Photovoltaic cell and method for producing a photovoltaic cell, photovoltaic module

Abstract

The application relates to a photovoltaic cell and a preparation method thereof, and a photovoltaic module. The preparation method of the photovoltaic cell comprises the following steps: providing a photovoltaic cell pre-product, the photovoltaic cell pre-product having opposite first and second surfaces in the thickness direction; depositing a first passivation anti-reflection layer on the first surface at a first temperature by using a first process gas; depositing a second passivation anti-reflection layer on the first passivation anti-reflection layer at a second temperature by using a second process gas; and depositing a third passivation anti-reflection layer on the second passivation anti-reflection layer at a third temperature by using a third process gas; wherein the second temperature is greater than the first temperature, and the second temperature is greater than the third temperature; the flow rate of hydrogen in the second process gas is greater than the flow rate of hydrogen in the first process gas and the flow rate of hydrogen in the third process gas; and the flow rate proportion of hydrogen in the second process gas is greater than the flow rate proportion of hydrogen in the first process gas and the flow rate proportion of hydrogen in the third process gas.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to photovoltaic cells and their preparation methods, and photovoltaic modules. Background Technology

[0002] The passivation and antireflection layer of a photovoltaic (PV) cell is a key component for improving its photoelectric conversion efficiency, primarily achieved by reducing light reflection and surface recombination. The materials used in PV passivation and antireflection layers typically include at least one of silicon oxide, silicon nitride, and silicon oxynitride. Traditional methods for preparing passivation and antireflection layers use silane, ammonia, and nitrous oxide as process gases and employ plasma-enhanced chemical vapor deposition (PECVD). However, the passivation and antireflection layers obtained using traditional methods suffer from low ionization rates (due to the inherent properties of silane and ammonia) and high-temperature evaporation (at high temperatures, free hydrogen easily escapes from the film), resulting in a free hydrogen content in the film typically below 20 at%, thus limiting the effectiveness of the passivation and antireflection layer in passing off surface defects in crystalline silicon PV cells. Summary of the Invention

[0003] Therefore, it is necessary to provide photovoltaic cells, their fabrication methods, and photovoltaic modules. The photovoltaic cell fabrication method of this application can prepare a passivation antireflection layer with a high free hydrogen content in the film layer, achieving a better passivation effect, thereby improving the conversion efficiency of the photovoltaic cell.

[0004] In a first aspect, this application provides a method for preparing a photovoltaic cell, comprising the following steps:

[0005] A photovoltaic cell pre-finished product is provided, the photovoltaic cell pre-finished product having opposing first and second surfaces along the thickness direction;

[0006] A first passivation and antireflection layer is deposited on the first surface using a first process gas at a first temperature, the first process gas including hydrogen, silane, nitrous oxide and ammonia;

[0007] A second passivation and antireflection layer is deposited on the first passivation and antireflection layer at a second temperature using a second process gas, wherein the second process gas includes hydrogen, silane, and ammonia.

[0008] A third passivation and antireflection layer is deposited on the second passivation and antireflection layer using a third process gas at a third temperature, the third process gas including hydrogen, silane, nitrous oxide and ammonia;

[0009] Wherein, the second temperature is greater than the first temperature and the difference between the two is less than or equal to 30°C; the second temperature is greater than the third temperature and the difference between the two is less than or equal to 30°C; the flow rate of hydrogen in the second process gas is greater than the flow rate of hydrogen in the first process gas and the flow rate of hydrogen in the third process gas; the proportion of hydrogen flow rate in the second process gas is greater than the proportion of hydrogen flow rate in the first process gas and the proportion of hydrogen flow rate in the third process gas.

[0010] In some embodiments, the second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps:

[0011] A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia;

[0012] A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia;

[0013] Wherein, the fourth temperature is greater than the fifth temperature and the difference between the two is greater than or equal to 60°C; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60°C; the absolute value of the difference between the fifth temperature and the first temperature and the third temperature is less than or equal to 30°C.

[0014] In some embodiments, the fourth temperature is 420°C to 480°C; and the fifth temperature is 330°C to 400°C.

[0015] In some embodiments, the second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps:

[0016] A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia;

[0017] A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia;

[0018] Wherein, the fourth temperature is less than the fifth temperature and the difference between the two is less than or equal to 30°C; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60°C; the fifth temperature is greater than the first temperature and the difference between the two is greater than or equal to 60°C; the fifth temperature is greater than the third temperature and the difference between the two is greater than or equal to 60°C.

[0019] In some embodiments, the fourth temperature is 420°C to 480°C; and the fifth temperature is 430°C to 490°C.

[0020] In some embodiments, the second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps:

[0021] The photovoltaic cell pre-product is preheated at a preheating temperature;

[0022] A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia;

[0023] A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia;

[0024] Wherein, the preheating temperature is greater than the first temperature, the second temperature, the third temperature, the fourth temperature, and the fifth temperature, and the difference between them is greater than or equal to 60°C; the fourth temperature is greater than the fifth temperature and the difference between them is less than or equal to 30°C; the fourth temperature is greater than the second temperature and the difference between them is less than or equal to 30°C; the absolute value of the difference between the fifth temperature and the first temperature is less than or equal to 30°C; and the absolute value of the difference between the fifth temperature and the third temperature is less than or equal to 30°C.

[0025] In some embodiments, the preheating temperature is 430℃~490℃; the preheating time is 300s~3600s; the fourth temperature is 340℃~410℃; and the fifth temperature is 330℃~400℃.

[0026] In some embodiments, the flow rate of hydrogen in the fourth process gas is greater than the flow rate of hydrogen in the fifth process gas; and the flow rate percentage of hydrogen in the fourth process gas is greater than the flow rate percentage of hydrogen in the fifth process gas.

[0027] In some embodiments, the flow rate of hydrogen in the fourth process gas is 5% to 60%; and the flow rate of hydrogen in the fifth process gas is 4% to 20%.

[0028] In some embodiments, the thickness of the fourth passivation antireflection layer is 40nm~80nm; the thickness of the fifth passivation antireflection layer is 40nm~100nm.

[0029] In some embodiments, the photovoltaic cell pre-product includes a silicon substrate and an N-type doped silicon layer and a P-type doped silicon layer respectively disposed on two opposing surfaces of the silicon substrate; the first passivation antireflection layer is prepared on the surface of the N-type doped silicon layer away from the silicon substrate; and the fourth passivation antireflection layer is prepared on the surface of the P-type doped silicon layer away from the silicon substrate.

[0030] In some embodiments, the first temperature is 330°C to 400°C; the second temperature is 340°C to 410°C; and the third temperature is 330°C to 400°C.

[0031] In some embodiments, the flow rate of hydrogen in the first process gas is 5% to 30%; the flow rate of hydrogen in the second process gas is 9% to 65%; and the flow rate of hydrogen in the third process gas is 5% to 30%.

[0032] In some embodiments, the thickness of the first passivation antireflection layer is 1 nm to 15 nm; the thickness of the second passivation antireflection layer is 60 nm to 120 nm; and the thickness of the third passivation antireflection layer is 5 nm to 40 nm.

[0033] Secondly, this application provides a photovoltaic cell, prepared by the photovoltaic cell preparation method described in any one of the above-mentioned methods, comprising:

[0034] A silicon substrate; an N-type doped silicon layer and a P-type doped silicon layer are respectively disposed on two oppositely disposed surfaces of the silicon substrate;

[0035] The first passivation antireflection layer, the second passivation antireflection layer, and the third passivation antireflection layer are sequentially stacked on the surface of the N-type doped silicon layer away from the silicon substrate;

[0036] And the fourth passivation antireflection layer and the fifth passivation antireflection layer are sequentially stacked on the surface of the P-type doped silicon layer away from the silicon substrate.

[0037] Thirdly, this application provides a photovoltaic module, comprising:

[0038] Cover plate;

[0039] At least one battery string, the battery string comprising a plurality of the aforementioned photovoltaic cells;

[0040] And an encapsulation layer, which is located between the cover plate and the battery string, and the cover plate is connected to the battery string through the encapsulation layer.

[0041] Hydrogen gas absorbs approximately 435 kJ of energy to dissociate into 2 mol of free hydrogen, while silane or ammonia gas requires approximately 800 kJ of energy to dissociate into 2 mol of free hydrogen. In the aforementioned photovoltaic cell fabrication method, introducing hydrogen into the process gas can increase the free hydrogen content in the passivation and antireflection layer. Specifically, the second passivation and antireflection layer, deposited at a relatively high deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage, serves as the primary passivation and antireflection layer, providing the main hydrogen content in the stacked passivation and antireflection layers. The first passivation and antireflection layer is located between the photovoltaic cell pre-product and the second passivation and antireflection layer. Prepared at a relatively lower deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage compared to the second passivation and antireflection layer, it achieves better contact between the passivation and antireflection layer and the photovoltaic cell pre-product, better passivation of surface defects in the photovoltaic cell pre-product, and less deposition damage to the photovoltaic cell pre-product, thus improving passivation performance. The third passivation antireflection layer is located on the surface of the second passivation antireflection layer, away from the photovoltaic cell preform. It is prepared using a relatively lower deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage compared to the second passivation antireflection layer, which reduces the leakage of free hydrogen from the second passivation antireflection layer. The photovoltaic cell preparation method of this application can prepare a passivation antireflection layer with a high free hydrogen content (above 25%), achieving a better passivation effect, reducing the bulk surface defect state density of the photovoltaic cell, reducing non-radiative recombination, and thus improving the conversion efficiency of the photovoltaic cell. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of a photovoltaic cell provided in one embodiment of this application;

[0043] Figure 2 This is a schematic diagram showing the results of the photoluminescence test of the photovoltaic cell in Embodiment 1 of this application;

[0044] Figure 3 This is a schematic diagram showing the results of the photoluminescence test of the photovoltaic cell in Embodiment 2 of this application;

[0045] Figure 4 This is a schematic diagram showing the results of the photoluminescence test of the photovoltaic cell in Embodiment 3 of this application;

[0046] Figure 5 This is a schematic diagram showing the results of the photoluminescence test of the photovoltaic cell in Comparative Example 1 of this application.

[0047] Explanation of reference numerals in the attached figures:

[0048] 10-Silicon substrate; 20-Tunneling oxide layer; 30-N-type doped silicon layer; 40-First passivation and antireflection layer; 50-Second passivation and antireflection layer; 60-Third passivation and antireflection layer; 70-First electrode; 80-P-type doped silicon layer; 90-Fourth passivation and antireflection layer; 100-Fifth passivation and antireflection layer; 110-Second electrode. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] One embodiment of this application provides a method for preparing a photovoltaic cell, comprising the following steps:

[0055] A photovoltaic cell pre-finished product is provided, which has a first surface and a second surface opposite to each other along the thickness direction;

[0056] A first passivation and antireflection layer 40 is deposited on a first surface using a first process gas at a first temperature. The first process gas includes hydrogen, silane, nitrous oxide, and ammonia.

[0057] A second passivation and antireflection layer 50 is deposited on the first passivation and antireflection layer 40 using a second process gas at a second temperature. The second process gas includes hydrogen, silane, and ammonia.

[0058] A third passivation and antireflection layer 60 is deposited on the second passivation and antireflection layer 50 using a third process gas at a third temperature. The third process gas includes hydrogen, silane, nitrous oxide, and ammonia.

[0059] Wherein, the second temperature is greater than the first temperature and the difference between the two is less than or equal to 30°C; the second temperature is greater than the third temperature and the difference between the two is less than or equal to 30°C; the flow rate of hydrogen in the second process gas is greater than the flow rate of hydrogen in the first process gas and the flow rate of hydrogen in the third process gas; the flow rate percentage of hydrogen in the second process gas is greater than the flow rate percentage of hydrogen in the first process gas and the flow rate percentage of hydrogen in the third process gas.

[0060] Hydrogen gas absorbs approximately 435 kJ of energy to dissociate into 2 mol of free hydrogen, while silane or ammonia gas requires approximately 800 kJ of energy to dissociate into 2 mol of free hydrogen. In the aforementioned photovoltaic cell fabrication method, introducing hydrogen gas into the process gas can increase the free hydrogen content in the passivation and antireflection layer. The second passivation and antireflection layer 50, deposited at a relatively high deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage, serves as the primary passivation and antireflection layer, providing the main hydrogen content in the stacked passivation and antireflection layers. The first passivation and antireflection layer 40 is located between the photovoltaic cell pre-product and the second passivation and antireflection layer 50. Prepared at a relatively lower deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage compared to the second passivation and antireflection layer 50, it achieves better contact between the passivation and antireflection layer and the photovoltaic cell pre-product, better passivation of surface defects in the photovoltaic cell pre-product, and less deposition damage to the photovoltaic cell pre-product, thus improving passivation performance. The third passivation antireflection layer 60 is located on the surface of the second passivation antireflection layer 50 away from the photovoltaic cell preform. It is prepared using a relatively lower deposition temperature, hydrogen flow rate, and hydrogen flow rate percentage compared to the second passivation antireflection layer 50, which reduces the leakage of free hydrogen from the second passivation antireflection layer 50. The photovoltaic cell preparation method of this application can prepare a passivation antireflection layer with a high free hydrogen content (above 25%), achieving a better passivation effect, reducing the bulk surface defect state density of the photovoltaic cell, reducing non-radiative recombination, and thus improving the conversion efficiency of the photovoltaic cell.

[0061] In some embodiments, the first temperature is 330°C to 400°C; the second temperature is 340°C to 410°C; and the third temperature is 330°C to 400°C.

[0062] Within the range of the first, second, and third temperatures mentioned above, it is convenient to prepare a passivation and antireflection layer with a high content of free hydrogen in the film, thereby achieving a better passivation effect, reducing the density of defect states on the surface of the photovoltaic cell, reducing non-radiative recombination, and thus improving the conversion efficiency of the photovoltaic cell.

[0063] Optionally, the first temperature is 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C, or the first temperature may be within the range of any two of the above temperatures.

[0064] Optionally, the second temperature is 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, or 410°C, or the second temperature may be within the range of any two of the above temperatures.

[0065] Optionally, the third temperature is 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C, or the third temperature may be within the range of any two of the above temperatures.

[0066] In some embodiments, the flow rate of hydrogen in the first process gas is 5% to 30%; the flow rate of hydrogen in the second process gas is 9% to 65%; and the flow rate of hydrogen in the third process gas is 5% to 30%.

[0067] Within the range of hydrogen flow rates in the aforementioned process gases, it is convenient to ensure that the second passivation antireflection layer 50 provides the main hydrogen content, the first passivation antireflection layer 40 achieves good direct contact with the photovoltaic cell pre-product and is effective in mitigating surface defects, and the third passivation antireflection layer 60 reduces the leakage of free hydrogen from the second passivation antireflection layer 50. This facilitates the preparation of a passivation antireflection layer with a high free hydrogen content, achieving a better passivation effect, reducing the bulk surface defect state density of the photovoltaic cell, reducing non-radiative recombination, and ultimately improving the conversion efficiency of the photovoltaic cell.

[0068] Optionally, the flow rate percentage of hydrogen in the first process gas is 5%, 8%, 10%, 15%, 20%, 25%, 28%, or 30%, or the flow rate percentage of hydrogen in the first process gas can be within the range of any two of the above flow rate percentages.

[0069] Optionally, the flow rate percentage of hydrogen in the second process gas is 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, or 65%, or the flow rate percentage of hydrogen in the second process gas can be within the range of any two of the above flow rate percentages.

[0070] Optionally, the flow rate percentage of hydrogen in the third process gas is 5%, 8%, 10%, 15%, 20%, 25%, 28%, or 30%, or the flow rate percentage of hydrogen in the third process gas can be within the range of any two of the above flow rate percentages.

[0071] In some embodiments, the thickness of the first passivation antireflection layer 40 is 1 nm to 15 nm; the thickness of the second passivation antireflection layer 50 is 60 nm to 120 nm; and the thickness of the third passivation antireflection layer 60 is 5 nm to 40 nm.

[0072] Optionally, the thickness of the first passivation antireflection layer 40 is 1 nm, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm or 15 nm, or the thickness of the first passivation antireflection layer 40 can be within any two of the above thicknesses.

[0073] Optionally, the thickness of the second passivation antireflection layer 50 is 60nm, 70nm, 80nm, 90nm, 100nm, 110nm or 120nm, or the thickness of the second passivation antireflection layer 50 may be within any two of the above thicknesses.

[0074] Optionally, the thickness of the third passivation antireflection layer 60 is 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm or 40nm, or the thickness of the third passivation antireflection layer 60 may be within any two of the above thicknesses.

[0075] In some embodiments, the material of the first passivation antireflection layer 40 includes at least one of hydrogenated silicon oxide and hydrogenated silicon oxynitride.

[0076] In some embodiments, the material of the second passivation antireflection layer 50 includes at least one of hydrogenated silicon oxide and hydrogenated silicon nitride.

[0077] In some embodiments, the material of the third passivation antireflection layer 60 includes at least one of hydrogenated silicon oxide and hydrogenated silicon oxynitride.

[0078] In some embodiments, the flow rate of silane in the first process gas is 500 sccm to 1500 sccm.

[0079] Optionally, the flow rate of silane in the first process gas is 500 sccm, 600 sccm, 700 sccm, 800 sccm, 900 sccm, 1000 sccm, 1100 sccm, 1200 sccm, 1300 sccm, 1400 sccm, or 1500 sccm, or the flow rate of silane in the first process gas may be within any two of the above flow rates.

[0080] In some embodiments, the flow rate of ammonia in the first process gas is 3000 sccm to 6000 sccm.

[0081] Optionally, the flow rate of ammonia in the first process gas is 3000 sccm, 3500 sccm, 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm or 6000 sccm, or the flow rate of ammonia in the first process gas may be within any two of the above flow rates.

[0082] In some embodiments, the flow rate of nitrous oxide in the first process gas is 4000 sccm to 7000 sccm.

[0083] Optionally, the flow rate of nitrous oxide in the first process gas is 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm, 6000 sccm, 6500 sccm or 7000 sccm, or the flow rate of nitrous oxide in the first process gas may be within the range of any two of the above flow rates.

[0084] In some embodiments, the flow rate of hydrogen in the first process gas is 1000 sccm to 3000 sccm.

[0085] Optionally, the flow rate of hydrogen in the first process gas is 1000 sccm, 1200 sccm, 1500 sccm, 1800 sccm, 2000 sccm, 2200 sccm, 2500 sccm, 2800 sccm, or 3000 sccm, or the flow rate of hydrogen in the first process gas may be within the range of any two of the above flow rates.

[0086] In some embodiments, the flow rate of silane in the second process gas is 1000 sccm to 3000 sccm.

[0087] Optionally, the flow rate of silane in the second process gas is 1000 sccm, 1200 sccm, 1500 sccm, 1800 sccm, 2000 sccm, 2200 sccm, 2500 sccm, 2800 sccm, or 3000 sccm, or the flow rate of silane in the second process gas may be within any two of the above flow rates.

[0088] In some embodiments, the flow rate of ammonia in the second process gas is 8000 sccm to 15000 sccm.

[0089] Optionally, the flow rate of ammonia in the second process gas is 8000 sccm, 9000 sccm, 10000 sccm, 11000 sccm, 12000 sccm, 13000 sccm, 14000 sccm, or 15000 sccm, or the flow rate of ammonia in the second process gas may be within any two of the above flow rates.

[0090] In some embodiments, the second process gas also includes nitrous oxide.

[0091] In some embodiments, the flow rate of nitrous oxide in the second process gas is 0~12000 sccm.

[0092] Optionally, the flow rate of nitrous oxide in the second process gas is 0, 1000 sccm, 2000 sccm, 3000 sccm, 4000 sccm, 5000 sccm, 6000 sccm, 7000 sccm, 8000 sccm, 9000 sccm, 10000 sccm, 11000 sccm, or 12000 sccm, or the flow rate of nitrous oxide in the second process gas can be within any two of the above flow rates.

[0093] In some embodiments, the flow rate of hydrogen in the second process gas is 3000 sccm to 20000 sccm.

[0094] Optionally, the flow rate of hydrogen in the second process gas is 3000 sccm, 5000 sccm, 7000 sccm, 9000 sccm, 11000 sccm, 13000 sccm, 15000 sccm, 17000 sccm, 19000 sccm, or 20000 sccm, or the flow rate of hydrogen in the second process gas can be within any two of the above flow rates.

[0095] In some embodiments, the flow rate of silane in the third process gas is 500 sccm to 1500 sccm.

[0096] Optionally, the flow rate of silane in the third process gas is 500 sccm, 600 sccm, 700 sccm, 800 sccm, 900 sccm, 1000 sccm, 1100 sccm, 1200 sccm, 1300 sccm, 1400 sccm, or 1500 sccm, or the flow rate of silane in the third process gas may be within any two of the above flow rates.

[0097] In some embodiments, the flow rate of ammonia in the third process gas is 3000 sccm to 6000 sccm.

[0098] Optionally, the flow rate of ammonia in the third process gas is 3000 sccm, 3500 sccm, 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm or 6000 sccm, or the flow rate of ammonia in the third process gas may be within the range of any two of the above flow rates.

[0099] In some embodiments, the flow rate of nitrous oxide in the third process gas is 4000 sccm to 7000 sccm.

[0100] Optionally, the flow rate of nitrous oxide in the third process gas is 4000 sccm, 4500 sccm, 5000 sccm, 5500 sccm, 6000 sccm, 6500 sccm or 7000 sccm, or the flow rate of nitrous oxide in the third process gas may be within the range of any two of the above flow rates.

[0101] In some embodiments, the flow rate of hydrogen in the third process gas is 1000 sccm to 3000 sccm.

[0102] Optionally, the flow rate of hydrogen in the third process gas is 1000 sccm, 1200 sccm, 1500 sccm, 1800 sccm, 2000 sccm, 2200 sccm, 2500 sccm, 2800 sccm, or 3000 sccm, or the flow rate of hydrogen in the third process gas may be within any two of the above flow rates.

[0103] Within the flow rate range of each gas in the aforementioned process gases, it is convenient to prepare a passivation and antireflection layer with a high free hydrogen content in the film layer, thereby achieving a better passivation effect, reducing the density of defect states on the surface of the photovoltaic cell, reducing non-radiative recombination, and thus improving the conversion efficiency of the photovoltaic cell.

[0104] In some embodiments, the second surface is textured, and the method for fabricating photovoltaic cells further includes the following steps:

[0105] A fourth passivation and antireflection layer 90 is deposited on the second surface at a fourth temperature using a fourth process gas, the fourth process gas including hydrogen, silane and ammonia.

[0106] A fifth passivation and antireflection layer 100 is deposited on the fourth passivation and antireflection layer 90 using a fifth process gas at a fifth temperature. The fifth process gas includes hydrogen, silane, nitrous oxide, and ammonia.

[0107] Among them, the fourth temperature is greater than the fifth temperature and the difference between the two is greater than or equal to 60℃; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60℃; the absolute value of the difference between the fifth temperature and the first and third temperatures is less than or equal to 30℃.

[0108] Understandably, for crystalline silicon solar cells, the front side is typically the light-facing side, with the emitter fabricated on a textured surface. The back side has a planar structure. This application addresses the morphological differences between the front and back sides by using differentiated processes to fabricate passivation and antireflection layers with different stacked structures on the front and back sides respectively. This reduces the risk of photovoltaic cell pre-product explosion during the preparation of the passivation and antireflection layers, while simultaneously achieving a passivation and antireflection layer with a high free hydrogen content (above 25%), resulting in better passivation, reducing the bulk defect state density of the photovoltaic cell, reducing non-radiative recombination, and thus improving the passivation performance, open-circuit voltage, and conversion efficiency of the photovoltaic cell.

[0109] In some embodiments, the fourth temperature is 420°C to 480°C; the fifth temperature is 330°C to 400°C.

[0110] Optionally, the fourth temperature is 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, or 480°C, or the fourth temperature may be within the range of any two of the above temperatures.

[0111] Optionally, the fifth temperature is 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C, or the fifth temperature may be within the range of any two of the above temperatures.

[0112] In some embodiments, the second surface is textured, and the method for fabricating photovoltaic cells further includes the following steps:

[0113] A fourth passivation and antireflection layer 90 is deposited on the second surface at a fourth temperature using a fourth process gas, the fourth process gas including hydrogen, silane and ammonia.

[0114] A fifth passivation and antireflection layer 100 is deposited on the fourth passivation and antireflection layer 90 using a fifth process gas at a fifth temperature. The fifth process gas includes hydrogen, silane, nitrous oxide, and ammonia.

[0115] Among them, the fourth temperature is less than the fifth temperature and the difference between the two is less than or equal to 30℃; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60℃; the fifth temperature is greater than the first temperature and the difference between the two is greater than or equal to 60℃; and the fifth temperature is greater than the third temperature and the difference between the two is greater than or equal to 60℃.

[0116] Understandably, for crystalline silicon solar cells, the front side is typically the light-facing side, with the emitter fabricated on a textured surface. The back side has a planar structure. This application addresses the morphological differences between the front and back sides by proposing a different method for fabricating passivation and antireflection layers with different stacked structures on the front and back sides using differentiated processes. This reduces the risk of photovoltaic cell pre-product explosion during passivation and antireflection layer fabrication while simultaneously achieving a passivation and antireflection layer with a high free hydrogen content (above 25%), resulting in better passivation, reduced bulk surface defect state density, and reduced non-radiative recombination. This, in turn, improves the passivation performance, open-circuit voltage, and conversion efficiency of the photovoltaic cell.

[0117] In some embodiments, the fourth temperature is 420°C to 480°C; the fifth temperature is 430°C to 490°C.

[0118] Optionally, the fourth temperature is 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, or 480°C, or the fourth temperature may be within the range of any two of the above temperatures.

[0119] Optionally, the fifth temperature is 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, or 490°C, or the fifth temperature may be within the range of any two of the above temperatures.

[0120] In some embodiments, the second surface is textured, and the method for fabricating photovoltaic cells further includes the following steps:

[0121] Preheating treatment is performed on pre-finished photovoltaic cells at a preheating temperature.

[0122] A fourth passivation and antireflection layer 90 is deposited on the second surface at a fourth temperature using a fourth process gas, the fourth process gas including hydrogen, silane and ammonia.

[0123] A fifth passivation and antireflection layer 100 is deposited on the fourth passivation and antireflection layer 90 using a fifth process gas at a fifth temperature. The fifth process gas includes hydrogen, silane, nitrous oxide, and ammonia.

[0124] Among them, the preheating temperature is greater than the first temperature, the second temperature, the third temperature, the fourth temperature, and the fifth temperature, and the difference between them is greater than or equal to 60℃; the fourth temperature is greater than the fifth temperature and the difference between them is less than or equal to 30℃; the fourth temperature is greater than the second temperature and the difference between them is less than or equal to 30℃; the absolute value of the difference between the fifth temperature and the first temperature is less than or equal to 30℃; and the absolute value of the difference between the fifth temperature and the third temperature is less than or equal to 30℃.

[0125] Understandably, for crystalline silicon solar cells, the front side is typically the light-facing side, with the emitter fabricated on a textured surface. The back side has a planar structure. This application addresses the morphological differences between the front and back sides by proposing a different method for fabricating passivation and antireflection layers with different stacked structures on the front and back sides using differentiated processes. First, the photovoltaic cell pre-product is preheated at a relatively high temperature, then the fourth passivation and antireflection layer 90 and the fifth passivation and antireflection layer 100 are deposited at a relatively low temperature. This reduces the risk of the photovoltaic cell pre-product bursting during the preparation of the passivation and antireflection layers, while simultaneously achieving a passivation and antireflection layer with a high free hydrogen content (above 25%), resulting in better passivation. This reduces the surface defect state density of the photovoltaic cell, decreases non-radiative recombination, and ultimately improves the passivation performance, open-circuit voltage, and conversion efficiency of the photovoltaic cell.

[0126] In some embodiments, the preheating temperature is 430℃~490℃; the preheating time is 300s~3600s; the fourth temperature is 340℃~410℃; and the fifth temperature is 330℃~400℃.

[0127] Optionally, the preheating temperature is 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, or 490°C, or the preheating temperature may be within any two of the above temperatures.

[0128] Optionally, the preheating time can be 300s, 600s, 900s, 1200s, 1600s, 2000s, 2400s, 2800s, 3200s or 3600s, or the preheating time can be within any two of the above times.

[0129] Optionally, the fourth temperature is 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, or 410°C, or the fourth temperature may be within the range of any two of the above temperatures.

[0130] Optionally, the fifth temperature is 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, or 400°C, or the fifth temperature may be within the range of any two of the above temperatures.

[0131] In some embodiments, the flow rate of hydrogen in the fourth process gas is greater than the flow rate of hydrogen in the fifth process gas; and the flow rate percentage of hydrogen in the fourth process gas is greater than the flow rate percentage of hydrogen in the fifth process gas.

[0132] In some embodiments, the flow rate of hydrogen in the fourth process gas is 5% to 60%; and the flow rate of hydrogen in the fifth process gas is 4% to 20%.

[0133] Optionally, the flow rate percentage of hydrogen in the fourth process gas is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%, or the flow rate percentage of hydrogen in the fourth process gas can be within the range of any two of the above flow rate percentages.

[0134] Optionally, the flow rate percentage of hydrogen in the fifth process gas is 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%, or the flow rate percentage of hydrogen in the fifth process gas can be within the range of any two of the above flow rate percentages.

[0135] In some embodiments, the thickness of the fourth passivation antireflection layer 90 is 40 nm to 80 nm; the thickness of the fifth passivation antireflection layer 100 is 40 nm to 100 nm.

[0136] Optionally, the thickness of the fourth passivation antireflection layer 90 is 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm or 80nm, or the thickness of the fourth passivation antireflection layer 90 may be within any two of the above thicknesses.

[0137] Optionally, the thickness of the fifth passivation antireflection layer 100 is 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm, or the thickness of the fifth passivation antireflection layer 100 may be within any two of the above thicknesses.

[0138] In some embodiments, during the deposition of the first passivation antireflection layer 40, the second passivation antireflection layer 50, the third passivation antireflection layer 60, the fourth passivation antireflection layer 90, or the fifth passivation antireflection layer 100, the power of the radio frequency discharge is 9000W~15000W.

[0139] Optionally, the power of the radio frequency discharge is 9000W, 10000W, 11000W, 12000W, 13000W, 14000W or 15000W, or the power of the radio frequency discharge may be within the range of any two of the above power values.

[0140] In some embodiments, the pressure is 1000 mTorr to 3000 mTorr during the deposition of the first passivation antireflection layer 40, the second passivation antireflection layer 50, the third passivation antireflection layer 60, the fourth passivation antireflection layer 90, or the fifth passivation antireflection layer 100.

[0141] Optionally, the pressure can be 1000 mTorr, 1200 mTorr, 1400 mTorr, 1600 mTorr, 1800 mTorr, 2000 mTorr, 2200 mTorr, 2400 mTorr, 2600 mTorr, 2800 mTorr, or 3000 mTorr, or the pressure can be within any two of the above pressure ranges.

[0142] In some embodiments, the photovoltaic cell preform includes a silicon substrate 10 and an N-type doped silicon layer 30 and a P-type doped silicon layer 80 respectively disposed on two opposing surfaces of the silicon substrate 10; a first passivation antireflection layer 40 is prepared on the surface of the N-type doped silicon layer 30 away from the silicon substrate 10; and a fourth passivation antireflection layer 90 is prepared on the surface of the P-type doped silicon layer 80 away from the silicon substrate 10.

[0143] In some embodiments, the method for preparing a photovoltaic cell includes the following steps:

[0144] S10: Provide a silicon substrate 10, the silicon substrate 10 having a third surface and a fourth surface opposite each other along the thickness direction, and perform texturing treatment on the fourth surface to obtain a textured surface;

[0145] S20: A tunneling oxide layer 20 and an N-type doped silicon layer 30 are sequentially stacked on the third surface; a P-type doped silicon layer 80 is prepared on the fourth surface;

[0146] S30: A fourth passivation antireflection layer 90 and a fifth passivation antireflection layer 100 are sequentially stacked on a P-type doped silicon layer 80;

[0147] S40: A first passivation antireflection layer 40, a second passivation antireflection layer 50, and a third passivation antireflection layer 60 are sequentially stacked on an N-type doped silicon layer 30.

[0148] S50: A first electrode 70 is fabricated on the third passivation antireflection layer 60, and the first electrode 70 is electrically connected to the N-type doped silicon layer 30; a second electrode 110 is fabricated on the fifth passivation antireflection layer 100, and the second electrode 110 is electrically connected to the P-type doped silicon layer 80.

[0149] Another embodiment of this application provides a photovoltaic cell, which is prepared by any of the photovoltaic cell preparation methods described above, comprising: a silicon substrate; an N-type doped silicon layer 30 and a P-type doped silicon layer 80 respectively disposed on two oppositely disposed surfaces of the silicon substrate 10; a first passivation antireflection layer 40, a second passivation antireflection layer 50 and a third passivation antireflection layer 60 disposed sequentially on the surface of the N-type doped silicon layer 30 away from the silicon substrate 10; and a fourth passivation antireflection layer 90 and a fifth passivation antireflection layer 100 disposed sequentially on the surface of the P-type doped silicon layer 80 away from the silicon substrate 10.

[0150] Refer again Figure 1 As shown, in some embodiments, the photovoltaic cell includes: a silicon substrate 10; the silicon substrate 10 has a third surface and a fourth surface opposite each other along the thickness direction, the fourth surface being textured; a tunneling oxide layer 20, an N-type doped silicon layer 30, a first passivation antireflection layer 40, a second passivation antireflection layer 50 and a third passivation antireflection layer 60 are sequentially stacked on the third surface; a P-type doped silicon layer 80, a fourth passivation antireflection layer 90 and a fifth passivation antireflection layer 100 are sequentially stacked on the fourth surface; a first electrode 70 is disposed on the third passivation antireflection layer 60, the first electrode 70 being electrically connected to the N-type doped silicon layer 30; a second electrode 110 is disposed on the fifth passivation antireflection layer 100, the second electrode 110 being electrically connected to the P-type doped silicon layer 80.

[0151] Another embodiment of this application provides a photovoltaic module, including:

[0152] Cover plate;

[0153] At least one battery string, the battery string comprising multiple photovoltaic cells as described above;

[0154] And the encapsulation layer, which is located between the cover plate and the battery string, with the cover plate connected to the battery string through the encapsulation layer.

[0155] The following are the specific implementation methods:

[0156] Example 1

[0157] Methods for preparing photovoltaic cells:

[0158] (1) A silicon substrate 10 is provided, the silicon substrate 10 having a third surface and a fourth surface opposite to each other along the thickness direction, and the fourth surface is texturized to obtain a textured surface; a tunneling oxide layer 20 and an N-type doped silicon layer 30 are sequentially stacked on the third surface; and a P-type doped silicon layer 80 is prepared on the fourth surface.

[0159] (2) A fourth passivation antireflection layer 90 is deposited on a P-type doped silicon layer 80 using a fourth process gas at a fourth temperature; the fourth process gas has the following flow rates: silane flow rate is 2000 sccm, ammonia flow rate is 15000 sccm, nitrous oxide flow rate is 6000 sccm, hydrogen flow rate is 11500 sccm, and the fourth temperature is 450℃.

[0160] The fifth passivation and antireflection layer 100 is deposited on the fourth passivation and antireflection layer 90 using the fifth process gas at the fifth temperature; the fifth process gas has the following flow rates: silane flow rate is 1000 sccm, ammonia flow rate is 4500 sccm, nitrous oxide flow rate is 10500 sccm, hydrogen flow rate is 2000 sccm, and the fifth temperature is 365℃.

[0161] The power of the radio frequency discharge is 12000W, and the voltage is 2000mTorr;

[0162] (3) A first passivation antireflection layer 40 is deposited on the N-type doped silicon layer 30 using a first process gas at a first temperature; in the first process gas, the flow rate of silane is 1000 sccm, the flow rate of ammonia is 4500 sccm, the flow rate of nitrous oxide is 5500 sccm, the flow rate of hydrogen is 2000 sccm, and the first temperature is 365°C.

[0163] A second passivation and antireflection layer 50 is deposited on the first passivation and antireflection layer 40 using a second process gas at a second temperature; in the second process gas, the flow rate of silane is 2000 sccm, the flow rate of ammonia is 11500 sccm, the flow rate of nitrous oxide is 6000 sccm, the flow rate of hydrogen is 11500 sccm, and the second temperature is 375°C.

[0164] A third passivation and antireflection layer 60 is deposited on the second passivation and antireflection layer 50 using a third process gas at a third temperature; in the third process gas, the flow rate of silane is 1000 sccm, the flow rate of ammonia is 4500 sccm, the flow rate of nitrous oxide is 5500 sccm, the flow rate of hydrogen is 2000 sccm, and the third temperature is 365°C.

[0165] The power of the radio frequency discharge is 12000W, and the voltage is 2000mTorr;

[0166] (4) A first electrode 70 is prepared on the third passivation antireflection layer 60, and the first electrode 70 is electrically connected to the N-type doped silicon layer 30; a second electrode 110 is prepared on the fifth passivation antireflection layer 100, and the second electrode 110 is electrically connected to the P-type doped silicon layer 80.

[0167] Example 2

[0168] The method for preparing the photovoltaic cell in Example 2 is basically the same as that in Example 1, with the only difference being:

[0169] In step (2), the fourth temperature is 450℃ and the fifth temperature is 460℃.

[0170] Example 3

[0171] The method for preparing the photovoltaic cell in Example 3 is basically the same as that in Example 1, with the only difference being:

[0172] Step (2): The silicon substrate 10 is preheated at a preheating temperature of 460°C for 2000 seconds.

[0173] A fourth passivation and antireflection layer 90 is deposited on a P-type doped silicon layer 80 using a fourth process gas at a fourth temperature; the fourth process gas has the following flow rates: silane flow rate is 2000 sccm, ammonia flow rate is 15000 sccm, nitrous oxide flow rate is 6000 sccm, hydrogen flow rate is 11500 sccm, and the fourth temperature is 375°C.

[0174] A fifth passivation and antireflection layer 100 is deposited on the fourth passivation and antireflection layer 90 using a fifth process gas at a fifth temperature; the fifth process gas has the following flow rates: silane flow rate is 1000 sccm, ammonia flow rate is 4500 sccm, nitrous oxide flow rate is 10500 sccm, hydrogen flow rate is 2000 sccm, and the fifth temperature is 365℃.

[0175] Comparative Example 1

[0176] The preparation method of the photovoltaic cell in Comparative Example 1 is basically the same as that in Example 1, with the only difference being:

[0177] In step (2), a front passivation antireflection layer is deposited on the P-type doped silicon layer 80 using the sixth process gas at the sixth temperature; the sixth process gas has the following flow rates: silane flow rate is 2000 sccm, ammonia flow rate is 15000 sccm, nitrous oxide flow rate is 6000 sccm, and the sixth temperature is 465℃.

[0178] In step (3), a back passivation antireflection layer is deposited on the N-type doped silicon layer 30 using the seventh process gas at the seventh temperature; the seventh process gas has the following flow rates: silane flow rate is 2000 sccm, ammonia flow rate is 11500 sccm, nitrous oxide flow rate is 6000 sccm, and the seventh temperature is 465℃.

[0179] Photoluminescence (PL) tests were performed on the photovoltaic cell precursors (without electrodes) prepared in Examples 1-3 and Comparative Example 1 to measure their passivation parameters. The test results are shown in Table 1 below:

[0180] Table 1

[0181]

[0182] The performance of the photovoltaic cells prepared in Examples 1 to 3 and Comparative Example 1 was tested, and the test results are shown in Table 2 below. It should be understood that the data in Table 2 are the average values ​​of the test results of multiple photovoltaic cells.

[0183] Table 2

[0184]

[0185] Based on the above test results and Figures 2-5As can be seen, the photovoltaic cell preparation method of this application can prepare a passivation and antireflection layer with a high content of free hydrogen in the film layer, achieve a good passivation effect, reduce the density of defect states on the surface of the photovoltaic cell, reduce non-radiative recombination, and thus improve the conversion efficiency of the photovoltaic cell.

[0186] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0187] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A method for preparing a photovoltaic cell, characterized in that, Includes the following steps: A photovoltaic cell pre-finished product is provided, the photovoltaic cell pre-finished product having opposing first and second surfaces along the thickness direction; A first passivation and antireflection layer is deposited on the first surface using a first process gas at a first temperature, the first process gas including hydrogen, silane, nitrous oxide and ammonia; A second passivation and antireflection layer is deposited on the first passivation and antireflection layer at a second temperature using a second process gas, wherein the second process gas includes hydrogen, silane, and ammonia. A third passivation and antireflection layer is deposited on the second passivation and antireflection layer using a third process gas at a third temperature, the third process gas including hydrogen, silane, nitrous oxide and ammonia; Wherein, the second temperature is greater than the first temperature and the difference between the two is less than or equal to 30°C; the second temperature is greater than the third temperature and the difference between the two is less than or equal to 30°C; the flow rate of hydrogen in the second process gas is greater than the flow rate of hydrogen in the first process gas and the flow rate of hydrogen in the third process gas; the proportion of hydrogen flow rate in the second process gas is greater than the proportion of hydrogen flow rate in the first process gas and the proportion of hydrogen flow rate in the third process gas.

2. The method for preparing a photovoltaic cell according to claim 1, characterized in that, The second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps: A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia; A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia; Wherein, the fourth temperature is greater than the fifth temperature and the difference between the two is greater than or equal to 60°C; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60°C; the absolute value of the difference between the fifth temperature and the first temperature and the third temperature is less than or equal to 30°C.

3. The method for preparing a photovoltaic cell according to claim 2, characterized in that, The fourth temperature is 420℃~480℃; the fifth temperature is 330℃~400℃.

4. The method for preparing a photovoltaic cell according to claim 1, characterized in that, The second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps: A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia; A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia; Wherein, the fourth temperature is less than the fifth temperature and the difference between the two is less than or equal to 30°C; the fourth temperature is greater than the second temperature and the difference between the two is greater than or equal to 60°C; the fifth temperature is greater than the first temperature and the difference between the two is greater than or equal to 60°C; the fifth temperature is greater than the third temperature and the difference between the two is greater than or equal to 60°C.

5. The method for preparing a photovoltaic cell according to claim 4, characterized in that, The fourth temperature is 420℃~480℃; the fifth temperature is 430℃~490℃.

6. The method for preparing a photovoltaic cell according to claim 1, characterized in that, The second surface is textured, and the method for preparing the photovoltaic cell further includes the following steps: The photovoltaic cell pre-product is preheated at a preheating temperature; A fourth passivation and antireflection layer is deposited on the second surface using a fourth process gas at a fourth temperature, the fourth process gas including hydrogen, silane and ammonia; A fifth passivation and antireflection layer is deposited on the fourth passivation and antireflection layer using a fifth process gas at a fifth temperature, the fifth process gas including hydrogen, silane, nitrous oxide and ammonia; Wherein, the preheating temperature is greater than the first temperature, the second temperature, the third temperature, the fourth temperature, and the fifth temperature, and the difference between them is greater than or equal to 60°C; the fourth temperature is greater than the fifth temperature and the difference between them is less than or equal to 30°C; the fourth temperature is greater than the second temperature and the difference between them is less than or equal to 30°C; the absolute value of the difference between the fifth temperature and the first temperature is less than or equal to 30°C; and the absolute value of the difference between the fifth temperature and the third temperature is less than or equal to 30°C.

7. The method for preparing a photovoltaic cell according to claim 6, characterized in that, The preheating temperature is 430℃~490℃; the preheating time is 300s~3600s; the fourth temperature is 340℃~410℃; and the fifth temperature is 330℃~400℃.

8. The method for preparing a photovoltaic cell according to any one of claims 2 to 7, characterized in that, The flow rate of hydrogen in the fourth process gas is greater than the flow rate of hydrogen in the fifth process gas; the flow rate percentage of hydrogen in the fourth process gas is greater than the flow rate percentage of hydrogen in the fifth process gas.

9. The method for preparing a photovoltaic cell according to claim 8, characterized in that, The hydrogen flow rate in the fourth process gas accounts for 5% to 60%; the hydrogen flow rate in the fifth process gas accounts for 4% to 20%.

10. The method for preparing a photovoltaic cell according to any one of claims 2 to 7 and 9, characterized in that, The thickness of the fourth passivation antireflection layer is 40nm~80nm; the thickness of the fifth passivation antireflection layer is 40nm~100nm.

11. The method for preparing a photovoltaic cell according to any one of claims 2 to 7 and 9, characterized in that, The photovoltaic cell pre-product includes a silicon substrate and an N-type doped silicon layer and a P-type doped silicon layer respectively disposed on two opposite surfaces of the silicon substrate; the first passivation antireflection layer is prepared on the surface of the N-type doped silicon layer away from the silicon substrate; the fourth passivation antireflection layer is prepared on the surface of the P-type doped silicon layer away from the silicon substrate.

12. The method for preparing a photovoltaic cell according to any one of claims 1 to 7 and 9, characterized in that, The first temperature is 330℃~400℃; the second temperature is 340℃~410℃; and the third temperature is 330℃~400℃.

13. The method for preparing a photovoltaic cell according to any one of claims 1 to 7 and 9, characterized in that, The hydrogen flow rate in the first process gas is 5% to 30%; the hydrogen flow rate in the second process gas is 9% to 65%; and the hydrogen flow rate in the third process gas is 5% to 30%.

14. The method for preparing a photovoltaic cell according to any one of claims 1 to 7 and 9, characterized in that, The thickness of the first passivation antireflection layer is 1 nm to 15 nm; the thickness of the second passivation antireflection layer is 60 nm to 120 nm; and the thickness of the third passivation antireflection layer is 5 nm to 40 nm.

15. A photovoltaic cell, characterized in that, The photovoltaic cell is prepared by the method described in any one of claims 1 to 14, comprising: A silicon substrate; an N-type doped silicon layer and a P-type doped silicon layer are respectively disposed on two oppositely disposed surfaces of the silicon substrate; The first passivation antireflection layer, the second passivation antireflection layer, and the third passivation antireflection layer are sequentially stacked on the surface of the N-type doped silicon layer away from the silicon substrate.

16. A photovoltaic module, characterized in that, include: Cover plate; At least one battery string, the battery string comprising a plurality of photovoltaic cells as described in claim 15; And an encapsulation layer, which is located between the cover plate and the battery string, and the cover plate is connected to the battery string through the encapsulation layer.

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