Method and device for passivation repair of damage from half-cell cutting in solar cell

Abstract

The present invention provides a method and device for passivation repair of damage from half-cell cutting in a solar cell. The method comprises: (1) providing a plate-type PEALD deposition device; (2) placing sliced solar cells in a carrier and enabling sliced sections to be completely exposed, and preheating same; (3) introducing TMA, water vapor, and nitrogen, and depositing an aluminum oxide thin film on the surfaces of the sliced sections; (4) carrying out nitrogen purging, introducing TMA, ammonia gas, and nitrogen, and depositing an aluminum nitride thin film on the surface of the aluminum oxide thin film; and (5) carrying out annealing treatment, and breaking the vacuum for unloading. In the present invention, by sequentially depositing an aluminum oxide layer and an aluminum nitride layer on the surfaces of the sliced sections of the sliced solar cells, the damage at a cell laser half-cell cutting position is passivated and repaired, so that the efficiency of the repaired half-cut solar cells is increased by 0.1-0.3%.

Description

A method and device for repairing passivation of solar cell half-cut damage Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a method and device for repairing passivation of a solar cell damaged by half-cutting. Background Art

[0002] Currently, mainstream cell production uses large-sized silicon wafers, such as 182mm*182mm and 210mm*210mm. To increase module power, the industry generally uses half-cell technology. This involves cutting the entire cell into half-cells, such as 182mm*91mm and 210mm*105mm, using lasers or other methods. This reduces the current flowing through each busbar to half, thus reducing the internal power loss of the half-cell module to one-quarter that of the full-cell module. Compared to full-cell modules, half-cell modules can increase power by 5%-10% and have become a standard technology for large-cell modules.

[0003] The half-cell cutting process includes two methods: pre-cutting (before cleaning the silicon rods and wafers) and post-cutting (after the battery cells are finished). Pre-cutting will greatly reduce the battery production efficiency. Except for some heterojunction battery (HJT) companies, which use pre-cutting due to the small number of processes, the industry currently basically uses post-cutting.

[0004] Finished cell halves are cut using laser cutting, which inevitably results in structural mechanical damage at the cuts, preventing stress release. Research indicates that laser-grooved edges are more prone to cracking, while full-size silicon wafer cell modules are more likely to crack at the main grid. Half-cut cells expose exposed silicon wafers and other process layers at the cross section, creating a strong damage recombination center that manifests itself in an increase in J02 current, one of the current losses. This ultimately results in a 0.2-0.3% reduction in cell efficiency. Calculated based on a 182mm cell module and 72 conventional modules, the power loss is 4-6W.

[0005] A Chinese patent document, published under the publication number CN111430506A, discloses a "crystalline silicon solar cell and its edge passivation method." This invention involves placing sliced ​​solar cells horizontally and neatly stacking them so that the sliced ​​cross-sections of each solar cell are in the same plane. These cells are then placed in a wafer cassette, which, along with the solar cells, is placed in an alumina deposition apparatus. A thin layer of alumina is deposited on the edges of the sliced ​​cross-sections, and the cells are then annealed in an electric injection annealing furnace. This patented invention utilizes conventional ALD alumina passivation equipment on the market, which requires manual loading and unloading, leading to production interruptions and prolonged idle time for half-cells after processing. Furthermore, alumina absorbs water, and the single-layer alumina film deposited on the cross-section cannot be stored for long periods of time. After 2-4 hours, due to moisture absorption, there is a risk of reduced module power and reliability, making continuous mass production impossible.

[0006] The Chinese patent literature discloses "a solar cell with a passivation layer on the cut edge and its preparation method", and its publication number is CN117153897A. This invention uses the PECVD method or the ALD method to deposit a first layer of silicon oxide and / or aluminum oxide on the cell after cutting and slicing, and then deposits a second layer of silicon nitride. Then, a light injection device is used to perform light injection hydrogen passivation, and finally the laser cutting damage is repaired, and the efficiency of half-cell cells is increased by 0.2%. This method reduces the carrier convergence rate of the laser cut surface of the cell to a certain extent, and improves the efficiency. However, as mentioned in the embodiment of the method, the deposition of the first layer requires stacking half-cell cells, placing them in the first device, and depositing the first layer of film at the exposed cut edge; then the cell needs to be taken out and placed in the second device, and the second layer of silicon nitride film is deposited by the PECVD method, and then placed in the light injection furnace of the third device for hydrogen passivation. The existing PECVD methods in the photovoltaic industry all use a single-piece coating method. When depositing the second layer of silicon nitride film, the stacked cells need to be divided into single pieces to deposit silicon nitride. However, there are silver-aluminum grid lines on the front and back of the half-cell. The separation will inevitably increase the wear of the silver-aluminum grid lines, resulting in a decrease in the grid line height, and a decrease in the FF and Isc of the cell. Each additional grid line wear reduces the efficiency by 0.02-0.05%. At the same time, this method requires adding at least three processes and equipment to the existing battery production line, which cannot meet the economic, scalable and continuous mass production requirements of industrialization. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method and device for passivation repair of damage caused by half-cutting of solar cell wafers, which is used to solve the problems of complex procedures, production interruptions, inability to continuously mass produce, and low efficiency of the resulting half-cell solar cell in the existing process of passivation repair of damage caused by half-cutting of solar cell wafers.

[0008] To achieve the above-mentioned and other related purposes, the present invention provides a method for repairing passivation of a solar cell damaged by half-cutting, comprising the following steps:

[0009] Step (1): providing a plate-type PEALD deposition device;

[0010] The plate-type PEALD deposition equipment includes a preheating chamber, a reaction chamber, and an annealing chamber in sequence along the production line; the plate-type PEALD deposition equipment is provided with a cell conveying device; the cell conveying device includes a plurality of carriers for loading solar cells and a conveying mechanism for driving the carriers into the preheating chamber, the reaction chamber, and the annealing chamber in sequence along the production line; the carriers are provided with a deposition opening, and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening;

[0011] Step (2): placing the sliced ​​solar cell in a carrier, and making the sliced ​​cross section completely exposed, using a solar cell conveying device to convey the carrier into a preheating chamber, evacuating the chamber, heating the preheating chamber, and preheating the solar cell;

[0012] Step (3): using a solar cell conveying device to convey the carrier into the reaction chamber, introducing TMA, water vapor and nitrogen, and depositing an aluminum oxide film on the surface of the sliced ​​section of the solar cell;

[0013] Step (4): purge the reaction chamber with nitrogen, introduce TMA, ammonia and nitrogen, and deposit an aluminum nitride film on the surface of the aluminum oxide film;

[0014] Step (5): Use the solar cell conveying device to convey the carrier into the annealing chamber, anneal the carrier, break the vacuum and exit the chamber, and complete the passivation repair of the solar cell half-cut damage.

[0015] The present invention adopts a plate-type PEALD deposition device to preheat, deposit an aluminum oxide layer and an aluminum nitride layer, and perform annealing treatment on the sliced ​​cross-section surface of the sliced ​​solar cell. First, a layer of aluminum oxide film is deposited. Based on the chemical passivation and field passivation effects of the aluminum oxide film, the efficiency loss of the half-cut cell can be greatly reduced, and the passivation effect is effectively improved. Compared with the existing untreated half-cut cell, the efficiency is increased by more than 0.1%; then a layer of aluminum nitride film that is resistant to high temperature, acid and alkali, and has good insulation is deposited, which can reduce the storage requirements of the half-cell and improve the reliability of the component, ensuring that the efficiency of the half-cell under normal storage conditions within 2 weeks is less than 0.05%.

[0016] The film structure of the cross section of the solar cell after repair in this application is aluminum oxide film and aluminum nitride film from the inside out, among which aluminum oxide is the main passivation layer, which is used to improve the efficiency of half-cell, and aluminum nitride is the external protective layer to prevent water vapor, dust, etc. from contaminating the cell, thereby improving the storage capacity of the cell and the reliability of the cell after it is made into a component, especially the reliability of TOPCON cells, DH1000, and DH2000 in wet heat tests. Only the coating sequence of this application can be used, and the coating sequence and type cannot be arbitrarily replaced or changed.

[0017] The above-mentioned technical solution of this application is used to passivate and repair the damage at the laser half-cut portion of the solar cell, so that the efficiency of the repaired half-cut solar cell is improved by 0.1~0.3% compared to the half-cut solar cell that has not been repaired. In addition, the PEALD deposition equipment used in this application is a plate-type PEALD time-type structure. The preheating chamber, reaction chamber and annealing chamber are integrated into the plate-type PEALD deposition equipment. Combined with the cell conveying device, the entire process of loading into the chamber, aluminum oxide coating, aluminum nitride coating, annealing, and unloading from the chamber can be completed, taking into account the characteristics of high film formation rate, good passivation effect, and good water vapor and dust isolation effect, meeting the needs of large-scale and continuous production of battery production lines.

[0018] Preferably, the sliced ​​solar cell is a solar cell that has been cut without loss by laser.

[0019] Preferably, in step (3), the deposition temperature is 150-300° C.; the deposition pressure is 0.1-1 torr; the flow rate of the TMA is 1000-15000 sccm, the flow rate of the water vapor is 1000-15000 sccm, and the flow rate of the nitrogen is 1000-30000 sccm.

[0020] Preferably, in step (4), the deposition temperature is 150-300° C.; the deposition pressure is 0.1-1 torr; the flow rate of the TMA is 1000-15000 sccm, the flow rate of the ammonia is 1000-15000 sccm, and the flow rate of the nitrogen is 1000-30000 sccm.

[0021] Preferably, in step (2), the preheating temperature is 150-300° C., and the preheating time is 10-60 min.

[0022] Preferably, in step (5), the annealing temperature is 250-500° C., and the annealing time is 10-60 min.

[0023] Preferably, in step (3), the aluminum oxide film is deposited to a thickness of 4 to 20 nm; and in step (4), the aluminum nitride film is deposited to a thickness of 5 to 15 nm. When the aluminum oxide film deposited by PEALD is thicker than 8 to 10 nm, further increasing the film thickness significantly reduces the passivation enhancement effect. Aluminum nitride films within the aforementioned thickness range exhibit good waterproofing and insulation effects. Using the aforementioned film deposition thickness ensures improved overall production capacity and efficiency of the repaired half-cell.

[0024] Preferably, in step (1), an infrared heating device is provided in the annealing chamber. Annealing with a top-mounted infrared heating device can directly conduct heat to the cross-section of the solar cell. This has high heat conduction efficiency, a simple structure, and is compatible with the chamber structure of the plate-type PEALD deposition equipment, facilitating equipment maintenance and energy conservation. Furthermore, the temperature at the cross-section can be effectively controlled to less than 500°C, thereby preventing the slices from sticking together after the process is completed. More preferably, the infrared heating device is an infrared lamp.

[0025] The present invention also provides a passivation repair device for solar cell half-cut damage, comprising a plate-type PEALD deposition device and a cell conveying device arranged in the plate-type PEALD deposition device, wherein the plate-type PEALD deposition device comprises a preheating chamber, a reaction chamber and an annealing chamber in sequence along the direction of the production line; the cell conveying device comprises a plurality of carriers for loading solar cells and a conveying mechanism for driving the carriers to enter the preheating chamber, the reaction chamber and the annealing chamber in sequence along the direction of the production line.

[0026] Preferably, the carrier is provided with a deposition opening, and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening.

[0027] More preferably, the carrier is composed of a bottom plate and side baffles vertically arranged around the bottom plate, and the bottom plate is surrounded by the side baffles to form a deposition opening.

[0028] Preferably, the annealing chamber is equipped with an infrared heating device. This heating device is installed on the top plate of the annealing chamber. This saves energy and reduces consumption while effectively controlling the temperature at the cut surface to less than 500°C, thus preventing the slices from sticking after the process. More preferably, the infrared heating device is an infrared lamp.

[0029] As described above, the present invention has the following beneficial effects:

[0030] (1) This application sequentially deposits an aluminum oxide layer and an aluminum nitride layer on the surface of the sliced ​​cross section of the sliced ​​solar cell to passivate and repair the damage at the laser half-cut portion of the cell, thereby increasing the efficiency of the repaired half-cut solar cell by 0.1 to 0.3% compared to the unrepaired half-cut cell.

[0031] (2) The film structure of the cross section of the repaired solar cell is composed of aluminum oxide film and aluminum nitride film from the inside out, taking into account the passivation efficiency improvement effect of aluminum oxide and the requirements of aluminum nitride for water vapor isolation and electrical insulation performance. It is the first film structure in the industry;

[0032] (3) The PEALD deposition equipment used in this application is a plate-type PEALD time-type structure. The preheating chamber, reaction chamber and annealing chamber are integrated into the plate-type PEALD deposition equipment. Combined with the battery cell conveying device, the entire process of loading into the chamber, aluminum oxide coating, aluminum nitride coating, annealing, and unloading from the chamber can be completed, taking into account the characteristics of high film formation rate and good aluminum oxide passivation effect, meeting the needs of large-scale and continuous production of battery production lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic structural diagram of a plate-type PEALD deposition apparatus.

[0034] FIG2 is a schematic structural diagram of a carrier.

[0035] Explanation of the accompanying drawings: 1. Preheating chamber; 2. Reaction chamber; 3. Annealing chamber; 31. Infrared heating device; 4. Carrier; 41. Bottom plate; 42. Side baffle; 43. Deposition opening; 5. Conveying mechanism; 51. Transport plate; 52. Roller; 6. Solar cell; 61. Aluminum oxide film; 62. Aluminum nitride film. DETAILED DESCRIPTION

[0036] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0037] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0038] Furthermore, it should be understood that the one or more method steps mentioned in the present invention do not exclude the presence of other method steps before or after the combination step, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the presence of other devices / apparatuses before or after the combination device / apparatus, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be considered within the scope of the present invention.

[0039] Example 1

[0040] As shown in Figure 1, an embodiment of the present application provides a solar cell half-cut damage passivation repair device, comprising a plate-type PEALD deposition apparatus and a cell conveying device disposed within the plate-type PEALD deposition apparatus. The plate-type PEALD deposition apparatus comprises, in sequence along the production line, a preheating chamber 1, a reaction chamber 2, and an annealing chamber 3. The cell conveying device comprises several carriers 4 for loading solar cells and a conveying mechanism 5 for driving the carriers into the preheating chamber, reaction chamber, and annealing chamber, respectively, along the production line. The annealing chamber is provided with an infrared heating device 31. The carriers are provided with a deposition opening 43. When a sliced ​​solar cell is placed in the carriers, the sliced ​​cross-section of the solar cell is fully exposed through the deposition opening. The conveying mechanism comprises a transport plate 51 and rollers 52 disposed at the bottom of the transport plate. The carriers are placed on the transport plate. A conveyor belt (not shown) is disposed around the rollers. The conveyor belt is connected to a motor (not shown). The motor and the conveyor belt drive the rollers to rotate, thereby driving the carriers.

[0041] As shown in FIG2 , the carrier is composed of a base plate 41 and side baffles 42 vertically arranged around the base plate. The base plate is surrounded by the side baffles to form a deposition opening 43. When the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening.

[0042] The present invention provides a method for repairing solar cell half-cut damage by passivation, comprising the following steps:

[0043] Step (1): providing a plate-type PEALD deposition device;

[0044] The plate-type PEALD deposition equipment includes a preheating chamber, a reaction chamber, and an annealing chamber in sequence along the production line; the plate-type PEALD deposition equipment is provided with a cell conveying device; the cell conveying device includes a plurality of carriers for loading solar cells and a conveying mechanism for driving the carriers into the preheating chamber, the reaction chamber, and the annealing chamber in sequence along the production line; the carriers are provided with a deposition opening, and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening;

[0045] Step (2): Place the sliced ​​solar cell in a carrier, and make the sliced ​​cross section completely exposed, use the solar cell conveying device to convey the carrier into the preheating chamber, evacuate the chamber, heat the preheating chamber, and preheat the solar cell; the preheating temperature is 250°C, and the preheating time is 40 minutes;

[0046] Step (3): using a solar cell conveying device to convey the carrier into the reaction chamber, introducing TMA, water vapor and nitrogen, and depositing an aluminum oxide film 61 with a thickness of 8 nm on the surface of the sliced ​​section of the solar cell; the deposition temperature is 250°C; the deposition pressure is 0.4 torr; the flow rate of the TMA is 6000 sccm, the flow rate of the water vapor is 6000 sccm, and the flow rate of the nitrogen is 15000 sccm;

[0047] Step (4): nitrogen is used to purge the reaction chamber, and TMA, ammonia and nitrogen are introduced to deposit an aluminum nitride film 62 with a thickness of 8 nm on the surface of the aluminum oxide film; the deposition temperature is 250° C.; the deposition pressure is 0.4 torr; the flow rate of the TMA is 6000 sccm, the flow rate of the ammonia is 8000 sccm, and the flow rate of the nitrogen is 15000 sccm;

[0048] Step (5): Use the solar cell conveying device to convey the carrier into the annealing chamber for annealing treatment. The annealing temperature is 400°C and the annealing time is 40 minutes. The vacuum chamber is broken to complete the passivation repair of the solar cell half-cut damage.

[0049] Example 2

[0050] The present invention provides a method for repairing solar cell half-cut damage by passivation, comprising the following steps:

[0051] Step (1): providing a plate-type PEALD deposition device;

[0052] The plate-type PEALD deposition equipment includes a preheating chamber, a reaction chamber, and an annealing chamber in sequence along the production line; the plate-type PEALD deposition equipment is provided with a cell conveying device; the cell conveying device includes a plurality of carriers for loading solar cells and a conveying mechanism for driving the carriers into the preheating chamber, the reaction chamber, and the annealing chamber in sequence along the production line; the carriers are provided with a deposition opening, and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening;

[0053] Step (2): Place the sliced ​​solar cell in a carrier, and make the sliced ​​cross section completely exposed, use the solar cell conveying device to convey the carrier into the preheating chamber, evacuate the chamber, heat the preheating chamber, and preheat the solar cell; the preheating temperature is 300°C, and the preheating time is 10 minutes;

[0054] Step (3): using a solar cell conveying device to convey the carrier into the reaction chamber, introducing TMA, water vapor and nitrogen, and depositing an aluminum oxide film with a thickness of 20 nm on the surface of the sliced ​​section of the solar cell; the deposition temperature is 300°C; the deposition pressure is 1 torr; the flow rate of the TMA is 15000 sccm, the flow rate of the water vapor is 15000 sccm, and the flow rate of the nitrogen is 30000 sccm;

[0055] Step (4): nitrogen is used to purge the reaction chamber, and TMA, ammonia and nitrogen are introduced to deposit a 5 nm thick aluminum nitride film on the surface of the aluminum oxide film; the deposition temperature is 300°C; the deposition pressure is 1 torr; the flow rate of the TMA is 1000 sccm, the flow rate of the ammonia is 1000 sccm, and the flow rate of the nitrogen is 1000 sccm;

[0056] Step (5): Use the solar cell conveying device to convey the carrier into the annealing chamber for annealing treatment. The annealing temperature is 500°C and the annealing time is 10 minutes. The vacuum chamber is broken to complete the passivation repair of the solar cell half-cut damage.

[0057] Example 3

[0058] The present invention provides a method for repairing solar cell half-cut damage by passivation, comprising the following steps:

[0059] Step (1): providing a plate-type PEALD deposition device;

[0060] The plate-type PEALD deposition equipment includes a preheating chamber, a reaction chamber, and an annealing chamber in sequence along the production line; the plate-type PEALD deposition equipment is provided with a cell conveying device; the cell conveying device includes a plurality of carriers for loading solar cells and a conveying mechanism for driving the carriers into the preheating chamber, the reaction chamber, and the annealing chamber in sequence along the production line; the carriers are provided with a deposition opening, and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening;

[0061] Step (2): Place the sliced ​​solar cell in a carrier, and make the sliced ​​cross section completely exposed, use the solar cell conveying device to convey the carrier into the preheating chamber, evacuate the chamber, heat the preheating chamber, and preheat the solar cell; the preheating temperature is 150°C, and the preheating time is 60 minutes;

[0062] Step (3): using a solar cell conveying device to convey the carrier into the reaction chamber, introducing TMA, water vapor and nitrogen, and depositing an aluminum oxide film with a thickness of 4 nm on the surface of the sliced ​​section of the solar cell; the deposition temperature is 150°C; the deposition pressure is 0.1 torr; the flow rate of the TMA is 1000 sccm, the flow rate of the water vapor is 1000 sccm, and the flow rate of the nitrogen is 1000 sccm;

[0063] Step (4): nitrogen is used to purge the reaction chamber, and TMA, ammonia and nitrogen are introduced to deposit a 15 nm thick aluminum nitride film on the surface of the aluminum oxide film; the deposition temperature is 150°C; the deposition pressure is 0.1 torr; the flow rate of the TMA is 15000 sccm, the flow rate of the ammonia is 15000 sccm, and the flow rate of the nitrogen is 30000 sccm;

[0064] Step (5): Use the solar cell conveying device to convey the carrier into the annealing chamber for annealing treatment. The annealing temperature is 250°C and the annealing time is 60 minutes. The vacuum chamber is broken to complete the passivation repair of the solar cell half-cut damage.

[0065] Comparative Example 1

[0066] Comparative Example 1 directly uses solar cells that have been non-destructively cut by laser without any repairing treatment.

[0067] Comparative Example 2

[0068] The difference between Comparative Example 2 and Example 1 is that step (4) is omitted, and the aluminum oxide film is only deposited on the sliced ​​cross section of the sliced ​​solar cell, and the rest of the process is exactly the same.

[0069] Comparative Example 3

[0070] The difference between Comparative Example 3 and Example 1 is that there is no step (3), and the aluminum nitride film is only deposited on the sliced ​​cross section of the sliced ​​solar cell, and the rest of the process is exactly the same.

[0071] Comparative Example 4

[0072] The difference between Comparative Example 4 and Example 1 is that the order of step (3) and step (4) is opposite, and the deposition order at the sliced ​​cross section of the sliced ​​solar cell is first aluminum nitride film and then aluminum oxide film, and the rest of the process is exactly the same.

[0073] The performance of the solar cells obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was characterized by the following test method: a Halm IV tester was used at 25 ± 2 ° C and a light intensity of 1000 ± 50 W / m 2 Standard test conditions.

[0074] The test results are shown in Table 1.

[0075] Table 1. Performance test results of solar cells obtained in Examples 1-3 and Comparative Examples 1-4

[0076]

[0077] In Table 1, Eff refers to the battery conversion efficiency, Voc is the open circuit voltage of the battery cell, Isc is the short circuit current of the battery cell, P max is the peak power of the battery cell.

[0078] As can be seen from Table 1, by comparing the experimental data of Example 1 with that of Comparative Example 1, it can be seen that the efficiency of the sliced ​​solar cell obtained after repair by the technical solution of the present application is improved; by comparing the experimental data of Example 1 with that of Comparative Example 2, it can be seen that only depositing an aluminum oxide film on the sliced ​​cross section of the sliced ​​solar cell cannot achieve the best damage repair effect. This is because the aluminum oxide film lacks the protective effect of the aluminum nitride film and the effect of increasing H passivation, resulting in the aluminum oxide film absorbing water, resulting in a decrease in the passivation effect; by comparing the experimental data of Example 1 with that of Comparative Example 3, it can be seen that only depositing an aluminum oxide film on the sliced ​​cross section of the sliced ​​solar cell cannot achieve the best damage repair effect. Depositing aluminum nitride film on the slice section cannot repair the damage well. This is because the aluminum nitride film mainly has a water vapor isolation effect, and the film layer does not have the function of passivating Si dangling bonds, and cannot improve efficiency. By comparing the experimental data of Example 1 and Comparative Example 4, it can be obtained that the order of depositing aluminum nitride film and aluminum oxide film on the slice section must follow the order of this application. Changing the deposition order cannot repair the damage well. This is because the aluminum nitride film layer does not have the effect of passivating Si dangling bonds. At the same time, the electrical shielding properties of the aluminum nitride layer isolate the electron transmission channel between the silicon substrate and the aluminum oxide film layer, making the chemical and field passivation of the aluminum oxide film layer invalid.

[0079] In summary, the film structure of the sliced ​​cross section of the repaired solar cell of the present invention is, from the inside out, an aluminum oxide film and an aluminum nitride film, taking into account the passivation efficiency-enhancing effect of aluminum oxide and the requirements of aluminum nitride for water vapor isolation and electrical insulation performance, and is the first film structure in the industry; the PEALD deposition equipment used is a plate-type PEALD time-type structure, and the preheating chamber, reaction chamber, and annealing chamber are integrated into the plate-type PEALD deposition equipment. Combined with the cell conveying device, the entire process of loading into the chamber, aluminum oxide coating, aluminum nitride coating, annealing, and unloading from the chamber can be completed, taking into account the characteristics of high film formation rate and good aluminum oxide passivation effect, meeting the needs of large-scale and continuous production of battery production lines. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has high industrial utilization value.

[0080] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for repairing passivation damage caused by cutting half a solar cell, characterized in that: The following steps are involved: Step (1): providing a plate-type PEALD deposition device; The plate-type PEALD deposition equipment comprises a preheating chamber (1), a reaction chamber (2) and an annealing chamber (3) in sequence along the production line; a cell conveying device is provided in the plate-type PEALD deposition equipment; the cell conveying device comprises a plurality of carriers (4) for loading solar cells and a conveying mechanism (5) for driving the carriers to sequentially enter the preheating chamber, the reaction chamber and the annealing chamber along the production line; the carriers are provided with a deposition opening (43), and when the sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening; Step (2): placing the sliced ​​solar cell in a carrier, and making the sliced ​​cross section completely exposed, using a solar cell conveying device to convey the carrier into a preheating chamber, evacuating the chamber, heating the preheating chamber, and preheating the solar cell; Step (3): using a solar cell conveying device to convey the carrier into the reaction chamber, introducing TMA, water vapor and nitrogen, and depositing an aluminum oxide film on the surface of the sliced ​​section of the solar cell; Step (4): purge the reaction chamber with nitrogen, introduce TMA, ammonia and nitrogen, and deposit an aluminum nitride film on the surface of the aluminum oxide film; Step (5): Use the solar cell conveying device to convey the carrier into the annealing chamber, anneal the carrier, break the vacuum and exit the chamber, and complete the passivation repair of the solar cell half-cut damage.

2. The method according to claim 1, wherein: In step (3), the deposition temperature is 150-300° C.; the deposition pressure is 0.1-1 torr; the flow rate of the TMA is 1000-15000 sccm, the flow rate of the water vapor is 1000-15000 sccm, and the flow rate of the nitrogen is 1000-30000 sccm.

3. The method according to claim 1, wherein: In step (4), the deposition temperature is 150-300° C.; the deposition pressure is 0.1-1 torr; the flow rate of the TMA is 1000-15000 sccm, the flow rate of the ammonia is 1000-15000 sccm, and the flow rate of the nitrogen is 1000-30000 sccm.

4. The method according to claim 1, wherein: In step (2), the preheating temperature is 150-300°C, and the preheating time is 10-60 minutes.

5. The method according to claim 1, wherein: In step (5), the annealing temperature is 250-500°C, and the annealing time is 10-60 minutes.

6. The method according to claim 1, wherein: In step (3), the deposition thickness of the aluminum oxide film is 4 to 20 nm; in step (4), the deposition thickness of the aluminum nitride film is 5 to 15 nm.

7. The method according to claim 1, wherein: In step (1), an infrared heating device (31) is provided in the annealing chamber.

8. A solar cell half-cut damage passivation repair device, characterized by: The method according to any one of claims 1 to 7 is adopted, comprising a plate-type PEALD deposition device and a cell conveying device arranged in the plate-type PEALD deposition device, wherein the plate-type PEALD deposition device comprises a preheating chamber (1), a reaction chamber (2) and an annealing chamber (3) in sequence along the direction of the production line; and the cell conveying device comprises a plurality of carriers (4) for loading solar cells and a conveying mechanism (5) for driving the carriers to enter the preheating chamber, the reaction chamber and the annealing chamber in sequence along the direction of the production line.

9. The device according to claim 8, characterized in that The carrier is composed of a bottom plate (41) and side baffles (42) vertically arranged around the bottom plate. The bottom plate is enclosed by the side baffles to form a deposition opening (43). When a sliced ​​solar cell is placed in the carrier, the sliced ​​cross section of the solar cell is completely exposed from the deposition opening.

10. The device according to claim 8, wherein: An infrared heating device (31) is provided in the annealing chamber.

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