Silicon solar cell edge passivation method

Abstract

The invention provides an edge passivation method for a silicon solar cell, and the method comprises the steps: respectively arranging a first buffer and a second buffer between a deposition chamber where the cell is located and a first precursor, and between the deposition chamber where the cell is located and a second precursor; the diluted first precursor and the diluted second precursor required by the single-cycle reaction period enter a deposition chamber where the battery piece is located, and passive film deposition is conducted on the edge of the battery piece; according to the edge passivation method, the source amount can be better controlled, the source concentration is effectively reduced, the uniformity of the whole cavity is improved, the film thickness uniformity of a passivation film is improved, the pFF can be increased by 0.1-0.4%, and the pEff of a battery piece is increased by more than 0.05%.

Description

Technical Field

[0001] The invention relates to the technical field of silicon solar cells, and in particular to a method for passivating the edge of a silicon solar cell. Background Art

[0002] With the development of silicon solar cell technology, the size of photovoltaic silicon wafers has been increasing, from 125mm to 156mm, 166mm, 182mm, and even 210mm. The power of photovoltaic modules has also increased rapidly with the increase of silicon wafer size, and the cost has been continuously reduced. However, as the size of silicon wafers increases, the current of single-cell batteries continues to increase, and the loss of single-string modules is also increasing. Now, modules often cut large-size cells into two, three, or even six pieces, that is, module half-cut technology, to reduce module current, reduce module internal losses, and thus increase module power.

[0003] The current half-cell technology requires the entire cell to be cut into half slices by slicing. The slicing process will damage the edge of the cell, resulting in increased edge recombination, affecting the cell opening voltage Voc and filling FF, and thus causing a decrease in efficiency. Edge recombination refers to the recombination of carriers at the edge of the solar cell where they are not processed or not completely processed, resulting in a decrease in the efficiency of the cell. With the development of silicon solar cell technology, especially when approaching the theoretical efficiency limit, the impact of edge recombination on solar cell performance is becoming more and more significant.

[0004] Two types of scribing processes are commonly used: the traditional laser scribing-mechanical breaking process or the thermal laser scribing process. After scribing with both processes, the cell efficiency dropped by 0.3% to 1.2%. The process limitations in the production process make the edge recombination problem become non-negligible. In addition, the separation processes commonly used in current industrial production, such as thermal laser separation, such as laser scribing and thermal cutting edges, will introduce edge recombination. New damage recombination centers appear on the cut surface of the cell after scribing, causing edge recombination and resulting in reduced cell efficiency, which is mainly manifested as the loss of opening voltage Voc and filling FF. In order to improve the efficiency of solar cells, it becomes important to passivate the edges of the cell.

[0005] CN111430506A discloses a crystalline silicon solar cell and its edge passivation method, which places the sliced ​​solar cells horizontally and stacks them neatly so that the slice sections of each solar cell are in the same plane, and then puts them into a sheet box, which is put into an alumina deposition device together with the solar cells, and a layer of alumina film is plated on the edge of the slice section of the solar cell, and then puts them into an electric injection annealing furnace for annealing. This method can reduce the carrier recombination rate of the laser cut surface of the cell to a certain extent, but the uniformity of the alumina film is poor, resulting in limited ability to repair damage to the solar cell after cutting; moreover, this method adopts the method of annealing in an electric injection annealing furnace after passivation. Since the electric injection annealing time is 5-180min, not only is the annealing time too long, but the possibility of defects is also increased.

[0006] In summary, a new method for edge passivation of silicon solar cells needs to be developed. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a method for passivating the edge of a silicon solar cell, by respectively arranging a first buffer and a second buffer between a deposition chamber where the cell is located and a first precursor and a second precursor, and using a double-punching method, the diluted first precursor and the second precursor required for a single-cycle reaction cycle are respectively introduced into the deposition chamber where the cell is located, and a passivation film is deposited on the edge of the cell; the edge passivation method of the present invention can better control the source flow, effectively reduce the source concentration, improve the uniformity of the entire chamber, and enhance the uniformity of the thickness of the passivation film.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] The object of the present invention is to provide a method for passivating the edge of a silicon solar cell, the method comprising the following steps:

[0010] Depositing a passivation film on the edge of the cell in a deposition chamber to complete the edge passivation of the silicon solar cell;

[0011] Among them, a first buffer and a second buffer are respectively arranged between a deposition chamber where the battery cell is located and the first precursor and the second precursor; firstly, the first buffer and the second buffer are respectively pressed once by carrying a source carrier gas with the first precursor and the second precursor, so that the first precursor and the second precursor required for a single cycle reaction cycle enter the first buffer and the second buffer respectively; then, the first buffer and the second buffer are respectively pressed twice by carrying a source carrier gas, so that the diluted first precursor and the second precursor required for the single cycle reaction cycle enter the deposition chamber where the battery cell is located, thereby completing the deposition.

[0012] The edge passivation method of the present invention is to respectively set a first buffer and a second buffer between the deposition chamber where the battery cell is located and the first precursor and the second precursor, and use a double-punching method to allow the diluted first precursor and the second precursor required for a single-cycle reaction cycle to enter the deposition chamber where the battery cell is located, and deposit a passivation film on the edge of the battery cell; the edge passivation method of the present invention can better control the source flow, effectively reduce the source concentration, improve the uniformity of the entire chamber, and enhance the uniformity of the thickness of the passivation film.

[0013] It should be noted that the scribing in the edge passivation method of the silicon solar cell described in the present invention adopts laser scribing mechanical breaking or thermal laser scribing to cut the finished cell, which belongs to the prior art and will not be described here; moreover, the source carrier gas is N2 or Ar, the first precursor can be an aluminum source or a silicon source, and the second precursor can be an oxygen source or a nitrogen source.

[0014] As a preferred technical solution of the present invention, the diluted first precursor and the second precursor required for a single-cycle reaction cycle enter the deposition chamber where the battery cell is located by spraying air from the top of the deposition chamber.

[0015] The edge passivation method of the present invention is based on the double-punching method and further adopts a spray-type air intake method from the top of the deposition chamber to spray the diluted first precursor and second precursor required for the single-cycle reaction cycle into the deposition chamber where the battery cell is located. Compared with the traditional method of introducing gas from the furnace mouth, the gas can better cover the entire cavity, further improving the uniformity of the entire cavity and enhancing the uniformity of the thickness of the passivation film.

[0016] As a preferred technical solution of the present invention, the total pressure of the first buffer and the second buffer is independently 10-800 Torr, such as 10 Torr, 50 Torr, 100 Torr, 300 Torr, 500 Torr, 600 Torr or 800 Torr, etc., wherein the pressure after the first stamping is 5-50% of the total pressure, such as 5%, 10%, 20%, 30%, 40% or 50%, etc., and the pressure after the second stamping is 50-95% of the total pressure, such as 95%, 90%, 80%, 70%, 60% or 50%, etc. It should be noted that the sum of the pressure after the first stamping and the pressure after the second stamping is the corresponding total pressure.

[0017] As a preferred technical solution of the present invention, in the one stamping, the flow values ​​of the source carrier gas are independently 2% to 80% of the MFC range, for example, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, etc., and the corresponding MFC range is 1 to 30slm, for example, 1slm, 5slm, 10slm, 15slm, 20slm, 25slm or 30slm, etc.

[0018] And / or, in the secondary stamping, the flow values ​​of the source carrier gas are independently 2% to 80% of the MFC range, for example, 2%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, etc., and the corresponding MFC range is 1 to 30slm, for example, 1slm, 5slm, 10slm, 15slm, 20slm, 25slm or 30slm, etc.

[0019] As a preferred technical solution of the present invention, the passivation film includes any one of a silicon oxide film, an aluminum oxide film, a silicon nitride film or a silicon oxynitride film, or a combination of at least two of them.

[0020] As a preferred technical solution of the present invention, atomic layer deposition is performed on the edge of the battery cell in an atomic layer deposition chamber.

[0021] As a preferred technical solution of the present invention, the deposition includes 60 to 300 single-cycle reaction cycles, such as 60, 100, 150, 200, 250 or 300.

[0022] As a preferred technical solution of the present invention, the single-cycle reaction cycle is a 6-step method, namely, passing the first precursor, purging the first source-carrying carrier gas, the first evacuation, passing the second precursor, purging the second source-carrying carrier gas, and the second evacuation are performed in sequence; or, the single-cycle reaction cycle is a 4-step method, namely, passing the first precursor, purging the first source-carrying carrier gas, passing the second precursor, and purging the second source-carrying carrier gas are performed in sequence.

[0023] It should be noted that if the single-cycle reaction cycle described in the present invention is a 6-step method, a first evacuation and a second evacuation are added compared to a 4-step method, in order to remove the unreacted first precursor and the unreacted second precursor from the deposition chamber as much as possible, to avoid the first precursor and the second precursor from reacting after contact, and to avoid the generation of dust; if the single-cycle reaction cycle described in the present invention is a 4-step method, the process is simplified and the production capacity can be effectively improved.

[0024] As a preferred technical solution of the present invention, in the single cycle reaction period, the time for passing the first precursor is 1 to 10 s, such as 1 s, 3 s, 5 s, 7 s, 8 s or 10 s, the time for purging the first source carrier gas is 1 to 30 s, such as 1 s, 5 s, 10 s, 15 s, 20 s, 25 s or 30 s, and the time for the first evacuation is 1 to 30 s, such as 1 s, 5 s, 10 s, 15 s, 20 s, 25 s or 30 s. , 25s or 30s, etc., the time for passing the second precursor is 1 to 15s, such as 1s, 5s, 8s, 10s, 12s or 15s, etc., the time for purging the second source carrier gas is 1 to 20s, such as 1s, 5s, 8s, 10s, 12s, 15s, 17s or 20s, etc., and the time for the second evacuation is 1 to 30s, such as 1s, 5s, 10s, 15s, 20s, 25s or 30s, etc.

[0025] As a preferred technical solution of the present invention, the pressure ratio between the first buffer and the second buffer is 1:(0.1-10), for example, 1:0.1, 1:0.5, 1:1, 1:3, 1:5, 1:7 or 1:10.

[0026] As a preferred technical solution of the present invention, the reaction temperature of the passivation film deposition is ≤350°C, preferably 120-350°C, for example, 120°C, 150°C, 180°C, 200°C, 230°C, 250°C, 270°C, 300°C, 330°C or 350°C, etc.; the edge passivation method of the silicon solar cell cell of the present invention is particularly suitable for performing atomic layer deposition on the edge of the cell cell in an atomic layer deposition chamber to generate an aluminum oxide film; the first precursor is an aluminum source, preferably trimethylaluminum (TMA for short), and the second precursor is an oxygen source, preferably water or O3.

[0027] It should be noted that, although the reaction temperature ≤ 350°C is a low temperature condition known in the industry, the reaction temperature of the atomic layer deposition described in the present invention is preferably 120-350°C, which is higher than the reaction temperature of the prior art, and can effectively improve the quality of the aluminum oxide film obtained by atomic layer deposition, and provide favorable conditions for integrating atomic layer deposition and annealing treatment in the same deposition chamber; moreover, the reaction temperature of the atomic layer deposition described in the present invention is ≤ 350°C, which results in fewer decomposition products of the reactants involved, reduces the CVD reaction, and improves the density of the aluminum oxide film.

[0028] As a preferred technical solution of the present invention, after the passivation film is deposited on the edge of the battery cell in the deposition chamber, an annealing treatment is performed, and the passivation film deposition and the annealing treatment are integrated in the same deposition chamber; further, the passivation film deposition and the annealing treatment are integrated in the same deposition chamber, and after the passivation film deposition is completed, a source carrier gas is used to return to normal pressure and constant temperature treatment, and the annealing treatment is performed after the temperature stabilizes; the heating time of the constant temperature treatment is 1 to 30 minutes, such as 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes or 30 minutes, etc., the target temperature of the constant temperature treatment is 150 to 350°C, such as 150°C, 180°C, 200°C, 230°C, 250°C, 270°C, 300°C, 330°C or 350°C, etc., and the annealing time is 1 to 60 minutes, such as 1 minute, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes or 60 minutes, etc.

[0029] The edge passivation method of silicon solar cell of the present invention integrates the deposition and annealing of aluminum oxide passivation film into the same machine, and can be completed simultaneously in one process, that is, the aluminum oxide film is first deposited by ALD equipment, and then annealed by ALD equipment, which not only reduces the process time, but also reduces the use of annealing equipment, while meeting the needs of cost reduction and efficiency improvement, and can also increase pFF by 0.1-0.4%, and the pEff of the cell by more than 0.05%

[0030] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0031] (1) The edge passivation method of the present invention is to respectively set a first buffer and a second buffer between the deposition chamber where the cell is located and the first precursor and the second precursor, and use a double-punching method to allow the diluted first precursor and the second precursor required for a single cycle reaction cycle to enter the deposition chamber where the cell is located, and deposit a passivation film on the edge of the cell; the edge passivation method of the present invention can better control the source flow, effectively reduce the source concentration, improve the uniformity of the entire chamber, and enhance the uniformity of the thickness of the passivation film;

[0032] (2) The edge passivation method of the present invention is based on the double-punching method and further adopts a spray-type air intake method from the top of the deposition chamber to spray the diluted first precursor and second precursor required for the single-cycle reaction cycle into the deposition chamber where the battery cell is located. Compared with the traditional method of introducing gas from the furnace mouth, the gas can better cover the entire cavity, further improving the uniformity of the entire cavity and enhancing the uniformity of the thickness of the passivation film. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1It is a schematic diagram of the process of the edge passivation method of the silicon solar cell according to the present invention. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0035] The present invention provides a method for passivating the edge of a silicon solar cell. Figure 1 As shown, the method for edge passivation of a silicon solar cell comprises the following steps:

[0036] The finished solar cells are diced, and the obtained half-cells are neatly stacked and placed in a deposition chamber, where a passivation film is deposited on the edges of the solar cells to complete the edge passivation of the silicon solar cell;

[0037] Among them, a first buffer and a second buffer are respectively arranged between a deposition chamber where the battery cell is located and the first precursor and the second precursor; firstly, the first buffer and the second buffer are respectively pressed once by carrying a source carrier gas with the first precursor and the second precursor, so that the first precursor and the second precursor required for a single cycle reaction cycle enter the first buffer and the second buffer respectively; then, the first buffer and the second buffer are respectively pressed twice by carrying a source carrier gas, so that the diluted first precursor and the second precursor required for the single cycle reaction cycle enter the deposition chamber where the battery cell is located, thereby completing the deposition.

[0038] Furthermore, after the deposition is completed, annealing treatment can be directly carried out in the same deposition chamber, that is, the passivation film deposition and annealing treatment are integrated in the same deposition chamber; specifically, after the passivation film deposition is completed, a source-carrying carrier gas is used to return to normal pressure and constant temperature treatment, and the annealing treatment is carried out after the temperature stabilizes.

[0039] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0040] Example 1

[0041] This embodiment provides a method for edge passivation of a silicon solar cell, comprising the following steps:

[0042] (1) Take the finished battery cell and cut the battery cell by thermal laser scribing process;

[0043] (2) The ALD machine is heated to 250°C and kept at a constant temperature for 30 minutes, ensuring that the machine temperature difference is ±1°C. The obtained half-cells are neatly stacked and inserted into a special aluminum boat, which is then sent into the machine process chamber. The temperature is again kept constant for 15 minutes before the process begins.

[0044] (3) The total pressure of the TMA buffer is 300 Torr, and the pressure ratio of the total pressure of the TMA buffer to the total pressure of the H2O buffer is 1:0.6. The TMA source bottle and the H2O source bottle are respectively pressed once by using high-purity N2 to carry TMA / H2O, and the source flow rate is 8000 sccm, wherein the MFC range of N2 is 30 slm, the TMA one-time pressing value is 40% of the total pressure of the TMA buffer, and the H2O one-time pressing value is 60% of the total pressure of the H2O buffer, so that the aluminum source and oxygen source required for a single cycle reaction cycle enter the aluminum source buffer and the oxygen source buffer respectively; high-purity N2 is used to carry TMA / H2O. The TMA buffer and the H2O buffer were respectively subjected to secondary stamping, the N2 flow rate was 12000sccm, the MFC range of N2 was 30slm, and accordingly, the TMA secondary stamping value was 60% of the total pressure of the TMA buffer, and the H2O secondary stamping value was 40% of the total pressure of the H2O buffer, so that the aluminum source and oxygen source required for the diluted single-cycle reaction period respectively entered the deposition chamber where the battery cell was located, and entered from the top of the deposition chamber in a spray-type air intake mode to complete the deposition of the single-cycle reaction period; wherein, the process was cycled 200 times, and the aluminum oxide thickness of 40nm was deposited, and the time of a single cycle was as follows:

[0045] 6-step method:

[0046] Pass TMA (5s) → N2 purge (12s) → wait (10s) → pass H2O (5s) → N2 purge (10s) → evacuate (10s);

[0047] (4) After the aluminum oxide film is deposited, N2 is used to return to normal pressure and constant temperature treatment. The heating time of the constant temperature treatment is 10 minutes, the target temperature of the constant temperature treatment is 250°C, and the annealing treatment is performed for 30 minutes.

[0048] Example 2

[0049] This embodiment provides a method for passivating the edge of a silicon solar cell. Compared with Embodiment 1, the only difference is that the annealing time in step (4) is shortened to 20 minutes.

[0050] Example 3

[0051] This embodiment provides a method for edge passivation of a silicon solar cell. Compared with Embodiment 1, the only difference is that the time for the annealing treatment in step (4) is shortened to 10 minutes.

[0052] Example 4

[0053] This embodiment provides a method for edge passivation of a silicon solar cell, comprising the following steps:

[0054] (1) Take the finished battery cell and cut the battery cell by thermal laser scribing process;

[0055] (2) The ALD machine is heated to 250°C and kept at a constant temperature for 30 minutes, ensuring that the machine temperature difference is ±1°C. The obtained half-cells are neatly stacked and inserted into a special aluminum boat, which is then sent into the machine process chamber. The temperature is again kept constant for 15 minutes before the process begins.

[0056] (3) The total pressure of the TMA buffer is 300 Torr, and the pressure ratio of the total pressure of the TMA buffer to the total pressure of the H2O buffer is 1:0.6. The TMA source bottle and the H2O source bottle are respectively pressed once by using high-purity N2 to carry TMA / H2O, and the source flow rate is 8000 sccm, wherein the MFC range of N2 is 30 slm, the TMA one-time pressing value is 40% of the total pressure of the TMA buffer, and the H2O one-time pressing value is 60% of the total pressure of the H2O buffer, so that the aluminum source and oxygen source required for a single cycle reaction cycle enter the aluminum source buffer and the oxygen source buffer respectively; high-purity N2 is used to carry TMA / H2O. The TMA buffer and the H2O buffer were respectively subjected to secondary stamping, the N2 flow rate was 12000sccm, the MFC range of N2 was 30slm, and accordingly, the TMA secondary stamping value was 60% of the total pressure of the TMA buffer, and the H2O secondary stamping value was 40% of the total pressure of the H2O buffer, so that the aluminum source and oxygen source required for the diluted single-cycle reaction period respectively entered the deposition chamber where the battery cell was located, and entered from the top of the deposition chamber in a spray-type air intake mode to complete the deposition of the single-cycle reaction period; wherein, the process was cycled 200 times, and the aluminum oxide thickness of 40nm was deposited, and the time of a single cycle was as follows:

[0057] 6-step method:

[0058] Pass TMA (5s) → N2 purge (12s) → wait (10s) → pass H2O (5s) → N2 purge (10s) → evacuate (10s);

[0059] (4) After the aluminum oxide film is deposited, the pressure is returned to normal using N2 and the film is naturally cooled to room temperature. The film is then placed in an electric injection annealing furnace for annealing at a temperature of 250°C for 30 minutes.

[0060] The cell sheets obtained by edge passivation in the above-mentioned Examples 1-4 were subjected to a film thickness uniformity test, and the test results are summarized in Table 1.

[0061] Table 1

[0062]

[0063]

[0064] The cells obtained by edge passivation in the above-mentioned Examples 1-4 were subjected to SunsVoc tests respectively. The test results are summarized in Table 2.

[0065] Table 2

[0066]

[0067] Comparing Example 1 with Example 4, it can be seen that Example 1 integrates the passivation film deposition and annealing treatment in the same deposition chamber, which can basically achieve the film thickness uniformity and SunsVoc test performance of Example 4. Example 1 not only reduces the time of the process, but also reduces the use of annealing equipment, while meeting the needs of cost reduction and efficiency improvement, and has more advantages for promotion.

[0068] In summary, in the edge passivation method of silicon solar cell described in the present invention, the passivation film adopts aluminum oxide film. Under low temperature conditions (≤350°C), the decomposition products of the participating reactants are less, which reduces the CVD reaction and improves the density of the aluminum oxide film. Compared with the traditional ALD equipment, the gas is introduced from the furnace port by controlling the flow rate of N2 or Ar. The spray-type air intake is controlled by pressure from the top, so that the gas can better cover the entire cavity. At the same time, the double-punching method can better control the source flow, effectively reduce the source concentration, and reduce the CVD reaction. The uniformity of the entire cavity is improved; the deposition and annealing of the aluminum oxide passivation film are integrated into the same machine, and can be completed simultaneously in one process, that is, the aluminum oxide film is first deposited using the ALD equipment, and then the ALD equipment is used for annealing, which not only reduces the process time, but also reduces the use of annealing equipment, while meeting the needs of cost reduction and efficiency improvement; through the field passivation and chemical passivation of the Al2O3 film, the aluminum oxide passivation film is activated by annealing at the same time, the passivation effect is enhanced, and the edge recombination effect after cutting is reduced, which can increase the pFF by 0.1-0.4%, and the pEff of the battery cell by >0.05%.

[0069] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0070] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0071] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0072] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for edge passivation of a silicon solar cell, characterized in that: The method for edge passivation of a silicon solar cell comprises the following steps: Depositing a passivation film on the edge of the cell in a deposition chamber to complete the edge passivation of the silicon solar cell; Among them, a first buffer and a second buffer are respectively arranged between a deposition chamber where the battery cell is located and the first precursor and the second precursor; firstly, the first buffer and the second buffer are respectively pressed once by carrying a source carrier gas with the first precursor and the second precursor, so that the first precursor and the second precursor required for a single cycle reaction cycle enter the first buffer and the second buffer respectively; then, the first buffer and the second buffer are respectively pressed twice by carrying a source carrier gas, so that the diluted first precursor and the second precursor required for the single cycle reaction cycle enter the deposition chamber where the battery cell is located, thereby completing the deposition.

2. The method for edge passivation of a silicon solar cell according to claim 1, characterized in that: The diluted first precursor and the second precursor required for the single-cycle reaction cycle enter the deposition chamber where the battery cell is located by spraying air from the top of the deposition chamber.

3. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: The total pressure of the first buffer and the second buffer is independently 10-800 Torr, wherein the pressure after the first stamping is 5-50% of the total pressure, and the pressure after the second stamping is 50-95% of the total pressure.

4. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: In the one-time punching, the flow value of the source carrier gas is independently 2-80% of the MFC range, and the corresponding MFC range is 1-30 slm; And / or, in the secondary stamping, the flow values ​​of the source-carrying carrier gas are independently 2% to 80% of the MFC range, and the corresponding MFC range is 1 to 30 slm.

5. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: After the passivation film is deposited on the edge of the battery cell in the deposition chamber, an annealing treatment is performed, and the passivation film deposition and the annealing treatment are integrated and completed in the same deposition chamber.

6. The method for edge passivation of a silicon solar cell according to claim 5, characterized in that: After the passivation film is deposited on the edge of the battery cell in the deposition chamber, the source-carrying carrier gas is used to return to normal pressure and constant temperature, and the annealing treatment is performed after the temperature is stabilized.

7. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: The reaction temperature of the passivation film deposition is ≤350°C, preferably 120-350°C.

8. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: The single-cycle reaction cycle is a 6-step method, namely, passing the first precursor, purging the first source-carrying carrier gas, first evacuation, passing the second precursor, purging the second source-carrying carrier gas, and second evacuation in sequence; Alternatively, the single-cycle reaction cycle is a four-step method, namely, passing the first precursor, purging the first source-carrying carrier gas, passing the second precursor, and purging the second source-carrying carrier gas are performed in sequence.

9. The method for edge passivation of a silicon solar cell according to claim 8, characterized in that: In the single-cycle reaction period, the time for passing the first precursor is 1 to 10 s, the time for purging the first source-carrying carrier gas is 1 to 30 s, the time for the first evacuation is 1 to 30 s, the time for passing the second precursor is 1 to 15 s, the time for purging the second source-carrying carrier gas is 1 to 20 s, and the time for the second evacuation is 1 to 30 s.

10. The method for edge passivation of a silicon solar cell according to claim 1 or 2, characterized in that: The pressure ratio between the first buffer and the second buffer is 1:(0.1-10).

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