Photovoltaic cell and passivation method and cutting passivation system thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a photovoltaic cell and a passivation method and a cutting passivation system thereof. The embodiment of the invention provides a photovoltaic cell. One end of the photovoltaic cell is a cutting surface; a passivation film is arranged on the cutting face and comprises perfluorinated sulfonic acid resin. In the first aspect of the embodiment of the invention, the passivation film is formed on the cutting surface by adopting the perfluorinated sulfonic acid resin, and the sulfonic acid group of the perfluorinated sulfonic acid resin can bond dangling bonds on the cutting surface with hydrogen ions to form Si-H bonds, so that the dangling bonds are filled, the purpose of saturating the dangling bonds is achieved, the passivation effect is improved, and the battery efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a photovoltaic cell and a passivation method and a cutting passivation system thereof. Background Art

[0002] At present, as the demand for grid parity of photovoltaic power stations becomes more and more urgent, the demand for the cost per kilowatt-hour is getting higher and higher. The photovoltaic module end can adopt a structure in which half-cell batteries are first connected in series and then in parallel, which is equivalent to two small modules connected in parallel, thereby ensuring that the overall output voltage and current are consistent with conventional modules. Half-cell batteries have the following advantages: 1. Due to the reduction of internal current and internal consumption, the packaging efficiency is improved; 2. The reduction of internal current and internal loss can reduce temperature loss and heat generation, which helps to reduce the operating temperature of the module and junction box, greatly reducing the probability of hot spots and the risk of damage to the entire module. 3. Compared with the whole cell, the number of battery strings in the half-cell battery module is doubled. When encountering shadow cover (leaves, bird droppings, etc.), the entire battery string will fail. At this time, bypass diodes can be used to prevent other battery strings from being affected, reducing the impact of shadows on the module.

[0003] The photovoltaic module needs to use a laser to cut the battery into two halves at the battery end. The laser cutting process will cause damage to the cut surface. Specifically, there will be surface dangling bonds on the cut surface, and the defects of the surface dangling bonds will form recombination centers, resulting in a large number of carrier recombination on the cut surface, affecting the battery efficiency.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a photovoltaic cell and a passivation method and a cutting passivation system thereof to solve or alleviate one or more of the technical problems mentioned above.

[0006] A first aspect of an embodiment of the present application provides a photovoltaic cell, one end of the photovoltaic cell being a cutting surface; A passivation film is disposed on the cutting surface, and the passivation film comprises perfluorosulfonic acid resin.

[0007] In the first aspect of the embodiments of the present application, a perfluorosulfonic acid resin is used to form a passivation film on the cut surface. Specifically, the perfluorosulfonic acid resin contains sulfonic acid groups. The strong acid atmosphere of the sulfonic acid groups can make the dangling bonds on the cut surface bond with hydrogen ions to form Si-H bonds, thereby filling the dangling bonds and achieving the purpose of saturating the dangling bonds, thereby enhancing the passivation effect and thus improving the battery efficiency.

[0008] A second aspect of the embodiment of the present application provides a passivation method for a photovoltaic cell, comprising the following operations: Providing a photovoltaic cell, wherein one end of the photovoltaic cell is a cutting surface; Etching the cut surface of the photovoltaic cell and then contacting it with a passivation solution to form a passivation film on the cut surface; Wherein, the passivation solution comprises a perfluorosulfonic acid resin solution with a mass fraction of 3% to 10%.

[0009] In the second aspect of the embodiment of the present application, a passivation film is formed on the cut surface of the photovoltaic cell by contacting the passivation solution, and the perfluorosulfonic acid resin in the passivation solution provides hydrogen passivation. In the second aspect of the embodiment of the present application, the process is simple, and harsh conditions of high temperature and vacuum are not required, which is easy to promote.

[0010] A third aspect of the embodiments of the present application provides a photovoltaic cell cutting and passivation system, including a cutting device and a passivation device; The cutting device includes a laser cutting head and a laser cutting table, which cooperate to perform laser cutting of photovoltaic cells to form a plurality of cut cells; The passivation device is used to make the laser cut surface of the cut battery contact with the passivation liquid inside to achieve passivation.

[0011] Thereby, the cutting and passivation of the photovoltaic cells are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0013] Figure 1 It is a structural schematic diagram of a laser cutting table provided in an embodiment of the present application; Figure 2 is a schematic diagram of the structure of a laser cutting table provided in an embodiment of the present application; Figure 3 It is a schematic diagram of the structure of the passivation device provided in the embodiment of the present application.

[0014] Explanation of the reference numerals: 1-loading area; 2-positioning area; 3-laser cutting area; 4-unloading area; 5-photovoltaic cell; 6-unloading robot arm; 7-unloading conveyor belt; 8-laser cutting table; 9-air hole; 10-air duct of the first adsorption area; 11-air duct of the second adsorption area; 12-cleaning tank; 13-travel track; 14-battery clamp. DETAILED DESCRIPTION

[0015] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0016] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0017] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0018] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0020] For laser-cut batteries, the cut surface needs to be passivated to reduce edge damage and thus improve battery efficiency. At present, common passivation methods include high-temperature thin film deposition methods, such as aluminum oxide films, silicon dioxide films, silicon nitride films, and their laminated composite films. However, thin film deposition usually needs to be carried out under vacuum and high temperature conditions. After the passivation layer is deposited, annealing, sintering and other heat treatment methods are often required to activate the passivation, which places stringent requirements on equipment, has high preparation costs, and a long process time.

[0021] The embodiment of the present application provides a photovoltaic cell and a passivation method thereof and a cutting passivation system technical solution. Based on this, the passivation problem of the cell after cutting is solved. See below for details.

[0022] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0023] A first aspect of the embodiments of the present application provides a photovoltaic cell. One end of the photovoltaic cell is a cutting surface; A passivation film is disposed on the cutting surface, and the passivation film comprises perfluorosulfonic acid resin.

[0024] In an embodiment of the present application, a perfluorosulfonic acid resin is used to form a passivation film on the cut surface. Specifically, the perfluorosulfonic acid resin contains sulfonic acid groups. The strong acid atmosphere of the sulfonic acid groups can make the dangling bonds on the cut surface bond with hydrogen ions to form Si-H bonds, thereby filling the dangling bonds and achieving the purpose of saturating the dangling bonds, thereby enhancing the passivation effect and thus improving the battery efficiency.

[0025] Furthermore, the thickness of the passivation film is 5 nm to 30 nm, for example, 5 nm, 10 nm, 20 nm, 30 nm. Thus, while achieving a good passivation effect, the H will not be hindered by the excessive thickness of the passivation film. + Permeability affects hydrogen passivation.

[0026] In some embodiments, the photovoltaic cell can be at least one of a P-type cell and an N-type cell. P-type silicon wafers are made by doping boron in silicon materials; N-type silicon wafers are made by doping phosphorus in silicon materials. P-type cell preparation technologies include traditional aluminum back surface field cells (AL-BSF) and passivated emitter back contact cells (PERC). There are many N-type cell preparation technologies, including tunneling oxide passivation contact cells (TOPCon), interdigitated back contact cells (IBC) and heterojunction cells (HJT). Therefore, the embodiments of the present application can passivate different types of cell cut surfaces. Taking HJT cells as an example, the process steps include: texturing and cleaning, amorphous silicon thin film deposition, TCO thin film deposition, and electrode metallization. The structure of the HJT cell is as follows: it includes an N-type silicon wafer, the front side of which is sequentially stacked with a first intrinsic amorphous silicon layer, a p-type amorphous silicon layer, and a first TCO layer (first transparent conductive oxide layer), and a front electrode is provided on the first TCO layer; and the back side of the N-type silicon wafer is sequentially stacked with a second intrinsic amorphous silicon layer, an n-type amorphous silicon layer, and a second TCO layer, and a back electrode is provided on the second TCO layer. Therefore, the cut surface of the HJT cell includes the sequentially stacked front electrode section, the first TCO layer section, the p-type amorphous silicon layer section, the first intrinsic amorphous silicon layer section, the N-type silicon wafer section, the second intrinsic amorphous silicon layer section, the n-type amorphous silicon layer section, the second TCO layer section, and the back electrode section. During the laser cutting process, laser damage such as surface morphology changes, fine surface cracks, lattice dislocations, and surface dangling bonds are easily formed on the cut surface. If the passivation film is not introduced, there will be a large amount of carrier recombination on the cut surface, which will affect the efficiency of the cell.

[0027] A second aspect of the embodiments of the present application provides a passivation method for a photovoltaic cell.

[0028] In some embodiments, the photovoltaic cell passivation method comprises the following operations: Providing a photovoltaic cell, wherein one end of the photovoltaic cell is a cutting surface; Etching the cut surface of the photovoltaic cell and then contacting it with a passivation solution to form a passivation film on the cut surface; Wherein, the passivation solution comprises a perfluorosulfonic acid resin solution with a mass fraction of 3% to 10%.

[0029] In the second aspect of the embodiment of the present application, a passivation film is formed on the cut surface of the photovoltaic cell by contacting the passivation solution, and the perfluorosulfonic acid resin in the passivation solution provides hydrogen passivation. The embodiment of the present application has a simple process and does not require high temperature and vacuum harsh conditions, which is easy to promote.

[0030] In an optional embodiment, in the passivation method of the photovoltaic cell, the passivation solution may be a 3% to 10% perfluorosulfonic acid resin solution by mass, for example, the mass fraction of the perfluorosulfonic acid resin solution is 3%, 5%, 7%, 10%, etc. Further, the solvent of the perfluorosulfonic acid resin solution may be at least one of water, ethanol, n-propanol, isopropanol, and methanol.

[0031] In an optional embodiment, in the passivation method of the photovoltaic cell, etching includes: placing one end of the photovoltaic cell where the cut surface is located in an acid solution or an alkaline solution for etching, thereby removing the deformation zone, crack zone and lattice dislocation zone of the cut surface. Exemplarily, the hydrogen ion concentration in the acid solution is 1mol / L to 2mol / L, for example, it can be 1mol / L, 1.5mol / L, 2mol / L; the hydroxide ion concentration in the alkaline solution is 1mol / L to 2mol / L, for example, it can be 1mol / L, 1.5mol / L, 2mol / L. Therefore, the use of a high concentration of acid or alkaline solution makes the removal of the deformation zone, crack zone and lattice dislocation zone of the cut surface more thorough.

[0032] In an optional embodiment, in the photovoltaic cell passivation method, the photovoltaic cell and the passivation solution are contacted in a manner including at least one of dipping, spin coating, spray coating, and slot die coating. Thus, the contacting manner does not require providing a high temperature and vacuum environment, and is easy to operate.

[0033] Furthermore, when contact is performed by immersion, the end of the photovoltaic cell where the cut surface is located is immersed in the passivation solution; wherein the maximum immersion depth H of the photovoltaic cell is less than h, where h is the immersion depth when the metal grid lines in the photovoltaic cell are flush with the passivation solution. Thus, the cut surface is fully in contact with the passivation solution while avoiding contamination of the metal grid lines.

[0034] A third aspect of the embodiments of the present application provides a photovoltaic cell cutting passivation system.

[0035] In some embodiments, see Figure 1 to Figure 3 The cutting and passivation system of the photovoltaic cell comprises a cutting device and a passivation device.

[0036] Furthermore, the cutting device includes a laser cutting head and a laser cutting table, which cooperate to perform laser cutting of the battery to form a plurality of batteries.

[0037] In some specific embodiments, the laser cutting station is Figure 1 The laser cutting table includes a rotating bracket, which is in a cross shape. The rotating bracket includes four connecting rods, and a laser cutting table surface is provided at the end of each connecting rod.

[0038] It is understood that the photovoltaic cell is placed on a laser cutting table and cut by a laser cutting head to cut the cell into several pieces, such as one into two, one into three, etc. Therefore, one end of the cell formed by laser cutting the cell must be a cutting surface. In addition, the cutting surface in the embodiment of the present application refers to the cross section formed by cutting the cell along each functional layer.

[0039] Furthermore, the laser cutting table is used to place batteries, specifically, to place and adsorb photovoltaic cells before laser cutting and batteries after laser cutting. Since the batteries need to be separated after cutting, the laser cutting table can be designed into independent adsorption areas. For example, the laser cutting table includes a plurality of independent adsorption areas, which are used together to adsorb photovoltaic cells before laser cutting, or the adsorption areas are used to adsorb photovoltaic cells generated after laser cutting. For example, see Figure 2 , two independent adsorption areas - the first adsorption area and the second adsorption area are provided on the laser cutting table 8, and air holes 9 are provided on the first adsorption area. The air holes 9 on the first adsorption area are connected to the first adsorption area air duct 10, and the air holes 9 on the first adsorption area are connected to the second adsorption area air duct 11. Therefore, the adsorption and desorption of the adsorption area can be controlled by the first adsorption area air duct 10 and the second adsorption area air duct 11, and each adsorption area is controlled separately, so that the cut batteries can be adsorbed independently.

[0040] In some embodiments, the laser cutting table includes a plurality of rotating laser cutting tables 8, see Figure 1, at this time, there are four rotating laser cutting tables 8; when cutting, the four laser cutting tables rotate, and when one of the laser cutting tables is located in the loading area, the loading robot arm loads the battery on the laser cutting table and rotates, and the laser cutting table reaches the positioning area 2, and adjusts the battery to match the size requirements during laser cutting; then rotates, the laser cutting table reaches the laser cutting area 3, and the photovoltaic cell 5 located thereon is cut into two by the laser cutting head; rotates again, and the laser cutting table reaches the unloading area 4, and the two half-batteries on the laser cutting table are grabbed by the unloading robot arm, placed on the unloading conveyor belt 7 and transmitted to the next process. The operation of the other three laser cutting tables is the same as the above laser cutting table, and will not be repeated here. Thus, the laser cutting table is used to cyclically load, position, adjust, laser cut and unload the cut batteries.

[0041] In some embodiments, the passivation device is used to make the laser cut area of ​​the battery contact with the passivation liquid therein to achieve passivation. In a specific embodiment, see Figure 3 The passivation device includes a cleaning tank 12, a travel track 13 and a battery clamp 14. The cleaning tank 12 is used to place the passivation liquid. The travel track 13 is arranged above the cleaning tank 12, and the battery clamp 14 is arranged on the travel track 13. Thus, the cut surface of the photovoltaic cell 5 contacts the passivation liquid through the battery clamp 14, and the battery clamp 14 can move on the travel track 13.

[0042] In some embodiments, a method for manufacturing a photovoltaic cell using a cutting passivation system for a photovoltaic cell is provided, comprising the following operations: (a) The laser cutting table rotates, and when the laser cutting table surface 8 reaches the loading area 1, the loading robot arm is used to load the battery; (b) Rotating the laser cutting table. When the laser cutting table surface 8 reaches the positioning area 2, a camera is used to take pictures to locate the center position of the battery, and the sensor is used to feed back to the control unit. The control unit fine-tunes the battery position accordingly to meet the consistency of the laser cutting to match the accuracy requirements of the subsequent process; In an optional embodiment, a single camera is used to photograph the battery, locate the four sides of the battery, and then locate the center of the battery.

[0043] Preferably, four Mark points are respectively set near the four corners of the battery, and four cameras are used to take pictures to locate the four Mark points, thereby locating the center of the battery, which has higher positioning accuracy.

[0044] (c) rotating the laser cutting table, where the laser cutting table surface 8 reaches the laser cutting area 3, and the laser cutting head performs laser cutting on the battery into a plurality of batteries; Specifically, the battery can be directly scribed and cut by laser, or it can be cut by opening the battery first and then scribe and cut by different lasers. (d) rotating the laser cutting table, and when the laser cutting table surface 8 reaches the unloading area 4, the unloading robot arm 6 is used to grab each battery on the unloading conveyor belt 7; Specifically, the unloading robot arm 6 can be provided with a suction cup to absorb the half-cell battery, and the unloading robot arm 6 rotates to place the battery on the unloading conveyor belt 7, and the unloading conveyor belt 7 can transport the unloaded battery to the passivation device; The other three laser cutting tables 8 also operate according to (a), (b), (c), and (d), and cycle through (a), (b), (c), and (d), thereby continuously performing the operations of loading, positioning, cutting, and unloading batteries, and continuously cutting batteries.

[0045] (e) Stack the half-cell batteries in the same direction manually or by automated equipment. The battery clamp 14 of the half-cell batteries clamps the stacked half-cell batteries and transfers them to the top of the cleaning tank along the edge passivation track 13. The battery clamp immerses the cut edges of the half-cell batteries into the solution in the tank for edge passivation. The passivation time is 10s to 60s. After the passivation process is completed, the batteries can be placed on the conveyor belt one by one by the robot arm for subsequent processes.

[0046] Furthermore, the passivation liquid may use a perfluorosulfonic acid resin (Nafion-H) solution with strong acid properties, which can be obtained by copolymerizing a perfluorovinyl ether monomer with a sulfonic acid group with tetrafluoroethylene. Nafion-H provides hydrogen passivation on the cut surface to eliminate dangling bonds.

[0047] Furthermore, the cleaning tank 12 can use two independent tank bodies, one tank body uses acid / alkali solution to etch the cutting edge to remove the surface deformation area, crack area, and lattice dislocation area; the other tank body is filled with perfluorosulfonic acid resin solution as a passivation liquid for passivating the battery cutting surface.

[0048] The immersion depth of the battery is determined not to exceed the position of the metal grid line of the battery. Exemplarily, the immersion depth is 100 μm to 1000 μm, such as 100 μm, 400 μm, 850 μm, 1000 μm, etc.

[0049] The following will conduct performance tests on the photovoltaic cell manufacturing method provided in the embodiments of the present application and related comparative examples.

[0050] [Preparation Example] The preparation process of HJT battery is as follows: (1) Provide an N-type silicon wafer with a thickness of 150 μm for texturing and cleaning; (2) Deposition of amorphous silicon thin film on the front side. The front side of the N-type silicon wafer is sequentially stacked with a 30nm first intrinsic amorphous silicon layer and a 50nm p-type amorphous silicon layer; (3) Deposition of an amorphous silicon thin film on the back side. The back side of the N-type silicon wafer is sequentially stacked with a 30nm second intrinsic amorphous silicon layer and a 50nm n-type amorphous silicon layer; (4) depositing a 500 nm indium tin oxide layer on the p-type amorphous silicon layer as the first TCO layer; (5) depositing a 500 nm indium tin oxide layer on the n-type amorphous silicon layer as the second TCO layer; (6) Using silver paste for metallization, prepare the front electrode on the first TCO layer and prepare the back electrode on the second TCO layer.

[0051] [Example 1] The method for cutting and passivating the HJT battery of the preparation example comprises the following operations: (1) The laser cutting table rotates. When the laser cutting table 8 reaches the loading area 1, the loading robot arm is used to load the HJT battery. (2) Rotating the laser cutting table. When the laser cutting table surface 8 reaches the positioning area 2, a camera is used to take pictures to locate the center position of the HJT battery, and the sensor is used to feed back to the control unit. The control unit fine-tunes the battery position accordingly to meet the consistency of the laser cutting and match the accuracy requirements of the subsequent processes. Specifically, four Mark points are set near the four corners of the HJT battery, and four cameras are used to take photos to locate the four Mark points, thereby locating the center of the battery; (3) Rotating the laser cutting table, when the laser cutting table surface 8 reaches the laser cutting area 3, the laser directly scribes and cuts the HJT cell, and laser cuts the HJT cell into two half-cells; (4) Rotating the laser cutting table, when the laser cutting table surface 8 reaches the unloading area 4, the unloading robot arm 6 is used to grab the two batteries and place them on the unloading conveyor belt 7; (5) The cut half-cell batteries are manually stacked in the same direction. The battery clamp 14 clamps the stacked half-cell batteries and transfers them along the travel track 13 to the top of the cleaning tank 12. The battery clamp 14 immerses the cut surface of the half-cell battery into the tank with an immersion depth of 100 μm. It is etched in a 1 mol / L NaOH solution for 10 seconds and then passivated in a 5% mass fraction perfluorosulfonic acid resin (Nafion-H) solution for 30 seconds to obtain a 15 nm passivation film.

[0052] Among them, perfluorosulfonic acid resin was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd. with a product number of lnb-1153; the solvent of the perfluorosulfonic acid resin solution was water, isopropanol, and methanol in a volume ratio of 4:4:1.

[0053] [Example 2] The other operations are the same as those in Example 1, except that, in step (5), the passivation is performed in a 3% by mass perfluorosulfonic acid resin (Nafion-H) solution for 60 seconds to obtain a 5 nm passivation film.

[0054] [Example 3] The other operations were the same as those in Example 1, except that, in step (5), the film was passivated in a 5% by mass perfluorosulfonic acid resin (Nafion-H) solution for 45 seconds to obtain a 30 nm passivation film.

[0055] [Example 4] The other operations are the same as those in Example 1, except that, in step (5), the passivation is performed in a 3% by mass perfluorosulfonic acid resin (Nafion-H) solution for 30 seconds to obtain a 3 nm passivation film.

[0056] [Example 5] The other operations are the same as those in Example 1, except that, in step (5), the passivation is carried out in a perfluorosulfonic acid resin (Nafion-H) solution with a mass fraction of 8% for 45 seconds to obtain a passivation film of 40 nm.

[0057] [Comparative Example 1] The other operations are the same as those in Example 1, except that, in step (5), the passivation is performed in a 5% by mass polystyrene sulfonic acid aqueous solution for 50 seconds to obtain a passivation film of 15 nm.

[0058] [Comparative Example 2] The other operations are the same as those in Example 1, except that, in step (5), an atomic layer deposition of a 15 nm aluminum oxide film is used as a passivation film.

[0059]

Test example

[0060] Table 1:

[0061] As can be seen from Table 1, Examples 1 to 3 use perfluorosulfonic acid resin solution for passivation, and the average efficiency is relatively high, among which Example 1 has the highest performance and the best edge passivation effect; the thickness of the passivation film of Example 4 is relatively low, which may cause the hydrogen passivation effect to be relatively low, and the average efficiency of this group is lower than that of Examples 1 to 3; the thickness of the passivation film of Example 5 is relatively high, which may cause the hydrogen passivation effect to be relatively low, and the average efficiency of this group is lower than that of Examples 1 to 3; +The ion permeability is negatively affected, thereby affecting the hydrogen passivation effect. The average efficiency of this group is also lower than that of Examples 1 to 3. Comparative Example 1 uses polystyrene sulfonic acid aqueous solution for passivation, and the passivation effect is not ideal, and the efficiency is lower than that of the passivated cell using perfluorosulfonic acid resin solution. Comparative Example 2 uses the traditional method of vacuum high-temperature deposition of aluminum oxide passivation film, and its passivation effect is better. The average efficiency of the cell with vacuum high-temperature deposition of aluminum oxide passivation film in Example 1 of the present application and Comparative Example 2 is equivalent.

[0062] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0063] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0064] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A photovoltaic cell, characterized in that: One end of the photovoltaic cell is a cutting surface; A passivation film is disposed on the cutting surface, and the passivation film comprises perfluorosulfonic acid resin.

2. The photovoltaic cell according to claim 1, characterized in that: The thickness of the passivation film is 5nm-30nm.

3. The photovoltaic cell according to claim 1, characterized in that: The photovoltaic cell includes at least one of an aluminum back field cell, a passivated emitter back contact cell, a tunneling oxide layer passivated contact cell, an interdigitated back contact cell and a heterojunction cell.

4. A method for passivating a photovoltaic cell, characterized in that: The following operations are included: Providing a photovoltaic cell, wherein one end of the photovoltaic cell is a cutting surface; Etching the cut surface of the photovoltaic cell and then contacting it with a passivation solution to form a passivation film on the cut surface; Wherein, the passivation solution comprises a perfluorosulfonic acid resin solution with a mass fraction of 3% to 10%.

5. The photovoltaic cell passivation method according to claim 4, characterized in that: The etching comprises: The end of the photovoltaic cell where the cut surface is located is placed in an acid solution or an alkali solution for etching.

6. The passivation method of a photovoltaic cell according to claim 4, characterized in that: The contacting method between the photovoltaic cell and the passivation solution includes: At least one of dipping, spin coating, spray coating, slot die coating.

7. The photovoltaic cell passivation method according to claim 6, characterized in that: When contacting by immersion, immerse the end of the photovoltaic cell where the cut surface is located into the passivation solution; The maximum immersion depth H of the photovoltaic cell is less than h, where h is the immersion depth of the photovoltaic cell when the metal grid lines in the photovoltaic cell are flush with the passivation liquid.

8. A photovoltaic cell cutting passivation system, characterized in that: including a cutting device and a passivation device; The cutting device comprises a laser cutting head and a laser cutting table, wherein the laser cutting head and the laser cutting table cooperate to perform laser cutting of photovoltaic cells to form a plurality of cut cells; The passivation device is used to provide a passivation liquid so that the laser cut surface of the cut battery contacts the passivation liquid for passivation.

9. The photovoltaic cell cutting passivation system according to claim 8, characterized in that: The laser cutting table includes a plurality of rotatably arranged laser cutting tabletops; The rotatably arranged laser cutting table is used for cyclically performing loading, positioning adjustment, laser cutting and unloading of the photovoltaic cells.

10. The photovoltaic cell cutting passivation system according to claim 9, characterized in that: The laser cutting table comprises a plurality of independent adsorption areas, and the adsorption areas are used together to adsorb the photovoltaic cells before laser cutting, or the adsorption areas are used separately to adsorb the photovoltaic cells generated after laser cutting.

11. The photovoltaic cell cutting passivation system according to claim 10, characterized in that: Each of the adsorption areas is independently provided with an air guide tube and a plurality of air holes (9); Wherein, all the air holes (9) on each adsorption area are connected to the air guide pipe on the adsorption area.

12. The photovoltaic cell cutting passivation system according to claim 8, characterized in that: It also includes a loading robot arm and a unloading robot arm; The loading robot arm is used to load batteries; The unloading robot arm is used for unloading batteries.

13. The photovoltaic cell cutting passivation system according to claim 8, characterized in that: The passivation device comprises a cleaning tank (12), a travel track (13) and a battery clamp (14); The cleaning tank (12) is used to place a passivation liquid, the travel track (13) is arranged above the cleaning tank (12), and the battery clamp (14) is arranged on the travel track (13).

14. The photovoltaic cell cutting passivation system according to claim 13, characterized in that: The cleaning tank (12) comprises two tank bodies, one of which is used to place an acid solution or an alkali solution, and the other of which is used to place a passivation solution.

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