can sinter the metal grid lines 11 printed on the surface of the solar cell 10. The first laser uses a laser head to output a continuous wave or a long pulse wave, which can sinter and solidify the metal paste forming the metal grid lines 11 printed on the surface of the solar cell 10. The first laser can scan along the location of the fine grid lines 111 or scan the entire surface of the solar cell 10, both methods completing the sintering process. When using the first laser to sinter the metal grid lines 11, scanning can be performed on the front side of the solar cell 10.

[0040] Step S130: Within a preset time, a second laser is used to cut the dividing area, so that the printing areas on both sides of the dividing area are separated.

[0041] After laser sintering of the solar cell 10, a second laser is used to cut the dividing area 101, separating the printed areas 102 on both sides of the dividing area 101, thus forming two half-cells from the original solar cell. The second laser uses an ultra-short pulse wave output from a laser head to reduce the heat-affected zone and microcracks. After the first cut, the half-cells can be further cut to form three- or four-cell cells. After dicing, the edges of the half-cells can be passivated to repair defects at the cut edges. In practice, non-destructive cutting can be used for dicing. After the second laser scan forms a microcrack, water cooling can be used to cause the solar cell 10 to break at the cut location, thus forming different cell segments.

[0042] In this configuration, the first laser and the second laser are emitted from the same laser head, or the laser head emitting the first laser and the laser head emitting the second laser are connected to the same laser via a beam splitter.

[0043] In other words, sintering lasers and scribing lasers can be emitted from the same laser head, or from laser heads on different optical paths split from the same laser. When using the same laser head to emit different lasers, time-division modulation can be used to emit lasers with the required energy at different processing stages. When using the same laser to connect multiple laser heads to emit different lasers, a beam splitter can be used to connect the multiple laser heads to different optical paths of the laser. By integrating sintering lasers and scribing lasers, laser sintering and scribing of solar cells can be performed at the same workstation, reducing the positioning process of the solar cell 10 and the transfer process between different workstations, thereby improving the processing efficiency and accuracy of solar cells. Furthermore, performing laser scribing within a short time after laser sintering can utilize the residual heat after laser sintering to reduce cutting stress, thereby reducing the occurrence of microcracks in the solar cell 10.

[0044] In practice, laser sintering and laser scribing of solar cells can be performed separately at two adjacent workstations. This reduces the difficulty of transferring the solar cells 10 and also lowers the positioning error of the solar cells 10 during different laser treatments. Different lasers can be emitted by different laser heads, which can be connected to the same laser through a beam splitter, allowing different laser heads to perform different laser treatments on the solar cells 10 at close range. Simultaneously, different laser heads can operate independently to avoid interference between them.

[0045] The solar cell fabrication method provided in some embodiments of this application involves laser scribing within a preset time after the solar cell 10 has undergone laser sintering. The first laser during sintering and the second laser during scribing can be emitted from the same laser head or from laser heads located on different optical paths of the laser, thus integrating the sintering laser and the scribing laser to perform the laser sintering and scribing processes of the solar cell in a coordinated manner. This improves the processing efficiency of the solar cell, reduces positioning errors, and increases processing accuracy.

[0046] When laser sintering and laser scribing the solar cell 10, the same galvanometer system can be used to complete the sintering scanning and cutting path planning, so as to reduce the positioning error. Compared with the solar cell 10 being sintered and scribed separately at different stations, the positioning error can be reduced from less than 20μm to less than 5μm.

[0047] The laser source can emit continuous or pulsed laser light. The laser head can emit picosecond, femtosecond, or nanosecond laser light. The wavelength of the laser can be selected from two different ranges, such as the common 1064nm and 532nm wavelengths. The laser can be a MOPA (Master Oscillator Power Amplifier) ​​laser, a QCW (Quasi Continuous Wave) laser, or a semiconductor laser.

[0048] In practice, power can be dynamically allocated between laser sintering and laser scribing. During laser sintering, the laser output is below 80% power, for example, a continuous wave laser output between 10 watts and 40 watts. During laser cutting, the laser switches to 80% to 100% peak power, for example, a short-pulse laser output between 40 watts and 200 watts. In the optical path design, a high-speed rotating diffractive optical element (DOE) can switch between homogenization and focusing modes within milliseconds, and a CCD (Charge Coupled Device) vision system compensates for optical path offset in real time. In homogenization mode, a flat-topped spot is formed for sintering, while in focusing mode, a Gaussian spot is formed for scribing.

[0049] In some embodiments, the preset time is greater than or equal to 5ms and less than or equal to 10ms.

[0050] By controlling the switching time between laser sintering and laser scribing, the residual heat after laser sintering can be effectively utilized to reduce the cutting stress during laser scribing. The preset time for switching between laser sintering and laser scribing can be from 5ms to 10ms, such as 5ms, 6ms, 7ms, 8ms, 9ms, or 10ms. By controlling the length of the preset time, it is possible to avoid failing to switch to the appropriate laser due to a preset time that is too short, and to avoid failing to effectively utilize the residual heat after laser sintering to cut the solar cell 10 due to a preset time that is too long. This ensures that the laser type switching is completed within a suitable time, and the residual heat of 200℃ to 300℃ remaining after laser sintering is used to cut the solar cell 10.

[0051] In practice, a laser parameter database can be established to provide energy model references for laser sintering and laser scribing processes. By controlling the laser emission to switch to slicing mode within 10ms after laser sintering, the residual heat after laser sintering can be used to reduce cutting stress, reducing the edge chipping rate of the solar cell 10 by 60%. Furthermore, after laser scribing, defects can be repaired on the cut edges of the solar cells 10 using low-energy laser annealing, reducing the cell efficiency loss from 0.8% to 0.2%. During the cutting process, an infrared thermal imager can be used to monitor the cutting temperature in real time and dynamically adjust the slicing laser power. When using the first laser for sintering, the laser energy density can be controlled between 1 joule per square centimeter and 20 joules per square centimeter, and the spot diameter can be controlled between 10 μm and 600 μm. When performing laser scribing, the pulse energy can be controlled at the millijoule level, the repetition frequency is 50kHz to 1000kHz, and the laser scanning speed can be controlled at 500mm / s to 5000mm / s.

[0052] In addition, when laser scribing the battery cell 10, the cutting debris can be removed by negative pressure adsorption to avoid affecting the processing quality of the battery cell 10.

[0053] In some embodiments, before cutting the boundary region with a second laser in step S130, the following steps may also be included:

[0054] Step S101: Use the first laser to scan the cutting position of the boundary area.

[0055] The first laser is a sintering laser, meaning that the sintering laser can be used to pre-scan and preheat the cutting position of the solar cell 10, precisely controlling the temperature at the cutting position. Preheating reduces the power of the subsequent scribing laser, thus narrowing the adjustment range when switching between the sintering and scribing lasers. Simultaneously, the energy of the sintering laser spot is relatively uniform, ensuring even heating of the scanned area and achieving a uniform temperature rise, effectively reducing stress at the cutting position.

[0056] In some embodiments, the step S120 of sintering the metal grid lines with a first laser may include the following steps:

[0057] Step S121: Use the first laser to sinter the metal grid lines on one side of the boundary area.

[0058] A printing area 102 is formed on each side of the dividing region 101, meaning that grid electrodes are printed on both sides of the dividing region 101. During sintering using the first laser, the two printing areas 102 can be scanned sequentially. Each of the two printing areas 102 corresponds to one or more cell segments. The sintering method of the first laser can be to scan multiple grid electrodes sequentially or to scan the entire printing area 102.

[0059] Step S122: Use the first laser to sinter the metal grid lines on the other side of the boundary area.

[0060] After the metal grid lines 11 on one side of the boundary region 101 are sintered, the metal grid lines 11 on the other side of the boundary region 101 can be sintered. Similarly, the sintering method of the first laser can be to scan multiple grid line electrodes sequentially, or to scan the entire printed area 102.

[0061] The scanning of the cutting position of the boundary area using the first laser in step S101 is after the sintering of the metal grid line on one side of the boundary area using the first laser in step S121, and before the sintering of the metal grid line on the other side of the boundary area using the first laser in step S122.

[0062] In other words, when the first laser sequentially sinters the metal grid lines 11 on both sides of the dividing region 101, a preheating scan of the cutting position of the dividing region 101 can be performed simultaneously. It should be noted that when the first laser sintersects the metal grid lines 11 in different regions, the irradiation spot will move along a predetermined trajectory on the surface of the solar cell 10. By incorporating the preheating scan of the first laser into the sintering scan of the first laser, the idle distance of the laser movement can be reduced, thereby improving processing efficiency.

[0063] In some embodiments, the beam width of the first laser when scanning the boundary region 101 can be from 300 μm to 600 μm.

[0064] The width of the spot formed by the first laser scanning the boundary region 101 is controlled within the range of 300μm to 600μm, which can be consistent with the width of the spot formed when the first laser scans the fine grid 111, so as to avoid affecting the sintering process due to laser adjustment.

[0065] In practice, the width of the laser spot when the first laser scans the boundary region 101 can be 300μm, 350μm, 400μm, 450μm, 500μm, 550μm or 600μm.

[0066] Furthermore, the first laser can scan the cutting position of the dividing zone 101 multiple times, and these multiple scans can overlap to a certain extent to ensure the preheating effect. Also, the first laser can create preheating over a relatively large area to accommodate the scanning range of the second laser.

[0067] In some embodiments, the diameter of the laser spot when the second laser cuts the boundary region 101 can be from 600 μm to 1300 μm.

[0068] The second laser uses a high-energy laser, which can effectively heat the cutting position using the Gaussian beam formed when the second laser is emitted, concentrating the laser energy at and around the cutting position. By controlling the diameter of the spot formed when the second laser irradiates, the area preheated by the first laser can be effectively covered, and the increased laser emission energy consumption due to an excessively large spot diameter can be avoided. In practice, the spot diameter of the second laser when cutting the dividing region 101 can be 600μm, 700μm, 800μm, 900μm, 1000μm, 1100μm, 1200μm, or 1300μm.

[0069] like Figure 2 As shown, the metal grid line 11 may include multiple fine grids 111. The step S120 of sintering the metal grid line using a first laser includes the following steps:

[0070] Step S1201: The first laser is used to scan along the extension path of multiple fine grids in sequence, and the areas traversed by the first laser when scanning two adjacent fine grids are adjacent to each other.

[0071] In other words, the first laser scans along the location of the fine grid 111, effectively covering the location of the metal grid line 11. The areas traversed by the first laser when scanning adjacent fine grids 111 are adjacent, avoiding overlap between the scanning areas of successive lasers, thus preventing damage to the solar cell 10 due to the superposition of laser energy. Figure 2 As shown, when the first laser scans along the fine grid 111, it forms an irradiation area 12. The irradiation areas 12 at two adjacent fine grids 111 are adjacent to each other. This allows for control over the first laser to prevent energy overlap during the sequential sintering process along the fine grids 111, thus avoiding damage to the solar cell 10. In practice, the scanning direction of the first laser is the extension direction of the fine grid 111. After scanning one fine grid 111, the laser head moves to scan the next fine grid 111. The laser scanning directions of two adjacent fine grids 111 can be opposite to reduce idle time and improve processing efficiency.

[0072] In practice, the solar cell 10 can be a cell with a main grid or a cell without a main grid. If the cell has a main grid, it can be a cell with multiple main grids or a cell with more than multiple main grids.

[0073] In some embodiments, after cutting the boundary region with a second laser in step S130, the following steps may also be included:

[0074] Step S131: Use a second laser to perform a second cut on the cut battery cell, and the diameter of the laser spot during the second cut is less than or equal to 100μm.

[0075] In other words, after the first laser scribing process, a second laser scribing process can be performed to form a larger number of segmented solar cells. In practice, the solar cells formed through multiple cuts can be three-segment, four-segment, or six-segment cells. By controlling the spot diameter of the second laser during the secondary cut, the sintering center region can be avoided, preventing damage to the metal grid lines 11 due to an excessively large irradiation area. For example, the spot diameter of the second laser during the secondary cut can be 60μm, 70μm, 80μm, 90μm, or 100μm.

[0076] Some embodiments of this application also provide a solar cell, which is manufactured using the solar cell fabrication method described above. The solar cell includes a cell with metal grid lines on its surface. The metal grid lines are subjected to a first laser sintering treatment, and the cell has a cut edge formed by a second laser scribing process.

[0077] Solar cells are formed through laser sintering and laser scribing. They can be single-sided or bi-sided, with metal grids located on one or both sides of the cell. The cells can be two-, three-, or four-cell cells. The cut edges of the cells can be scanned using a low-energy laser to repair defects at the cut edges.

[0078] Because the first and second lasers are emitted from the same laser head, or the laser head emitting the first laser and the laser head emitting the second laser are connected to the same laser via a beam splitter, laser sintering and laser cutting can be performed at the same station. This allows for coordinated laser sintering and laser scribing processes, improving processing accuracy and efficiency. After the solar cells have undergone laser scribing, the resulting diced cells can be tested to assess the performance of the final solar cells.

[0079] Some embodiments of this application also provide a photovoltaic module, such as... Figure 3 As shown, the photovoltaic module includes a cell string 100, an encapsulating film 200, and a cover plate 300. The cell string 100 includes multiple solar cells as described above or solar cells manufactured by the aforementioned solar cell fabrication method. The encapsulating film 200 covers the surface of the cell string 100. The cover plate 300 covers the surface of the encapsulating film 200 away from the cell string 100.

[0080] Different solar cells 10 are connected by solder ribbons 20 to form a solar cell string 100. The encapsulating film 200 includes a front encapsulating film and a back encapsulating film. The front encapsulating film covers the front of the solar cell, and the back encapsulating film covers the back of the solar cell. The encapsulating film 200 can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film, or it can also be an EP film, EPE film, or PVP film. Specifically, EP film refers to a co-extruded film composed of stacked EVA and POE films; EPE film refers to a co-extruded film formed by sequentially stacking EVA, POE, and EVA films; and PVP film refers to a co-extruded film formed by stacking POE, EVA, and POE films. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0081] In reality, there is a boundary line between the front and back films before lamination. After the photovoltaic module is formed by lamination, there is no longer a concept of front and back films. That is, the front and back films have been combined into a single encapsulation film 200.

[0082] In some embodiments, the cover plate 300 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 300 facing the encapsulating film 200 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 300 includes a first cover plate and a second cover plate, the first cover plate being opposite to the front encapsulating film before the encapsulating film 200 is formed, and the second cover plate being opposite to the back encapsulating film before the encapsulating film 200 is formed.

[0083] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for preparing a solar cell, characterized in that, include: A battery cell is provided, the surface of which has a dividing region and printing areas located on both sides of the dividing region, the printing areas being printed with metal grid lines; The metal grid lines are sintered using a first laser. Within a preset time, a second laser is used to cut the boundary area, separating the printed areas on both sides of the boundary area; Wherein, the first laser and the second laser are emitted by the same laser head, or the laser head emitting the first laser and the laser head emitting the second laser are connected to the same laser via a beam splitter; The preset time is greater than or equal to 5ms and less than or equal to 10ms; Before using a second laser to cut the boundary region, the process also includes: The first laser is used to scan the cutting position of the boundary area.

2. The method for preparing a solar cell according to claim 1, characterized in that, The width of the laser spot when the first laser scans the boundary region is 300 μm to 600 μm.

3. The method for preparing a solar cell according to claim 1, characterized in that, The diameter of the laser spot when the second laser cuts the boundary region is 600 μm to 1300 μm.

4. The method for preparing a solar cell according to claim 1, characterized in that, The metal grid line comprises multiple fine grids, and the sintering of the metal grid line using a first laser includes: The first laser is used to scan along the extension path of multiple fine grids in sequence, and the areas traversed by the first laser when scanning two adjacent fine grids are adjacent to each other.

5. The method for preparing a solar cell according to claim 1, characterized in that, After cutting the boundary region using a second laser, the process further includes: The second laser is used to perform a secondary cut on the cut battery cell, and the diameter of the laser spot during the secondary cut is less than or equal to 100 μm.

6. A solar cell, manufactured using the method for preparing a solar cell according to any one of claims 1 to 5, characterized in that, include: The battery cell has metal grid lines on its surface, the metal grid lines are subjected to a first laser sintering treatment, and the battery cell has a cut edge, the cut edge being formed by a second laser scribing process.

7. A photovoltaic module, characterized in that, include: A battery string includes a plurality of solar cells made by the method of preparing a solar cell according to any one of claims 1 to 5 or the solar cell according to claim 6; An encapsulating film is used to cover the surface of the battery string; A cover plate that covers the surface of the encapsulating film away from the battery string.

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