Method for manufacturing a photovoltaic module and photovoltaic module

Abstract

The application relates to a preparation method of a photovoltaic module and the photovoltaic module. The preparation method comprises the following steps: laminating and packaging a photovoltaic laminated piece after lamination of a photovoltaic laminated piece, to obtain a photovoltaic laminated piece; and performing laser sintering treatment on the photovoltaic laminated piece; the laser sintering treatment comprises the following steps: applying a bias voltage to the photovoltaic laminated piece, and simultaneously scanning a grid line structure on a surface of a cell piece in the photovoltaic laminated piece by using a laser. After the lamination process, the bias voltage is applied to the photovoltaic laminated piece, and the laser sintering treatment is performed on the grid line structure on the surface of the cell piece, the bias voltage is used for forming a current path by electrification, and the laser is used for locally heating the grid line, so that the ohmic contact deterioration caused by high-temperature lamination is repaired, the contact resistance between the grid line and a silicon matrix is effectively reduced, the series resistance of the whole photovoltaic module is reduced, and therefore the conversion efficiency and the output power are improved, and the operation stability and the reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic modules, in particular to a preparation method of a photovoltaic module and the photovoltaic module. BACKGROUND

[0002] With the development of photovoltaic technology, N-type TOPCon photovoltaic modules are becoming the industry mainstream due to their high conversion efficiency.

[0003] In the related art, N-type TOPCon photovoltaic modules are usually framed into finished products after lamination. Since the battery piece has undergone two processes of series welding and lamination, the ohmic contact of the metal grid line with the silicon substrate or the passivation contact structure on the surface of the silicon substrate will deteriorate, resulting in a significant increase in contact resistance (Rc). This problem is particularly prominent when using ultra-narrow line width grid lines, because the fine grid lines themselves have higher resistance and are more sensitive to changes in contact resistance.

[0004] In summary, the increase in contact resistance directly leads to an increase in the series resistance (Rs) of the module, resulting in a decrease in the power output (Pmax) and conversion efficiency (η) of the photovoltaic module, causing local heat loss to intensify when the photovoltaic module is working, potentially increasing the risk of hot spot, and affecting long-term reliability. SUMMARY

[0005] Therefore, it is necessary to provide a preparation method of a photovoltaic module and the photovoltaic module to solve the problems of an increase in contact resistance after lamination of the grid line structure of the photovoltaic module, a decrease in output power and conversion efficiency of the photovoltaic module, and the like.

[0006] A preparation method of a photovoltaic module, comprising:

[0007] lamination packaging of the photovoltaic laminated piece after the lamination of the stack is performed to obtain a photovoltaic laminated piece;

[0008] laser sintering treatment is performed on the photovoltaic laminated piece;

[0009] The laser sintering treatment comprises: applying a bias voltage to the photovoltaic laminated piece while scanning the grid line structure on the surface of the battery piece in the photovoltaic laminated piece by laser.

[0010] In one embodiment, in the step of laser sintering treatment, the front surface of the photovoltaic laminated piece is arranged downward, one or more lasers are used to scan from below the photovoltaic laminated piece, and the bias voltage is applied by a power supply device located above the photovoltaic laminated piece.

[0011] In one embodiment, the power supply device is configured such that its positive contact is pressed against the negative lead-out end of the photovoltaic laminated piece, and its negative contact is pressed against the positive lead-out end of the photovoltaic laminated piece.

[0012] In one of the embodiments, the laser sintering process is performed after the lamination and before the framing.

[0013] In one of the embodiments, the bias voltage is a direct current voltage of 5V-30V.

[0014] In one of the embodiments, the pulse width of the laser is 0.1ns-500ns.

[0015] In one of the embodiments, the energy density of the laser is 1J / cm2-60J / cm2; the wavelength of the laser is 300nm-1200nm; the scanning speed of the laser is 100mm / s-2000mm / s.

[0016] In one of the embodiments, the width of the grid line structure is 5μm-20μm.

[0017] In one of the embodiments, the grid line structure is a fine grid line on the surface of the cell.

[0018] In one of the embodiments, the fine grid line is scanned by a laser spot generated by the laser; the width of the spot is 10μm-30μm; the path of the laser scanning is a path extending along the fine grid line.

[0019] In one of the embodiments, multiple lasers are used to perform laser scanning simultaneously; the arrangement direction of the multiple lasers is perpendicular to the length direction of the multiple cell strings in the photovoltaic laminate; the spot coverage area of each laser corresponds to the fine grid line area on one or more cell strings.

[0020] The above method for manufacturing a photovoltaic module includes applying a bias voltage to a photovoltaic laminate after a lamination process and performing laser sintering on the grid line structure on the surface of the cell of the photovoltaic laminate; the bias voltage is used to form a current path, and the laser is used to locally heat the grid line, thereby repairing the Ohmic contact deterioration caused by the high-temperature lamination, effectively reducing the contact resistance between the grid line and the silicon substrate, reducing the series resistance of the entire photovoltaic module, and improving the conversion efficiency and output power, the operation stability, and the reliability.

[0021] According to another purpose of the present application, a photovoltaic module is provided, which is manufactured by the above method for manufacturing a photovoltaic module.

[0022] The grid line structure on the surface of the cell in the above photovoltaic module is effectively sintered by the laser, thereby effectively reducing the Ohmic contact between the grid line structure and the silicon substrate, reducing the contact resistance, reducing the series resistance of the photovoltaic module, and improving the fill factor and the output power. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Flowchart of the preparation method of the photovoltaic module of the embodiment of the present application Figure 1 .

[0024] Figure 2 Flowchart of the preparation method of the photovoltaic module of the embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0025] In order to make the above objectives, characteristics and advantages of the present application more apparent, clear and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to provide a comprehensive understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0026] In the description of the present application, it should be understood that if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0027] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0028] In the present application, unless otherwise explicitly specified and limited, if the terms "mounting", "connecting", "connecting", "fixing" and the like appear, these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] In this application, unless otherwise explicitly specified and limited, if there is a description such as "on" or "under" or the like between a first feature and a second feature, it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature can be "above", "over" and "on" the second feature, which can be directly above or obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature can be "below", "under" and "under" the second feature, which can be directly below or obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0030] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.

[0031] In the current manufacturing process of N-type TOPCon photovoltaic modules, the ohmic contact between the metal grid lines of the cell and the silicon substrate will deteriorate after the string welding and lamination process, resulting in an increase in contact resistance (Rc), causing the series resistance (Rs) of the photovoltaic module to rise, leading to a decrease in the output power and conversion efficiency of the photovoltaic module, and causing local heating to intensify and the risk of hot spots to increase, seriously affecting the performance and long-term reliability of the photovoltaic module.

[0032] As shown in Figure 1 , the flowchart of the preparation method of the photovoltaic module of the embodiment of the present application is shown in Figure 1 . Figure 1 .

[0033] To solve the above technical problems, an embodiment of the present application provides a preparation method of a photovoltaic module, comprising the following steps:

[0034] Step S1, laminating and packaging the photovoltaic laminated piece after the lamination of the stack to obtain a photovoltaic laminated piece;

[0035] Step S2, laser sintering treatment is performed on the photovoltaic laminated piece;

[0036] Step S3, the laser sintering treatment comprises: applying a bias voltage to the photovoltaic laminated piece, and simultaneously scanning the grid line structure on the surface of the cell in the photovoltaic laminated piece with a laser.

[0037] In step S1, firstly, multiple N-type TOPCon bifacial solar cells are provided. The doping element of the N-type silicon substrate can be one or more of phosphorus, arsenic, and antimony. Then, the multiple solar cells are wired together to form a solar cell string using interconnect strips. Subsequently, the upper glass layer, the upper encapsulating film, the solar cell string, the lower encapsulating film, and the lower glass layer are stacked in a stacking sequence to form a photovoltaic laminate. The upper encapsulating film is an ethylene-vinyl acetate copolymer (EVA) film; the lower encapsulating film is an EVA film.

[0038] Next, the photovoltaic laminate is fed into a laminator for lamination and encapsulation. During the lamination process, the temperature is 150°C to 170°C, and pressure is applied and maintained in a vacuum environment for a period of time. After lamination, it is cooled to obtain an integrated photovoltaic laminate.

[0039] In step S2, the obtained photovoltaic laminate is placed on a laser processing platform and laser-processed to repair the deterioration of the ohmic contact between the metal grid lines of the solar cell and the underlying silicon substrate during the high-temperature lamination process.

[0040] In step S3, the positive and negative leads of the photovoltaic laminate are connected to the negative and positive output terminals of a DC regulated power supply, respectively, thereby applying a reverse bias voltage to the entire photovoltaic laminate. This reverse bias voltage enables current to flow through the scanned grid line region during subsequent laser scanning.

[0041] Simultaneously, a laser beam generated by a nanosecond pulsed laser is used to scan along the extension path of the grid line structure on the surface of the solar cell in the photovoltaic laminate. During the laser scanning process, the laser energy is absorbed by the grid line structure, generating heat energy, which heats the metal material and interface layer of the grid line. A synchronously applied reverse bias voltage ensures that the current forms a path at the laser heating point, producing a synergistic effect, promoting metal atom diffusion, optimizing the contact interface morphology, and thus reducing the contact resistance (Rc) between the grid line and the silicon substrate.

[0042] After laser sintering, the photovoltaic laminate is framed and fitted with junction boxes to obtain the finished photovoltaic module.

[0043] In summary, after the lamination process, a bias voltage is applied to the photovoltaic laminate, and the grid line structure on the surface of the cell is laser-sintered. The bias voltage is used to conduct electricity and form a current path, while the laser is used to locally heat the grid line. Together, they repair the ohmic contact degradation caused by high-temperature lamination, effectively reduce the contact resistance between the grid line and the silicon substrate, reduce the series resistance of the entire photovoltaic module, thereby improving conversion efficiency and output power, and enhancing operational stability and reliability.

[0044] like Figure 2 As shown,Figure 2 Flowchart of the method for preparing a photovoltaic module according to an embodiment of the present application Figure 2 In one embodiment, in the step S3 of the laser sintering process, the front side of the photovoltaic laminate is placed downward, one or more lasers are used to perform laser scanning from below the photovoltaic laminate, and the bias voltage is applied by a power supply device located above the photovoltaic laminate.

[0045] The photovoltaic laminate obtained in step S1 is transferred to a laser processing platform including a laser and a power supply device. The laser performs laser scanning from below the photovoltaic laminate, and the power supply device performs electrical connection from above the photovoltaic laminate to apply a reverse bias voltage.

[0046] The photovoltaic laminate is placed with the front side downward, i.e. the side with the grid line structure of the cell facing downward. One or more power supply devices are electrically connected to the electrode lead-out wires on the back side of the photovoltaic laminate from above the photovoltaic laminate to apply a reverse bias voltage thereto. At the same time, one or more lasers are used to perform laser scanning on the grid line structure of the front side of the photovoltaic laminate from below the photovoltaic laminate to perform sintering.

[0047] Placing the front side of the photovoltaic laminate downward is beneficial for heat dissipation during the laser processing process, avoiding heat accumulation and reducing the impact on the encapsulating material. The power supply device is electrically connected to the photovoltaic laminate from above the photovoltaic laminate, and is separated from the laser, optimizing the use of space and improving the flexibility of operation.

[0048] In one embodiment, in the step S3 of the laser sintering process, the power supply device is configured such that its positive contact is pressed against the negative lead-out end of the photovoltaic laminate, and its negative contact is pressed against the positive lead-out end of the photovoltaic laminate.

[0049] The power supply device includes a positive contact and a negative contact. The positive contact of the power supply device is pressed against the negative lead-out end of the photovoltaic laminate to achieve electrical connection, and the negative contact of the power supply device is pressed against the positive lead-out end of the photovoltaic laminate to achieve electrical connection. The power supply device provides a direct current stabilized power supply to apply a reverse bias voltage to the photovoltaic laminate to reduce the contact resistance between the grid line structure of the photovoltaic laminate and the silicon substrate.

[0050] Further, the power supply device includes a probe or a conductive spring. The positive contact of the power supply device is a positive probe, and the negative contact of the power supply device is a negative probe. The positive probe is electrically connected to the negative lead-out end of the photovoltaic laminate, and the negative probe is electrically connected to the positive lead-out end of the photovoltaic laminate.

[0051] In one embodiment, the laser sintering process is performed after laminating and encapsulating and before framing.

[0052] The string of series-connected batteries is laminated with glass, adhesive film and other materials, and then is laminated and packaged in a laminator at a temperature of 150°C to 170°C under vacuum conditions. After cooling, a photovoltaic laminate is obtained. The photovoltaic laminate is placed with the front face downward on a laser processing platform, and the grid line structure on the front face is subjected to laser scanning treatment. At the same time, a reverse bias voltage is applied to the back face. After laser sintering treatment, framing and installation of a junction box are performed to obtain a finished photovoltaic module.

[0053] After lamination and packaging, the adhesive film and other structures inside the photovoltaic laminate have been preliminarily cured, but have not yet been completely cross-linked, and the interface material still has a certain activity. In this state, laser sintering treatment is performed, and heat energy is more easily transferred to the contact interface, improving the repair effect of ohmic contact. Laser sintering treatment is performed before the framing process, without the need to change the equipment and steps of the framing process, reducing the operation difficulty. And laser sintering treatment is performed before framing, which can avoid the shielding of the frame and other components, facilitate electrical connection or laser scanning, and improve the processing efficiency.

[0054] In one embodiment, the bias voltage is a direct current voltage of 5V-30V.

[0055] A direct current stabilized power supply is used to apply a reverse bias voltage to the photovoltaic laminate. The bias voltage is a direct current voltage of 5V-30V. Further, the bias voltage is one of 5V, 10V, 15V, 20V, 25V and 30V. A stable electric field is provided by using a direct current voltage, so as to form an effective current path during laser scanning, optimize the contact interface, and be conducive to reducing the contact resistance.

[0056] If the bias voltage is lower than 5V, the driving electric field may be insufficient, resulting in limited optimization effect. If the bias voltage is higher than 30V, it may have adverse effects on the battery PN junction or packaging materials. Therefore, the bias voltage in the above range is used to ensure the stability of the electric field.

[0057] The specific value of the bias voltage is adjusted according to the actual battery characteristics, grid line design and laser parameters.

[0058] In one embodiment, the pulse width of the laser is 0.1ns-500ns.

[0059] A nanosecond pulsed laser is used to laser scan the grid line structure on the surface of a photovoltaic laminate cell. The pulse width of the laser is 0.1ns-500ns. More specifically, the pulse width is one of 0.1ns, 10ns, 50ns, 100ns, 150ns, 200ns, 250ns, 300ns, 350ns, 400ns, 450ns, or 500ns. Shorter pulses can generate higher peak power, achieving rapid heating and reducing thermal stress damage to the silicon substrate or encapsulation material. Longer pulses can provide a longer thermal action time, improving repair capabilities.

[0060] The specific value of the laser pulse width can be adjusted according to the actual grid design and laser parameters.

[0061] In one embodiment, the energy density of the laser is 1 J / cm²-60 J / cm².

[0062] A laser is used to scan the grid line structure on the surface of a photovoltaic laminate cell. The energy density of the laser is 1 J / cm²-60 J / cm². More specifically, the laser energy density is one of 1 J / cm², 10 J / cm², 20 J / cm², 30 J / cm², 40 J / cm², 50 J / cm², or 60 J / cm². If the laser energy density is lower than 1 J / cm², insufficient energy input may occur, failing to effectively improve the ohmic contact; if the laser energy density is higher than 60 J / cm², excessive thermal effects may be introduced, easily damaging the silicon substrate or encapsulation material. Therefore, using a laser energy density within the above range effectively improves the ohmic contact while ensuring the stability of the encapsulation material.

[0063] The specific value of the laser energy density can be adjusted according to the actual grid design and laser parameters.

[0064] In one embodiment, the wavelength of the laser is 300nm-1200nm.

[0065] A laser is used to scan the grid line structure on the surface of a photovoltaic laminated cell. The wavelength of the laser is 300nm-1200nm. More specifically, the laser wavelength is one of 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, or 1200nm. This wavelength range ensures that the laser energy is fully absorbed by the grid line structure; shorter wavelengths have higher photon energy and are easily absorbed by the metal grid lines; longer wavelengths have greater penetration depth, which helps improve laser processing efficiency.

[0066] The specific wavelength of the laser can be adjusted according to the actual grating design and laser parameters.

[0067] In one embodiment, the laser scanning rate is 100 mm / s to 2000 mm / s.

[0068] A laser scans the grid structure on the surface of a photovoltaic laminate cell along a preset path. The laser scanning rate is 100 mm / s to 2000 mm / s. More specifically, the laser scanning rate can be one of 100 mm / s, 200 mm / s, 500 mm / s, 1000 mm / s, 1200 mm / s, 1500 mm / s, or 2000 mm / s. A higher laser scanning rate reduces laser processing time and improves laser processing efficiency. A lower laser scanning rate allows for a longer duration of laser energy application, ensuring sufficient thermal contact and improving the repair effect on ohmic contacts.

[0069] The specific value of the laser scanning rate can be adjusted according to actual production capacity requirements and laser parameters.

[0070] In one embodiment, the width of the gate line structure is 5μm-20μm.

[0071] The solar cell has a metal grid structure on its front side, with a grid width of 5μm-20μm. More specifically, the grid width can be one of the following: 5μm-20μm. Using grids within this width range reduces the light-shielding area on the cell surface and improves conversion efficiency. However, the contact resistance of grids within this width range is relatively sensitive; therefore, laser sintering is used to sinter the grids, while a reverse bias voltage is applied to the photovoltaic laminate to optimize the ohmic contact at the interface.

[0072] The width of the grid lines can be adjusted by screen printing or laser transfer.

[0073] In one embodiment, the grid structure is a fine grid line on the surface of the battery cell; the fine grid line is laser-scanned by a light spot generated by the laser.

[0074] The grid structure includes fine grid lines, which are scanned by a laser spot generated by the laser. The laser spot scans along the extension path of the fine grid lines while a reverse bias voltage is applied to ensure that current flows through the scanned fine grid line region. Furthermore, the size of the laser spot is configured to match or slightly exceed the width of the fine grid lines to ensure that laser energy is applied uniformly to the fine grid lines, improving the repair effect.

[0075] The laser spot is circular or elliptical in shape to ensure that the laser energy is concentrated on the fine grid lines while avoiding impact on the silicon substrate.

[0076] In one embodiment, the width of the light spot is 10μm-30μm.

[0077] The laser beam generated by the laser scans the fine grid lines on the surface of the solar cell. The width of the beam is 10μm-30μm. More specifically, the beam width can be one of 10μm, 15μm, 20μm, 25μm, or 30μm. A beam within this width range can concentrate energy on the grid lines, ensuring effective repair while avoiding damage to the silicon substrate or encapsulation materials.

[0078] The width of the light spot refers to the size of the light spot perpendicular to the scanning direction. The specific value of the light spot width can be adjusted according to the actual width of the grid lines.

[0079] In one embodiment, multiple lasers are used to perform laser scanning simultaneously; the arrangement direction of the multiple lasers is perpendicular to the length direction of multiple battery strings in the photovoltaic laminate, and the spot coverage area of ​​each laser corresponds to the fine grid line area on one or more battery strings.

[0080] The arrangement of multiple lasers is perpendicular to the length direction of multiple cell strings in the photovoltaic laminate, i.e., the cell layout direction. In other words, the laser array is arranged perpendicular to the cell strings. The scanning area covered by the light spot generated by each laser corresponds to the fine grid line area on one or more cell strings. The lasers scan sequentially along the extension direction of the fine grid lines on the cell strings. Simultaneously, a reverse bias voltage is applied to the entire photovoltaic laminate.

[0081] By employing multiple lasers to scan different areas of the battery string, laser processing time is reduced and laser processing efficiency is improved. The laser array is arranged perpendicular to the length of the battery string, allowing multiple lasers to scan in a single direction, thus covering all fine grid lines and improving scanning speed and uniformity.

[0082] In one embodiment, a photovoltaic module is also provided, which is manufactured using the photovoltaic module manufacturing method described above.

[0083] The photovoltaic module includes multiple cells interconnected by string welding, an encapsulating film covering the cells, and an upper cover plate and a lower cover plate located on the outermost side. The cells, encapsulating film and cover plate are laminated to form a photovoltaic laminate.

[0084] First, the wired battery strings are stacked with materials such as glass and encapsulant film, and then laminated and encapsulated in a laminator at a temperature of 150°C to 170°C under vacuum conditions. After cooling, a photovoltaic laminate is obtained.

[0085] Secondly, the photovoltaic laminate is placed face down on the laser processing platform, and its front grid structure is laser-scanned; at the same time, a reverse bias voltage is applied to its back side.

[0086] Finally, the laser-sintered photovoltaic laminates are framed and fitted with junction boxes to obtain the finished photovoltaic modules.

[0087] After laser sintering, the grid line structure on the surface of the solar cell in the above-mentioned photovoltaic module effectively reduces the ohmic contact between the grid line structure and the silicon substrate, reduces the contact resistance, thereby reducing the series resistance of the photovoltaic module and improving the fill factor and output power.

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a photovoltaic module, characterized in that, include: The photovoltaic laminated components are then laminated and encapsulated to obtain photovoltaic laminates. The photovoltaic laminate is subjected to laser sintering treatment; The laser sintering process includes: applying a bias voltage to the photovoltaic laminate while simultaneously scanning the grid line structure on the surface of the solar cells in the photovoltaic laminate using a laser; the grid line structure has a width of 5μm-20μm fine grid lines; In the laser sintering process, the photovoltaic laminate is positioned with its front side facing down, and one or more lasers are used to perform laser scanning from below the photovoltaic laminate. The bias voltage is applied through a power supply device located above the photovoltaic laminate.

2. The method for preparing a photovoltaic module according to claim 1, characterized in that, The power supply device is configured such that its positive contact presses against the negative lead of the photovoltaic laminate, and its negative contact presses against the positive lead of the photovoltaic laminate.

3. The method for preparing a photovoltaic module according to claim 1, characterized in that, The laser sintering process is performed after lamination and encapsulation but before framing.

4. The method for preparing a photovoltaic module according to any one of claims 1-2, characterized in that, The bias voltage is a DC voltage of 5V-30V.

5. The method for preparing a photovoltaic module according to claim 1, characterized in that, The pulse width of the laser is 0.1ns-500ns.

6. The method for preparing a photovoltaic module according to claim 1, characterized in that, The energy density of the laser is 1 J / cm². 2 -60J / cm 2 The wavelength of the laser is 300nm-1200nm; the laser scanning speed is 100mm / s-2000mm / s.

7. The method for preparing a photovoltaic module according to claim 1, characterized in that, The laser generates a spot to scan the fine grating lines; the width of the spot is 10μm-30μm; the laser scanning path extends along the fine grating lines.

8. The method for preparing a photovoltaic module according to claim 7, characterized in that, Multiple lasers are used to perform laser scanning simultaneously; the arrangement direction of the multiple lasers is perpendicular to the length direction of the multiple battery strings in the photovoltaic laminate, and the light spot coverage area of ​​each laser corresponds to the fine grid line area on one or more of the battery strings.

9. A photovoltaic module, characterized in that, It is manufactured using the photovoltaic module manufacturing method as described in any one of claims 1-8.

Images